RESUMO
BACKGROUND: Health anxiety is a prevalent and debilitating disorder associated with extensive use of healthcare services and reduced quality of life (QoL). Regional variability in specialised clinics or specialist healthcare providers limits access to evidence-based treatment, which may be overcome by internet-delivered Acceptance and Commitment Therapy (iACT). OBJECTIVE: This study investigated the cost effectiveness of iACT for severe health anxiety in adults. METHODS: Based on a Danish randomised controlled trial (March 2016-March 2017), the economic evaluation compared costs and effects between iACT and an active control condition (iFORUM). Effectiveness was measured using self-report questionnaires. The cost analysis applied a societal perspective. Resource use and healthcare costs were extracted from the Danish National Registries. Linear regression analysis was applied using change in costs/effectiveness outcomes as the dependant variable. Time, group, and interaction between time and group were independent variables. The primary outcome was the proportion of clinically significant improvements, defined as a ≥ 25% reduction in two measures of health anxiety. The probability of cost effectiveness was presented in a cost-effectiveness acceptability curve for a range of threshold values for willingness to pay. RESULTS: No significant differences were detected in healthcare costs between groups; however, the iACT group significantly improved in all effectiveness outcomes. The economic analysis showed that, from the healthcare perspective, iACT was associated with an incremental cost-effectiveness ratio of 33 per additional case of clinically significant improvement compared with iFORUM and that, from the societal perspective, iACT dominated iFORUM because it was more effective and less expensive. CONCLUSIONS: We found no statistically significant differences in costs between groups; however, iACT for severe health anxiety may be cost effective, as evidenced by significant differences in effect. TRIAL REGISTRY NUMBER: Clinicaltrials.gov, no. NCT02735434.
