Exercise in patients with cancer : Effects on health-related quality of life, costs, and cost-effectiveness during oncological treatment

Sammanfattning: Background: Short and long-term side effects of oncological treatment negatively affect daily living and health-related quality of life (HRQoL) in patient with cancer. Exercise during treatment is beneficial for HRQoL, however evidence as to what exercise intensity is most optimal for improving HRQoL and cost-effectiveness is lacking. Cost-effectiveness is important information for decisionmakers when implementing healthcare interventions, such as exercise programmes. The overall aim of this thesis was to study functioning in daily life, HRQoL, costs, and cost-effectiveness of an exercise intervention of different exercise intensities in patients with cancer receiving oncological treatment. Method: Study I was qualitative and explored how individuals with cancer receiving curative treatment and participating in an exercise intervention experienced their functioning in daily life. Semi-structured individual interviews (n =21) were performed and analysed with thematic analysis. Studies II–IV were quantitative and used data from a randomised controlled trial (RCT) of high-intensity (HI) and low-to-moderate-intensity (LMI) exercise of combined resistance and endurance training with or without self-regulatory behaviour change support. The RCT was preceded by a descriptive longitudinal study with usual care (UC). Participants were diagnosed with breast, prostate, or colon cancer and received (neo)adjuvant oncological treatment. Study II evaluated the effects on HRQoL of exercising at HI (n =288) and LMI (n =289) versus UC (n =89) up to 18 months after start of oncological treatment, using the EORTC QLQ-C30 questionnaire. Data were analysed using descriptive and multivariate statistics. Study III evaluated resource utilisation and societal costs of the exercise intervention in the RCT (n =534) versus UC (n =85), and of HI (n =269) versus LMI (n =265) exercise 18 months after start of oncological treatment. Societal costs included costs of healthcare resource utilisation (healthcare visits, hospitalisation, prescribed medication), productivity loss (disability pensions and sick leave), and the exercise intervention. Study IV evaluated the cost-effectiveness of the exercise intensities in the RCT (HI: n =99 and LMI: n =90) at 1-year follow-up post intervention. Cost data were retrieved from Study III and health outcome were collected using the EQ-5D-5L questionnaire and calculated for quality-adjusted life-years. Cost-effectiveness was evaluated as the incremental cost-effectiveness ratio (ICER). Results: Participants experienced impairments from oncological treatment but strove to maintain function in daily life. The exercise programme improved physical and psychological wellbeing during treatment (Study I). There were no significant differences in HRQoL between exercise intensities up to 1 year after the exercise intervention. The exercise groups scored significant better HRQoL compared to UC over time (Study II). There was no significant difference in mean societal costs between the exercise intervention and UC, nor between the exercise intensities (Study III). There was no significant difference in cost or in effect between the exercise intensities. Although the mean ICER indicated that HI was cost-effective compared to LMI, the uncertainty was large (Study IV). Conclusion: Participating in an exercise programme during oncological treatment was a positive and supportive experience that contributed to increase physical and psychological wellbeing. Exercise of HI and LMI during oncological treatment had similar effect on HRQoL and societal costs. In addition, the exercise group had beneficial effects on HRQoL and no significant difference in societal costs compared to UC, meaning the exercise programme did not save or add societal cost. Thus, based on cost-effectiveness we suggest decisionmakers and clinicians implement exercise programmes including both HI and LMI in cancer care and recommend exercise regardless of intensity according to the patient’s preferences to improve or to maintain aspects of HRQoL during oncological treatment.