Impact of adapted physical activity and diet counselling on health-related quality of life in women undergoing adjuvant breast cancer therapy

Abstract

In the monocentric APAD1 trial, 143 women with non-metastatic breast cancer were randomised to undergo either an adapted physical activity and diet counselling (APAD) program or usual care. Health-related quality of life (HRQoL) was prospectively evaluated using the EORTC QLQ-C30 questionnaire at baseline, during treatment (adjuvant chemotherapy and radiotherapy) and during follow-up. Our objective was two-fold: to analyse the impact of APAD on HRQoL using three approaches; to illustrate the advantages and disadvantages of each approach, and derive methodological recommendations. Analytical approaches utilised were: statistical testing to compare the mean HRQoL scores between baseline and end of study in both groups and the mean HRQoL scores between the two groups at the different assessment times; linear mixed models that modelled the longitudinal score data in both groups and tested whether the score trajectories were different between the groups; a survival analysis comparing the time to deterioration of HRQoL between the groups using a minimal clinically important difference. This study shows a substantial clinical benefit of the APAD intervention on HRQoL, especially for global health status/HRQoL, functioning scales and the fatigue symptom scale. Furthermore, this study highlights the advantages and disadvantages of three standard approaches used to analyse HRQoL data.Trial registration: The APAD1 study was registered with ClinicalTrials.gov (number NCT01495650, date 20/12/2011).

Keywords: Breast cancer; Clinical trial; Health-related quality of life; Linear mixed models; Longitudinal data; Time to deterioration.

Fig. 1

Predicted mean score trajectories from the LMMs for the ten scales with significant time and/or group-by-time interaction effect. The predicted values at each time are given by Eq. (1) where the random (thus, individual) part has been removed and the fixed effect parameters replaced by their estimates, that is, given by: in the APAD group and in the UC group.

Fig. 2

TTD analysis in the UC and APAD groups for the scales where the survival estimates were significantly different for at least one definition of MCID (from top to bottom: global health status/HRQoL, physical functioning, role functioning): Kaplan-Meier curves of the 10-point MCID (left-hand side) and the 20-point MCID (right-hand side). Vertical lines on the curves represent right-censored times.