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

Audit-enhanced monitoring system

Since 1989, data have been collected on all type 2 diabetes patients at the time of diagnosis and during all regular (quarterly) diabetes-related outpatient visits. In 1992, a structured annual review, based on guidelines from the Dutch College of Family Physicians,¹⁹ was added. Starting in 1992, monitoring has consisted of the assessment of (1) compliance with 3 monthly control visits and an annual review visit; (2) glycemic control (ie, fasting blood glucose and Hb A_1c); (3) diabetes-related complications (ie, retinopathy, creatinine clearance, and foot problems); (4) cardiovascular risk factors (ie, smoking behavior, blood pressure, and lipid profile); (5) cardiovascular morbidity (ie, myocardial infarction, angina pectoris, heart failure, peripheral vascular disease, transient ischemic attack, or cerebrovascular accident). In addition, all reasons for dropping out, including cause of death, were recorded. Morbidity and causes of death were defined as in the International Classification of Health Problems in Primary Care.

To facilitate data collection, a computerized Research Registration System (RRS) was developed. The system was integrated into a standard Dutch electronic record system for family practice (Promedico, Euroned). The RRS generates templates for recording data at the quarterly or annual diabetes control visits into the patient’s electronic record. Templates guide the delivery of care and a reminder system is integrated into the RRS. Office assistants contact patients who do not come in for visits at regular intervals, both those (< 1%) who usually do not come in and those who are supposed to but fail to do so.

Family physicians sent the RRS data files to the University Department of Family Practice, where they were processed into a feedback report on process of care and outcome of care measures on 3 levels: (1) total study population; (2) practice population; (3) individual patient. Process and outcome measures were compared with external criteria based on guidelines from the Dutch College of Family Medicine and with average performance at the other practices. Feedback items were selected in consultation with the participating physicians. In this way, feedback corresponded with daily practice needs. During the project, the feedback was gradually extended from process to outcome measures. The feedback was standard to all practices.

Feedback was discussed at University Department of Family Medicine meetings, which maintained uniform registration and safeguarded the progress of the project. The feedback was also sent to every practice and participating GP. This report contained practice-level as well as physician-level data. The Figure demonstrates one way in which data are presented at the meetings and shows the percentage of patients who attended their annual diabetes control visit in the year studied.

Targets for care

Targets for care consisted of 2 elements: process and outcome measures. The key marker for process of care was compliance to the annual diabetes control visit. Key markers for desired outcome of care were (1) Hb A_1c < 8.5%,¹⁹ (2) blood pressure less than 160/90 mm Hg (revised to 150/85 mm Hg in 1999),^8,19 and (3) lipids in accordance with Dutch guidelines for general practice⁸: (a) cholesterol < 5 mmol (192 mg/dL) for patients with cardiovascular morbidity; (b) cholesterol/HDL ratio < 5.0 in smokers without cardiovascular morbidity; and (c) cholesterol/HDL < 6.0 in nonsmokers without cardiovascular morbidity. These guidelines for lipid-lowering therapy are based on sex, a life expectancy of at least 5 years, smoking status, presence of cardiovascular morbidity, total cholesterol levels, high-density lipoprotein (HDL) cholesterol levels, and triglyceride levels. If even 1 of these variables is absent, the potential value of lipid lowering cannot be determined.⁸

Analysis

Cross-sectional analysis was performed on the outcome of diabetes care in patients with type 2 diabetes who were treated by their family physicians in 1993 and 1999. The comparison was based on all patients who had been treated for the full calendar year in 1993 and 1999; therefore, it was based on a dynamic population. Process and outcome measures are compared using the chi-squared, unpaired t, or Mann–Whitney test, as appropriate. Results are expressed as means plus or minus standard deviations or as proportions. Multilevel analysis was performed to assess factors that contributed to the variance in compliance with the annual review and the desired glycemic level (Hb A_1c < 8.5%).

Results

In 1993, 540 type 2 diabetes patients (prevalence 1.3%) were included in the AEMS. Of these, 51 had been newly diagnosed (incidence 1.2/1000); 37 had been treated by a specialist (7%); and 20 did not participate (4%). Excluding the 108 patients in the latter 3 categories left a total of 432 patients for analysis. In 1999, 851 patients were included (prevalence 1.9%). Of these, 138 had been newly diagnosed (incidence 3.0/1000); 88 had been treated by a specialist (10%); and 31 did not participate (4%). Excluding the 257 patients in those 3 categories left 594 for analysis. Table 1 shows the baseline characteristics of patients included in the analysis.