NGC uses standard terminology also known as "Controlled Vocabulary Concepts" to classify various guideline attributes represented in the NGC guideline summary. This standard "classification scheme" makes it easier to search for and retrieve information from the NGC Web site. In addition, the scheme standardizes key guideline attributes to facilitate review and comparison of the guidelines.
NGC classifies the following attributes:
New vocabulary concepts are added to the classification scheme as needed. Refer to the Glossary for definitions of select terms.
The following concepts classify the clinical specialties that might use the guideline professionally:
- Allergy and Immunology
- Anesthesiology
- Cardiology
- Chiropractic
- Colon and Rectal Surgery
- Critical Care
- Dentistry
- Dermatology
- Emergency Medicine
- Endocrinology
- Family Practice
- Gastroenterology
- Geriatrics
- Hematology
- Infectious Diseases
- Internal Medicine
- Medical Genetics
- Nephrology
- Neurological Surgery
- Neurology
- Nuclear Medicine
- Nursing
- Nutrition
- Obstetrics and Gynecology
- Oncology
- Ophthalmology
- Optometry
- Orthopedic Surgery
- Otolaryngology
- Pathology
- Pediatrics
- Pharmacology
- Physical Medicine and Rehabilitation
- Plastic Surgery
- Podiatry
- Preventive Medicine
- Psychiatry
- Psychology
- Pulmonary Medicine
- Radiation Oncology
- Radiology
- Rheumatology
- Sleep Medicine
- Speech-Language Pathology
- Sports Medicine
- Surgery
- Thoracic Surgery
- Urology
Disease concepts are classified using Medical Subject Headings (MeSH) produced by the U.S. National Library of Medicine (NLM) 
, along with other controlled vocabularies, such as the International Classification of Diseases (ICD) and Systematized Nomenclature of Medicine - Clinical Terms (SNOMED CT), incorporated into NLM's Unified Medical Language System (UMLS) .
The following concepts classify the major focus area(s) of each guideline:
- Assessment of Therapeutic Effectiveness
- Counseling
- Diagnosis
- Evaluation
- Management
- Prevention
- Rehabilitation
- Risk Assessment
- Screening
- Technology Assessment
- Treatment
Health Services Administration
Health Services Administration concepts are classified using Medical Subject Headings (MeSH) produced by the U.S. National Library of Medicine (NLM) , along with other controlled vocabularies, such as Systematized Nomenclature of Medicine - Clinical Terms (SNOMED CT), incorporated into NLM's Unified Medical Language System (UMLS) .
The following concepts identify various methods used by the guideline developer(s) to disseminate and implement their guideline:
- Audit Criteria/Indicators
- Chart Documentation/Checklists/Forms
- Clinical Algorithm
- Foreign Language Translations
- Patient Resources
- Personal Digital Assistant (PDA) Downloads
- Pocket Guide/Reference Cards
- Quality Measures
- Quick Reference Guides/Physician Guides
- Resources
- Slide Presentation
- Staff Training/Competency Material
- Tool Kits
- Wall Poster
Institute of Medicine (IOM) Care Need
The following concepts classify the IOM Care Need categories according to the guideline's primary clinical focus:
- End of Life Care
- Getting Better
- Living with Illness
- Staying Healthy
Institute of Medicine (IOM) Domain
The following concepts classify the IOM Domain categories according to the guideline's primary clinical focus:
- Effectiveness
- Patient-centeredness
- Safety
- Timeliness
The following concepts classify the intended users of each guideline:
- Advanced Practice Nurses
- Allied Health Personnel
- Chiropractors
- Clinical Laboratory Personnel
- Dentists
- Dietitians
- Emergency Medical Technicians/Paramedics
- Health Care Providers
- Health Plans
- Hospitals
- Managed Care Organizations
- Nurses
- Occupational Therapists
- Optometrists
- Pathology Assistants
- Patients
- Pharmacists
- Physical Therapists
- Physician Assistants
- Physicians
- Podiatrists
- Psychologists/Non-physician Behavioral Health Clinicians
- Public Health Departments
- Respiratory Care Practitioners
- Social Workers
- Speech-Language Pathologists
- Students
- Substance Use Disorders Treatment Providers
- Utilization Management
Method of Guideline Validation
The following concepts summarize the methods used to review or validate the recommendations of the guideline. Validation is defined as "the results of any external review, comparison with guidelines from other groups or clinical testing of guideline use" (Hayward RS, Wilson MC, Tunis SR, et al. More informative abstracts of articles describing clinical practice guidelines, Ann Intern Med 1993 May 1;118[9]:731-7).
- Clinical Validation-Pilot Testing
- Clinical Validation-Trial Implementation Period
- Comparison with Guidelines from Other Groups
- External Peer Review
- Internal Peer Review
- Peer Review
Methods Used to Analyze the Evidence
The following concepts classify the methods used by the guideline developer(s) to evaluate the data in the evidence they reviewed:
- Decision Analysis
- Meta-Analysis
- Meta-Analysis of Individual Patient Data
- Meta-Analysis of Observational Trials
- Meta-Analysis of Randomized Controlled Trials
- Meta-Analysis of Summarized Patient Data
- Review
- Review of Published Meta-Analyses
- Systematic Review
- Systematic Review with Evidence Tables
Methods Used to Assess the Quality and Strength of the Evidence
The following concepts classify methods used by the guideline developer(s) to determine the relative importance or worth of the evidence reviewed:
- Expert Consensus
- Expert Consensus (Committee)
- Expert Consensus (Delphi Method)
- Subjective Review
- Weighting According to a Rating Scheme (Scheme Given)
- Weighting According to a Rating Scheme (Scheme Not Given)
Methods Used to Collect/Select the Evidence
The following concepts classify methods used by the guideline developer(s) to collect the evidence they evaluated:
- Hand-searches of Published Literature (Primary Sources)
- Hand-searches of Published Literature (Secondary Sources)
- Searches of Electronic Databases
- Searches of Patient Registry Data
- Searches of Unpublished Data
Methods Used to Formulate the Recommendations
The following concepts classify the methods used by the guideline developer(s) to create or formulate the guideline recommendations:
- Informal Expert Consensus
- Expert Consensus
- Expert Consensus (Delphi Method)
- Expert Consensus (Nominal Group Technique)
- Expert Consensus (Consensus Development Conference)
- Balance Sheets
The following concepts classify the guideline developer(s), guideline endorser(s), and issuing organization(s) by major designation or function:
- Academic Institution
- Disease Specific Society
- Federal Government Agency (U.S.)
- Hospital/Medical Center
- Independent Expert Panel
- International Agency
- Managed Care Organization
- Manufacturer
- Medical Specialty Society
- National Government Agency (Non-U.S.)
- Nursing Home/Extended Care Facility
- Private Nonprofit Organization
- Private Nonprofit Research Organization
- Private For Profit Organization
- Private For Profit Research Organization
- Professional Association
- Public For Profit Organization
- State/Local Government Agency (U.S.)
- State/Local Government Agency (Non-U.S.)
For the purposes of searching, NGC indexes and classifies the target population by age and sex. The following concepts are used:
- Infant, Newborn (to 1 month)
- Infant (1 to 23 months)
- Child (2 to 12 years)
- Adolescent (13 to 18 years)
- Adult (19 to 44 years)
- Middle Age (45 to 64 years)
- Aged (65 to 79 years)
- Aged, 80 and over
- Male
- Female
Treatment/Intervention concepts are classified using Medical Subject Headings (MeSH) produced by the U.S. National Library of Medicine (NLM) , along with other controlled vocabularies, such as the U.S. Centers for Medicare & Medicaid Services (CMS) [formally known as the Health Care Financing Administration (HCFA)] Common Procedure Coding System and ECRI Institute's Universal Medical Device Nomenclature System (UMDNS), incorporated into NLM's Unified Medical Language System (UMLS) .
