Diabetes in urban African-Americans. XVII. Availability of rapid HbA1c measurements enhances clinical decision-making.

Abstract

OBJECTIVE: To assess the impact of rapid-turnaround HbA1c results on providers' clinical decision-making and on follow-up HbA1c levels. RESEARCH DESIGN AND METHODS: The research design was a randomized clinical trial in which rapid HbA1c 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 HbA1c values >7% or not intensified for HbA1c values < or =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 HbA1c availability on subsequent glycemic control. RESULTS: Rapid HbA1c availability resulted in more appropriate management compared with conventional HbA1c availability (79 vs. 71%, P = 0.003). This difference was due mainly to less frequent intensification when HbA1c levels were < or =7% (10 vs. 22%, P < 0.0001) and slightly to more frequent intensification for patients with HbA1c 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 HbA1c results were more likely to intensify therapy in patients who already had HbA1c levels < or =7%. Over 2-7 months of follow-up, HbA1c rose more in patients with conventional HbA1c results compared with rapid results (0.8 vs. 0.4%, P = 0.02). In patients with initial HbA1c >7%, rapid HbA1c results had a favorable impact on follow-up HbA1c independent of the decision to intensify therapy (P = 0.03). CONCLUSIONS: Availability of rapid HbA1c determinations appears to facilitate diabetes management. The more favorable follow-up HbA1c profile in the rapid HbA1c group occurs independently of the decision to intensify therapy, suggesting the involvement of other factors such as enhanced provider and/or patient motivation.