J.E. Strijk

The Vital@Work Study. The systematic development of a lifestyle intervention to improve older workers' vitality and the design of a randomised controlled trial evaluating this intervention

BackgroundA major contributor of early exit from work is a decline in health with increasing age. As healthy lifestyle choices contribute to better health outcomes, an intervention aimed at an improved lifestyle is considered a potentially effective tool to keep older workers healthy and vital, and thereby to prolong labour participation.MethodsUsing the Intervention Mapping (IM) protocol, a lifestyle intervention was developed based on information obtained from 1) literature, 2) a short lifestyle questionnaire aimed at indentifying the lifestyle behaviours among the target group, and 3) focusgroup (FG) interviews among 36 older workers (aged 45+ years) aimed at identifying: a) key determinants of lifestyle behaviour, b) a definition of vitality, and c) ideas about how vitality can be improved by lifestyle.The main lifestyle problems identified were: insufficient levels of physical activity and insufficient intake of fruit and vegetables. Using information from both literature and FG interviews, vitality consists of a mental and a physical component. The interviewees suggested to improve the mental component of vitality by means of relaxation exercises (e.g. yoga); physical vitality could be improved by aerobic endurance exercise and strength training.The lifestyle intervention (6 months) consists of three visits to a Personal Vitality Coach (PVC) combined with a Vitality Exercise Programme (VEP). The VEP consists of: 1) once a week a guided yoga group session aimed at relaxation exercises, 2) once a week a guided aerobic workout group session aimed at improving aerobic fitness and increasing muscle strength, and 3) older workers will be asked to perform once a week for at least 45 minutes vigorous physical activity without face-to-face instructions (e.g. fitness). Moreover, free fruit will be offered at the group sessions of the VEP. The lifestyle intervention will be evaluated in a RCT among older workers of two major academic hospitals in the Netherlands. At baseline, after 6 and 12 months, measurements (primary: lifestyle and vitality, and secondary: work-engagement and productivity) will take place.DiscussionThe lifestyle programme is developed specifically tailored to the needs of the older workers and which is aimed at improving their vitality.Trial registrationNTR1240

A worksite vitality intervention to improve older workers' lifestyle and vitality-related outcomes: results of a randomised controlled trial

Objective To evaluate the effectiveness of a worksite vitality intervention on vigorous physical activity (VPA), fruit intake, aerobic capacity, mental health and need for recovery after work among older hospital workers (ie, 45 years and older). Methods The 6-month intervention was evaluated using a randomised controlled trial design. Workers who were randomised to the intervention group (n=367; control: n=363) received the Vital@Work intervention containing (1) a Vitality Exercise Program (VEP) combined with (2) three visits to Personal Vitality Coach. The VEP consisted of a weekly yoga session, a weekly workout session and weekly unsupervised aerobic exercising. Free fruit was provided at the VEP. Data on the outcome measures were collected (ie, year 2009–2010) at baseline (n=730) and 6 months of follow-up after baseline (n=575) using questionnaires, accelerometers and 2 km walk tests. Effects were analysed according to the intention-to-treat principle with complete cases (n=575) and imputed data (n=730) using linear regression analyses. Additional analyses were performed for high yoga and workout compliance (ie, >mean number of sessions). Results Effects were found for sports activities (β=40.4 min/week, 95% CI 13.0 to 67.7) and fruit intake (β=2.7 pieces/week, 95% CI 0.07 to 4.7) and were stronger for workers with high compliance to yoga (sport: β=49.6 min/week, 95% CI 13.9 to 85.2; fruit: β=3.8 pieces/week, 95% CI 1.1 to 6.4) and workout sessions (sport: β=72.9 min/week, 95% CI 36.1 to 109.8; fruit: β=4.0 pieces/week, 95% CI 1.1 to 6.4). The intervention group lowered their need for recovery, when compared to controls (β=−3.5, 95% CI −6.4 to −0.54), with stronger effects for high workout compliance (β=−5.3, 95% CI −9.3 to −1.3). No effects were found on VPA, aerobic capacity or mental health. Conclusions Implementation of worksite yoga and workout facilities and minimal fruit interventions should be considered by employers to promote transitions into healthier lifestyles and thereby health.

The role of work ability in the relationship between aerobic capacity and sick leave: a mediation analysis

Objectives To examine: (1) the relationships between aerobic capacity, work ability and sick leave; (2) the potential mediating effect of work ability in the relationship between aerobic capacity and sick leave; and (3) the influence of age on these relationships. Methods Information on aerobic capacity (predicted VO2max), age, gender, type of work, cardiovascular risk and body mass index was collected from 580 workers at baseline. Work ability was assessed with the Work Ability Index at first follow-up (mean 3.4±1.3 years after baseline). The second follow-up period was defined as the time between completing the Work Ability Index and the first registered sick leave episode. Mediation analyses were performed using linear and Cox regression models. Results A lower aerobic capacity was found to be significantly related to sick leave (HR=0.98; τ=−0.018; 95% CI 0.970 to 0.994). There was a significant positive relationship between aerobic capacity and work ability (α=0.165; 95% CI 0.122 to 0.208). Also, lower work ability was significantly related to sick leave after controlling for aerobic capacity (HR=0.97; β=−0.033; 95% CI 0.949 to 0.987). The mediating effect of work ability in the relationship between aerobic capacity and sick leave was −0.005 (SE=0.002), and mediated 27.8% (95% CI 10.4 to 45.2) of the total effect of aerobic capacity on sick leave. Age did not influence the relationship between aerobic capacity and sick leave. Conclusions Fit workers had better work ability, and both fit workers and workers with higher work ability were at lower risk of starting an episode of sick leave.

Evaluation of occupational health interventions using a randomized controlled trial: challenges and alternative research designs

Occupational health researchers regularly conduct evaluative intervention research for which a randomized controlled trial (RCT) may not be the most appropriate design (eg, effects of policy measures, organizational interventions on work schedules). This article demonstrates the appropriateness of alternative designs for the evaluation of occupational health interventions, which permit causal inferences, formulated along two study design approaches: experimental (stepped-wedge) and observational (propensity scores, instrumental variables, multiple baseline design, interrupted time series, difference-in-difference, and regression discontinuity). For each design, the unique characteristics are presented including the advantages and disadvantages compared to the RCT, illustrated by empirical examples in occupational health. This overview shows that several appropriate alternatives for the RCT design are feasible and available, which may provide sufficiently strong evidence to guide decisions on implementation of interventions in workplaces. Researchers are encouraged to continue exploring these designs and thus contribute to evidence-based occupational health.

A cost-effectiveness and return-on-investment analysis of a worksite vitality intervention among older hospital workers: results of a randomized controlled trial.

Objective: To conduct a cost-effectiveness and return-on-investment analysis comparing a worksite vitality intervention with usual care. Methods: A total of 730 older hospital workers were randomized to the intervention or control group. The 6-month intervention consisted of yoga and aerobic exercising, coaching, and fruit. At baseline, and 6 and 12 months, general vitality, work-related vitality, and need for recovery were determined. Cost data were collected on a 3-monthly basis. The cost-effectiveness analysis was performed from the societal perspective and the return-on-investment analysis from the employers perspective using bootstrapping techniques. Results: No significant differences in costs and effects were observed. Incremental cost-effectiveness ratios in terms of general vitality (range, 0 to 100), work-related vitality (range, 0 to 6), and need for recovery (range, 0 to 100) were, respectively, &OV0556;280, &OV0556;7506, and &OV0556;258 per point improvement. Per euro invested, &OV0556;2.21 was lost. Conclusions: The intervention was neither cost-effective nor cost-saving.

Associations between VO2max and vitality in older workers: a cross-sectional study

BackgroundTo prevent early exit from work, it is important to study which factors contribute to healthy ageing. One concept that is assumed to be closely related to, and therefore may influence healthy ageing, is vitality. Vitality consists of both a mental and a physical component, and is characterised by a perceived high energy level, decreased feelings of fatigue, and feeling fit. Since VO2max gives an indication of ones aerobic fitness, which can be improved by increased levels of physical activity, and because feeling fit is one of the main characteristics of vitality, it is hypothesised that VO2max is related to vitality. Therefore, the aim of this study was to investigate the associations between VO2max and vitality.MethodsIn 427 older workers (aged 45 + years) participating in the Vital@Work study, VO2max was estimated at baseline using the 2-km UKK walk test. Vitality was measured by both the UWES Vitality Scale and the RAND-36 Vitality Scale. Associations were analysed using linear regression analyses.ResultsThe linear regression models, adjusted for age, showed a significant association between VO2max and vitality measured with the RAND-36 Vitality Scale (β = 0.446; 95% CI: 0.220-0.673). There was no significant association between VO2max and vitality measured with the UWES (β = -0.006; 95% CI:-0.017 - 0.006), after adjusting for age, gender and chronic disease status.ConclusionsVO2max was associated with a general measure of vitality (measured with the RAND-36 Vitality Scale), but not with occupational health related vitality (measured with the UWES Vitality Scale). The idea that physical exercise can be used as an effective tool for improving vitality was supported in this study.Trial registrationNTR1240