Fatigue, functional status, health and pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Sammanfattning: The aim of this thesis was to describe fatigue, functional limitations due to fatigue and health in patients with chronic obstructive pulmonary disease (COPD), as well as to compare patients with individuals from the general population and to test if pulmonary rehabilitation can reduce fatigue and functional limitations, and thus improve health. A further aim was to test the Fatigue Impact Scale (FIS) among patients with COPD.Two studies (I, II) had a descriptive comparative design with data from 36 and 151 patients with COPD respectively, and 37 and 95 individuals respectively, randomly selected from the general population. One study (III) was a randomised pre-test post-test study with 12 patients with COPD randomised to 12 weeks’ pulmonary rehabilitation and 14 patients in a control group. In a further study (IV), the FIS was tested for validity and reliability among 296 patients with COPD who reported fatigue.Assessments: Structured questions frequency, duration and severity of fatigue, functional limitations due to fatigue with FIS, six minutes’ walking distance, hand grip strength, functional performance and satisfaction with Canadian Occupational Performance Measure and health with St George’s Hospital Respiratory Questionnaire and Short Form-36.Almost half of the patients with COPD had a problem with fatigue every day and experienced fatigue as a severe symptom. More than 44% reported that fatigue was one of the worst symptoms. The experience of fatigue was related to the patients’ functional performance and health perceptions. Patients with COPD experienced a higher frequency, longer daily duration and greater severity of fatigue than individuals from the general population. After a 12 week pulmonary rehabilitation programme, there were no statistically significant differences between the patients randomised to the rehabilitation group and those in the control group. The patients in the rehabilitation group improved walking distances, performance and satisfaction with regard to their own selected activities compared with baseline.Confirmatory factor analysis on the three-factor model proposed for FIS showed that the fit of the model was not acceptable. Further validation of the FIS resulted in a removal of 15 items (FIS-25) and support for Pipers´ theoretical framework of subjective manifestations of fatigue including physical, emotional and cognitive dimensions and a general behavioural factor. The internal consistency, sensitivity and stability correlations of FIS-25 were satisfactory.In conclusion, fatigue is a major concern among patients with COPD, impacting on functioning and health. Interventions with 12 weeks’ pulmonary rehabilitation might not be effective enough to reduce fatigue and the functional limitations due to fatigue. More research is needed to solve the symptom burden of fatigue and its impact on functioning and health in patients with COPD.