Variation in clinical preventive services

Preventive services are not delivered at optimal rates in primary care settings, and the literature suggests that a systems approach is key to improvement. Studying variation among clinics could help us to understand the extent of system use in practice.

The proportion of patients who are up-to-date for preventive services in 44 primary care practices in the Midwest. PREVENTIVE SERVICES EXAMINED: Papanicolaou (Pap) smear, cholesterol testing, mammography, clinical breast examination, blood pressure measurement, influenza and pneumococcal vaccinations, and advice on tobacco use.

6830 patients surveyed after their clinic visit (response rate, 85%).

The proportion of patients up-to-date for preventive services varied widely among clinics. For example, up-to-date rates for Pap smear testing ranged from 70% to 93% and 45% to 88% for cholesterol screening. There was little correlation between a clinic's performance on one preventive service (relative to the other 43 clinics) and its performance on others. When correlations between pairs of up-to-date rates within clinics were examined, only 4 of 28 service pairs were positive and statistically significant and only 1 had a correlation coefficient that exceeded 0.5 (for mammography and clinical breast examination).

There is wide variation in the rates at which various preventive services are performed, both between and within clinics. This variation, which is probably due to a lack of organized prevention systems that cover multiple services, provides a clear target for improvement efforts.