ACP American College of Physicians - Internal Medicine - Doctors for Adults

Effective Clinical Practice

A Primer on HEDIS 287

November/December 1999

Although many people talk about "report cards" for medical care, there are few working examples. The most prominent is the Health Plan Employer Data and Information Set -- better known as HEDIS. Used by over 400 health plans, HEDIS is a set of standardized performance measures intended to help purchasers and patients compare health plans in terms of quality (instead of simply comparing costs).

HEDIS is perhaps best thought of as a standardized test for health plans. Like most standardized tests there are different sections to test different domains (e.g. mathematics, language skills). Within each domain, there are a series of performance measures (e.g. individual questions). Table 1 shows the seven HEDIS domains and selected performance measures.

Table 1. HEDIS domains.

Domain Selected Performance Measures
Effectiveness of care See Tables II and III.
Access/Availability of Care Proportion of enrollees with preventive/ambulatory health visit in reporting year (calculated separately for children and adults)
Number of Providers (Primary Care, Behavioral Health Care, Obstetrical and Prenatal Care, and Dentists)
Availability of Language Interpretation Services
Satisfaction with Experience of Care Member satisfaction
Health Plan Stability Disenrollment
Provider Turnover
Indicators of Financial Stability (e.g. revenue, loss, reserves held by Plan)
Use of Services Visits (Prenatal Care, Well-Child, Adolescent Well-care, other Ambulatory Care)
Frequency of Selected Procedures
Cesarean Section Rate
Vaginal Birth After Cesarean Rate (VBAC-Rate)
Inpatient Utilization (Acute Care, Maternity Care, Newborns, Mental Health, Chemical Dependency)
Outpatient Drug Utilization
Cost of Care Actual expense per member per month
High-Occurrence/High-Cost DRG's (e.g. Stroke, TIA, Pneumonia, Asthma, COPD, Chest Pain, Angina Pectoris, Heart Failure and Shock, Major Joint Replacement)
Health Plan Descriptive Information Total Enrollment and by Payer
Provider Characteristics (Board Certification, Residency Completion, Compensation)
Report of Plan Affiliations with Public Health, community-based and school-based agencies
Cultural Diversity of Medicaid Membership

The HEDIS measures of greatest interest to clinicians are in the Effectiveness of Care domain.

Table 2 lists the performance measures, describes how each is calculated, and reports the most recent averages available for the Alliance of Community Health Plans and the national average (representing all participating plans). In each case, a higher proportion is presumed to represent better care. Some patients, however, may have an informed preference to forgo some of these services, such as certain immunizations.

Table 2. Current Performance Measures in Effectiveness of Care Domain.

Performance Measure Numerator Denominator 1997 ACHP Average 1997 National Average
Childhood Immunization Rate DTP, Polio, MMR, Hepatitis B, Hib 2 yr olds 78% 65%
Adolescent Immunization Rate 2nd MMR, Hepatitis B, chicken pox 13 yr olds 12% 8%
Advice to Quit Smoking Received advice to quit adults >18 yr who are current smokers 69% 64%
Breast Cancer Screening Rate one or more mammograms in the past two years women age 52-69 yr 77% 71%
Cervical Cancer Screening one or more Pap test in past three years women age 21-64 yr 77% 71%
Prenatal Care in First Trimester Rate prenatal care visit between 176 and 280 days prior to delivery women who delivered live births 88% 83%
Check-Ups After Delivery postpartum visit between 21 and 56 days after delivery women who delivered live births 73% 66%
Beta Blocker Treatment Rate -blocker dispensed within 7 days after AMI discharge adults >35 yr admitted with a diagnosis of AMI 79% 74%
Diabetic Retinal Exam Rate retinal examination by eye-care professional adults >31 yr who have diabetes 53% 39%
Follow-up After Hospitalization for Mental Illness Rate visit with mental health provider within 30 days of discharge individuals >6 yr admitted with a mental health diagnosis 77% 67%

The individual performance measures have evolved over time. When HEDIS was initiated in 1991, the effectiveness measures focused on vaccination and screening rates. Subsequently, measures were added to reflect the treatment quality in diabetes and following myocardial infarction. New measures examining care of hypertension, asthma, Chlamydia, and menopause have been proposed for the next version of HEDIS (Table 3).

Table 3. New Effectiveness of Care Performance Measures for HEDIS 2000.

Performance Measure Numerator Denominator
Controlling High Blood Pressure BP controlled to below 140/90 enrollees with high blood pressure
Appropriate Medications for People with Asthma received medications for long term control (e.g. inhaled corticosteriods) enrollees with chronic asthma
Chlamydia Screening tested for chlamydia sexually active woman aged 15-25
Management of Menopause breadth, depth and personalization of menopause counseling* menopausal woman
* This measure encourages plans to discuss with woman the pros and cons of various treatment options such as hormone replacement therapy so they can make more informed choices.

As HEDIS performance measures become more complex, however, so do the questions about measurement methods. (e.g. Does 145/95 constitute hypertension requiring control?, What constitutes a sufficient discussion of treatment options?)

HEDIS is managed by the National Committee for Quality Assurance (NCQA).

NCQA is encouraging the broad use of HEDIS data by employers, consumers, and others to compare health plans. Further information can be found at