Frequency monitoring of hemoglobin A1c, low-density lipoprotein, and urine protein laboratory testing: a College of American Pathologists Q-Probes study.

Context: Ensuring laboratory tests are performed at intervals consistent with established, evidence-based guidelines in diabetic patients is an important aspect of laboratory utilization.

Objectives: To measure how frequently diabetes mellitus patients are tested for hemoglobin A1c (HbA1c), low-density lipoprotein, and urine protein and to determine whether the frequencies with which these analytes are tested are consistent with recognized guidelines.

Design: Participants prospectively identified up to 40 patients with a current HbA1c result and at least 2 previous measurements within the past 24 months. For each patient identified with at least 3 HbA1c measurements during a 24-month period, participants also determined the number of low-density lipoprotein and spot or random urine protein tests that were performed during those 24 months.

Results: Participants from 49 institutions submitted a total of 1915 cases that met the study criteria of at least 3 HbA1c test results within the past 24 months. Approximately 95% of patients had 8 or fewer HbA1c tests in the past 24 months; 79% of patients with at least 3 HbA1c tests had at least 2 low-density lipoprotein tests and 27% had at least 2 urine protein tests reported during the 24-month study period.

Conclusion: Participating laboratories were generally successful in documenting appropriate utilization of HbA1c testing in diabetes mellitus monitoring, but had more difficulty documenting that diabetes mellitus patients had annual testing for low-density lipoprotein and urine protein.