BHPR -

April 2004

Chapter 4. Factors Related to the DHPPI

This chapter summarizes a series of statistical analyses performed to help understand the relationship between the DHPPI and a variety of measures of the supply of oral health practitioners, different aspects of the dental hygiene profession, and access to oral health services across the 50 States. It includes the following subsections:

Introduction
Literature Review
Hypotheses
Data and Methods
Results
Conclusions

Introduction

Oral health is an integral aspect of overall health. Recent studies have demonstrated that oral health may be systemically linked to overall health, yet oral healthcare has traditionally been marginalized in society, as reflected in most health insurance policies. National health policy has been focusing increasingly on both the identification and the reduction of inequities in access to health care, including oral health care. Health inequities are regularly observed across a number of broad socio-economic categories, such as race/ethnicity, income, education, etc…

To date, however, no State-level analysis of factors relevant to the number of dental practitioners, the utilization of dental services, and oral health outcomes has been conducted, although preliminary national statistics and survey research has been developed. The analyses in this chapter explore the relationship between the professional practice of dental hygienists, the supply of dental practitioners, access to dental care, the use of dental services, and selected oral health outcomes across States in the United States.

Dental hygiene is a profession in the United States that reflects some of the attributes of an “authentic” profession but falls short on others. For example, DHs earn comparatively high salaries for their level of education (on average, $52,000 a year for a two year degree in 2000)[CDC] ; however, in most States they work under the direct supervision of dentists, displaying little professional autonomy. DHs have not ascended as far up the “professional ladder” as some other healthcare professionals, e.g., nurse practitioners (NPs), physician assistants (PAs), and certified nurse midwives (CNMs), who function with increasing autonomy in concert with their physician counterparts. However, given the fact that professionals like NPs, PAs, and CNMs have played increasingly important roles in contemporary healthcare, an examination of relationships between dental hygienists and dentists, and between dental hygienists and pertinent oral health outcomes, provides important insights for policymakers concerned with access to care.

Literature Review

Racial disparities exist with respect to oral health; untreated dental caries are more prevalent among African American children and Hispanic children than white children (36 percent and 43 percent versus 26 percent) [(National Center for Health Statistics. National Health and Nutrition Examination Survey III, 1988-1994. Hyattsville MD, Centers for Disease Control and Prevention (CDC)]. Individuals who are poor are 2.7 times more likely to have untreated tooth decay than non-poor adults [“Going Beyond Poor/Non-Poor Comparisons in Studying Oral Health Inequalities. T.F. Drury and J.G. Corrigan, National Institute of Dental and Craniofacial Research] Poor adults were found to be 2.6 times less likely to have visited a dentist or a dental hygienist in the past 12 months than those adults who were not poor [“Going Beyond Poor/Non-Poor Comparisons in Studying Oral Health Inequalities. T.F. Drury and J.G. Corrigan, National Institute of Dental and Craniofacial Research]. Other studies have found that socioeconomic status (SES) is an important factor as well. Using NHANES III survey data, Drury et al found that those with lower SES scores were at least 1½ - 2 times more likely to have gingivitis than those with higher SES scores (“Socioeconomic Disparities in Adult Oral Health in the United States” T.F. Drury, I. Garcia, and M. Adesanya (National Institute of Dental and Craniofacial Research, NIH). Furthermore, they found that those with lower SES scores were 6.1 times more likely to have untreated coronal decay, 7.2 times more likely to have untreated root decay, 7.5 times more likely to have a restoration or tooth condition involving pulpal pathology or a retained root that might benefit from treatment compared with those individuals with higher SES scores (“Socioeconomic Disparities in Adult Oral Health in the United States” T.F. Drury, I. Garcia, and M. Adesanya. National Institute of Dental and Craniofacial Research, NIH). In addition, one study found the five-year survival rate for oral and pharyngeal cancer is lower among African Americans compared to whites (34 percent versus 56 percent). [NIH. SEER Cancer Statistics Review 1973-1996. Bethesda, MD 1999. National Cancer Institute, NIH] www.seer.ims.sci.nih.gov/Publications/CSR1973_1996. June 15, 1999.]

Many people in the U.S. do not receive necessary dental care, which can have a significant impact upon their quality of life. One recent survey indicated that while 50 percent of non-Hispanic whites visited a dentist within the past year, only 30 percent of Hispanics and 27 percent of African Americans had done so. Moreover, while 55 percent of those with some college had visited a dentist in the past year, only 24 percent of those with less than a high school education had done so. [“Use of Dental Services; An Analysis of Visits, Procedures and Providers 1996. R. Manski, J. Moeller Journal of the American Dental Association 133: February 2002 167-175; Medical Expenditure Panel Survey 1996;]. One study found that black/white differences in oral health were only partially explained by SES and recent use of dental services (R.M. Adesanya, T. F. Drury, “Black/White Disparities in Oral Health Status of American Adults, National Institute of Dental and Craniofacial Research, NIH). Another study found evidence for gender differences with respect to oral health; women were less likely to have untreated coronal decay, untreated root decay, gingivitis, gingival recession, advanced loss of attachment; they were also more likely to have visited a dentist or a dental hygienist in the past 12 months, compared to men (T.F. Drury, M. Redford, I. Garcia, and M. Adesanya “Identifying and Estimating Oral Health Disparities Among U.S. Adults, National institute of Dental and Craniofacial Research, NIH, Bethesda MD).

Hypotheses

Insights gleaned from previous health research and from discussions conducted as part of this study suggest a number of hypotheses related to the Dental Hygiene Professional Practice Index that can be tested as part of this study.

Hypothesis 1: The relationship between dental hygienists and dentists is a complementary one given the fact that the work environment for dental hygienists is predicated upon the supervision of dentists in almost every State. A positive relationship between the number of dentists per capita and the number of dental hygienists per capita would be anticipated.

Hypothesis 2: The professional practice index will positively co-vary with the number of dental hygienist practitioners, as it is expected that dental hygienists would elect to operate in more autonomous work environments.

Hypothesis 3: The dental hygiene professional practice index would be positively correlated with salary levels; States with more favorable work environments for dental hygienists should have higher overall dental hygienist salaries.

Hypothesis 4. Greater professional latitude in professional work environments for dental hygienists should be reflected in more favorable oral health measures within the population.

Hypothesis 5. Socio-economic factors should be positively correlated with the utilization of dental care and with favorable oral health outcomes. Although not directly related to the work in this study on the DHPPI, this hypothesis is relevant to the broader question of access to dental services.

Hypothesis 6. A positive statistical relationship should exist between the utilization of dental care and the available supply of dental practitioners per capita.

Hypothesis 7. States with larger numbers of dental practitioners per capita are associated with greater access to oral health care and more favorable oral health outcomes.

Data and Methods

The State level data has been collected from a variety of official sources, including the American Dental Association, the American Dental Hygienist Association, the Bureau of the Census, the Center for Disease Control, the Health Resources and Services Administration, the Statistical Abstracts of the United States, the Behavioral Risk Factor Surveillance System Survey (BRFSS), and the National Center for Education Statistics. Information regarding dental insurance, utilization of dental services (visits to the dentist, dental cleanings), and oral health outcomes (number of teeth removed due to tooth decay or gum disease) have been gathered from the CDC’s Behavioral Risk Factor Surveillance System Survey and aggregated up to the State level (unweighted). ). Final weights were not available for all years and were missing from years 1998, 1999, and 2000. One or more of the variables necessary to compute the final weights for those years were missing. As the years for the dental variables spanned 1995-2001, it was thought to be methodologically more prudent to keep all aggregated totals similarly unweighted than to have some weighted and others not. Moreover, comparisons were made between those States with weighted percentages and those with unweighted percentages; in all but a handful of cases differences between the weighted and unweighted percentages were less than 2 percent; almost all fell within the 95 percent confidence intervals listed for the weighted percentages. Given that the unweighted percentages for nearly all States fell within the 95 percent confidence intervals for the weighted State estimates, it was determined that unweighted percentages were methodologically justified.

Table 4-1 summarizes the variable used in the different analyses and their sources. Non-parametric correlations (Spearman’s Rho) and stepwise regression analysis are employed. Each variable and its source is listed below.

Table 4-1. Variables Included in Statistical Analyses, With Sources

Variable	Definition	Source
DH ’01	DHs for 2001	ADHA Report
DH ‘80 & ‘90	DHs for 1980 and 1990	Area Resource File
Population ’87, ’91, ’95, ’98, ‘01	Civilian Pop in U.S., 1987, 1991, 1995, 1998, 2001	US Bureau of the Census
Dentists ‘01	Dentists, 2001	CDC
Dentists ’87, ’91, ’95, ‘98	Dentists, 1987, 1991, 1995, 1998	ADA
DH / Pop ’80, ’90, & ‘01	DHs per 100K Pop, 1980, 1990, and 2001	Computed
Dentists/Pop ’87, ’91, ’95, ’98, ‘00	Dentists per 100K Pop, 1987, 1991, 1995, 1998, 2001	Computed
DH Salaries, 2000	Mean and Mean Hourly and Mean Annual Salaries of DHs, 2000	CDC Website
% Pop w/ Bach Degree	% of Pop w/ Bachelor’s Degrees or Higher:	NCES Online
% Pop White, Black, Hispanic, Asian, Indian	% Pop White, Black, Hispanic, Asian, Indian	US Census Bureau
Per capita income 1991, 2000	Per capita income 1991, 2000	Statistical Abstract of U.S., 1994, 2003
Per capita expenditure on dental 1991	Per capita expenditure on dental 1991	Statistical Abstract of U.S., 1994
Dental use variables	Dental insurance, Dental visits, # teeth removed, & Reason for not visiting dentist	Aggregated to the State level from BRFSS survey (CDC),
Unemployment rate, 1999	Unemployment rate, 1999	Statistical Abstracts of the United States, 2002
People in dental HPSAs, 2001.	People in dental HPSAs, 2001.	Health Resources and Services Administration
% of Pop living in Dental HPSA, 2001	People in Dental HPSAs / State Pop 2001	Computed
% of Pop by Age Category, 1996	% of Pop by Age Category, 1996	Statistical Abstracts of the United States, 2000

Results

We find a positive relationship between the DHPPI and the supply of dental practitioners per capita, one of which is just shy of statistical significance. As previously hypothesized, this is not surprising given the nature of dental hygienists’ work and the requirement for dental oversight. Table 4-2 summarizes this relationship.

Table 4-2. Relationship Between Dental Hygienists per capita in 2001 and Dentists per Capita in 1998 and 2001
Dentists per capita 1998	+0.25 (p=0.073)
Dentists per capita 2001	+0.27 (p=0.056)

Moreover, the dental hygiene professional practice index is uncorrelated with either the number of dentists per capita in 1998, the number of dentists per capita in 2001, or the number of dental hygienists per capita in 2001; however, the direction is positive (Table 4-3), indicating that more favorable work environments are associated with a greater supply of dental practitioners.

Table 4-3. Relationship Between the 2001 DHPPI and The Supply of Oral Health Professions and Occupations
Dentists per capita 1998	+0.23 (p=0.101)
Dentists per capita 2001	+0.13 (p=0.365)
Dental hygienists per capita 2001	+0.13 (p=0.355)

Since the value ascribed to the skills of a profession is in part reflected by higher salary levels, it is reasonable to expect that the dental hygiene professional practice index would be positively correlated with various measures of monetary success. This is validated by our findings; the higher the dental hygiene professional practice index, the higher the dental hygiene salary, whether median hourly, mean hourly, or annual (Table 4-4). The correlation between the DHPPI and dentists’ salaries is, however, not statistically significant. Thus, we observe that the professional practice environment of dental hygienists has a positive impact upon measures of professional success, such as monetary outcomes.

Table 4-4. Relationship Between the 2001 DHPPI and Several Measures of Incomes of Dental Hygienists
Dental hygienist median hourly salary, 2000	+0.31 *
Dental hygienist median hourly salary, 2001	+0.57 **
Dental hygienist mean hourly salary, 2000	+0.32 *
Dental hygienist mean hourly salary, 2001	+0.60 **
Dental hygienist mean annual salary, 2000	+0.33 *
Dental hygienist mean annual salary, 2001	+0.66 **

An important component of the DHPPI is the scope of practice permitted to dental hygienists. By scope of practice we mean the tasks permitted to the profession under varying levels of supervision. Extending beyond positive outcomes measures for dental hygienists (monetary success), it is reasonable to suppose that a broader scope of practice (more tasks permitted to DHs with less restrictive supervision) among dental hygienists should have a positive impact upon utilization of dental services among the general population by making such services more widely available. A corollary assumption is that greater utilization of dental hygiene service should have a positive impact upon the overall oral health status of those who receive services.

Considerable support for these hypotheses was found. Drawing upon data from the Center for Disease Control’s BRFSS survey, aggregated up to the State level, we find the DHPPI linked to several positive outcomes (Table 4-5). The negative relationships between the DHPPI and poor oral health status as well as the positive correlation with good oral health support the hypothesis that utilization of oral health services tends to be greater in States where the DHPPI is higher.

Table 4-5. Relationship Between the 2001 DHPPI and Several Measures of Oral Health Problems
% not visiting a dentist in the past year due to no reason to go	-0.29 *
% having 1-5 permanent teeth removed due to tooth decay or gum disease	-0.38 **
% having 6 or more, but not all, teeth removed due to tooth decay / gum disease	-0.52 **
% having all teeth removed due to tooth decay or gum disease	-0.39 **
% having no teeth removed due to tooth decay or gum disease	+0.49 **

Clearly the professional environment in which dental hygienists operate has a strong impact upon both the utilization of dental services and the oral health of the population. More autonomous professional practice environments contribute to increased dental visitations.

Table 4-5 shows that the professional practice environment for dental hygienists has a positive impact upon oral health status. In States where professional practice environments for dental hygienists were more favorable, the percentage of respondents having no teeth removed due to tooth decay or gum disease were significantly higher. In addition, the percentage of respondents having 1-5, 6, or all teeth removed due to tooth decay or gum disease was significantly lower. This is evidence that the professional practice environment for dental hygienists has a positive impact not only upon the utilization of dental services, but also on the oral health of the population.

Although not statistically significant, the DHPPI was positively correlated with the percentage of respondents having their teeth cleaned by a dentist or dental hygienist within the past year, and negatively associated with the percentage having their teeth cleaned by a dentist or a dental hygienist further back in time (1-5 years ago, or even never).

The DHPPI is clearly not the only factor related to access to dental care. To help understand how several factors impact access to oral health services, other measures that affect utilization of oral health services and affect oral health outcomes are examined in the following analysis.

The percentage of the population with dental insurance is often hypothesized to be a critical determinant of both the utilization of services and oral health outcomes. These hypotheses are supported by the figures in Table 4-6. The percentage of respondents with dental insurance is positively correlated with the percentage having visited a dentist between 1 and 12 months ago, and negatively correlated with the percentage visiting a dentist further back in time (2 to 5 years ago, 5 or more years ago). The percentage with dental insurance is also positively correlated with the percentage having their teeth cleaned (a task typically performed by DHs) between 1 and 12 months ago, and negatively correlated with the percentage having their teeth cleaned further back in time (2 to 5 years ago, 5 or more years ago, or never). Moreover, the percentage with dental insurance is also positively correlated with the percentage having no teeth removed due to tooth decay or gum disease, and negatively correlated with the percentage having some teeth removed for tooth decay or gum disease. Thus, dental insurance has a profound impact upon not only the utilization of dental services, but also on oral health outcomes.

Table 4-6. Correlation Between Percentage of Population Having Dental Insurance and Selected Measures of Access to Dental Care
% Visited a dentist 1-12 months ago	+0.70 **
% Visited a dentist 2-5 years ago	-0.34 *
% Visited a dentist 5 or more years ago	-0.78 **
% Had 1-5 teeth removed due to decay	-0.38 *
% Had 6 or more removed due to decay	-0.37 **
% Had all teeth removed due to decay	-0.74 **
% Had no teeth removed due to decay	+0.61 **
% Had teeth cleaned 1-12 months ago	+0.52 **
% Had teeth cleaned 1-2 years ago	-0.32 *
% Had teeth cleaned 2-5 years ago	-0.28 *
% Had teeth cleaned 5 or more years ago	-0.60 **
% Never have had teeth cleaned	-0.59 **

Another economic factor often hypothesized to have a significant impact on both the utilization of dental services and oral health outcomes is per capita income. As seen in Table 4-7, per capita income by State is positively correlated with the percentage of the population having their teeth cleaned 1 to 12 months ago and negatively correlated with the percentage having their teeth cleaned further back in time (1 to 2 years ago, 2 to 5 years ago, 5 or more years ago, or never). Per capita income is also positively correlated with the percentage visiting a dentist recently (within the past 12 months) and negatively correlated with the percentage visiting a dentist further back in time (1 to 2 years ago, 2 to 5 years ago, or 5 or more years ago). Per capita income is also positively correlated with the percentage having no teeth removed due to tooth decay or gum disease, and negatively correlated with the percentage having some teeth removed due to tooth decay or gum disease. These correlations are statistically significant irrespective of the time period in which the relationship is examined (i.e., whether per capita income is temporally prior to or temporally concurrent with the various utilization/status measures).

Table 4-7. Relationship Between 2000 Per Capita Income in States and Selected Measures of Access to Dental Services
	Per Capita Income 1991	Per Capita Income 1998
% Visited dentist 1-12 mo. ago	+0.644 **	+0.662 **
% Visited dentist 1-2 yrs ago	-0.271 (p=0.055)	-0.378 **
% Visited dentist 2-5 yrs ago	-0.368 **	-0.449 **
% Visited dentist 5+ yrs ago	-0.680 **	-0.679 **
% Had 6+ teeth removed decay	-0.312 *	-0.331 *
% Had all teeth removed decay	-0.578 **	-0.578 **
% Had no teeth removed decay	+0.364 **	+0.399 **
% Had teeth cleaned 1-12 months ago	+0.542 **	+0.590 **
% Had teeth cleaned 1-2 years ago	-0.326 *	-0.408 **
% Had teeth cleaned 5+ years ago	-0.538 **	-0.585 **
% Never had teeth cleaned	-0.606 **	-0.585 **

Another indication that financial or economic factors have a significant impact upon both the utilization of services and oral health outcomes is observed in the correlation between the unemployment rate and a number of aggregated dental questions from the BRFSS survey. Table 4-8 shows that unemployment rates are negatively correlated with the percentage having their teeth cleaned by a dentist or a dental hygienist recently (1 to 12) months ago, and positively correlated with the percentage having their teeth cleaned further back in time (1 to 2 years ago, 2 to 5 years ago, 5 or more years ago, or never). The unemployment rate is negatively correlated with the percentage visiting a dentist recently (1 to 12 months ago) and positively correlated with the percentage visiting a dentist further back in time (1 to 2 years ago, 2 to 5 years ago, 5 or more years ago, or never). Furthermore, the unemployment rate is positively associated with the percentage having 1 to 5 teeth removed due to tooth decay or gum disease (an indicator of inadequate preventive care generally provided by DHs).

Table 4-8. Relationship Between State Unemployment Rate in 1999 and Selected Measures of Access to Dental Care
% Visited dentist 1-12 mo. ago	-0.335 *
% Visited dentist 1-2 yrs ago	0.349 *
% Visited dentist 2-5 yrs ago	0.440 **
% Never visited a dentist	0.316 *
% Had 1-5 teeth removed due to decay	0.455 **
% Had teeth cleaned 1-12 months ago	-0.459 **
% Had teeth cleaned 1-2 years ago	0.402 **
% Had teeth cleaned 2-5 years ago	0.444 **
% Had teeth cleaned 5+ years ago	0.398 **
% Never had teeth cleaned	0.373 **

Another economic factor correlated with access to dental services and oral health outcomes is per capita expenditures on dental care. As one might expect, greater expenditures on dental care are positively correlated to both recent utilization of dental services and negatively correlated with bad oral health outcomes (Table 4-9).

Table 4-9. Relation Between Per capita Personal Expenditure on Dental Care in 1991 and Selected Measures of Access to Dental Care
% Visited a dentist 1-12 months ago 1999-2001	+0.646 **
% Visited a dentist 2-5 years ago 1999-2001	-0.314 *
% Visited a dentist 5+ years ago 1999-2001	-0.727 **
% Not visited a dentist in past year due to cost 1995-2001 excluding 1999	+0.423 **
% Had 1-5 permanent teeth removed decay 1999-2001	-0.307 *
% Had 6+ teeth removed due to decay 1999-2001	-0.411 **
% Had no teeth removed due to decay 1999-2001	+0.586 **
% Had teeth cleaned 1-12 months ago 1999-2001	+0.478 **
% Had teeth cleaned 5 or more years ago 1999-2001	-0.529 **
% Never had teeth cleaned 1999-2001	-0.654 **

Economic factors are clearly important correlates of both utilization of dental services and oral health outcomes, but they are not the only factors of interest. As was previously hypothesized, one would expect that the number of oral health practitioners would be also positively correlated with utilization of services and oral health outcomes.

These hypotheses were strongly supported by the data. The numbers of dental hygienists per capita in 2001 are significantly correlated with both the utilization of services and oral health outcomes in the population (spanning the years 1995-2001). The numbers of dentists per capita in 2001 are also significantly correlated with both the utilization of services as well as oral health outcomes within the population (spanning 1995-2001). This is evident whether one correlates access measures and oral health status measures with the percentage of the population living within a dental HPSA (Table 4-10), or with numbers of dental practitioners per capita (Table 4-11).

Table 4-10. Relationship Between the Percentage of State Population Living in a Dental HPSA in 2000 and Selected Measures of Access to Dental Care
% Visited a dentist 1-12 months ago 1999-2001	-0.376 **
% Visited a dentist 5 or more years ago 1999-2001	0.395 **
% Had teeth cleaned 1-12 months ago 1999-2001	-0.333 *
% Had teeth cleaned 5 or more years ago 1999-2001	0.391 **
% Never had their teeth cleaned 1999-2001	0.347 *

Table 4-11. Relationship Between the Numbers of Dentists and Dental Hygienists in 2001 and Selected Measures of Access to Dental Care in 2001
	Dentists per capita, 2001	Dental Hygienists per capita, 2001
% Visited dentist 1-12 months ago	0.639 **	0.472 **
% Visited a dentist 1-2 years ago	-0.240 (p=0.089)	-0.542 **
% Visited a dentist 2-5 years ago	-0.387 **	-0.478 **
% Visited a dentist 5 or more years ago	-0.696 **	-0.352 *
% Had 1-5 teeth removed due to decay	Not Significant	-0.389 **
% Had 6 or more teeth removed due to decay	-0.282 *	Not Significant
% Had all teeth removed due to decay	-0.559 **	-0.288 *
% Had no teeth removed due to decay	0.409 **	0.377 **
% Had teeth cleaned 1-12 months ago	0.525 **	0.494 **
% Had teeth cleaned 1-2 years ago	-0.262 (p=0.064)	-0.510 **
% Had teeth cleaned 2-5 years ago	-0.320 *	-0.437 **
% Had teeth cleaned 5 or more years ago	-0.562 **	-0.356 **
% Never had teeth cleaned	-0.561 **	-0.457 **
% Have dental insurance	0.607 **	0.347 *

The financial status and educational background of the population are also significantly correlated with the numbers of DHs per capita and recent visits to the dentist (Table 4-12). Both per capita personal income in 2001 and the percentage of the population with a bachelors degree in 2000 were positively correlated with per capita expenditures on dental care in 2000, the percentage of the population that visited the dentist in the past year in 1999-2001, and the number of dental hygienists per capita in 2001.

Table 4-12. Correlations Among Selected Measures of Population Characteristics and Access to Dental Care and Numbers of Dental Hygienists per Capita
	Per Cap Exp on Dental Care ‘00	Per Cap Income 2000	% of Pop w/ Bach Degree, 2000	% Visit Dentist Within 1 Year	Dental Hygienists per capita, 2001
PC Expenditures on Dental Care, 2000	1.00	-	-	-	-
PC Income, 2000	0.814**	1.00	-	-	-
Percent of Pop with Bach Degree, 2000	0.728**	0.728**	1.00	-	-
% Visit dentist 1-12 months ago 1999-2001	0.646**	0.644**	0.665**	1.00	-
Dental Hygienists per Capita, 2001	0.467**	0.316*	0.273*	0.472**	1.00

Table 4-13 shows that the financial status of the population is also significantly correlated with the number of dentists per capita in 1998, and the percentage of the population having no teeth removed due to tooth decay or gum disease in 1999-2001.

Table 4-13. Correlations Between Per Capita Income, Numbers of Dentists, and Percent of Population with No Teeth Removed Due to Decay
	Per Capita Personal Income, 2000	Dentists per Capita, 1998	% w/ No Teeth Removed Due to Decay ‘99-‘01
Per Capita Personal Income 2000	1.00	-	-
Number of Dentists per Capita 1998	0.717 **	1.00	-
% w/ No Teeth Removed Due to Decay 1999-2001	0.364 **	0.515 **	1.00

Demographics and Dental Professionals

Among racial/ethnic groups in a State level analysis, Asians rate the best with respect to both utilization of dental care as well as oral health status. Table 4-14 shows that Asians are more likely than other racial/ethnic groups to have dental insurance, more likely to visit the dentist regularly, and more likely to have no teeth pulled as a result of tooth decay or gum disease. Hispanics are more likely than some racial/ethnic groups to have dental insurance and more likely to have better oral health (no teeth pulled due to tooth decay or gum disease); they are also less likely to have visited a dentist further back in time (5 or more years ago). The percentages of the population that is white or black are largely uncorrelated with various measures of utilization of care and oral health at the State level, apart from the negative correlation between percent black and the percentage having dental insurance. American Indians are generally associated with lower levels of recent visits to the dentist or having one’s teeth cleaned recently.

Table 4-14. Relationships Between Proportions of Population in Different Racial-Ethnic Groups and Selected Measures of Access to Dental Services and Oral Health Outcomes
	% White	% Black	% Asian	% Hispanic	% American Indian
% Visited dentist 1-12 months ago	n.s.	n.s.	0.430**	n.s.	-0.305*
% Visited dentist 1-2 years ago	n.s.	n.s.	n.s.	n.s.	0.535 **
% Visited dentist 2-5 years ago	n.s.	n.s.	n.s.	n.s.	0.411**
% Visited dentist 5 or more years ago	n.s.	n.s.	-0.632**	-0.292*	n.s.
% Never visited a dentist	n.s.	n.s.	n.s.	0.328*	n.s.
% Didn’t visit dentist in past year due to cost	n.s.	n.s.	n.s.	0.390**	0.422**
% Had 6 or more teeth removed due to decay	n.s.	n.s.	-0.508**	-0.491**	-0.411**
% Had all teeth removed due to decay	n.s.	n.s.	-0.778**	-0.611**	n.s.
% Had no teeth removed due to decay	n.s.	n.s.	0.546**	0.384**	n.s.
% Had teeth cleaned 1-12 months ago	n.s.	n.s.	n.s.	n.s.	-0.436**
% Had teeth cleaned 1-2 years ago	n.s.	n.s.	n.s.	n.s.	0.575**
% Had teeth cleaned 2-5 years ago	n.s.	n.s.	n.s.	n.s.	0.449**
% Had teeth cleaned 5 or more years ago	n.s.	n.s.	-0.402**	n.s.	n.s.
% Have dental insurance	n.s.	-0.297*	0.736**	0.410**	n.s.

Another demographic factor related to utilization of care and oral health is age. Table 4-15 shows that younger age groups are more likely to have dental insurance, more likely to have visited a dentist recently, more likely to have no teeth removed due to decay or gum disease, and more likely to have had their teeth cleaned recently.

Table 4-15

Conclusions

Consistent with previous research, numerous socio-demographic factors were found to be relevant to oral health in the United States. However, this analysis was able to go beyond existing findings by incorporating not only the level of professionalism of dental hygienists, but also the number of dental practitioners within the population and the ways in which the numbers of dental practitioners impacts both the utilization of care as well as oral health outcomes.

The professionalism of dental hygienists is highly relevant to the utilization of care, oral health outcomes, as well as the supply of practitioners. The supply of dental professionals (both dentists and dental hygienists) are significantly correlated with both utilization of dental care and oral health outcomes.

Financial factors (including per capita income, possession of dental insurance, unemployment rates, and personal expenditure on dental care per capita) were found to be highly correlated with both the utilization of dental care as well as oral health outcomes. Age plays a role as well: younger adults are more likely to have dental insurance, to utilize dental care, and to have more positive oral health outcomes than are older adults.