Article

OBJECTIVE: To investigate the longitudinal association between the impact of
fatigue and health-related quality of life and to determine if potential
confounders distorted this association. DESIGN: Baseline, 3-, 6- and 12-week
assessments of a randomized clinical trial were used.
SETTING: Outpatient
rehabilitation centre. SUBJECTS: Patients with idiopathic Parkinson's disease.
METHODS: Quality of life was assessed with the Parkinson's Disease
Questionnaire-39 and the Multidimensional Fatigue Inventory was used to assess
fatigue. Time-independent and time-dependent factors were investigated for their
bivariate association with quality of life by applying random coefficient
analysis. Candidate confounders were successively added to the longitudinal
association model to determine if the relationship between quality of life and
fatigue was distorted. A change beyond 15% of found regression coefficient of the
Multidimensional Fatigue Inventory was considered significant. RESULTS: One
hundred and fifty-three patients were included. Impact of fatigue was
significantly associated with poorer quality of life (beta = 0.24, 95% confidence
interval = 0.18 to 0.30). This association was significantly distorted by
depression (30.0%) and anxiety (24.1%). No distortion was found for other
factors. After controlling for confounders, fatigue remained significantly
associated with quality of life (beta = 0.12, 95% confidence interval = 0.06 to
0.18, r (2) = 2.3%). CONCLUSIONS: Our results suggest that patients who
experience fatigue tend to report lower levels of quality of life. However, this
longitudinal relationship is confounded by depression and anxiety and suggests
that the unique contribution of fatigue to overall quality of life is rather small.

Langue : ANGLAIS