To examine individual outcomes after tailored lifestyle (PROfeel) or generic dietary advice as self-management intervention for persistent fatigue in adolescents and young adults with a chronic condition, to compare participants who did and did not benefit and to explore changes to factors in the biopsychosocial model of fatigue after PROfeel. A multiple single-case AB-phase design was embedded in a randomized crossover trial (N = 45). Intensive longitudinal data (ILD) on outcomes 'fatigue severity', 'self-efficacy' and 'quality of life' (QoL) were collected through weekly smartphone measurement for 20 weeks. ILD on biopsychosocial factors were collected through experience sampling methodology for 28 days pre-post first intervention. Baseline characteristics were compared with t-tests and chi-square tests. Permutation distancing tests were used to assess change over time in all ILD. Regarding weekly measurements, nineteen participants (42.22%) showed small to large positive outcomes (drange = .05 to 2.59), mostly after PROfeel. Eleven participants (24.44%) showed small to moderate negative outcomes (drange = -.02 to -2.46), mostly after dietary advice. Fatigue severity improved most, followed by self-efficacy. Participants who benefitted showed higher QoL levels and lower fatigue and pain levels compared with others at baseline (all p < .02). When positive outcomes were observed after PROfeel, typically ≥1 biopsychosocial factor had been targeted successfully. Self-management advice has more potential when tailored to individual characteristics, including the biopsychosocial model of fatigue. PROfeel appears particularly useful as fatigue intervention for individuals with relatively less severe symptoms.
Read full abstract