The Clinician's Handbook of Preventive Services, a practical and comprehensive guide to clinical preventive services, is the cornerstone of the Put Prevention Into Practice (PPIP) initiative. The goal of PPIP, which was developed by the US Public Health Service's Office of Disease Prevention and Health Promotion, is to enhance the delivery of clinical preventive services. This handbook discusses screening tests for early detection of disease, immunizations and prophylaxis to prevent disease, and counseling to modify risk factors that lead to disease.

The Clinician's Handbook is written for a wide variety of readers including health care providers, educators, students, and health service administrators and planners. It can be used as a reference book for clinical preventive guidelines, or as a practical guide to delivering clinical preventive services and implementing a preventive care protocol. In addition, the Clinician's Handbook provides references for patient and provider educational materials and resources.

The Clinician's Handbook has been organized to facilitate quick reference. The main text is divided into two sections: preventive services for children/adolescents (up to age 18 years) and preventive services for adults/older adults. The overview chapters provide background information on topics such as: the basic epidemiologic principles of prevention, occupational and environmental considerations, and the implementation of a preventive care protocol. In addition, several appendices provide supplementary information including timelines and risk factor tables (Appendix A); general information on immunizations, including information on reporting adverse effects (Appendix B); notifiable diseases (Appendix C); and a list of major authorities cited (Appendix D).

The Children and Adolescents and Adults and Older Adults sections are divided into three subsections: (1) screening guidelines, (2) immunization and prophylaxis recommendations, and (3) counseling information.

Chapters are broken down into six subsections. Each chapter is organized in the following format:

The criterion for inclusion of a preventive service in the Clinician's Handbook is a recommendation for its routine use in the care of asymptomatic persons by a major US authority such as: a Federal health agency (eg, Centers for Disease Control and Prevention, National Institutes of Health), a non-Federal expert panel (eg, US Preventive Services Task Force), a national professional organization (eg, American Academy of Family Physicians, American Academy of Pediatrics), or a national voluntary health organization (eg, American Cancer Society, American Heart Association). Recommendations of the Canadian Task Force on the Periodic Health Examination have also been included.

Because the Clinician's Handbook focuses on preventive care for the general population without special risk factors, the following types of preventive care have not been included: tertiary prevention (treatment to prevent progression of known disease), prenatal and perinatal care, and preventive care for certain high-risk groups. Preventive services not recommended by at least one major authority have been excluded. However, the exclusion of a medical procedure does not suggest that it is ineffective in diagnosing and treating disease. The clinician should exercise judgement on a case-by-case basis with respect to preventive services not addressed in the Clinician's Handbook.

Every effort has been made to ensure that recommendations of major authorities listed in each chapter accurately represent the current positions of these authorities. Recommendations are listed alphabetically by organization. Similar recommendations are often grouped together to facilitate comparisons by the reader. Appearance in the Clinician's Handbook does not imply that either the US Department of Health and Human Services or the Public Health Service endorses a specific authority or its recommendations; clinicians are encouraged to consult the references provided to evaluate the scientific basis for each organization's recommendations. Similarly, the citation of a group's recommendations does not imply that the group has endorsed the Clinician's Handbook or its contents.

The "Basics" of providing services sections were derived from a compilation of sources, including expert opinion. In many instances, the recommendations of major authorities, as well as expert researchers, were combined.

The items listed in the "Patient and Provider Resource" sections of the chapters have been selected after an extensive review of materials solicited from government agencies and professional and voluntary organizations. However, this list is not exhaustive and there are undoubtedly other, equally useful publications that have not been included. The materials listed provide a starting point for clinicians to build a library of high-quality literature and resources for themselves and their patients. The individual clinician must determine the appropriateness of each material in any specific case.

The publications listed in the "Selected References" sections were chosen because of their use in preparing the chapters and their potential usefulness to the clinician. These lists are not intended to be a comprehensive bibliography of the literature, but provide a core set of references for the reader.

No single set of preventive services is appropriate for all patients in all settings. The Clinician's Handbook is designed to facilitate the design and implementation of a preventive care program for practices of all sizes and types. Chapter ii discusses the principles of prevention, such as general principles of screening, immunizations, and counseling. This information, when combined with the more specific recommendations of authorities, relevant patient risk factors given in each chapter, and the summary risk-factor tables in Appendix A, should help clinicians select a set of preventive services appropriate for their patients and practice. Chapter iv provides practical information on establishing and implementing a preventive care protocol.

A goal of the Clinician's Handbook is to describe areas of consensus among the recommendations of major authorities regarding clinical preventive services. Important clinical differences in recommendations are reflected. However, the differences in the processes by which authorities arrived at their recommendations are not described. Some recommendations of major authorities are based strictly on expert opinion and others incorporate evidence-based approaches. Names and addresses of all major authorities cited are listed in Appendix D and readers are encouraged to contact the organization to ascertain how guidelines were formulated.

The data for the Clinician's Handbook were obtained from scientific literature identified by searching computerized data bases and reference lists of primary sources; policy statements and position papers issued by government agencies, professional groups, and voluntary associations; educational brochures, booklets, and other materials from government agencies, professional groups, and voluntary associations; and consultation with experts.

Oversight of the Put Prevention Into Practice campaign is provided by the National Coordinating Committee on Clinical Preventive Services (NCCCPS). The NCCCPS was formed in 1989 to accelerate the integration of clinical preventive services into primary care delivery in the United States. Members of this group provided extensive review of the Put Prevention Into Practice materials during their development. NCCCPS member organizations include:

Ambulatory Pediatric Association

American Academy of Family Physicians

American Academy of Pediatrics

American Academy of Physician Assistants

American Association of Colleges of Nursing

American Association of Health Plans

American College of Obstetricians and Gynecologists

American College of Occupational and Environmental Medicine

American College of Physicians

American College of Preventive Medicine

American Hospital Association

American Medical Association

American Nurses Association

American Osteopathic Association

American Osteopathic College of Occupational and Preventive Medicine

American Public Health Association

Association of Academic Health Centers

Association of American Medical Colleges

Association of Health Services Research

Association of Schools of Public Health

Association of State and Territorial Health Officials

Association of Teachers of Preventive Medicine

Blue Cross Blue Shield Association

Institute of Medicine

National Alliance of Nurse Practitioners

National Association of Community Health Centers

National Association of County and City Health Officials

North American Primary Care Research Group

Society of General Internal Medicine

Society for Public Health Education

Society of Teachers of Family Medicine

Department of Health and Human Services

Agency for Health Care Policy and Research

Centers for Disease Control and Prevention

Food and Drug Administration

Indian Health Service

Health Resources and Services Administration

Health Care Financing Administration

National Institutes of Health

Office of the Assistant Secretary for Planning and Evaluation

Substance Abuse Mental Health Services Administration

Department of Defense

Department of Transportation

US Coast Guard

Department of Veterans Affairs

Office of Personnel Management

The chapters of this book have been reviewed for scientific accuracy by experts in the following divisions in the Department of Health and Human Services:

Administration for Children and Families

Agency for Health Care Policy and Research

Administration on Aging

Centers for Disease Control and Prevention

Food and Drug Administration

Health Care Financing Administration

Health Resources and Services Administration

Indian Health Service

National Institutes of Health

Office of HIV/AIDS Policy

Office of Minority Health

Office of Population Affairs

Office of the Surgeon General

Office on Women's Health

Substance Abuse and Mental Health Services Administration

Preparation of this Clinician's Handbook of Preventive Services was coordinated by staff in the Office of Disease Prevention and Health Promotion, Office of Public Health and Science, US Department of Health and Human Services, under the general supervision of Claude Earl Fox, III, MD, MPH, Deputy Assistant Secretary for Health (Disease Prevention and Health Promotion).

Principal staff responsible for the preparation of this edition were:

Rika Maeshiro, MD, MPH, Co-Editor

Lynn M. Soban, MPH, RN, Project Coordinator and Co-Editor

Other staff members of the Office of Disease Prevention and Health Promotion who contributed to the preparation of this edition were:

David R. Baker

Kate-Louise Gottfried, JD, MSPH

Kathryn McMurry, MS

Linda D. Meyers, PhD

Janice T. Radak

Mark Smolinski, MD, MPH

Valuable research and writing contributions were made by the following preventive medicine residents during rotations at the Office of Disease Prevention and Health Promotion:

Liz Ribadenyra, MD	University of Maryland
Annette Kussmaul, MD	State University of New York at Stony Brook
Tamera Coyne-Beasley, MD	University of North Carolina, Chapel Hill
Margaret Savage, MD	Johns Hopkins University
Ron Hale, MD	Johns Hopkins University
Allen Brinker, MD	University of Maryland
Renee Kanan, MD	University of Washington
Robert A. Gilchick, MD	San Diego State University/University of California, San Diego
Shelley Levesque, MD	University of Massachusetts Medical Center
Linda E. Hertz, MD	University of South Carolina

Special thanks to the following individuals and organizations for their contributions:

Larry L. Dickey, MD, MPH, Office of Clinical Preventive Medicine, California Department of Health Services, who updated the Recommendations of Major Authorities;

Bradley Evanoff, MD, MPH, Assistant Professor, Section of Occupational and Environmental Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, who prepared the chapter on Occupational and Environmental Exposures;

Crystal Wilkinson, MSN, RN, CNS, Texas Department of Health, who prepared the chapter on Implementing a Preventive Care Protocol;

The American Society of Clinical Pathologists for their contributions to the chapter on Papanicolaou Smear Screening.

Other contributors included:

Jacqelyn B. Admire, MSPH

Patti Auer, RN, MSN

Susan Bradford

Cheri Hahn, MS, RN

Melissa Koenig

Tammy L. Lin, MD

Rosemarie Perrin

Kristine Samson

Yu Ning Wong

Preparation of the Clinician's Handbook of Preventive Services was coordinated by staff in the Office of Disease Prevention and Health Promotion, Public Health Services, US Department of Health and Human Services, under the general supervision of J. Michael McGinnis, MD, Deputy Assistant Secretary for Health (Disease Prevention and Health Promotion). Principal staff responsible for the preparation of this book were:

Larry L. Dickey, MD, MPH, Luther Terry Senior Fellow

(Scientific editor and principal writer)

Hurdis M. Griffith, PhD, RN, Senior Policy Advisor

(review coordinator and writer)

Douglas B. Kamerow, MD, MPH, Director, Clinical Preventive Services Staff

(managing editor)

Other staff members of the Office of Disease Prevention and Health Promotion who contributed to preparation of this book were:

David R. Baker

Rachel Ballard-Barbash, MD, MPH

Elena Carbone, MS, RD

Carolyn DiGuiseppi, MD, MPH

Walter H. Glinsman, MD

Linda D. Meyers, PhD

Janice T. Radak

Susan Simmons, RN, PhD

Marilyn G. Stephenson, MS, RD

Valuable research and writing contributions were made by the following preventive medicine residents from Johns Hopkins University and the University of Maryland during rotations at the Office of Disease Prevention and Health Promotion.

Robert Beardall, MD, MPH

Karen S. Collins, MD, MPH

Paul Denning, MD, MPH

Tina Farup, MD

Clarice Green, MD

Lana Jeng, MD, MPH

S. Patrick Kachur, MD, MPH

Cynthia Mobley, MD, MPH

Peter W. Pendergrass, MD, MPH

Donald Robinson, MD, MPH

William Schluter, MD

Suzanne Steinberg, MD

Material on preventive services for older adults was researched and prepared by fellows of the Multi campus Division of Geriatric Medicine and Gerontology at the University of California, Los Angeles (listed below). David B. Reuben, MD was supervising editor for this component of Clinician's Handbook preparation.

Nelson C. Apostol, MD

Christopher J. Bula, MD

Russel E. Hoxie, MD

David Kelley, MD

Michael E. Lim, MD

Matthew K. McNabney, MD

Alison A. Moore, MD

Michael Temporal, MD

Emil Yagudin, MD

Michael P. Zeitlin, MD

Assistance in researching and preparing the chapters on sexually transmitted diseases was provided by C. Patrick Chaulk, MD, MPH, Johns Hopkins School of Hygiene and Public Health.

Copy editor was Barbara Ravage.

"Clinicians should be selective in ordering tests and providing preventive services." ¹

This chapter introduces fundamental aspects of preventive services, including the epidemiologic principles that help influence decisions regarding the appropriateness of preventive services, the concepts that help determine the usefulness of screening tests, guidance for counseling patients, and an examination of prevention at the community or population level.

The primary and secondary clinical preventive services presented in the Clinician's Handbook target asymptomatic persons based on individual risk profiles. The basic epidemiologic principles used to develop preventive services guidelines also provide the context in which to consider these general recommendations and their relevance to particular populations, communities, and patients. The following questions have been adapted from Woolf (1996) for clinicians to consider when prioritizing their assessment of risk factors that can increase a patient's potential for future disease. These questions can be applied to all clinical preventive services:

• How important is the target condition?
• How important is the risk factor?
• Is the preventive service effective?
• How accurately can the risk factor or target condition be identified?

The target condition is the health or disease outcome that the preventive care intervention avoids (primary prevention) or identifies early (secondary prevention). The frequency and the severity of target conditions help define their importance. The frequency of a target condition is usually measured by its incidence rate and prevalence rate (Key Concepts 1).

The severity of a target condition can be described by several measures: mortality, morbidity, and survival rates. Target conditions with higher frequencies in specific populations, as well as conditions of greater severity, may merit greater preventive attention.

Risk factors are the attributes associated with target conditions. They can help predict outcomes but may not cause the target condition. Risk factors include demographic variables, such as gender, ethnicity, or age; behavioral risk factors, such as smoking or driving without seatbelts; and environmental factors, such as the area of residence. Ascertaining the presence or absence of risk factors (risk assessment) is accomplished through thorough patient histories, targeted examinations, and laboratory tests. Specific health risk appraisal tools have also been developed to ascertain risk status (chapter iv).

The frequency and magnitude of risks contribute to their importance. The frequency of risk factors are also described by their incidence and prevalence in the population of interest (Key Concepts 2).

The magnitude of risk helps to quantify the association between the risk factor and the target condition. Because a variety of risk measures exist, clinicians need to be aware that there are important differences between these risk measures and their implications for disease prevention. An understanding of basic risk measures may aid clinicians in interpreting risks for their patients (Key Concepts 3).

The strongest quality of scientific evidence to evaluate the effects of preventive services comes from well designed intervention studies and observational studies that link risk modification with improved outcomes. Many major authorities rely on scientific evidence to guide their recommendations. The US Preventive Services Task Force (USPSTF), a body of preventive care experts convened by the US Public Health Service, has developed a system for rating the quality of scientific evidence used in its deliberations. The USPSTF rating system for grading scientific evidence is given in Table ii.1.

Even with good evidence that an intervention is efficacious (the intervention results in true effects under ideal conditions), the intervention may be less effective in a routine practice setting. Potential benefits of a preventive intervention must be weighed against potential harms, costs, and implementation considerations.

Recently, outcome measures have been developed incorporating quality-of-life measures that attempt to capture functional status and preference as outcomes of clinical interventions, including preventive services. Quality-adjusted life-years and disability-adjusted life-years are measures that attempt to standardize quantitative and qualitative information into summary measures that can be used to compare various conditions and outcomes for different prevention strategies.

Unfortunately, for most of medical practice, there is insufficient evidence that a service is or is not effective in improving process or outcome measures. Therefore, decision-makers at the policy and at the clinical level often need to consider factors other than scientific evidence in determining whether to offer a preventive service. Particularly for asymptomatic patients, thresholds for performing preventive services differ depending on their potential for harm in the absence of strong evidence of benefit. Frame and Carlson (1975) summarized the circumstances that must exist for screening tests to be useful:

• The condition must have a significant effect on the quality and quantity of life.
• Acceptable methods of treatment must be available.
• The condition must have an asymptomatic period during which detection and treatment significantly reduce morbidity or mortality.
• Treatment in the asymptomatic phase must yield a therapeutic result superior to that obtained by delaying treatment until symptoms appear.
• Tests that are acceptable to patients must be available, at a reasonable cost, to detect the condition in the asymptomatic period.
• The incidence of the condition must be sufficient to justify the cost of the screening.

"The clinician and patient should share decision-making." ²

Clinicians are responsible for providing patients with the best available information about potential benefits and harms of the preventive service, translating what is known and not known about the likelihood of various outcomes, and explaining the probable consequences of different decisions. Patient preferences, which are important in all clinical decisions, are paramount to consider when contemplating preventive services of uncertain benefit.

Efforts to detect risk factors or target conditions by screening tests may be ineffective or harmful if the test is inaccurate. The accuracy of a screening test is measured by its sensitivity and specificity (Key Concepts 4).

Positive predictive value (PPV) is the proportion of positive test results that are correct (true positives). The predictive value of a test for a particular condition in an individual depends on the prevalence of that condition in the population. If the prevalence of the condition is low, the positive predictive value also will be very low regardless of the accuracy of the screening test. The higher the prevalence, the more likely the positive test result reflects a true positive. This is the basis for utilizing a "high-risk" strategy for screening illustrated in Appendix A.

"Interventions that address patients' personal health practices are vitally important." ³

The most prominent identifiable contributors to premature death in the United States are tobacco, diet and physical activity patterns, alcohol, microbial agents, toxic agents, firearms, sexual behavior, motor vehicles, and illicit use of drugs (McGinnis 1993). Because behavioral choice is critical to most of these risk factors, the USPSTF has suggested that clinician counseling that leads to improved personal health practices may be more valuable to patients than conventional clinical activities such as diagnostic testing. The following are general guidelines to consider when providing clinical counseling:

"For some health problems, community-level interventions may be more effective than clinical preventive services." ⁴

Preventive services impact the health status of individuals and populations. However, many health patterns in populations are related to an uneven distribution of societal resources. These resources encompass social, economic, and political advantages such as knowledge, money, and social connections that influence people's ability to avoid risks and to minimize the consequences of disease once it occurs. The broad influence of these resources is associated with multiple risk factors and disease outcomes. Interventions such as school-based curricula, community programs, and regulatory and legislative initiatives may be effective in addressing these more global issues. Being aware of community programs, encouraging patient participation and involvement, acting as a consultant for communities implementing programs or introducing legislation, and serving as an advocate to initiate and maintain effective community interventions are suggested roles for the interested clinician. An appreciation of the link between specific risk factors and general societal factors that influence health patterns may enhance the clinicians' contribution to prevention efforts.

"It is a well-known fact that there are no social, no industrial, no economic problems which are not related to health."

Dr. William H. Welch,
Founder, Johns Hopkins School of Hygiene and Public Health

The concepts of prevention, as discussed in the earlier part of this section, are used to prioritize prevention strategies. These concepts include: measures of frequency and severity of the health condition; magnitude of risk associated with risk factors; accuracy of screening tests; and the strength of evidence in support and magnitude of an intervention's effectiveness. These concepts were used by some of the major authorities to direct their guideline process and to support their preventive services recommendations. These recommendations can assist the clinician in prioritizing prevention strategies for individual patients and practice population.

Preventive services for individuals may comprise a "core set" of preventive services that apply broadly to most individuals from the "average-risk" population. The average-risk approach used in the Clinician's Handbook stratifies individuals based on age and gender. In addition, a more targeted strategy can be offered to individuals at a relative "high-risk" based on their risk profile. The average-risk and high-risk strategies are complementary. Appendix A, which consists of risk tables and time lines for preventive care, illustrates the link between the two strategies. The purpose of and relationship between the risk tables and time lines are discussed further in the introduction to Appendix A.

Key Concepts 1

Incidence Rate during a given time period = number of new cases of a target condition during the given time period population at risk for developing the target condition during the given time period The denominator, "population at risk for developing the target condition," does not refer to any specific high risk group, but includes all members of the population of interest whose probability of becoming a new case is greater than zero. Thus, if one is studying the annual incidence of HIV seropositivity among US adolescent males, then the population at risk for developing the target condition (HIV seropositivity) includes all adolescent males residing in the US, with the exception of those who are already HIV positive prior to the beginning of the time period. One cannot become a new case of HIV seropositivity if one is already HIV positive prior to the start of the time period. EXAMPLE: In a year, there are an estimated 1,500,000 new or recurrent episodes of coronary attacks* among 101,570,000 Americans age 29 years and over. The annual incidence of new or recurrent coronary attacks* among Americans aged 29 years and over is 1,500,000 101,570,000 = .015 = 1.5%. Each year, 15 of every 1000 Americans age 29 years and over (1.5%) have a new or recurrent episode of coronary attack.* Prevalence Rate during a given time = total number of new cases (new and old) of a target condition at the given time total population at the given time EXAMPLE: In 1994, approximately 13,670,000 out of 185,390,000 Americans age 20 years and over had a history of coronary heart disease.* The prevalence of coronary heart disease* among Americans age 20 years and over in 1994 is 13,670,000 185,390,000 = .074 = 7.4%. In 1994, 74 of every 1000 Americans age 20 years and over (7.4%) had a history of coronary heart disease.* * Both terms, "coronary attack" and "coronary heart disease," refer to a group of diagnoses under the general heading of ischemic heart disease, specifically ICD-9 410-414. Source: American Heart Association. 1997 Heart and Stroke Statistical Update. Dallas, Tex: American Heart Association; 1996.

Key Concepts 2

Incidence Rate during a given time period = number of new individuals exhibiting the risk factor during the given time period population at risk for developing the risk factor in the given time period EXAMPLE: In 1995, approximately 4.5 million out of 22.2 million youths age 12-17 were current smokers. If approximately 1 million youths become smokers annually, the annual incidence rate of smoking among youths age 12-17 is 1,000,000 new smoking youths 17,700,000* million non-smoking youths = .056 = 5.6% In 1995, 56 of every 1000 youths ages 12 to 17 (5.6%) who had not been smokers began to smoke. * The 17.7 million nonsmoking youths are calculated by subtracting the already smoking youths from the total population of 12 to 17 year old youths (22.2 million - 4.5 million). Prevalence Rate at a given time period = total number of individuals exhibiting the risk factor at the given time total population at the given time EXAMPLE: In 1995, approximately 56.4 million of the 189.3 million adults age >18 years were current cigarette smokers. The prevalence of current cigarette smoking in the United States among adults age >18 years is 56,400,000 million current adult smokers >18 years 189,300,000 million adults >18 years = 0.298 = 29.8% In 1995, 298 of every 1000 Americans age 18 years or older (29.8%) were current smokers. Source: Substance Abuse and Mental Health Services Administration, US Department of Health and Human Services. Preliminary Estimates from the 1995 National Household Survey on Drug Abuse. Rockville, Md: Substance Abuse and Mental Health Services Administration, US Department of Health and Human Services; 1995.

Key Concepts 3

The absolute risk is the incidence of the target condition in the population with the risk factor. EXAMPLE: Out of 1000 men who smoke, 172 will develop lung cancer. The absolute risk for lung cancer in men who smoke is 172/1000 = .172 = 17.2%. The relative risk ratio is the ratio of the incidence of disease among persons with the risk factor to the incidence of disease among those without the risk factor. Relative risk does not measure the probability that any given person with the risk factor will develop the condition. EXAMPLE: The risk of death from lung cancer in men who smoke is 341.3 deaths per 100,000 person years. The risk of death from lung cancer in men who do not smoke is 14.7 deaths per 100,000 person years. The relative risk of death from lung cancer in men who smoke is 341.3 deaths from lung cancer per 100,000 person years 14.7 deaths from lung cancer per 100,000 person years = 23.2 Men who smoke have 23.2 times the risk of dying from lung cancer of men who do not smoke. The attributable risk measures the amount of risk that can be attributed to one particular risk factor and is calculated by subtracting the incidence rate of the population without the factor from the incidence rate among the population with the factor. The excess amount experienced by the exposed group represents the attributable risk. EXAMPLE: The attributable risk for death from lung cancer that is associated with smoking is 341.3 - 14.7 326.6 deaths from lung cancer per 100,000 person years deaths from lung cancer per 100,000 person years Of the 341.3 lung cancers occurring in smokers, 326.6 can be attributed to smoking. Source: Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention; US Department of Health and Human Services.

Key Concepts 4

Sensitivity refers to the proportion of persons with a condition who correctly test positive when screened. A test with poor sensitivity will miss many cases and therefore produce a large proportion of false-negative results. Specificity refers to the proportion of persons without the condition who correctly test negative when screened. A test with poor specificity incorrectly labels persons as having the condition. The incorrect labeling of true negative results produce false-positive cases. False positive results can produce a series of adverse consequences including psychological stress and the risks associated with further tests and procedures. Relative risk reduction is the percent reduction in risk of disease morbidity or mortality achieved through active prevention compared to a control group. Absolute risk reduction is the actual difference between the risk of a condition with and without the preventive service. Number needed to treat (or screen) is the reciprocal of absolute risk reduction and represents the number of patients needed to treat in order to prevent one case.

A comprehensive approach to preventive health care includes understanding and assessing risks related to occupational and environmental exposures. This chapter discusses the principal issues surrounding occupational health; Appendix A addresses selected occupational and environmental risks.

Every year, 6.3 million workplace injuries and over 500,000 work-related illnesses are reported to the Federal government. Many others remain unreported. Six thousand fatalities resulting from workplace trauma are reported each year, and the National Institute for Occupational Safety and Health (NIOSH) estimates that over 50,000 people die annually from work-related illnesses, most of which go unreported.

Illnesses which are often unrecognized as occupational or environmental in origin include musculoskeletal disorders of the upper extremity, irritant or allergic dermatitis, asthma, chronic obstructive lung disease, reproductive abnormalities, hearing loss, and cancers of the lung, skin, and bladder. Several of these are discussed in more detail later in this chapter.

Occupational exposures provide unique opportunities for effective disease prevention, because elimination of the exposure may prevent the disease. Unfortunately, total elimination is often difficult, and workers continue to contract preventable illnesses from exposures that have long been recognized, such as lead and silica. Clinicians may not have the opportunity to effect primary prevention efforts in the workplace but can offer important counseling to their patients.

Clinicians will see patients suffering from occupational disorders. For these patients, recognition by the health provider of the role played by workplace exposures in causing or exacerbating illnesses can have important consequences:

• Recognition of a work-related disorder along with follow-up counseling can help prevent disease among co-workers who share the same exposures.
• Recognition of occupational hazards along with follow-up counseling can prevent exposure of a worker's family members to substances such as lead, pesticides, and allergens, which can be carried home on a worker's clothing and contaminate the home.
• Knowledge of a patient's work activities may be important in treating non-work related conditions. Examples include deciding when a patient may safety return to work following a hospitalization, and adjusting medication dosing for patients who work night shifts.
• Failure to recognize a disorder as work-related may render treatment ineffective if the patient's work exposures are not altered.

Recognizing the important role that clinicians may have in the prevention, diagnosis, and treatment of occupational and environmental illnesses, the Institute of Medicine has recommended substantive changes in medical education: "At a minimum, all primary care [clinicians] should be able to identify possible occupationally or environmentally induced conditions and make the appropriate referrals for follow-up." ¹ To achieve this minimum level of expertise, the Institute concluded that all clinicians must learn some basic principles of occupational and environmental medicine, must learn how to take an appropriate occupational and environmental history, must understand their role in worker's compensation, must know how and when to report hazards to public health and regulatory agencies, and must be aware of the legal, social, and ethical implications of diagnosing an occupational or environmental illness.

Primary prevention of occupational diseases can be achieved only through the reduction or elimination of exposures to chemical, physical, or biological hazards. Clinicians must recognize these exposures to participate meaningfully in preventive efforts. As noted below, the basic occupational history is the cornerstone of preventive efforts and needs to be obtained from each patient. Reduction of exposures can be achieved through the hierarchy of controls, listed here in descending order of importance and desirability:

Clinicians should inquire about exposure reduction strategies used in their patients' workplaces. When appropriate, clinicians need to urge employers and employee representatives to adopt better control measures. Clinicians need to encourage their patients to wear personal protective equipment when warranted by job exposures that are not otherwise adequately controlled.

The initial step for achieving better recognition of occupational and environmental exposures is for all clinicians to take a basic occupational history from their patients. This history should include:

• the patient's past and current job titles and industries
• a description of past and current work duties
• any known exposures to chemical, physical, or biological hazards
• the presence of any symptoms in relation to work

This initial screening history will suffice for most patients. Unfortunately, a number of studies have documented that most clinicians obtain few or no elements of the occupational history from their patients. A more detailed history is warranted in patients who report potential occupational hazards in their initial occupational screening. A number of self-administered questionnaires exist to aid the clinician in obtaining a more detailed occupational history; Table iii.1 represents one possibility.

Because workplace exposures can have additive or synergistic effects with other exposures, clinicians also need to take into account patient activities outside of work. For example, workers in noisy occupations should be counseled about the additive effects of noise exposure from work and from such avocational pursuits as shooting and the use of power tools. Counseling patients about exacerbation of occupational illness through nonemployment-related activities is not a substitute for primary prevention focused at reducing work site exposures, but does represent an additional step that clinicians can take to reduce the overall burden of occupational disease among their patients.

In addition to potentially hazardous exposures, symptoms or health conditions that have a significant likelihood of being related to occupational exposures also require a more detailed occupational history. Several such sentinel health conditions are discussed below. They do not comprise a comprehensive listing of work-related disorders, but represent some of the disorders which have been targeted by NIOSH and other authorities. Other conditions besides the ones detailed below in which occupational exposures should be evaluated include peripheral neuropathy, encephalopathy, hepatitis, nephropathy, and cancers of the skin, lung, and bladder.

The skin is an important exposure route for chemicals. Some 66,000 cases of work-related dermatitis are reported annually, though it is likely that the true number of cases is far higher. For example, almost 2% of workers surveyed in the National Health Interview Survey reported dermatitis related to work exposures. Irritant contact dermatitis can result from occupational exposures to a wide variety of compounds such as solvents and cutting fluids, while allergic contact dermatitis can result from exposure to a long list of substances, such as metals (nickel and chromium), rubber additives (epoxies and acrylates), formaldehyde and poison ivy (a common occupational and nonoccupational exposure). Rapid identification of skin problems as work related and removal of the offending exposure can hasten recovery and prevent the progression of dermatitis to a chronic skin disease.

Mortality and morbidity from asthma is increasing in the United States, partly as a result of occupational exposures. Over 9 million workers are exposed to agents that are known sensitizers and irritants associated with asthma. As many as 28% of adult asthma cases may be attributable to work exposures, and annual costs of occupational asthma are estimated at $400 million. In addition to those who develop occupational asthma as a result of workplace exposures, there are many patients with asthma whose condition is worsened by work exposures. The morbidity of occupational asthma can be substantially reduced by early intervention. The likelihood of complete resolution of symptoms and pulmonary function abnormalities is greatest when exposures are terminated early in the course of illness, making early diagnosis a critical element for effective intervention.

A well-documented relationship exists between COPD and workplace exposures such as coal dust, grain dust, and cotton dust. Those with lung disease from other causes are especially vulnerable to occupational respiratory hazards. Although cigarette smoking is the primary cause of COPD, a substantial fraction (as much as 14%) may be attributable to environmental and occupational exposures. Occupational dust exposure provides an additional reason to encourage these workers not to smoke. All patients with lung disease should be questioned about workplace exposures as a possible contributor to their disease.

A few occupational and environmental exposures have been shown to contribute to reproductive disorders including birth defects, developmental disorders, spontaneous abortion, and infertility. Though a few such exposures are well known (eg, lead, high levels of ionizing radiation), the overall contribution of environmental and occupational exposures on fertility is unknown. Most chemicals in commercial use have undergone little or no reproductive testing; among the more than 1000 workplace chemicals that have been demonstrated to cause reproductive disorders in animal experiments, few have been studied in humans. Occupational exposures should be documented in pregnancy, in pre-conception counseling, and in the evaluation of infertility and adverse reproductive outcomes.

Occupational hearing loss, although largely preventable, is the most common occupational disease in the United States. It has proven difficult to convince employers and workers to adopt the appropriate preventive strategies, as hearing loss is sometimes accepted as a normal consequence of employment rather than as a preventable disorder that can seriously degrade quality of life. Millions of workers are exposed to hazardous noise and are thus at risk for hearing loss. Although hearing loss is irreversible, the prevention of further exposures can prevent worsening hearing loss. Workers in noisy settings, such as machine shops or firing ranges, should be counseled to wear hearing protection and to seek other noise-reduction strategies through their employers.

Low back pain and upper extremity musculoskeletal disorders such as tendinitis and nerve entrapments are often related to workplace exposures. Risk factors contributing to musculoskeletal disorders include high force exertion, repetitive activities, awkward body postures, and vibration. Identification and remediation of causal or exacerbating workplace factors are often essential to providing rest to the affected area and in preventing the recurrence of these disorders.

There is little data regarding the effectiveness of secondary prevention activities in preventing occupational diseases. For a number of specific exposures, there is federal or state mandated screening; many employers also conduct regular screening for some employee groups. Screening procedures are dependent on the specific exposures incurred by workers. Examples of screening programs include:

• periodic chest X-rays for workers exposed to asbestos
• spirometry for workers exposed to agents known to cause asthma or COPD
• periodic blood or urine testing for lead and cadmium in exposed workers
• urine cytology for workers exposed to bladder carcinogens

Probably the most widespread periodic screening is regular audiometry for workers in noisy occupations. In theory, such a program can detect early hearing loss and help to prevent further noise-induced hearing loss. However, few data exist to document the effectiveness of this and other screening programs in practice.

In summary, health care providers need to be involved in the prevention of occupational and environmental illness. Although most clinicians will find themselves limited in their ability to influence primary preventive measures at their patients' work sites or other public settings, some degree of primary prevention for the patient, patient's co-workers, and patient's family may be achieved by attending to details of the occupational history and counseling accordingly based on the potential hazardous exposures revealed, and/or by notifying the appropriate agencies when potentially hazardous conditions are suspected to exist at an employment site. Secondary prevention of occupational and environmental illness through periodic screenings targeted toward a patient's specific work and exposure history can also involve the primary care provider, although the effectiveness of such screening measures needs to be further elucidated through appropriate research.

Agency for Toxic Substances and Disease Registry (ATSDR), 1600 Clifton Rd, NE, Atlanta GA 30333. Telephone: (404)639-6000 (Division of Toxicology); (404)639-6206 (Division of Health Education). Internet address: http://atsdr1.atsdr.cdc.gov:8080/atsdrhome.html/. Part of the US Public Health Service (USPHS), the ATSDR provides toxicologic profiles and clinically useful case studies in environmental medicine.

American College of Occupational and Environmental Medicine (ACOEM), 55 W. Seegers Rd., Arlington Heights, IL 60005-3919. Telephone: (847)228-6850. Internet address: http://www.acoem.org/. The ACOEM lists physicians who are board-certified in occupational-environmental medicine and members of the college; it also conducts educational programs on occupational health, impairment, and the worker's compensation system.

Association of Occupational and Environmental Clinics (AOEC), 1010 Vermont Ave., Suite 513, Washington, DC 20005. Telephone: (202)347-4976. Internet address: http://152.3.65.120/oem/aoec.htm. The AOEC is a network of academically based occupational-environmental medicine clinics throughout the United States. Member clinics provide professional training, community education about toxic substances, exposure and risk assessment, clinical evaluation, and consultation. Clinicians can contact the AOEC for clinical referrals to assist in the diagnosis, management, therapy, and prevention of occupational disorders.

Environmental Protection Agency (EPA), 401 M Street, SW, Washington, DC 20460. Telephone: (202)260-5922. Internet address: http://www.epa.gov/epahome/. The EPA is an independent United States federal agency whose stated mission is to protect public health and to safeguard and improve the natural environment upon which human life depends. EPA's goals include ensuring that federal environmental laws are implemented and enforced fairly and effectively and that environmental protection is an integral consideration in US policy. Their web site provides numerous sources on a wide array of environmental and health-related issues.

National Center for Environmental Health (NCEH), Centers for Disease Control and Prevention, Mail Stop F-29, 4770 Buford Highway, NE, Atlanta, GA 30341-3724. Telephone: (770)488-7030. Internet address: http://www.cdc.gov/nceh/ncehhome.htm. The NCEH is a division of the Department of Health and Human Services within the Centers for Disease Control and Prevention. Its mission is to promote health and quality of life by preventing and controlling disease, birth defects, disability, and death resulting from interactions between people and their environment. Some of its activities include: public health surveillance; applied research; dissemination of standards, guidelines, and recommendations; and technical and financial assistance to state and local health agencies.

National Institute of Environmental Health Sciences (NIEHS), P.O. Box 12233, Research Triangle Park, ND 27709. Telephone: (909)541-3345. Internet address: http://www.niehs.nih.gov/. A division of the Department of Health and Human Services within the National Institutes of Health, the NIEHS has as its stated mission to reduce the burden of human illness and dysfunction from environmental causes by understanding the interaction between environmental factors, individual susceptibility, and age. It engages in multidisciplinary biomedical research programs, prevention and intervention efforts, and communication strategies that encompass training, education, technology transfer, and community outreach.

National Institute for Occupational Safety and Health (NIOSH), Robert A. Taft Laboratories, 4676 Columbia Pkwy, Cincinnati, OH 45226-1998. Telephone: (800)356-4674. Internet address: http://www.cdc.gov/niosh/Homepage.html. A division of the Department of Health and Human Services within the Centers for Disease Control and Prevention, NIOSH provides information about substance toxicity and workplace hazards. The health-hazard evaluation program can investigate work sites at which physicians, employees, or employers suspect work-related illness and injury to have occurred. NIOSH offers training in occupational safety and health and funds continuing-medical-education courses.

Occupational Safety and Health Administration (OSHA), Department of Labor, 200 Constitution Ave., NW, Washington, DC 20210. Telephone: (202)219-8148 (general information); (202)219-9308 (compliance officer); (202)219-4667 (publications). Fax: (900) 555-3400 (OSHA FAX). Internet address: http://www.osha.gov/. OSHA sets US standards for health and safety in the workplace, investigates compliance, and issues citations. The publications-distribution office has articles about many occupational diseases. OSHA FAX is a fax-on-demand data-base service providing documents for a nominal telephone charge.

"Clinicians must take every opportunity to deliver preventive services, especially to those with limited access to care." ¹

Most clinicians acknowledge the importance of incorporating preventive care into their practices; however, delivery of preventive services, even those about which all authorities agree, is far from satisfactory. Providing consistent delivery of preventive care requires organizational commitment, time, and a critical analysis of the systems designed to deliver that care. Ensuring the consistent delivery of preventive services may require changes in office systems or clinic organization.

In the current health care environment, accurate documentation of the delivery of preventive services has become essential. Delivery of clinical preventive services is now one of several indicators used to rate the performance of clinicians, their practices, and health plans.

One example of such measures is the Health Plan Employer Data and Information Set (HEDIS), a set of health care quality indicators developed by the National Committee for Quality Assurance. The preventive services currently being monitored include immunizations, mammography, and smoking cessation counseling. Performance ratings in the area of preventive services serve as potential criteria for accreditation as well as the awarding of contracts.

This chapter presents practical instructions for implementing a system for delivering preventive care services. These instructions will facilitate putting prevention into your practice.

If preventive care services are being provided, assess how well your current system works. The services provided by some practices may not require significant changes. Determining the current status of a preventive care delivery system is important before implementing big changes. The best way to assess the need for a new system is to examine clinical records. A baseline chart audit can help determine if changes are needed and can also establish a baseline for demonstrating future improvements.

As is true about any process that requires change, assessing readiness to change is beneficial. Two commonly cited barriers to implementing preventive care in clinical practice are clinicians' attitudes about prevention and problems within office systems (eg, lack of time, staff, and resources). The effect of these barriers can be minimized if they are viewed in the context of "readiness" for change. The following questions should be addressed as part of readiness assessment:

If the answer to the majority of the questions is "yes," implementation of a preventive care system can begin. If the majority of answers is "no," attention should focus on resolving the issues associated with the questions before attempting to make a change. Use of this simple questionnaire will save significant time and energy by identifying potential barriers that need to be addressed and potential facilitators of the process and allowing time to plan for successful implementation based on information collected.

Communication and teamwork are critical factors to successful implementation. Involving the staff is critical to ensuring that preventive services are a routine part of office practice. Include everyone who will be impacted by the changes in the planning and implementation process. Clearly define the role of all staff members and include them in the planning and problem-solving. You may discover untapped resources by encouraging staff members to creatively consider their roles in prevention delivery.

Recent research indicates that appointing a facilitator to introduce the tools and the process for change increases the chance of successful implementation. The responsibilities of a facilitator include:

• planning and setting goals for the implementation process
• coordinating implementation activities
• ensuring good communication between all involved staff members
• helping to establish a quality-improvement process to track progress
• giving feedback on performance and encouraging progress
• facilitating creative problem-solving

Table iv.1 is a sample tool for performing chart audits.

Develop a protocol of preventive care that meets the particular needs of your specific practice and its patients. The Clinician's Handbook is designed to facilitate this process. Recommendations of major authorities, emphasizing age and periodicity for preventive screening, appear at the beginning of each chapter. By reviewing these recommendations, clinicians can decide which guidelines to select or can set their own standards based on current recommendations. A set of standards, even if minimal, needs to be identified and adopted as a policy. Concentrate efforts on selecting preventive services that truly can be provided in light of limited time, available staff, and other resources. Periodically examine the selected standards, updating them as needed based on current research and the changing needs of the patient population.

Once policy is set, familiarize the entire staff with the criteria and incorporate the standards into a preventive care flow sheet for tracking purposes. The flow sheet permits quick determination of a particular patient's need for preventive care services and allows the provider to deliver preventive care at all patient visits. If time limitations prevent delivery of such services during a visit, the patient may be informed of what care is needed, and a plan to obtain it can be established (eg, referral, follow-up appointment). After protocols for preventive care service are identified, the next step is to establish systems that ensure consistent, efficient delivery of these services.

The physical layout of a practice and the direction of patient flow can significantly influence the delivery of preventive services. Effective organization of clinic systems and patient flow, along with utilization of all staff members' skills, can improve delivery of services. Analyzing patient flow patterns can be as simple as mapping a patient's path through the office on paper, thus identifying areas where health education messages can be provided or reinforced. The analysis should consider who the patient encounters and what is done at each step. Such an analysis can provide a basis upon which clinic efficiency can be improved.

The use of simple office tools can improve the delivery of preventive health care. The following tools are components of the Put Prevention Into Practice initiative. Many of the tools can be altered to meet individual specifications.

The most basic tool for tracking and prompting preventive services is a flow sheet. For flow sheets to be useful, data must be promptly entered onto the forms. The assistance of staff in updating and maintaining chart flow sheets is very important. The entire staff must be familiar with the format of the sheets and how to use them. Over time, flow sheets prove to be useful tools for tracking and auditing the performance and results of preventive care, encouraging increased compliance with preventive care standards and early detection and treatment of preventable conditions.

Postcards or letters can be useful tools for reminding patients to come in for needed preventive care. Such reminders can easily be created by individual organizations, or preprinted cards can be obtained from outside sources. Computerized systems are capable of generating such mailed prompts. Telephone calls may also be used for reminding patients of the need for preventive care visits; however, telephone calls have been found to be less cost-effective than mailed prompts. Patient reminders can greatly increase the rate at which clients return for services.

Use posters (eg, Put Prevention Into Practice, adult and child preventive care timelines) as visual prompts in the office and all examination rooms to remind both office staff and patients of the need for continuing preventive care services.

Patients play a critical role in tracking and prompting their own preventive care. Studies have shown that patient-held (or parent-held) records, such as those used to promote childhood immunization programs, are well-received by both clinicians and patients.

The Personal Health Guide and the Child Health Guide were designed to:

• provide patients with information on a range of preventive services
• facilitate a structured dialogue between patients and providers
• assist patients in tracking their own care

When explaining how to use the Personal Health Guide and the Child Health Guide:

• let patients know that you think the information in the Guides is important
• discuss topics that apply to the patient's personal health behavior as well as areas in which he/she desires to make changes; instruct patients to bring the Guides to each visit for review and updating
• advise patients to read or review the information
• reinforce health messages and assist patients to set realistic goals for changing health behaviors
• reinforce positive behavior changes

Other useful office tools include chart reminders, behavioral change contracts, health risk appraisals, and electronic medical records.

• Chart reminders alert clinicians to the specific preventive care needs of individual patients
• Prevention prescriptions and behavioral change contracts facilitate behavior change by clearly defining the patient's and the clinician's expectations. In addition, a written plan of action, based on an agreement between the patient and the clinician, emphasizes the patient's ability and responsibility to contribute to his/Her own disease prevention and health promotion. Follow-up telephone calls to determine progress are also helpful for encouraging compliance with health-related recommendations.
• Health risk appraisals can ensure that clients are questioned about all possible risk factors, increase patient awareness of health risks, and provide the clinician with a second source of information other than the patient interview. However, health risk appraisals should be done in the proper context and with an appropriate amount of time allotted for follow-up counseling to ensure that patients understand the implications of such assessments and the steps to be taken in addressing the various risk factors revealed.
• Computerized tracking and prompting systems are commercially available. Some features to look for include: the ability to prompt for preventive services, customize preventive care schedules, send out patient reminders, and determine a practice's performance.

The most efficient approach to implementing prevention care services is to delegate and share responsibilities among as many staff members as possible. Tasks, such as reviewing charts, administering immunizations, counseling patients, and screening, can be successfully provided by members of the office staff. Another important role for staff is facilitating patients' access to community resources, such as local mammography centers or smoking cessation support groups. Appropriate standards for assuring patient privacy must be maintained, regardless of the number of staff involved in a patient's care.

Follow-up chart audits will assist in evaluating both the consistency with which tools are used and the impact of tools on service delivery. Use this information as feedback in quality improvement activities in order to modify your service delivery plan.

• Assess your current preventive service delivery system
• Elicit input from entire staff
• Establish a preventive care protocol
• Choose tools that are suited to your setting and system
• Personalize or adapt tools using input from all staff members involved in the process
• Ensure that all staff members understand the intent and purpose of the tools
• Distribute responsibilities across the entire staff
• Perform follow-up evaluations

The following is one example of a systematic approach to the delivery of preventive care services:

• The medical record is reviewed by a designated staff member and flagged with notes or stickers for preventive care needs determined from the record
• A staff member sends a postcard or calls the patient to encourage making an appointment for preventive care services

• The receptionist or nurse provides patient with a Personal Health Guide and explains how to use it; if a patient has previously received a Personal Health Guide, the receptionist or nurse checks to determine if he/she has brought it and reviews the Guide.
• The nursing staff completes a health-risk assessment, elicits a health history, determines which preventive care screening exams are needed, cues the clinician to complete or order exams, and reinforces health counseling
• The nursing staff initiates health education or risk-reduction counseling

• The clinician assesses health risk and health history information, verifying/updating as necessary
• The clinician questions the patient about identified health risks and his/Her compliance with behavioral change contracts at every visit
• The clinician encourages the patient to ask questions about preventive health topics
• The clinician completes or orders screening services as necessary
• The clinician provides appropriate referrals

• A staff member assists the patient in recording information (exam dates and test results) in the Personal Health Guide and encourages the patient to bring the Guide to every visit
• A staff member provides patient education and encourages the patient to ask questions
• A staff member provides patient-relevant health promotion literature
• A staff member reinforces recommended behavior changes, using a prevention prescription pad or a patient contract
• A staff member ensures that the patient understands any instructions and knows when to return for services
• A staff member completes follow-up with reminder postcards or telephone calls

Personal Health Guide or Child Health Guide. AHCPR Publications Clearinghouse, P.O. Box 8547, Silver Spring, MD 20907 (800-358-9295). Internet address: http://www.ahcpr.gov/ppip/

Copies of the "Health Risk Profile," a health risk appraisal used by the Texas Department of Health, can be obtained by calling or writing the Adult Health Program, Bureau of Chronic Disease Prevention and Control, Texas Department of Health, 1100 W 49th Street, Austin, TX 78756; (512)458-7534.

The Clinician's Handbook of Preventive Services, 2nd Edition; Waiting Room Poster; and Preventive Care Timeline Posters. AHCPR Publications Clearinghouse, P.O. Box 8547, Silver Spring, MD 20907 (800-358-9295). Internet address: http://www.ahcpr.gov/ppip/

Patient Reminder Postcards and Preventive Care Flowsheets. Internet address: http://www.ahcpr.gov/ppip/