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Journal of Clinical Oncology, Vol 26, No 4 (February 1), 2008: pp. 599-605 © 2008 American Society of Clinical Oncology. DOI: 10.1200/JCO.2007.12.2838 Prevalence, Severity, and Impact of Symptoms on Female Family Caregivers of Patients at the Initiation of Radiation Therapy for Prostate Cancer
From the University of California, San Francisco; Alta Bates Comprehensive Cancer Center, Berkeley, CA; and the University of Nebraska Medical Center, Omaha, NE Corresponding author: Christine A. Miaskowski, RN, PhD, FAAN, Department of Physiological Nursing, University of California, 2 Koret Way, Box 0610, San Francisco, CA 94143-0610; e-mail: chris.miaskowski{at}nursing.ucsf.edu
Purpose In a sample of family caregivers (FCs) of patients with prostate cancer who were to begin radiation therapy (RT), the purposes were to determine the prevalence and severity of depression, anxiety, pain, sleep disturbance, and fatigue; determine the relationships among these symptoms and between these symptoms and functional status and quality of life (QOL); evaluate for differences in functional status and QOL between FCs with low and high levels of these symptoms; and determine which factors predicted FCs’ functional status and QOL. Patients and Methods FCs were recruited before patients initiated RT and completed self-report questionnaires that evaluated demographic characteristics, symptoms, functional status, and QOL. Results Sixty female FCs participated in the study. On the basis of established cut point scores for each symptom questionnaire, 12.2% of the FCs had clinically meaningful levels of depression, 40.7% anxiety, 15.0% pain, 36.7% sleep disturbance, 33.3% morning fatigue, and 30.0% evening fatigue. FCs who were older and who had lower levels of state anxiety and higher levels of depression, morning fatigue, and pain reported significantly poorer functional status (R2 = 38.7%). FCs who were younger, had more years of education, were working, and who had higher levels of depression, morning fatigue, sleep disturbance, and lower levels of evening fatigue reported significantly lower QOL scores (R2 = 70.1%). Conclusion A high percentage of FCs experienced clinically meaningful levels of a variety of symptoms. These symptoms have a negative impact on the FCs’ functional status and QOL.
An estimated 44.4 million Americans provide some level of care to an adult family member, and this number is likely to increase.1 As medical management of cancer becomes more complex, family caregivers (FCs) must perform a variety of activities (eg, coordination of medical appointments, provision of physical and emotional care), which can have a negative impact on their physical and emotional health.2,3 It is reasonable to hypothesize that the negative consequences of caregiving may manifest as physical (ie, pain, fatigue, sleep disturbance) and psychological (ie, depression, anxiety) symptoms and that these symptoms may have a negative impact on FCs’ functional status and quality of life (QOL), as well as on their ability to provide care to the patient. However, very little information is available on the prevalence or severity of symptoms in FCs of patients with cancer. In fact, in a recent review,4 only 25 descriptive studies that evaluated symptoms in these FCs were identified. The most frequently assessed symptom was depression (92% of the studies), followed by anxiety (32%), fatigue (24%), and sleep disturbance (20%). No studies were found that evaluated for chronic pain. Of note, in some of these studies, higher symptom severity scores were associated with decreases in QOL,5-9 health status,7,9-12 and life satisfaction.13 However, given the paucity of research, no definitive conclusions can be drawn about the prevalence, severity, and impact of each of these symptoms on FCs of patients with cancer. Therefore, the purposes of this study, in a sample of FCs of patients with prostate cancer who were to begin radiation therapy (RT) were to determine the prevalence and severity of depression, anxiety, pain, sleep disturbance, and fatigue; determine the relationships among these symptoms and between these symptoms and FC outcomes of functional status and QOL; evaluate for differences in functional status and QOL between those FCs with low and high levels of these symptoms; and determine which factors predicted FCs’ functional status and QOL.
Participants and Settings This descriptive, correlational study is part of a larger longitudinal study that evaluated multiple symptoms in both patients who underwent primary or adjuvant RT and their FCs. Although it is difficult to determine when a family member assumes the role of a caregiver, in most studies of symptoms in FCs,4 the caregiver role is linked to the trajectory of the patient's treatment. Therefore, to obtain a "baseline" assessment of symptoms and outcomes, FCs were recruited with patients before the initiation of RT. Patients and their FCs were recruited from RT departments in a comprehensive cancer center and a community hospital at the time of the patient's simulation visit. Patients had been diagnosed with prostate cancer for 9.7 ± 15.1 months (approximately 50% of the patients had early-stage disease and had undergone watchful waiting). The study was approved by the committee on human research at each of the study sites. After recruitment of the patients with prostate cancer, they were asked to identify the person most involved in their care (ie, their FC). If the FC was with the patient, the research nurse explained the study and obtained written informed consent from the FC. FCs who were not with the patient were contacted by phone to determine their interest in study participation. The research nurse visited those FCs at home, obtained informed consent, and had them complete the study questionnaires.
FCs were eligible to participate if they were an adult (
Instruments The demographic questionnaire provided information on age, sex, marital status, education, race/ethnicity, employment status, and the presence of 26 comorbid conditions. In addition, to evaluate the FCs’ functional status, they completed the KPS scale.14 The Center for Epidemiologic Studies Depression Scale (CES-D) consists of 20 items selected to represent the major symptoms in the clinical syndrome of depression.15 Scores can range from 0 to 60, with scores of 16 or higher indicating the need for participants to seek a clinical evaluation for major depression. The CES-D has well-established concurrent and construct validity.16,17 In this study, its Cronbach's alpha was 0.84. The Spielberger State Trait Anxiety Inventory (STAI-T and STAI-S) each consist of 20 items that are rated from 1 to 4.18 The scores for each scale are summed and can range from 20 to 80. A higher score indicates greater anxiety. The STAI-T measures an individual's predisposition to anxiety determined by his/her personality make-up. The STAI-S measures an individual's transitory emotional response to a stressful situation. The STAI-T and STAI-S have well-established criteria and construct validity and internal consistency reliability coefficients.19-21 In this study, the Cronbach's alphas for the STAI-T and the STAI-S were 0.89 and 0.93, respectively. Worst pain intensity was evaluated using a descriptive numeric rating scale (NRS) that ranged from 0 (no pain) to 10 (excruciating pain). A descriptive NRS is a valid and reliable measure of pain intensity.22 The General Sleep Disturbance Scale (GSDS) consists of 21 items that evaluate various aspects of sleep disturbance. Each item was rated on an NRS that ranged from 0 (never) to 7 (every day), and the 21 items were summed to yield a total score that could range from 0 (no disturbance) to 147 (extreme disturbance). The GSDS has well-established validity and reliability in shift workers, pregnant women, and patients with cancer and HIV.23-28 In this study, its Cronbach's alpha was 0.79. A fatigue severity score was calculated as the mean of the 13 items from the Lee Fatigue Scale (LFS) and could range from 0 to 10, with higher scores indicating higher levels of fatigue. The LFS has been used to measure the severity of fatigue in healthy individuals,27,29 as well as in patients with cancer30 and HIV.26 The LFS was chosen as the fatigue measure for this study because it is relatively short and easy to administer. In addition, it does not focus on cancer fatigue, and as such, is appropriate for FCs. The LFS has established validity and internal consistency reliability coefficients.29 In this study, the Cronbach's alphas for the LFS were 0.96 (morning) and 0.95 (evening). The Quality of Life Scale–Family Version (QOL-FV) consists of 37 items that measures various dimensions of QOL in FCs of patients with cancer using 0 to 10 NRSs.31 A total QOL score was calculated, with higher scores indicating a better QOL. In this study, its Cronbach's alpha was 0.95. After obtaining written informed consent, FCs completed all of the study questionnaires. The LFS was completed in the evening before bed (ie, evening fatigue) and again on awakening (ie, morning fatigue) to evaluate diurnal variations in fatigue. This assessment coincided with the patients’ simulation visit and was considered the baseline assessment for the larger longitudinal study.
Statistics
To determine the prevalence rates for the various symptoms, cut point scores were chosen for each of the questionnaires on the basis of published reports of clinically meaningful differences in symptom scores (ie, scores above a certain value on a particular questionnaire warrant a clinical evaluation for management of that symptom). The cut point score for each questionnaires was as follows: CES-D
Family Caregiver and Patient Characteristics As summarized in Table 1, FCs were slightly younger (64.2 years) than patients (68.1 years). The majority of the participants were white (  80.0%), married/partnered (93.3%), and well educated. Twenty-three different comorbid conditions were identified by at least one FC, and their mean (± standard deviation, throughout) number of comorbid conditions was 4.8 ± 3.0.
Prevalence and Severity of Symptoms in FCs The mean symptom severity scores for the total sample, as well as the percentage of FCs in the low and high symptom groups and each groups’ mean symptom severity scores, are listed in Table 2.
Depression. The mean CES-D score for the total sample was 8.4 ± 6.5. Twelve percent of FCs had CES-D scores of 16 or higher. The mean CES-D score for the high symptom group was 21.0 (± 5.2). Anxiety. The mean trait and state anxiety scores for the total sample were 35.3 (± 9.6) and 32.6 (± 10.6), respectively. Both of these scores are above the cut point for clinically significant levels of anxiety. Approximately 57.6% of the FCs were categorized in the high group based on their mean trait anxiety scores, and 40.7% were in the high group on the basis of their mean state anxiety scores. Pain. The mean worst pain intensity score for the total sample was 1.4 (± 3.1). Only 15% of the FCs reported a worst pain score of 7 or higher. Sleep disturbance. The mean GSDS score for the total sample was 39.9 (± 16.2). More than 36% of the FCs reported GSDS scores that were higher than the cut point of 43.0. Fatigue. In the total sample, morning fatigue scores (2.5 ± 2.1) were lower than evening fatigue scores (4.3 ± 2.3). Approximately 30% of the FCs reported morning and evening fatigue scores that were above the cut points for clinically meaningful levels of fatigue.
Relationships Among the Various Symptoms and KPS and QOL Score
Differences in Functional Status and QOL Scores Between FCs in the Low and High Symptom Groups KPS. The mean KPS for the entire sample was 94.0 (± 10.5). As shown in Figure 1A, significantly lower KPS was reported by FCs in the high symptom group compared with the low group for trait anxiety (t = 2.3, P = .025), worst pain (t = 2.8, P = .007), sleep disturbance (t = 2.1, P = .047), and morning fatigue (t = 2.2, P = .037).
QOL score. The mean total QOL-FV score for the entire sample was 7.2 (± 1.4). As shown in Figure 1B, significantly lower total QOL scores were reported by FCs in the high symptom group compared with the low symptom group for depression (t = 3.7, P = .001), trait anxiety (t = 4.8, P < .0001), state anxiety (t = 4.5, P < .0001), worst pain (t = 2.1, P = .04), morning fatigue (t = 5.2, P < .0001), and evening fatigue (t = 2.5, P = .014).
Predictors of Functional Status and QOL
Predictors of the QOL score. The same 11 variables were entered into the regression analysis to identify potential predictors of FCs’ QOL and the same approach was used to identify a parsimonious model. As presented in Table 5, using the total QOL-FV score as the dependent variable, age, years of education, working for pay, and levels of depression, morning fatigue, evening fatigue, and sleep disturbance explained 70.1% of the variance in FCs’ QOL. FCs who were younger, had more years of education, were working, and who had higher levels of depression, morning fatigue, and sleep disturbance, but lower levels of evening fatigue, reported significantly lower QOL scores.
This study is the first to our knowledge to evaluate the prevalence and severity of five common symptoms in the same sample of FCs of patients with prostate cancer. Of note, for state and trait anxiety and morning fatigue, the mean symptom severity scores for the total sample were higher than the established cutoffs for clinically meaningful symptom severity. In addition, for trait and state anxiety, as well as for sleep disturbance and morning and evening fatigue, 30% to 58% of the sample was found to have clinically meaningful severity scores. As noted in Table 2, all of the prevalence rates for these five symptoms in the high group are higher than the prevalence rates reported for depression,34-37 anxiety,34 chronic pain,38-42 sleep disturbance,43-46 and fatigue,47,48 in the general population of a similar age. In addition, consistent with two previous reports,6,7 the majority of these symptoms have negative effects on FCs’ functional status and QOL. The high correlation between anxiety and depression found in this study is consistent with previous cross-sectional studies of FCs of patients with cancer.9-11 This finding warrants additional research because of the growing body of literature that suggests that the occurrence of depression and anxiety is associated with significant morbidity.10,12,49 One of the advantages of the symptom scales used in this study is that they have established cut points for clinically meaningful scores (ie, scores that, if reached or exceeded, warrant a clinical evaluation for management of the symptom). Therefore, we were able to evaluate the impact of clinically meaningful levels of each of these symptoms on FC outcomes. FCs with high levels of trait anxiety, worst pain, sleep disturbance, and morning fatigue reported significantly lower KPS. These differences in KPS between the high and low groups for each symptom represent not only statistically but also clinically meaningful differences in functional status based on calculations of effect sizes (ie, d = 0.59 for trait anxiety, 1.06 for worst pain, 0.68 for sleep disturbance, 0.80 for morning fatigue). Similarly, the differences in the total QOL scores between the high and low groups based on a calculation of effect sizes were clinically meaningful for depression (d = 1.3), trait anxiety (d = 1.1), state anxiety (d = 1.1), worst pain (d = 0.70), morning fatigue (d = 1.1), and evening fatigue (d = 0.70). This conclusion is based on reports that suggest that clinically meaningful differences in QOL are in the range of 0.20 to 0.50 standard deviation units.33,50,51 A surprising finding in this study is the relatively low prevalence of pain (only 15%) in this sample of older women. This finding may be attributed to the fact that the cut point score for pain was relatively high. However, this cut point of 7 was chosen because, in a previous study, it was associated with deleterious effects on function.32 It should be noted that in the group of FCs who reported significant pain, 82% had pain at or higher than 7. In addition, the most common comorbidities reported by this group of FCs were back problems (100%), headaches (64%), and arthritis (55%). The findings from the regression analyses suggest that depression had the greatest impact on FCs’ functional status (ie, 11.6% of unique explained variance) and QOL (23.8% of unique explained variance), and are in concert with previous reports.7,52 Although the total percentage of explained variance was large for both functional status and QOL, these results should be considered preliminary and warrant verification in larger samples of FCs of patients with cancer. Several limitations of this study are worth noting. The generalizability of the study findings is limited by inclusion of only female FCs and because the majority of these FCs were white, well educated, had high levels of function, and lived with the patient. In addition, these FCs were caring for patients who had early-stage prostate cancer who were relatively well. Therefore, these findings may be an underestimate of the symptom experience of FCs of patients with late-stage or metastatic cancer. Despite these limitations, the findings from this relatively small sample of female FCs suggest that clinically meaningful levels of anxiety, sleep disturbance, and fatigue occur in more than 30% of FCs. In addition, these symptoms, as well as depression and pain, have negative effects on FC outcomes. Additional research is warranted to determine the co-occurrence of multiple symptoms and symptom clusters in FCs, as well as how these symptoms change over time and in relationship to the patient's disease trajectory. In the meantime, oncology clinicians need to be aware of the symptom burden of the FCs of their patients and the potential impact that these symptoms may have on the FC's ability to provide care to the patient.
The author(s) indicated no potential conflicts of interest.
Conception and design: Steven M. Paul, Marylin J. Dodd, Claudia West, Bruce Cooper, Kathryn Lee, Christine A. Miaskowski Provision of study materials or patients: Patrick Swift, William Wara Collection and assembly of data: Claudia West, Christine A. Miaskowski Data analysis and interpretation: Barbara Swore Fletcher, Steven M. Paul, Claudia West, Bruce Cooper, Christine A. Miaskowski Manuscript writing: Barbara Swore Fletcher, Steven M. Paul, Marylin J. Dodd, Karen Schumacher, Claudia West, Bruce Cooper, Kathryn Lee, Bradley Aouizerat, Patrick Swift, William Wara, Christine A. Miaskowski Final approval of manuscript: Barbara Swore Fletcher, Steven M. Paul, Marylin J. Dodd, Karen Schumacher, Claudia West, Bruce Cooper, Kathryn Lee, Bradley Aouizerat, Patrick Swift, William Wara, Christine A. Miaskowski
Supported by Grant No. NR04835 from the National Institute of Nursing Research (NINR); National Institutes of Health Roadmap for Medical Research Grant No. K12RR023262 (B.A.); and NINR T32 Grant No. NR07088 (B.S.F.); and unrestricted grants from Endo Pharmaceuticals LP, PriCara Unit of Ortho-McNeil Inc, and Purdue Pharma LP (C.A.M.). Authors’ disclosures of potential conflicts of interest and author contributions are found at the end of this article.
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Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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ABSTRACT
INTRODUCTION
18 years of age); were able to read, write, and understand English; gave written informed consent; had a Karnofsky performance score (KPS) of more than 60; were living with the patient; and did not have a diagnosed sleep disorder. 
.05.
