Age-associated differences in fatigue among patients with cancer.

Abstract

There has been some suggestion that the fatigue experienced by older cancer patients is more severe than that of younger cohorts; however, there is little empirical evidence to support this claim. The goal of the present study was to determine the differential impact of age and cancer diagnosis on ratings of fatigue using a validated self-report instrument. The Functional Assessment of Chronic Illness Therapy-Fatigue subscale consists of 13 items measuring fatigue experience and its impact on daily life, with scores ranging from 0 (severe fatigue) to 52 (no fatigue). Fatigue data were available from the U.S. general population (n=1075; 51.3% female, 45.9+/-16.5 years) and a sample of mixed-diagnosis cancer patients (n=738; 64.3% female, 58.7+/-13.6 years). General population participants were recruited using an Internet-based survey panel; patients with cancer were recruited from Chicago-area oncology clinics. On average, the cancer patient group reported more severe fatigue than the general population group (36.9 vs. 46.6; F[1,1797]=271.95, P<0.001). There was evidence for increased fatigue with age (F[6,719]=2.56, P<0.02) among patients with cancer, but not in the general population (P=0.06). Furthermore, the group x age interaction was not significant (P=0.44). Hemoglobin (Hgb) was treated as a covariate for 430 patients with available data; there was no main effect for age in this analysis. Older adults, whether they had a cancer diagnosis, reported more fatigue than younger adults. These differences may be explained, in part, by Hgb level. Future research would be helpful to explore longitudinal changes in fatigue in the general population and guide fatigue management for the older cancer patient.