The effectiveness of theory- and model-based lifestyle interventions on HbA1c among patients with type 2 diabetes: a systematic review and meta-analysis

Highlights

• This study presents results of theory- and model-based interventions on HbA1c among diabetic patinets.

• The results quantified reducing level of HbA1c (mmol/mol).

• Our results show that which educational theory has the most effect on HbA1c.

Abstract

Objectives

The prevalence of type 2 diabetes is rising rapidly around the world. A number of systematic reviews have provided evidence for the effectiveness of lifestyle interventions on diabetic patients. The effectiveness of theory- and model-based education-lifestyle interventions for diabetic patients are unclear. The systematic review and meta-analysis aimed to evaluate and quantify the impact of theory-based lifestyle interventions on type 2 diabetes.

Study design

A literature search of authentic electronic resources including PubMed, Scopus, and Cochrane collaboration was performed to identify published papers between January 2002 and July 2016.

Methods

The PICOs (participants, intervention, comparison, and outcomes) elements were used for the selection of studies to meet the inclusion and exclusion criteria. Mean differences and standard deviations of hemoglobin A1c (HbA1c [mmol/mol]) level in baseline and follow-up measures of studies in intervention and control groups were considered for data synthesis. A random-effects model was used for estimating pooled effect sizes. To investigate the source of heterogeneity, predefined subgroup analyses were performed using trial duration, baseline HbA1c (mmol/mol) level, and the age of participants. Meta-regression was performed to examine the contribution of trial duration, baseline HbA1c (mmol/mol) level, the age of participants, and mean differences of HbA1c (mmol/mol) level. The significant level was considered P < 0.05.

Results

Eighteen studies with 2384 participants met the inclusion criteria. The pooled main outcomes by random-effects model showed significant improvements in HbA1c (mmol/mol) −5.35% (95% confidence interval = −6.3, −4.40; P < 0.001) with the evidence of heterogeneity across studies.

Conclusion

The findings of this meta-analysis suggest that theory- and model-based lifestyle interventions have positive effects on HbA1c (mmol/mol) indices in patients with type 2 diabetes. Health education theories have been applied as a useful tool for lifestyle change among people with type 2 diabetes.

Introduction

Diabetes is a common metabolic disease with adverse impact on the lives of patients that reduces life expectancy by up to one-third of adults.¹ The prevalence of type 2 diabetes is rising rapidly around the world. The World Health Organization estimates that diabetes is the 7 leading cause of death, and by the year 2030 there will be 366 million adults with diabetes in 2030.²

To prevent acute and long-term complications of diabetes, educational lifestyle interventions are considered as a fundamental aspect of care among diabetic patients. Diabetic patients' education is an ongoing process of receiving information from clinician-educators to develop knowledge, skills and ability for continuing self-care, and management of the diseases.³ Education plays an important role in the process of care and treatment to improve clinical outcomes, health status, and quality of life for diabetic patients.⁴ A number of systematic reviews have provided evidence for the effectiveness of educational lifestyle interventions on diabetic patients.5, 6, 7 Choi et al.⁵ 2016 has focused on the effect of different diabetes education approaches on glycemic control for Chinese patients. They reported that diabetes education in any format generates glycemic improvement for Chinese patients and in studies using information reinforcement strategies, the glycemic control was further enhanced. Different education and psychological interventions have been aimed at the management of type 2 diabetes. A systematic review has explored effectiveness of self-management educational studies on diabetic adults, findings show that self-management educations significantly decrease hemoglobin A1c (HbA1c) levels.⁷ In a similar study, Zhao et al.⁸ synthesized the effects of self-management educational interventions on patients with type 2 diabetes. The results indicated that patients who underwent diabetes self-management educations significantly improved HbA1c, self-efficacy, and knowledge levels.

Although both theories and models explain behavior and suggest ways to achieve behavior change, there are some differences between theories and models. A theory is a set of broad and interrelated concepts that help to describe events generally. Models help the understanding of a specific problem in a particular population and context. They are often used to explain empirical findings and informed by more than one theory.⁹ Theories and models both include concepts and constructs that help to explain individual behavior. To increase the effectiveness of intervention programs, theories and models can provide a systematic framework for designing, implementation, and evaluation of the program.¹⁰ Despite this fact that implementing theory- and model-based lifestyle interventions is an essential method to change behavior and modify the consequences of the diabetes,¹¹ the effectiveness of theory- and model-based education-lifestyle interventions for diabetic patients are unclear. This systematic review and meta-analysis aimed to identify, evaluate, and quantify the impact of theory- and model-based lifestyle interventions on type 2 diabetes.