Abstract
BACKGROUND: Patients with limited English proficiency (LEP) and type 2 diabetes mellitus (T2DM) have several health disparities, including suboptimal patient-provider interactions, poorer glycemic control, and T2DM complications. Understanding existing interventions for improving T2DM outcomes in this population is critical for reducing disparities. METHODS: We performed a systematic review of randomized controlled trials (RCTs) and observational studies examining the effectiveness of interventions in improving T2DM outcomes among patients with LEP in North America. Quality was assessed using the Cochrane risk of bias tool for RCTs and the Newcastle-Ottawa Scale for non-RCT studies. Meta-analysis was conducted using the random-effects model. RESULTS: Fifty-four studies, 39 of which reported sufficient data for meta-analysis of glycemic control, were included. The interventions were associated with a statistically significant reduction in hemoglobin A(1c) (HbA(1c)) (weighted difference in means, -0.84% [95% CI, -0.97 to -0.71]) that was, however, very heterogeneous across studies (I(2) = 95.9%). Heterogeneity was explained by study design (lower efficacy in RCTs than non-RCTs) and by intervention length and delivery mode (greater reduction in interventions lasting <6 months or delivered face-to-face); P < 0.05 for all three covariates. The interventions were also associated in most studies with improvement in knowledge, self-efficacy in diabetes management, quality of life, blood pressure, and low-density lipoprotein cholesterol. DISCUSSION: Multiple types of interventions are available for T2DM management in patients with LEP. Multicomponent interventions delivered face-to-face seem most effective for glycemic control. More research is needed to better understand other aspects of multicomponent interventions that are critical for improving important outcomes among patients with T2DM and LEP.