Effectiveness and safety of patient activation interventions for adults with type 2 diabetes: systematic review, meta-analysis, and meta-regression

Abstract

Background: Patient activation interventions (PAIs) engage patients in care by promoting increased knowledge, confidence, and/or skills for disease self-management. However, little is known about the impact of these interventions on a wide range of outcomes for adults with type 2 diabetes (DM2), or which of these interventions, if any, have the greatest impact on glycemic control.

Methods: Electronic databases were searched from inception through November 2011. Of 16,290 citations, two independent reviewers identified 138 randomized trials comparing PAIs to usual care/control groups in adults with DM2 that reported intermediate or long-term outcomes or harms. For meta-analyses of continuous outcomes, we used a random-effects model to derive pooled weighted mean differences (WMD). For all-cause mortality, we calculated the pooled odds ratio (OR) using Peto's method. We assessed statistical heterogeneity using the I (2) statistic and conducted meta-regression using a random-effects model when I (2) > 50 %. A priori meta-regression primary variables included: intervention strategies, intervention leader, baseline outcome value, quality, and study duration.

Results: PAIs modestly reduced intermediate outcomes [A1c: WMD 0.37 %, CI 0.28-0.45 %, I (2) 83 %; SBP: WMD 2.2 mmHg, CI 1.0-3.5 mmHg, I (2) 72 %; body weight: WMD 2.3 lbs, CI 1.3-3.2 lbs, I (2) 64 %; and LDL-c: WMD 4.2 mg/dL, CI 1.5-6.9 mg/dL, I (2) 64 %]. The evidence was moderate for A1c, low/very low for other intermediate outcomes, low for long-term mortality and very low for complications. Interventions had no effect on hypoglycemia (evidence: low) or short-term mortality (evidence: moderate). Higher baseline A1c, pharmacist-led interventions, and longer follow-up were associated with larger A1c improvements. No intervention strategy outperformed any other in adjusted meta-regression.

Conclusions: PAIs modestly improve A1c in adults with DM2 without increasing short-term mortality. These results support integration of these interventions into primary care for adults with uncontrolled glycemia, and provide evidence to insurers who do not yet cover these programs.

Figure 1

Effects of longer duration (> 2 years) patient activation intervention studies on all cause mortality in adults with Type 2 diabetes. IG=Intervention group; UC= Usual care; CG = Minimal control group; N = Number; CI= Confidence Interval.

Figure 2

Unadjusted meta-analyses and adjusted meta-regression results for A1c by intervention strategy. *Meta-regression results show beta coefficients adjusted for all other listed intervention strategies and for significant variables found in univariate meta-regression analyses, or for key variables felt to be important for adjustment: mean baseline A1c, pharmacist-led interventions (Y vs. N), country of origin (Other vs. Europe, Canada and the US), Jadad quality score, and initial intervention setting (diabetes clinic vs. primary clinic vs. other/NR). N= Number of studies, CI = 95 % confidence interval, and CHW= community health worker, NR=Not reported.