Diabetes in urban African-Americans. XVII. Availability of rapid HbA(1c) measurements enhances clinical decision-making

OBJECTIVE - To assess the impact of rapid-turnaround HbA(1c) results on providers' clinical decision-making and on follow-up HbA(1c) levels. RESEARCH DESIGN AND METHODS - The research design was a randomized clinical trial in which rapid HbA(1c) results were made available to providers on even days of the month (rapid, n = 575), but delayed by 24 h on odd days (conventional, n = 563). Adjustment of therapy for patients with type 2 diabetes was considered appropriate if therapy was intensified for HbA(1c) values >7% or not intensified for HbA(1c) values ≤7%. A post-hoc analysis was also performed using patients (n = 574) who returned for follow-up 2-7 months later to ascertain the effect of rapid HbA(1c) availability on subsequent glycemic control. RESULTS - Rapid HbA(1c) availability resulted in more appropriate management compared with conventional HbA(1c) availability (79 vs. 71%, P = 0.003). This difference was due mainly to less frequent intensification when HbA(1c) levels were ≤7% (10 vs. 22%, P < 0.0001) and slightly to more frequent intensification for patients with HbA(1c) values >7% (67 vs. 63%, P = 0.33). For both groups, intensification was greatest for patients on insulin (51%) compared with patients on oral agents (35%) and diet alone (14%) (P < 0.0001). Regression analysis confirmed that providers receiving conventional HbA(1c) results were more likely to intensify therapy in patients who already had HbA(1c) levels ≤7%. Over 2-7 months of follow- up, HbA(1c) rose more in patients with conventional HbA(1c) results compared with rapid results (0.8 vs. 0.4%, P = 0.02). In patients with initial HbA(1c) >7%, rapid HbA(1c) results had a favorable impact on follow-up HbA(1c) independent of the decision to intensify therapy (P = 0.03). CONCLUSIONS - Availability of rapid HbA(1c) determinations appears to facilitate diabetes management. The more favorable follow-up HbA(1c) profile in the rapid HbA(1c) group occurs independently of the decision to intensify therapy, suggesting the involvement of other factors such as enhanced provider and/or patient motivation.