Review: Quality improvement strategies reduce HbA1c, LDL cholesterol, and BP in diabetes

Researchers reviewed more than 140 randomized trials of quality improvement (QI) strategies for managing adult patients with diabetes. Some of the most commonly studied strategies were clinician education, case management, team changes, patient education and promotion of self-management. After conducting a meta-analysis with a random effects model, the reviewers concluded that overall the QI strategies reduced glycated hemoglobin levels, low-density lipoprotein cholesterol levels, and blood pressure compared to results in control patients.

The study was published by The Lancet on June 9. The following commentary by Sean F. Dinneen, MD, and Máire O’Donnell, PhD, was published in the ACP Journal Club section of the Oct. 16 Annals of Internal Medicine.

The health systems, institutions, and traditions within which we function often make it difficult for us to deliver care to the highest standard. QI initiatives represent an attempt to achieve these high standards within the constraints of the day-to-day working environment. The comprehensive systematic review and meta-analysis by Tricco and colleagues include studies that evaluate a wide range of QI interventions and make heartening reading. The authors report the effects of QI interventions across a wide range of outcomes, including frequency of use of certain drugs (including statins and aspirin), compliance with screening (for microvascular complications), and smoking cessation rates. QI strategies were, in general, effective over a median follow-up of 12 to 18 months. However, the effects were modest at best, as shown by only marginal—and not statistically significant—improvements in the proportion of patients achieving smoking cessation, using statins, or with control of hypertension.

An interesting aspect of the analysis is the dominance of hemoglobin A1c (HbA1c) as the preferred outcome measure in QI trials. Of 142 trials included in the review, 120 included HbA1c as an outcome; the next most common outcome measure was blood pressure (65 trials). With strategies as diverse as education of patients and health care professionals, team changes, and “facilitated relay” of clinical information included in the analysis, it seems unlikely that a biochemical measure of glycemic control will adequately reflect overall effects on care. Others have also noted an overreliance on measures of glycemic control when evaluating education programs for patients with diabetes. Nevertheless, until we devise easier-to-measure, standardized approaches for other patient-important outcomes, HbA1c will continue to be used as the primary quality measure for diabetes care.