A population-based lifestyle intervention to promote healthy weight and physical activity in people with cardiac disease: The PANACHE (Physical Activity, Nutrition And Cardiac HEalth) study protocol

<p>Abstract</p> <p>Background</p> <p>Maintaining a healthy weight and undertaking regular physical activity are important for the secondary prevention of cardiovascular disease (CVD). However, many people with CVD are overweight and insufficiently active. In addition, in Australia only 20-30% of people requiring cardiac rehabilitation (CR) for CVD actually attend. To improve outcomes of and access to CR the efficacy, effectiveness and cost-effectiveness of alternative approaches to CR need to be established.</p> <p>This research will determine the efficacy of a telephone-delivered lifestyle intervention, promoting healthy weight and physical activity, in people with CVD in urban and rural settings. The control group will also act as a replication study of a previously proven physical activity intervention, to establish whether those findings can be repeated in different urban and rural locations. The cost-effectiveness and acceptability of the intervention to CR staff and participants will also be determined.</p> <p>Methods/Design</p> <p>This study is a randomised controlled trial. People referred for CR at two urban and two rural Australian hospitals will be invited to participate. The intervention (healthy weight) group will participate in four telephone delivered behavioural coaching and goal setting sessions over eight weeks. The coaching sessions will be on weight, nutrition and physical activity and will be supported by written materials, a pedometer and two follow-up booster telephone calls. The control (physical activity) group will participate in a six week intervention previously shown to increase physical activity, consisting of two telephone delivered behavioural coaching and goal setting sessions on physical activity, supported by written materials, a pedometer and two booster phone calls. Data will be collected at baseline, eight weeks and eight months for the intervention group (baseline, six weeks and six months for the control group). The primary outcome is weight change. Secondary outcomes include physical activity, sedentary time and nutrition habits. Costs will be compared with outcomes to determine the relative cost-effectiveness of the healthy weight and physical activity interventions.</p> <p>Discussion</p> <p>This study addresses a significant gap in public health practice by providing evidence for the efficacy and cost-effectiveness of a low cost, low contact, high reach intervention promoting healthy weight and physical activity among people with CVD in rural and urban areas in Australia. The replication arm of the study, undertaken by the control group, will demonstrate whether the findings of the previously proven physical activity intervention can be generalised to new settings. This population-based approach could potentially improve access to and outcomes of secondary prevention programs, particularly for rural or disadvantaged communities.</p> <p>Trial Registration</p> <p>ACTRN12610000102077</p

A systematic review of patient reported factors associated with uptake and completion of cardiovascular lifestyle behaviour change

Background: Healthy lifestyles are an important facet of cardiovascular risk management. Unfortunately many individuals fail to engage with lifestyle change programmes. There are many factors that patients report as influencing their decisions about initiating lifestyle change. This is challenging for health care professionals who may lack the skills and time to address a broad range of barriers to lifestyle behaviour. Guidance on which factors to focus on during lifestyle consultations may assist healthcare professionals to hone their skills and knowledge leading to more productive patient interactions with ultimately better uptake of lifestyle behaviour change support. The aim of our study was to clarify which influences reported by patients predict uptake and completion of formal lifestyle change programmes. Methods: A systematic narrative review of quantitative observational studies reporting factors (influences) associated with uptake and completion of lifestyle behaviour change programmes. Quantitative observational studies involving patients at high risk of cardiovascular events were identified through electronic searching and screened against pre-defined selection criteria. Factors were extracted and organised into an existing qualitative framework. Results: 374 factors were extracted from 32 studies. Factors most consistently associated with uptake of lifestyle change related to support from family and friends, transport and other costs, and beliefs about the causes of illness and lifestyle change. Depression and anxiety also appear to influence uptake as well as completion. Many factors show inconsistent patterns with respect to uptake and completion of lifestyle change programmes. Conclusion: There are a small number of factors that consistently appear to influence uptake and completion of cardiovascular lifestyle behaviour change. These factors could be considered during patient consultations to promote a tailored approach to decision making about the most suitable type and level lifestyle behaviour change support

Application of approximate variances of variance components and their ratios in genetic tests

The application and underlying assumptions of formulae used to estimate the variance of variance components and ratios of variance components are fully described for (1) variance components estimated using Henderson's Method 3 (HM3) and Restricted Maximum Likelihood (REML) and (2) ratios of variance components commonly used in genetic tests - biased and unbiased heritabilities. A first-order Taylor series approximation is often used to estimate the variance of a ratio of two random variables (e.g., heritability), however the formula is complicated, thus making calculations prone to errors. Dickerson's approximation is considerably simpler, though relatively rarely used. In case studies using data from 148 slash pine full-sib progeny tests, Dickerson's method was found to be slightly more conservative than the Taylor series approximation when estimating the variance of heritability estimates, regardless of test size, age, or the trait (volume, which is a continuous trait, and rust resistance, which is a bernoulli trait). Both the Taylor series and Dickerson approximations compared favorably with an empirical estimate of the variance of heritability estimates, however there is some evidence of small-sample bias associated with the use of the asymptotic variance-covariances from REML variance component estimation. © 1995 Springer-Verlag