The Diabetes Quality Improvement Project established performance indicators that were adopted by The National Committee for Quality Assurance in the Diabetes Physician Recognition Program (DPRP) (1,2). The HbA1c (A1C) factors heavily in the scoring system, accounting for 15 of a possible 80 points. To achieve full credit, <20% of a random sampling of patients may have an A1C >9.0% and at least 40% must be <7.0%. This methodology may bias against diabetes consultants who are referred patients in worse control. Improvements in A1C may more readily reflect quality of care. The American Diabetes Association recommends an A1C of <7.0% (3) and in previous guidelines set ≥8.0% as a level whereupon “additional action is suggested” (4). The Diabetes Control and Complications Trial (DCCT) demonstrated that a decline in the A1C of 1% reduced microvascular complications by 30% or more (5). Therefore, poor control and clinically meaningful improvements may be defined by an A1C of ≥8% and −1%, respectively. The purpose of the present study is to evaluate change in A1C as a marker of quality of care.
Patients from one physician were evaluated, and all were referred from other providers. A1C data were collected prospectively in new patients from 1 January 2003 through 31 December 2004. Data were included if the baseline A1C (collected the day of the consult or within 90 days prior) was ≥8.0%, and at least one subsequent A1C, performed after 3 months, was measured. A third A1C was collected in patients who had been seen for ≥6 months at the time of data collection. The mean ± SD A1C was calculated for each of the three time points, and a t test was performed to determine statistical significance between levels.
A total of 96 patients met the entry criteria. Of these, 54 (56%) had a third data point. The remainder had not yet been followed long enough at the time of data collection (n = 32) or did not adhere to follow up (n = 9). The mean A1C at entry was 10.36 ± 1.66%. The mean first and second follow-up A1C levels were 8.06 ± 1.68 and 7.68 ± 1.38%, respectively. Changes from entry to first and second A1C were both statistically significant (P < 0.001). Seventy-four percent of patients at first follow-up A1C and 80% at the second demonstrated an A1C decline of ≥1%.
In this brief observation, the majority of patients who were referred for endocrine consultation to evaluate and treat poor diabetes control showed clinically meaningful improvements in A1C. In evaluating quality of care, the DPRP looks at a cross section of randomly chosen patients. In a consultation practice, the diabetes specialist may accumulate many poorly controlled patients. Therefore, the impression is that quality of care is poor. Moreover, provider recognition may be less likely under the current scoring system. Yet, the DCCT demonstrated that reductions in microvascular complications, in particular retinopathy, can be seen with sustained A1C reductions even if the target of <7% is not achieved (5). Change in A1C may be a useful marker for quality of care given by diabetes consultants and can be used as an adjunct to the current DPRP standards, especially if longer-term data are used.
