Interinstitutional variation in glycohemoglobin monitoring and glycemic control of diabetic patients

Objectives.-To compare how frequently institutions monitor glycohemoglobin in diabetic patients, the level of glycemic control achieved and to identif y institutional factors associated with higher rates of monitoring and lowe r glycohemoglobin levels. Methods.-A total of 212 institutions retrospectively abstracted laboratory and outpatient records of up to 30 diabetic patients who had initial glycoh emoglobin monitoring performed in their laboratories. Data from a cohort of 5586 diabetic patients and 17365 assays were analyzed. Results.-Overall, 31.3% of patients underwent glycohemoglobin monitoring at least quarterly, the frequency recommended by the American Diabetes Associ ation (ADA) to stabilize patients at target hemoglobin A(1c) (HbA(1c)) leve ls. A total of 64.9% of patients were monitored at least semiannually, the ADA recommendation for patients with stable diabetes in glycemic control (f inal HbA(1c) level <7%). When we compared the top and bottom deciles of the 212 institutions, there was more than an eightfold difference in the propo rtion of patients monitored at least quarterly and more than a twofold diff erence in the proportion of patients monitored at least semiannually. Glyce mic control was assessed by examining the value of the last glycohemoglobin determination on record after at least 8 months of management. For all 558 6 diabetic patients, the median value of the last HbA(1c) assay was 7.4%, C omparing the top and bottom deciles, there was almost a fourfold difference among institutions in the proportion of diabetic patients in glycemic cont rol. The use of reminders to order glycohemoglobin monitoring was associate d with higher rates of semiannual monitoring (P < .05) and tighter glycemic control (P < .05). In addition, patients who were monitored more frequentl y experienced glycohemoglobin reductions of greater magnitude (P < .001). T he presence of diabetes clinics and the use of rapid methods for testing gl ycohemoglobin were not associated with monitoring frequency or glycohemoglo bin levels. Conclusions.-There is wide interinstitutional variation in the frequency wi th which diabetic patients are monitored and the level of glycemic control achieved. The use of prompting systems to remind providers to order glycohe moglobin monitoring was associated with more frequent monitoring and superi or glycemic control.