Outcomes of audit-enhanced monitoring of patients with type 2 diabetes

FIGURE
Percentage of patients with annual review (target = 75%) in 1999 (n=594)

Discussion

During 7 years of structured audit-enhanced monitoring of patients with type 2 diabetes in an academic family practice research network, the intermediate measures of diabetes care improved. In particular, the mean Hb A1c of 7.1% can be seen as a measure of good quality of care. The number of patients treated according to Dutch family practice guidelines (a process of care outcome) also increased.⁸

While our data were collected during normal daily care (effectiveness), the findings come close to the outcome of care under ideal trial conditions (efficacy).²¹ In the UK Prospective Diabetes Study (UKPDS), the median Hb A_1c level for all newly diagnosed patients in the group with intensive blood glucose control over 10 years reached a comparable level of 7.0%.¹ Thus, the outcome of our study approaches that achieved under trial conditions. When we analyzed patients without outcome data as poorly controlled (worst-case scenario), Hb A_1c was less than 8.5% in 28%.

The trend of improvement in glycemic control could have been a result of improved overall diabetes care in the Netherlands during the study period. Data about the outcome of diabetes care in the family medicine setting in the Netherlands during the study period are scarce and, when available, are derived from other research networks. In these networks a mean Hb A_1c of 7.0% to 7.6% was reached.²² Yet indicators from other studies suggest that our results were far better than outcome from usual care. Recently published data on such outcomes in family medicine in the Netherlands showed that Hb A_1c, blood pressure, and lipids were measured in less than 30% of patients.^23,24 Outcomes from usual care as reported in research studies appear to be strongly biased by selection and probably cannot serve as a valid reference value.

The disappointing effect on the percentage of patients who reached the target blood pressure could have resulted from evaluating the data prematurely. When the study began, the primary objective was to improve glycemic control. Shortly after the publication of the Scandinavian Simvastatin Survival Study (4S)³ and the UKPDS,¹² the guidelines of the Dutch College of Family Physicians were changed⁸ and more attention was paid to blood pressure and lipid control. This new approach was discussed with the participating family physicians. Consequently, the target for blood pressure was revised from 160/90 mm Hg to 150/85 mm Hg and lipid-lowering therapy was tailored to each patient’s cardiovascular risk profile. The 1999 outcome with respect to blood pressure and lipid control was measured only 1 year after these changes had been announced. Nevertheless, mean diastolic blood pressure in hypertensive patients and total cholesterol and triglyceride levels decreased significantly, and more patients reached target levels for lipids in 1999 than in 1993.

Our outcome was reached through enhanced compliance to guidelines. Therefore, the outcome in 1999 was based on a larger percentage of available patients. Because the AEMS studied a dynamic group of patients, the study groups in 1993 and 1999 were not identical. Theoretically, improvement in outcome could have been reached by including more easily manageable patients. However, no patient factors such as sex, age, duration of diabetes, treatment modality, or cardiovascular morbidity were related to compliance with annual review. The higher fasting blood glucose levels in patients who were noncompliant with annual review probably reflected under-treatment rather than more severe illness status. Therefore, we are confident that the findings reflect improved overall diabetes care.

The data on process measures in this study compare favorably with those of multipractice audits of diabetes care in the United Kingdom.^25-29 The high prevalence rate of 2.0% (exclusively patients with type 2 diabetes) supports the validity of our data.^25-27 Among our patients, 96% had been seen at least once during the previous year. In the large studies by Khunti and Bennett, only 85% had been seen during the previous year.^25,26 The mean annual compliance rate of nearly 85% with Hb A_1c and blood pressure measurements in our study was high. In particular, compliance with lipid control^25,26,28 and funduscopy^26,28 was better in our study. In 2 longitudinal studies that used an organized care system in which feedback was provided to the participating family physicians, compliance rates in process measures of up to 75% were reported.^30,31

The outcomes of this study were achieved in an academic family practice research network, with specific facilities for the proactive supervision of patients with chronic diseases. These results cannot and should not be generalized to “routine” family practice. Monitoring and feedback in routine family practice are in themselves insufficient to improve the quality of care.¹⁰ Care assessment should preferably take a more comprehensive approach in which evidence-based goals for care are formulated, care is improved to reach those goals, and care is measured to see whether those goals have been achieved.¹¹ Our academic network provides this comprehensive approach.