Socio-economic status and HbA1c in type 2 diabetes: A systematic review and meta-analysis.

Up until now, differences in HbA1c levels by socio-economic status (SES) have been identified, but not yet quantified in people with type 2 diabetes. The aim of this study was therefore to assess the difference in HbA1c levels between people with type 2 diabetes of different SES in a systematic review and meta-analysis. A systematic literature search was conducted in MEDLINE, Embase, Ebsco, and the Cochrane Library until January 14, 2018. Included studies described adults with type 2 diabetes in whom the association between SES and HbA1c levels was studied. Studies were rated for methodological quality and data were synthesized quantitatively (meta-analysis) and qualitatively (levels of evidence), stratified for type of SES variable, i.e., education, income, deprivation, and employment. Fifty-one studies were included: 15 high, 27 moderate, and 9 of low methodological quality. Strong evidence was provided that people of low SES have higher HbA1c levels than people of high SES, for deprivation, education, and employment status. The pooled mean difference in HbA1c levels between people of low and high SES was 0.26% (95% CI, 0.09-0.43) or 3.12 mmol/mol (95% CI, 1.21-5.04) for education and 0.20% (95% CI, -0.05 to 0.46) or 2.36 mmol/mol (95%CI, -0.61 to 5.33) for income. In conclusion, our systematic review and meta-analysis showed that there was an inverse association between SES and HbA1c levels in people with type 2 diabetes. Future research should focus on finding SES-sensitive strategies to reduce HbA1c levels in people with type 2 diabetes.

Consumer willingness to invest money and time for benefits of lifestyle behaviour change: an application of the contingent valuation method.

OBJECTIVE: To use contingent valuation (CV) to derive individual consumer values for both health and broader benefits of a public-health intervention directed at lifestyle behaviour change (LBC) and to examine the feasibility and validity of the method. METHOD: Participants of a lifestyle intervention trial (n = 515) were invited to complete an online CV survey. Respondents (n = 312) expressed willingness to invest money and time for changes in life expectancy, health-related quality of life (HRQOL) and broader quality of life aspects. Internal validity was tested for by exploring associations between explanatory variables (i.e. income, paid work, experience and risk factors for cardiovascular diseases) and willingness to invest, and by examining ordering effects and respondents' sensitivity to the scope of the benefits. RESULTS: The majority of respondents (94.3%) attached value to benefits of LBC, and 87.4% were willing to invest both money and time. Respondents were willing to invest more for improvements in HRQOL (€42/month; 3 h/week) and broader quality of life aspects (€40/month; 2.6 h/week) than for improvements in life expectancy (€24/month; 2 h/week). Protest answers were limited (3%) and findings regarding internal validity were mixed. CONCLUSION: The importance of broader quality of life outcomes to consumers suggests that these outcomes are relevant to be considered in the decision making. Our research showed that CV is a feasible method to value both health and broader outcomes of LBC, but generalizability to other areas of public health still needs to be examined. Mixed evidence regarding internal validity pleads for caution to use CV as only the base for decision making.

Resource use and costs of type 2 diabetes patients receiving managed or protocolized primary care: a controlled clinical trial.

BACKGROUND: The increasing prevalence of diabetes is associated with increased health care use and costs. Innovations to improve the quality of care, manage the increasing demand for health care and control the growth of health care costs are needed. The aim of this study is to evaluate the care process and costs of managed, protocolized and usual care for type 2 diabetes patients from a societal perspective. METHODS: In two distinct regions of the Netherlands, both managed and protocolized diabetes care were implemented. Managed care was characterized by centralized organization, coordination, responsibility and centralized annual assessment. Protocolized care had a partly centralized organizational structure. Usual care was characterized by a decentralized organizational structure. Using a quasi-experimental control group pretest-posttest design, the care process (guideline adherence) and costs were compared between managed (n = 253), protocolized (n = 197), and usual care (n = 333). We made a distinction between direct health care costs, direct non-health care costs and indirect costs. Multivariate regression models were used to estimate differences in costs adjusted for confounding factors. Because of the skewed distribution of the costs, bootstrapping methods (5000 replications) with a bias-corrected and accelerated approach were used to estimate 95% confidence intervals (CI) around the differences in costs. RESULTS: Compared to usual and protocolized care, in managed care more patients were treated according to diabetes guidelines. Secondary health care use was higher in patients under usual care compared to managed and protocolized care. Compared to usual care, direct costs were significantly lower in managed care (€-1.181 (95% CI: -2.597 to -334)) while indirect costs were higher (€ 758 (95% CI: -353 to 2.701), although not significant. Direct, indirect and total costs were lower in protocolized care compared to usual care (though not significantly). CONCLUSIONS: Compared to usual care, managed care was significantly associated with better process in terms of diabetes care, fewer secondary care consultations and lower health care costs. The same trends were seen for protocolized care, however they were not statistically significant. TRIAL REGISTRATION: Current Controlled trials: ISRCTN66124817.

Economic evaluation of a lifestyle intervention in primary care to prevent type 2 diabetes mellitus and cardiovascular diseases: a randomized controlled trial.

BACKGROUND: Cost-effectiveness studies of lifestyle interventions in people at risk for lifestyle-related diseases, addressing 'real-world' implementation, are needed. This study examines the cost-effectiveness of a primary care intervention from a societal perspective, compared with provision of health brochures, alongside a randomized controlled trial. METHODS: Adults aged 30-50 years, at risk of type 2 diabetes (T2DM) and/or cardiovascular disease (CVD), were recruited from twelve general practices in The Netherlands. They were randomized to the intervention (n = 314) or control group (n = 308). The intervention consisted of up to six face-to-face counseling sessions with a trained practice nurse, followed by three-monthly sessions by phone. Costs were collected using three-monthly retrospective questionnaires. Quality of life was measured with the EuroQol-5D-3L, at baseline, 6, 12 and 24 months. Nine-year risk of developing T2DM and ten-year risk of CVD mortality were estimated using the ARIC and SCORE formulae, respectively, based on measurements at baseline and 24 months while applying a fixed age of 60 years at both time points. RESULTS: Small, statistically non-significant differences in effects were found between the intervention and control group with regard to risk scores and Quality Adjusted Life Years (QALYs) gained. The mean difference in costs between the intervention and control group was €-866 (95% confidence interval -2372; 370). The probability that the intervention was cost-effective varied from 93% at €8000/QALY to 88% at €80,000/QALY. CONCLUSION: A primary care lifestyle intervention aimed at adults at increased risk of T2DM and/or CVD could result in cost savings over a two-year period. However, due to methodological uncertainty no advice can be given regarding the implementation of the intervention in Dutch general practices. TRIAL REGISTRATION: Current Controlled Trials ISRCTN59358434.

Consumer preferences for health and nonhealth outcomes of health promotion: results from a discrete choice experiment.

OBJECTIVE: Health promotion (HP) interventions have outcomes that go beyond health. Such broader nonhealth outcomes are usually neglected in economic evaluation studies. To allow for their consideration, insights are needed into the types of nonhealth outcomes that HP interventions produce and their relative importance compared with health outcomes. This study explored consumer preferences for health and nonhealth outcomes of HP in the context of lifestyle behavior change. METHODS: A discrete choice experiment was conducted among participants in a lifestyle intervention (n = 132) and controls (n = 141). Respondents made 16 binary choices between situations that can be experienced after lifestyle behavior change. The situations were described by 10 attributes: future health state value, start point of future health state, life expectancy, clothing size above ideal, days with sufficient relaxation, endurance, experienced control over lifestyle choices, lifestyle improvement of partner and/or children, monetary cost per month, and time cost per week. RESULTS: With the exception of "time cost per week" and "start point of future health state," all attributes significantly determined consumer choices. Thus, both health and nonhealth outcomes affected consumer choice. Marginal rates of substitution between the price attribute and the other attributes revealed that the attributes "endurance," "days with sufficient relaxation," and "future health state value" had the greatest impact on consumer choices. The "life expectancy" attribute had a relatively low impact and for increases of less than 3 years, respondents were not willing to trade. CONCLUSIONS: Health outcomes and nonhealth outcomes of lifestyle behavior change were both important to consumers in this study. Decision makers should respond to consumer preferences and consider nonhealth outcomes when deciding about HP interventions.

Effects of a cognitive behavioural treatment in patients with type 2 diabetes when added to managed care; a randomised controlled trial.

Effects of a cognitive behavioural treatment (CBT) in type 2 diabetes patients were studied in a randomised controlled trial. Patients were recruited from a diabetes care system (DCS). The intervention group (n = 76) received managed care from the DCS and CBT. The control group (n = 78) received managed care only. Effects on risk of developing coronary heart disease (CHD), clinical characteristics, lifestyle, determinants of behaviour change, quality of life, and depression were assessed after 6 and 12 months. The intervention did not result in a significant reduction of CHD risk (difference between intervention and control group was -0.32 % (95 % CI: -2.27; 1.63). The amount of heavy physical activity increased significantly in the intervention group at 6 months [intervention versus control group was 20.14 min/day (95 % CI: 4.6; 35.70)]. Quality of life and level of depression improved as well. All effects disappeared after 6 months. No effects were found on clinical characteristics.

Exploring non-health outcomes of health promotion: the perspective of participants in a lifestyle behaviour change intervention.

OBJECTIVE: To provide insights into health promotion outcomes that are not captured by conventional measures of health outcome used in economic evaluation studies, such as EQ5D based QALYs. METHODS: Twelve semi-structured interviews and five focus group discussions were conducted with participants of a randomized controlled trial (n=52) evaluating the effectiveness of a theory-based lifestyle intervention in Dutch adults at risk for diabetes mellitus and/or cardiovascular disease. Transcripts were analysed by two independent researchers using a thematic analysis approach. RESULTS: In total we identified twelve non-health outcome themes that were important from the participant perspective. Four of these were reported as direct outcomes of the lifestyle intervention and eight were reported as consequences of lifestyle behaviour change. Our findings also suggest that lifestyle behaviour change may have spillover effects to other people in the participants' direct environment. CONCLUSION: This study provides evidence that in the context of lifestyle behaviour change EQ5D based QALYs capture health promotion outcomes only partially. More insights are needed into non-health outcomes and spillover effects produced by health promotion in other contexts and how participants and society value these. Methods to account for these outcomes within an economic evaluation framework need to be developed and tested.

Quality criteria were proposed for measurement properties of health status questionnaires.

OBJECTIVES: Recently, an increasing number of systematic reviews have been published in which the measurement properties of health status questionnaires are compared. For a meaningful comparison, quality criteria for measurement properties are needed. Our aim was to develop quality criteria for design, methods, and outcomes of studies on the development and evaluation of health status questionnaires. STUDY DESIGN AND SETTING: Quality criteria for content validity, internal consistency, criterion validity, construct validity, reproducibility, longitudinal validity, responsiveness, floor and ceiling effects, and interpretability were derived from existing guidelines and consensus within our research group. RESULTS: For each measurement property a criterion was defined for a positive, negative, or indeterminate rating, depending on the design, methods, and outcomes of the validation study. CONCLUSION: Our criteria make a substantial contribution toward defining explicit quality criteria for measurement properties of health status questionnaires. Our criteria can be used in systematic reviews of health status questionnaires, to detect shortcomings and gaps in knowledge of measurement properties, and to design validation studies. The future challenge will be to refine and complete the criteria and to reach broad consensus, especially on quality criteria for good measurement properties.