Course of normal and abnormal fatigue in patients with chronic obstructive pulmonary disease, and its relationship with domains of health status

Objective: To examine the difference between patients with normal and patients with abnormal fatigue on aspects of health status, and investigate the natural course of fatigue in patients with Chronic Obstructive Pulmonary Disease (COPD).

Methods: Fatigue, physiological functioning, functional impairment, symptoms, and Quality of Life (QoL) were measured in 168 patients with COPD, and longitudinal data on fatigue of 77 patients were collected.

Results: Fifty percent of patients had abnormal fatigue. Patients with abnormal fatigue reported significantly more problems on the sub-domains of functional impairment (except actual physical activity), symptoms, and QoL as compared to patients with normal fatigue. With respect to physiological functioning patients with normal fatigue scores had better exercise capacity. Four years later the percentage of patients with abnormal fatigue was increased to 64%. In 1/3 of the patients an increase of more than the minimal clinically important difference was found.

Conclusion: Many COPD patients suffer from abnormal fatigue. Patients with abnormal fatigue have more limitations on many aspects of health status, especially on symptoms, functional impairment, and QoL.

Practice implications: Fatigue should be evaluated in usual care with a questionnaire that corrects for normal fatigue in order to tailor treatment to patients' need.