Working on Wellness (WOW) Intervention

Study Design:

"Working on Wellness - WOW" is a randomised controlled trial in South African worksites with a 12 month follow-up. Randomisation will take place at the company level, where participating companies will be assigned to either the intervention or the control group.

Study Population and Recruitment The study will be conducted in cooperation with a major national health insurer. Large companies (>300 employees) that are clients of this insurer, offering health and wellness days from August 2009 to February 2010 and that are based in Cape Town and Johannesburg will be approached to participate in this study.

Thereafter, over the course of two months all employees from these companies will be invited to participate in the wellness day(s) of their company. The invitation will take place as part of the feedback session at the wellness day and comprehensive information will be provided about the study. Employees agreeing to participate will be asked to sign an informed consent and to provide their email address and contact details. Participants will receive a small incentive at the start of the research study, and again upon completion.

Because all the companies hosting wellness days in this research study are clients of a major national health insurer, we will be able to access data for employees who do not volunteer for the screening activities. The data for the employees who choose not to participate will be sent to the researchers without any personal identifiers, thus ensuring employee confidentially. Being able to describe the non-responders is one of the strengths of this study design, and the insured population with whom we are working, providing insight into the problem of selection bias.

Control Group The employees in the control group will receive usual care. This comprises of feedback at the health and wellness day, referring employees to their physician if needed, and encouraging them to increase their level of physical activity and to improve nutrition in a generic way. They will receive general health promotion material detailing the risks for CVD and with advice on improving lifestyle behaviour. The participants from the control companies will also participate in follow up measurements at 6 and 12 months.

Intervention Group Individuals in the intervention group will receive the same advice and health promotion materials as those in the control group. Additionally, they will be offered an individually tailored intervention that consists of one-on-one counselling and educational materials. The counselling sessions will incorporate motivational interviewing techniques, to help the employee identify goals and strategies to improve their lifestyle.

An intervention mapping (IM) approach will be conducted at the start of the research study 13. This IM process will further inform the type and nature of intervention, including variables such as the optimal number of face-to face contacts and telephone contacts. Based on the research study by Groeneveld et al. it is envisaged that approximately two face to face and four telephone contacts will be required 8.

Outcome Measures

Health Risk Appraisal (HRA) Questionnaire The HRA is comprised of demographic, health and lifestyle factors, as well as questions related to stages of change for the various risk behaviours. The demographic variables include age and gender; while the lifestyle measures include smoking status, fruit and vegetable intake, habitual alcohol consumption and habitual physical activity. For smoking, fruit and vegetable intake and habitual physical activity, the participant also reports on readiness to change or improve these behaviours. The questions on readiness to change are based on the Transtheoretical Model stages of change 2.

Global Physical Activity Questionnaire Habitual physical activity will be measured using the 'Global Physical Activity Questionnaire' (GPAQ) 14. This is a self administered questionnaire that includes questions on habitual levels of light, moderate and vigorous activity. Furthermore, a sub sample of employees will be randomly selected to wear a pedometer for 4 consecutive days to measure the number of steps taken per day 15. This will provide a more objective measure of physical activity at baseline, 6 and 12 months.

Dietary Habits Habitual dietary fat intake will be measured using the Short Fat Questionnaire 16. In addition, participants will complete a food frequency questionnaire where they will record the type and amount of food consumed in an average week.

Presenteeism and Absenteeism The Healthy Days Questionnaire devised and tested by the US Centers for Disease control, will be used to measure health-related quality of life. Healthy days are calculated using a series of 4 questions, focusing on general perceived health, self-rated physical and mental health and the extent to which physical and/or mental health may have limited activity within the past 30 days 17. Absenteeism data will be obtained from the company's Human Resource office, in addition to the participant keeping a log book.

Clinical Measures All screening will conducted by qualified, trained staff, provided by the health insurer and will form part of their wellness day which is offered to their corporate clients. The following clinical measures will be performed at the wellness days.

Cholesterol screening will be conducted using finger-prick capillary blood samples (Accutrend ® GC analysers, Roche Diagnostics) to measure total serum cholesterol concentrations.

Blood pressure will be measured twice per person using an automated sphygmomanometer. Employees will be instructed to sit quietly for approximately three minutes before being measured.

Standing height (cm) will be measured to the nearest 0.1 cm, using a stadiometer. Body weight will be measured using a portable calibrated scale and recorded to the nearest 0.1 kg. Body Mass Index (BMI) will be calculated as body mass (kg) divided by height (m) squared (kg/m2).

Process Evaluation A process evaluation will be conducted to determine if the intervention was implemented as intended. The counselors and participants' will be required to critically appraise the various components of the intervention and to grade their experience. Fidelity intervention will be measured by the research team, using the MITI software to monitor contents and quality of interviews having taken place, attendance and number of missed and re-scheduled appointments).

Cost-effectiveness analysis The cost-effectiveness of the intervention programme will be determined from the societal perspective. The two main outcomes are the change in habitual physical activity levels and CVD risk profile to be determined by SCORE.

The intervention costs that will be included in models include the cost of the wellness days for NCD risk screening, training of counsellors, employment costs of counsellors, opportunity cost that may be lost if employee's sessions are during working hours, health promotion material, incentives, travel and telephone calls. Direct health care costs will be based on health-related claims data that will be obtained from the medical insurer. Indirect costs include costs for sickness absenteeism and costs for presenteeism. In addition, participants will keep a medical costs and absenteeism diary every 3 months.

Statistical Analyses STATISTICA software package was used for all the analyses (Stasoft, Inc. 184-199, Tulsa OK, SA) and intention to treat analysis will be performed for each of the outcomes. Mean, standard deviation and standard error will be calculated for the continuous variables. Frequency tables will be used to determine the percentage of individuals at risk, and also for the stages of change data. Chi squared analysis will be done to compare the percentage of employees meeting physical activity recommendations before and after the intervention. An Analysis of Variance (ANOVA) will be performed to determine whether there were significant changes in physical activity habits and nutrition in the intervention and control groups at 6 and 12 months. Logistic regression analyses will be completed, both before and after adjusting for confounders such as age.

For the economic evaluation, cost effective ratio's will be calculated by dividing the difference between the mean total costs of the intervention and usual care groups, by the difference in the means effects (such as change in physical activity). The confidence intervals of all the ratios will be determined using the bootstrapping technique. Furthermore, each of the cost effective ratios will be graphically presented on a cost effectiveness plane.