Performance-based physician reimbursement and influenza immunization rates in the elderly. The Primary-Care Physicians of Monroe County. Primary and preschool immunisation in Grampian: progress and the 1990 contract.
To investigate the effect of performance-based financial incentives on the influenza immunization rate in primary care physicians' offices.
                Randomized controlled trial during the 1991 influenza immunization season.
                Rochester, New York, and surrounding Monroe County during the Medicare Influenza Vaccine Demonstration Project.
                A total of 54 solo or group practices that had participated in the 1990 Medicare Demonstration Project.
                All physicians in participating practices agreed to enumerate their ambulatory patients aged 65 or older who had been seen during the 1990 or 1991 calendar years, and to track the immunization rate on a weekly basis using a specially designed poster from September 1991 to January 1, 1992. Additionally, physicians agreed to be randomized, by practice group, to the control group or to the incentive group, which could receive an additional $.80 per shot or $1.60 per shot if an immunization rate of 70% or 85%, respectively, was attained.
                The main outcome measures are the 1991 immunization rate and the improvement in immunization rate from the 1990 to 1991 influenza seasons for each group practice.
                For practices in the incentive group, the mean immunization rate was 68.6% (SD 16.6%) compared with 62.7% (SD 18.0%) in the control group practices (P = .22). The median practice-specific improvement in immunization rate was +10.3% in the incentive group compared with +3.5% in the control group (P = .03).
                Despite high background immunization rates, this modest financial incentive was responsible for approximately 7% increase in immunization rate among the ambulatory elderly. To examine changes in immunisation performance in Grampian region after the introduction of the 1990 contract for general practitioners.
                Retrospective descriptive study using data held on the Grampian immunisation record system's computer.
                All 95 general practices in Grampian region (313 general practitioners).
                All children in the primary immunisation and preschool booster age groups. This formed two groups of children for each of the four calendar quarters of 1990 and first three quarters of 1991 analysed as (a) those aged 2 years on the first day of the relevant quarter and (b) those aged 5 years on the first day of the relevant quarter, with an average population of 6600 and 6400 respectively.
                Percentage immunised by practice.
                For primary immunisation the number of practices achieving immunisation rates of at least 95% increased from 29 (31%) to 76 (81%), and practices achieving 90% rates rose from 69 (73%) to 87 (93%). For preschool boosters, the number of practices achieving at least 95% immunisation rates increased from 22 (23%) to 61 (64%). By the end of September 1991, 76 (80%) practices were achieving at least 90% levels compared with 36 (39%) at the beginning of 1990. Since the beginning of 1989 the proportion of immunisations not given by general practitioners declined from 14% to 2%.
                Primary and preschool immunisation rates for preschool children in Grampian showed a sustained improvement during 1990 and consolidation in 1991. Although overall trends were unchanged, 18 months after the introduction of the 1990 contract only one practice failed to meet lower target levels of 70% for both primary and preschool immunisation. By September 1991 more than three out of four practices had reached levels of at least 95% for primary immunisation.
The evidence from the studies identified in this review is not of sufficient quality or power to obtain a clear answer to the question as to whether target payment remuneration provides a method of improving primary health care. Additional efforts should be directed in evaluating changes in physicians' remuneration systems. Although it would not be difficult to design a randomised controlled trial to evaluate the impact of such payment systems, it would be difficult politically to conduct such trials.