Measurement of fatigue in cancer, stroke, and HIV using the Functional Assessment of Chronic Illness Therapy — Fatigue (FACIT-F) scale

Abstract

Objective

Given the importance of fatigue in cancer, stroke and HIV, we sought to assess the measurement properties of a single, well-described fatigue scale in these populations. We hypothesized that the psychometric properties of the Functional Assessment of Chronic Illness Therapy — Fatigue (FACIT-F) subscale would be favorable and that the scale could serve as a useful indicator of fatigue in these populations.

Methods

Patients were eligible for the study if they were outpatients, aged 18 or older, with a diagnosis of cancer (n = 297), stroke (n = 51), or HIV/AIDS (n = 51). All participants were able to understand and speak English. Patients answered study-related questions, including the FACIT-F using a touch-screen laptop, assisted by the research assistant as necessary. Clinical information was abstracted from patients' medical records.

Results

Item-level statistics on the FACIT-F were similar across the groups and internal consistency reliability was uniformly high (α > 0.91). Correlations with performance status ratings were statistically significant across the groups (range r = − 0.28 to − 0.80). Fatigue scores were moderately to highly correlated with general quality of life (range r = 0.66–0.80) in patients with cancer, stroke, and HIV. Divergent validity was supported in low correlations with variables not expected to correlate with fatigue.

Conclusions

Originally developed to assess cancer-related fatigue, the FACIT-F has utility as a measure of fatigue in other populations, such as stroke and HIV. Ongoing research will soon allow for comparison of FACIT-F scores to those obtained using the fatigue measures from the Patient-Reported Outcomes Measurement Information System (PROMIS®; www.nihpromis.org) initiative.

Introduction

Fatigue is the most prevalent symptom among individuals with cancer and may be due to the disease itself, its treatment, and/or psychosocial variables [1]. Depending on the patient population and means of measuring fatigue, prevalence estimates among cancer patients are generally high, ranging from 60 to over 90% [1]. Patients may describe their experience of fatigue in terms of being exhausted, tired, weak, or slowed. Furthermore, in a large sample of patients with advanced cancer who have received chemotherapy, fatigue was spontaneously endorsed and ranked as the most important symptom that should be monitored [2]. Although common, cancer-related fatigue remains poorly understood [3]. In clinical practice, fatigue may be neglected or under-detected due to the fact that it is a subjective experience that is assessed by patient self-report. Treatment of cancer-related fatigue is further complicated by its multifactorial clinical manifestations, involving both psychological and physical components.

Stroke is the leading cause of disability in adults and often results in reduced functional status, impaired psychological well-being, and economic hardship [4]. Persistent fatigue is a common symptom following stroke [5], with prevalence estimates ranging from 23 to 75%, likely reflecting variations in measurement and sampling approaches [5], [6]. The frequency of self-reported fatigue is roughly twice as high in patients post stroke as it is in matched controls, and 27% of stroke survivors experience fatigue every day [7]. Little research has focused on how best to measure post-stroke fatigue quantitatively.

People with HIV infection have reported fatigue as one of their most frequent complaints, regardless of how advanced their HIV infection or their use of Highly Active Antiretroviral Therapy [8]. For example, a study of 317 men and women who had been diagnosed with HIV for several years found that the three most frequently reported symptoms, using the Memorial Symptom Assessment Scale, were all fatigue-related: “lack of energy” (65%); “feeling drowsy” (57%); and “difficulty sleeping” (56%) [9]. Furthermore, fatigue has been shown to affect the physical, social, familial, and psychological aspects of the lives of individuals with HIV [10]. Women and older persons with HIV infection have reported more fatigue than men and younger persons with HIV [11]. Despite the prevalence and impact of fatigue in the lives of people with HIV, family and physicians often do not acknowledge fatigue as a significant concern [12].

Fatigue may develop for different reasons in cancer, stroke, and HIV. However, given the importance of fatigue across these three chronic conditions, we sought to assess the measurement properties of a single, well-described fatigue scale in these populations. We hypothesized that the psychometric of the Functional Assessment of Chronic Illness Therapy — Fatigue subscale [13] would be favorable and that the scale could serve as a useful indicator of fatigue in clinical research across these populations.