The Patient’s Experience of Fatigue: A Cross-Sectional Study of Cancer Patients.

INTRODUCTION: Cancer-related anemia can contribute to fatigue among cancer patients (pts). Few large scale surveys of cancer pts have been conducted to characterize fatigue from the patient’s perspective. This study was conducted to assess the prevalence of fatigue in cancer pts and examine relationships between fatigue, anxiety, depression, and somatization (physical symptoms).

METHODS: A cross-sectional survey was conducted from April to May 2006 using a random sample of pts from a chronic illness panel of 550,233 pts. Inclusion criteria were being at least 18 years of age, diagnosed with cancer, and receiving chemotherapy and/or radiotherapy either currently or during the 12 months prior to participating in the study. An 8-item brief fatigue questionnaire developed from four validated instruments (scores ranging from 0–100, higher being better status) and the 13-item Functional Assessment of Cancer Therapy - Fatigue (FACT-F; scores ranging from 0–52, higher being better status) were used to assess fatigue. The 18-item Brief Symptom Inventory (BSI; scores ranging from 0–100, higher being worse status) was used to measure anxiety, depression, somatization and to obtain a global severity index. Single items with numerical rating scales ranging from 0 to 10 were used to assess degree of debilitation related to fatigue and importance of fatigue reduction. Pearson correlation coefficients were used to assess relationships between continuous variables.

RESULTS: A total of 1,569 cancer pts were surveyed. Online interviews were conducted with 1,302 pts and phone interviews with 267 pts. No significant differences were found between phone and online respondents. Most patients were white (84%) and 50% were males. Most females were diagnosed with breast cancer (56%) and most males with prostate cancer (40%). Approximately 79% of pts rated fatigue as the most common symptom of cancer treatment. One in three patients considered a reduction in fatigue to be very important. Approximately 54% of patients rated their fatigue to be debilitating (six or higher on a ten point scale). Worse levels of fatigue measured by the FACT-F were significantly associated with higher levels of anxiety (r = −0.56, p < 0.0001), depression (r = −0.63, p < 0.0001), somatization (r = −0.75, p < 0.001), and the global severity index (−0.71, p < 0.001). Scores from the brief fatigue questionnaire confirmed results obtained with the FACT-F.

CONCLUSIONS: Fatigue was the most common symptom reported in this study and was significantly associated with anxiety and depression. More research is needed to examine the relationship between physical and psychological symptoms in cancer patients.