Effectiveness of chronic care models for the management of type 2 diabetes mellitus in Europe: a systematic review and meta-analysis

Abstract

Objectives: We evaluated the effectiveness of European chronic care programmes for type 2 diabetes mellitus (characterised by integrative care and a multicomponent framework for enhancing healthcare delivery), compared with usual diabetes care.

Design: Systematic review and meta-analysis.

Data sources: MEDLINE, Embase, CENTRAL and CINAHL from January 2000 to July 2015.

Eligibility criteria: Randomised controlled trials focussing on (1) adults with type 2 diabetes, (2) multifaceted diabetes care interventions specifically designed for type 2 diabetes and delivered in primary or secondary care, targeting patient, physician and healthcare organisation and (3) usual diabetes care as the control intervention.

Data extraction: Study characteristics, characteristics of the intervention, data on baseline demographics and changes in patient outcomes.

Data analysis: Weighted mean differences in change in HbA1c and total cholesterol levels between intervention and control patients (95% CI) were estimated using a random-effects model.

Results: Eight cluster randomised controlled trials were identified for inclusion (9529 patients). One year of multifaceted care improved HbA1c levels in patients with screen-detected and newly diagnosed diabetes, but not in patients with prevalent diabetes, compared to usual diabetes care. Across all seven included trials, the weighted mean difference in HbA1c change was -0.07% (95% CI -0.10 to -0.04) (-0.8 mmol/mol (95% CI -1.1 to -0.4)); I²=21%. The findings for total cholesterol, LDL-cholesterol and blood pressure were similar to HbA1c, albeit statistical heterogeneity between studies was considerably larger. Compared to usual care, multifaceted care did not significantly change quality of life of the diabetes patient. Finally, measured for screen-detected diabetes only, the risk of macrovascular and mircovascular complications at follow-up was not significantly different between intervention and control patients.

Conclusions: Effects of European multifaceted diabetes care patient outcomes are only small. Improvements are somewhat larger for screen-detected and newly diagnosed diabetes patients than for patients with prevalent diabetes.

Keywords: Europe; Managed care; Meta-analysis; Systematic review; Type 2 diabetes mellitus.

Figure 1

Flow chart summarising the identification of studies for inclusion in the review.

Figure 2

Risk of bias graph. Review authors' judgements about each risk of bias item presented as percentages across all included studies. Studies included are Cleveringa et al (2008); Sönnichsen et al (2008), Frei et al (2010), Olivarius et al (2001), Janssen et al (2009), Webb et al (2010), Lauritzen et al (2000) and Echouffo et al (2009). The studies from Lauritzen and Echouffo were included in the risk of bias assessment since their 5-year follow-up data had been included in the Addition-Europe meta-analysis by Griffin et al. As the Addition-Europe publication only reported pooled data, no comprehensive overview of results was available for the studies by Lauritzen and Echouffo, which resulted in the blanks in the risk of bias graph.

Figure 3

Mean difference in change (95% CI) in HbA1c levels (%) after multifaceted care between intervention and control groups. Results are stratified by type of diabetes patient. IV, generic inverse variance method. The three studies including patients with prevalent diabetes has an intervention duration of 1-year. The methodology for calculating the difference in change between intervention and control group that Cleveringa et al. have used (subtracting the HbA1c change over time for the control group from the change over time for the intervention group) was the opposite of that used by the other trials (subtracting the HbA1c change over time for the intervention group from the change over time for the control group). Since this would result in a misleading visual presentation of the findings from Cleveringa et al., we have recalculated their HbA1c results according to the methodology used by the other studies. The study of Webb et al. had an intervention duration of one year and the study of Griffin et al. combined the 5-year intervention data from all four Addition studies, including the five-year data from Webb et al. The study including patients with newly detected diabetes had an intervention duration of six years.

Figure 4

Mean difference in change (95% CI) in total cholesterol levels (mmol/L) after multifaceted care between intervention and control groups. Results are stratified by type of diabetes patient. IV, generic inverse variance method. The three studies including patients with prevalent diabetes has an intervention duration of 1-year. The methodology for calculating the difference in change between intervention and control group that Cleveringa et al. have used (subtracting the HbA1c change over time for the control group from the change over time for the intervention group) was the opposite of that used by the other trials (subtracting the HbA1c change over time for the intervention group from the change over time for the control group). Since this would result in a misleading visual presentation of the findings from Cleveringa et al., we have recalculated their HbA1c results according to the methodology used by the other studies. The study of Webb et al. had an intervention duration of one year and the study of Griffin et al. combined the 5-year intervention data from all four Addition studies, including the five-year data from Webb et al. The study including patients with newly detected diabetes had an intervention duration of six years.