CONSORT-EHEALTH Checklist V1.6.2 Report

1b-i) Key features/functionalities/components of the intervention and comparator in the METHODS section of the ABSTRACT "Methods. The economic evaluation, conducted from a societal perspective, was part of a 2-year randomized controlled trial including three study groups. All groups received personalized health risk appraisals based on the guidelines for physical activity, fruit intake, vegetable intake, alcohol consumption, and smoking. Additionally, respondents in the sequential condition received personal advice about one lifestyle behaviour in the first year and regarding a second behaviour in the second year; respondents in the simultaneous condition received personal advice about all unhealthy behaviours in both years. During a period of 24 months, health care use, medication use, absenteeism from work and quality of life (EQ-5D-3L) were assessed every three months using web-based questionnaires. Demographics were assessed at baseline, and lifestyle behaviours both at baseline and after 24 months. Cost-effectiveness and cost-utility analyses were performed based on the outcome measures lifestyle factor (the number of guidelines respondents adhered to) and quality of life, respectively. We accounted for uncertainty using bootstrapping techniques and sensitivity analyses." 1b-ii) Level of human involvement in the METHODS section of the ABSTRACT 1b-iii) Open vs. closed, web-based (self-assessment) vs. face-to-face assessments in the METHODS section of the ABSTRACT 1b-iv) RESULTS section in abstract must contain use data "A total of 1,733 respondents were included in the analyses. From a willingness to pay of €4,594 per one additional guideline met, the sequential intervention (n = 552) was likely to be the most cost-effective, whereas from a willingness to pay of €10,850, the simultaneous intervention (n = 517) was likely to be most cost-effective. The control condition (n = 664), on the other hand, was probably preferred with regard to quality of life." 1b-v) CONCLUSIONS/DISCUSSION in abstract for negative trials "Both the sequential and the simultaneous lifestyle interventions were likely to be cost-effective where it concerned the lifestyle factor, whereas the control condition was when it concerned quality of life. However, there is no accepted cut-off point for the willingness to pay per gain in lifestyle behaviours, making it impossible to draw firm conclusions. Further economic evaluations of lifestyle interventions are needed." INTRODUCTION 2a-i) Problem and the type of system/solution Our intervention is intended as a stand-alone intervention for adults of the general population; however, it was conntected to the Adult Health Monitor of different Regional Health Authorities in the Netherlands. "Computer-tailoring can be used successfully as an intervention to promote behaviours associated with a healthy lifestyle [7]. When applying computertailoring, personalised feedback is generated by a computer programme based on an individual assessment [8]. Earlier studies have demonstrated that tailored information is perceived as more relevant than non-tailored information [9]. Moreover, computer-tailored interventions have proven to be effective in stimulating a healthier lifestyle, e.g. in reaching smoking cessation [10], preventing smoking relapse [11], encouraging healthy nutrition [12], lowering alcohol intake [13], and increasing physical activity [14]. Previous research has also indicated that changing multiple lifestyle related behaviours is likely to be more effective than changing only a single behaviour [15]. A recent study has shown that tailored interventions which aim to reducing multiple health risk behaviours are not only successful in reducing unhealthy behaviours but also in simultaneously enhancing the overall wellbeing of the individual [16]. The delivery of computer-tailored interventions targeting multiple health risk behaviours through the internet has various benefits: these programmes can be applied in privacy and at a time and place the respondent finds convenient; many people can be reached at relatively low intervention cost, since more than 90% of the Dutch population has internet access nowadays [17]; and since the system is computerized it can be easily combined with, and/or integrated in other programmes or interventions." 2a-ii) Scientific background, rationale: What is known about the (type of) system "Some economic evaluations of web-based and/or computer-tailored programmes have been conducted to date [e.g., 18-23]. In general, these studies have given a first indication that these interventions – most were single behaviour change interventions – can indeed be cost-effective. To our knowledge, however, so far no economic evaluation of a web-based computer-tailored intervention targeting multiple health risk behaviours has been conducted. Web-based computer-tailored lifestyle interventions are an interesting and promising option to make the healthcare system more sustainable, because of their proven clinical effectiveness and their potential cost-effectiveness due to relatively low intervention costs and wide reach." METHODS 3a) CONSORT: Description of trial design (such as parallel, factorial) including allocation ratio "The aim of the present study, therefore, is to assess from a societal perspective the cost-effectiveness and cost-utility of two different versions (sequential and simultaneous) of a web-based computer-tailored lifestyle intervention for adults, compared to a control group that received only a minimal intervention." 3b) CONSORT: Important changes to methods after trial commencement (such as eligibility criteria), with reasons "Respondents were included in the analyses when their LFS at baseline was available and when the measurement regarding the economic evaluation was completed at least at baseline." 3b-i) Bug fixes, Downtimes, Content Changes We sent additional (not planned) reminders in order to increase the response. 4a) CONSORT: Eligibility criteria for participants