282 Journal of Pain and Symptom Management Vol. 46 No. 2 August 2013

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1 282 Journal of Pain and Symptom Management Vol. 46 No. 2 August 2013 Brief Report Comparing the Retrospective Reports of Fatigue Using the Fatigue Symptom Index With Daily Diary Ratings in Women Receiving Chemotherapy for Gynecologic Cancer Kristin M. Phillips, PhD, Leigh Anne Faul, PhD, Brent J. Small, PhD, Paul B. Jacobsen, PhD, Sachin M. Apte, MD, and Heather S.L. Jim, PhD Moffitt Cancer Center (K.M.P., B.J.S., P.B.J., S.M.A., H.S.L.J.), Tampa, Florida; Georgetown University / Lombardi Comprehensive Cancer Center (L.A.F.), Washington, DC; and University of South Florida (B.J.S.), Tampa, Florida, USA Abstract Context. Fatigue, one of the most common side effects of chemotherapy, is typically assessed via retrospective recall (e.g., over the past week). It is unknown how such retrospective recall of fatigue correlates with daily ratings among people receiving chemotherapy. Objectives. The current study compared fatigue recorded in daily diaries with retrospective ratings using the Fatigue Symptom Inventory (FSI) in patients receiving chemotherapy for gynecologic cancer. Methods. During the week before and the week after their first infusion of chemotherapy, patients completed daily diaries at 10 AM, 2, and 6 PM and the FSI at the end of each week. Results. FSI and diary ratings of peak, lowest, and average fatigue were significantly correlated (P < 0.001). When peak, end, average, and variance diary ratings were regressed separately on the average FSI item, each was significant prechemotherapy (P < 0.01) and post-chemotherapy (P < 0.05). However, when entered into a stepwise regression model, only the average fatigue diary rating was retained, explaining 52% of the variance pre-chemotherapy and 54% of the variance post-chemotherapy average FSI item (P < 0.001). Conclusion. The FSI keyed to the past week accurately reflects daily ratings of fatigue among patients receiving chemotherapy. This study has important implications, as completing retrospective ratings of fatigue may be less burdensome for cancer patients than daily assessments. J Pain Symptom Manage 2013;46:282e288. Ó 2013 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved. Address correspondence to: Heather S.L. Jim, PhD, Department of Health Outcomes and Behavior, Moffitt Cancer Center, Magnolia Drive, MRC-PSY, Ó 2013 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved. Tampa, FL 33612, USA. heather.jim@ moffitt.org Accepted for publication: August 6, /$ - see front matter

2 Vol. 46 No. 2 August 2013 Retrospective Versus Daily Rating of Fatigue 283 Key Words Fatigue, chemotherapy, cancer, recall, self-report Introduction Fatigue is one of the most common symptoms among cancer patients. 1,2 When assessing fatigue, researchers and clinicians typically rely on patients retrospective recall. For example, the Fatigue Symptom Inventory (FSI) 3,4 asks patients to retrospectively recall fatigue in the past week. Prior work has determined the FSI to be reliable and valid using comparisons with existing retrospective measures of fatigue. 3 The FSI has not been validated with ratings of fatigue obtained using daily diaries. Understanding how fatigue assessed retrospectively using the FSI compares with daily ratings is important, as research suggests retrospective recall of symptoms may be inflated compared with averaged diary ratings. 5 Momentary self-reports assess the self in the moment and retrospective self-reports assess the self through time. 6 Although conceptually distinct, to be valid, retrospective ratings should correspond to the mean of momentary ratings. 6 Research on associations between momentary assessments and retrospective recall of pain and fatigue has been conducted in chronic pain patients 5,7,8 and has been based on peak-end heuristics, which suggest people attend to the most intense and most recent levels of symptoms. 9 In studies of pain and fatigue in rheumatology patients, retrospectively recalled pain and fatigue were higher than diary ratings; 5 although peak and end levels created a bias in recall of pain, they did not bias recall of fatigue. 8 Higher variability in realtime pain has been associated with higher levels of pain recalled retrospectively, but was not examined for fatigue. 7 Whether the daily ratings of fatigue are associated with weekly recall is particularly relevant to patients receiving chemotherapy because symptoms roller coaster during treatment. Fatigue rises in the days after an infusion, then subsides before the next infusion. 10e12 Although momentary assessments of fatigue have been studied in cancer patients, 13e15 it has not been evaluated whether peak, end, or variability in daily ratings of fatigue bias retrospective recall in chemotherapy patients. Our aim was to compare the ratings of fatigue assessed though daily diaries with retrospective ratings using the FSI in a sample of gynecologic cancer patients in the week before and the week after their first cycle of chemotherapy. Based on previous research, 5 we hypothesized that retrospective recall of fatigue would be higher than daily diary ratings. We also explored how much of the variance in the item of the FSI that assesses patients average fatigue level over the week was accounted for by peak, end, average, and variance in diary fatigue ratings. Methods Participants and Procedures Participants were recruited from September 2007 to July 2009 as part of a larger institutional review board-approved study examining the side effects of platinum-based chemotherapy for gynecologic cancer on symptoms of sleep disturbances, depression, and fatigue. 16 Eligibility criteria were: 18 years of age or older, scheduled to receive intravenous platinum-based chemotherapy for gynecologic cancer at Moffitt Cancer Center, no chemotherapy treatment for two or more months, free of documented or observable psychiatric or neurologic disorders that could interfere with participation, able to speak and read English, and able to provide informed consent. Informed consent was obtained before the start of chemotherapy. Participants were provided with actigraphs, which they continuously wore on their nondominant wrist one week before and one week after their first chemotherapy infusion. Actigraphs beeped daily at regularly scheduled intervals when participants were likely to be awake (i.e., 10 AM, 2 PM, and 6 PM) to remind patients to complete the diaries. Questionnaires were completed on the day they received chemotherapy (prechemotherapy) and one week later (postchemotherapy).

3 284 Phillips et al. Vol. 46 No. 2 August 2013 Eighty women agreed to participate. Three participants did not provide any data, one was missing diaries at both time points, four were missing diaries at one time point, two were missing both diaries and FSI at one time point, and two were missing FSI at one time point; 68 women had complete data. Measures Demographic information was assessed via self-report and clinical information was obtained via medical chart review. Daily ratings of fatigue were assessed using diaries. At 10 AM, 2 PM, and 6 PM during assessment days (i.e., three ratings per day for eight days), participants were asked to rate How much fatigue are you experiencing now? (0 ¼ no fatigue at all and 10 ¼ as fatigued as I could be). From this information, the authors identified the highest (i.e., peak), lowest, and last (i.e., end) diary fatigue ratings. The authors also calculated the mean of the 24 diary ratings to obtain an average diary rating; the standard deviation (SD) of diary ratings was calculated to obtain the variance in diary ratings for each participant. Retrospective ratings of fatigue were measured using the FSI. 3 For comparisons with diary data, the three FSI items of interest were: Rate your level of fatigue on the day you felt most fatigued during the past week (i.e., peak), Rate your level of fatigue on the day you felt least fatigued during the past week (i.e., lowest), and Rate your level of fatigue on average during the past week (i.e., average). FSI items were rated on the same 11- point scale (0 ¼ no fatigue at all to 10 ¼ as fatigued as I could be). Analyses To evaluate associations between diary and FSI ratings, correlations and 95% confidence limits were computed using Pearson correlation coefficients and Fisher s r-to-z transformation. 17 Discrepancies between diary and FSI ratings of peak, lowest, and average fatigue were determined by subtracting diary scores from the FSI score, such that higher scores indicated the FSI ratings were higher than the diary ratings. Participants were then classified as having FSI scores higher, lower, or the same as diary ratings, and Chi squared tests were used to test for differences from pre- to post-chemotherapy. Regression was used to determine whether peak, end, or variability in diary ratings were associated with the FSI item that asked participants to rate their average level of fatigue during the past week. Analyses were based on participants with complete data (N ¼ 68). Data were analyzed using in SAS v9.2 (SAS Institute Inc., Cary, NC). Results were considered significant if P < 0.05 (two-tailed). Results Participants (N ¼ 68) were women (ages 33e87 years; mean SD ¼ years) receiving intravenous chemotherapy for stages I (21%), II (13%), III (51%), or IV (15%) gynecologic cancer. Median time since diagnosis was 79.5 days (range 13e4868, SD ¼ 1028) and time since surgery was 44 days (range 13e4868, SD ¼ 765). Most participants were being treated with a taxane (85%); 28% had experienced a disease recurrence and 19% had received radiotherapy. Most participants were non-hispanic (97%) and Caucasian (96%); 26% had graduated from college. MeansandSDsofFSIanddiaryratingsare presented in Table 1. Correlations between the FSIanddiariesforratingsofpeak,lowest,and average fatigue were all significant (P < 0.001; Table 2). Evaluating whether participants were statistically more likely to report higher, lower, or the same scores on the FSI from pre-chemotherapy to post-chemotherapy (Table 3), there were significant changes for the lowest fatigue rating (P ¼ 0.007), but no changes in concordance rates of peak or average fatigue ratings (P > 0.05). More participants reported lower lowest fatigue rating on the FSI relative to diaries post-chemotherapy (18%) than pre-chemotherapy (4%) (c 2 ¼ 8.91, P ¼ 0.003). There were no changes in the percentages of participants who reported higher or the same FSI scores compared with the diary ratings of lowest fatigue pre- to post-chemotherapy (P > 0.05). To evaluate how much of the variance in the retrospectively recalled average FSI item was accounted for by peak, end, average, and variance in diary ratings of fatigue, we ran univariate regression analyses. Analyses were conducted for pre- and post-chemotherapy ratings. Peak diary fatigue rating explained 36% (P < 0.001) and 39% (P < 0.001) of the variance in average FSI item pre- and post-chemotherapy, respectively. End diary rating of fatigue explained 28%

4 Vol. 46 No. 2 August 2013 Retrospective Versus Daily Rating of Fatigue 285 Table 1 Means, Standard Deviations, and Ranges of Fatigue Symptom Inventory and Daily Diary Ratings (N ¼ 68) FSI Daily Diary Variables Mean (SD) Range Mean (SD) Range Pre-chemotherapy Peak fatigue 4.76 (2.77) 0e (2.82) 0e10 Lowest fatigue 1.96 (1.89) 0e (1.63) 0e7 Average fatigue 3.00 (2.13) 0e (2.27) 0e9 Post-chemotherapy Peak fatigue 6.26 (2.65) 0e (2.64) 0e10 Lowest fatigue 1.85 (1.98) 0e (1.82) 0e6 Average fatigue 3.81 (2.22) 0e (2.27) 0e8 FSI ¼ Fatigue Symptom Inventory. (P < 0.001) and 34% (P < 0.001) of the variance in average FSI item pre- and post-chemotherapy, respectively. Average diary ratings explained 52% (P < 0.001) and 54% (P < 0.001) of the variance in average FSI item pre-chemotherapy and post-chemotherapy, respectively. Variance in diary fatigue ratings explained 9% of the variance in average FSI item both pre-chemotherapy (P ¼ 0.010) and post-chemotherapy (P ¼ 0.011) (Table 4). To determine which of the diary ratings accounted for the greatest amount of variability in average FSI item in multivariate analysis, peak, end, average, and variance ratings were entered into a stepwise regression model. Only average diary rating was retained in the pre- (R 2 ¼ 0.52, b ¼ 0.70, P < 0.001) and post-chemotherapy (R 2 ¼ 0.54, b ¼ 0.72, P < 0.001) model. Discussion Overall, the retrospective ratings of fatigue as assessed by the FSI showed good concordance with diary ratings. Diary ratings of fatigue were significantly correlated with their corresponding FSI scores. Evaluating how much of the variance in the average FSI item was accounted for by peak, end, average, and variance in diary ratings of fatigue, in univariate regression analyses each diary rating explained a significant proportion of the variance in average FSI item. However, when entered into a stepwise regression model, only the average of the 24 weekly diary ratings was retained in the model. Prior research demonstrated that retrospective ratings of pain and fatigue are inflated related to averaged real-time ratings. 5 The current study found significant correlations between the peak fatigue level, lowest fatigue level, and average fatigue level recorded in daily diaries and the corresponding ratings from the retrospectively recalled FSI. The pattern of significant correlations was the same pre- and post-chemotherapy. Concordance rates of diary and FSI ratings were consistent pre- to post-chemotherapy for peak and average ratings. However, participants were more likely to report lower levels of lowest fatigue on the FSI relative to diaries post-chemotherapy than pre-chemotherapy. Because fatigue levels Table 2 Calculation and Test of Correlations Between Fatigue Symptom Inventory and Daily Diary Data (N ¼ 68) 95% CI Variables r Lower Limit Upper Limit Peak fatigue Pre-chemotherapy 0.69 a Post-chemotherapy 0.70 a Lowest fatigue Pre-chemotherapy 0.67 a Post-chemotherapy 0.63 a Average fatigue Pre-chemotherapy 0.72 a Post-chemotherapy 0.73 a FSI ¼ Fatigue Symptom Inventory. a P <

5 286 Phillips et al. Vol. 46 No. 2 August 2013 Table 3 Concordance and Discordance Rates Between Fatigue Symptom Inventory and Daily Diaries (N ¼ 68) Variables Concordance Pre-Chemotherapy Week Post-Chemotherapy Week c 2 Peak fatigue (%) þ Lowest fatigue (%) a þ Average fatigue (%) þ ¼FSI lower than daily diary ratings; 0 ¼ FSI same as daily diary ratings; þ¼fsi higher than daily diary ratings. a P < are higher post-chemotherapy than prechemotherapy (as we reported previously 16 ), the higher fatigue post-treatment may bias patients retrospective recall of their lowest fatigue level. Alternatively, patients lowest levels of fatigue may not have occurred during the times they were asked to complete the dairy. Prior work with chronic pain patients found more variability in momentary measures of pain predicted retrospectively recalled pain, but fatigue was not assessed in that study. 7 A study of rheumatology patients that included measures of both pain and fatigue found peak and end ratings of pain contributed to retrospectively recalled pain; however, peak and end ratings were not associated with retrospectively recalled fatigue. 8 In the current study, univariate analyses indicated that higher peak diary rating, higher end diary rating, higher average diary ratings, and greater variance in diary ratings were each associated with higher average FSI item. However, using stepwise regression, because of collinearity only the average daily fatigue rating was retained in the model; it explained 52% of the variance in pre-chemotherapy average FSI item and 54% of the variance in postchemotherapy average FSI item. Our finding that the mean of diary ratings corresponds to retrospective recall lends support to the validity of the FSI. 6 Our data suggest that the FSI is an acceptable substitute for diary ratings of fatigue in patients receiving chemotherapy. Additional support for using a weekly measure of fatigue comes from a study of cancer patients that found the seven-day Functional Assessment of Chronic Illness Therapy-Fatigue was more precise and informative than the four-day measure. 18 Because receiving chemotherapy can be stressful for patients, it is important to Table 4 Univariate Regression Analyses for Diary Rating of Fatigue on Average Fatigue Symptom Inventory Variable R 2 b SE t Pre-chemotherapy Peak diary rating a End diary rating a Average diary rating a Variance in diary rating b Post-chemotherapy Peak diary rating a End diary rating a Average diary rating a Variance in diary rating c Diary ¼ daily diary; R 2 ¼ squared multiple correlation; b ¼ standardized beta weight. In stepwise regression models, only average diary rating was retained both pre- and post-chemotherapy. a P < b P < c P < 0.05.

6 Vol. 46 No. 2 August 2013 Retrospective Versus Daily Rating of Fatigue 287 identify symptom measures that minimize patient burden. Study strengths include the use of a fatigue measure designed for cancer patients and a diary format using the same 0e10 rating scale, focus on gynecologic cancer patients beginning chemotherapy (for whom fatigue is likely to be a significant problem 19 ), and inclusion of preand post-chemotherapy assessments. Limitations include the lack of a time and date stamp for diaries. Prior research suggests some patients may complete paper assessments at a later time, 20 leading to greater congruence between diary ratings and retrospective recall. However, our actigraph beeped to remind patients to complete diaries, which may have increased the likelihood of real-time ratings. Momentary assessments using electronic devices have higher compliance rates 20 and have been useful in assessing fatigue in people receiving hematopoietic stem cell transplantation. 13 Future researchers should replicate these results using an electronic device that documents the exact time of rating. FSI scores keyed to the past week are a good approximation of fatigue ratings reported in daily diaries in the week before and after chemotherapy. Findings support the use of this retrospective measure of fatigue for patients receiving chemotherapy, which may be less burdensome than daily ratings. Disclosures and Acknowledgments This study was supported by National Cancer Institute grant number R The authors have no financial disclosures. The authors wish to acknowledge the contributions of the Moffitt Cancer Center Survey Methods Shared Resource. References 1. Servaes P, Verhagen C, Bleijenberg G. Fatigue in cancer patients during and after treatment: prevalence, correlates and interventions. Eur J Cancer 2002;38:27e Prue G, Rankin J, Allen J, Gracey J, Cramp F. Cancer-related fatigue: a critical appraisal. Eur J Cancer 2006;42:846e Hann DM, Jacobsen PB, Azzarello LM, et al. Measurement of fatigue in cancer patients: development and validation of the Fatigue Symptom Inventory. Qual Life Res 1998;7:301e Donovan KA, Jacobsen PB. The Fatigue Symptom Inventory: a systematic review of its psychometric properties. Support Care Cancer 2010;19: 169e Broderick JE, Schwartz JE, Vikingstad G, et al. The accuracy of pain and fatigue items across different reporting periods. Pain 2008;139:146e Conner TS, Barrett LF. Trends in ambulatory self-report: the role of momentary experience in psychosomatic medicine. Psychosom Med 2012;74: 327e Stone AA, Schwartz JE, Broderick JE, Shiffman SS. Variability of momentary pain predicts recall of weekly pain: a consequence of the peak (or salience) memory heuristic. Pers Soc Psychol Bull 2005;31:1340e Schneider S, Stone AA, Schwartz JE, Broderick JE. Peak and end effects in patients daily recall of pain and fatigue: a within-subjects analysis. J Pain 2011;12:228e Fredrickson BL. Extracting meaning from past affective experiences: the importance of peaks, ends, and specific emotions. Cogn Emot 2000;14: 577e Liu L, Fiorentino L, Natarajan L, et al. Pre-treatment symptom cluster in breast cancer patients is associated with worse sleep, fatigue and depression during chemotherapy. Psychooncology 2009;18: 187e Berger AM, Higginbotham P. Correlates of fatigue during and following adjuvant breast cancer chemotherapy: a pilot study. Oncol Nurs Forum 2000;27:1443e de Jong N, Kester ADM, Schouten HC, Abu- Saad HH, Courtens AM. Course of fatigue between two cycles of adjuvant chemotherapy in breast cancer patients. Cancer Nurs 2006;29:467e Hacker ED, Ferrans CE. Ecological momentary assessment of fatigue in patients receiving intensive cancer therapy. J Pain Symptom Manage 2007;33: 267e Curran SL, Beacham AO, Andrykowski MA. Ecological momentary assessment of fatigue following breast cancer treatment. J Behav Med 2004;27: 425e Glaus A. Assessment of fatigue in cancer and non-cancer patients and in healthy individuals. Support Care Cancer 1993;1:305e Jim HS, Small B, Faul LA, et al. Fatigue, depression, sleep, and activity during chemotherapy: daily and intraday variation and relationships among symptom changes. Ann Behav Med 2011;42: 321e Steiger JH. Testing pattern hypotheses on correlation matrices: alternative statistics and some

7 288 Phillips et al. Vol. 46 No. 2 August 2013 empirical results. Multivariate Behav Res 1980;15: 335e Lai JS, Cook K, Stone A, Beaumont J, Cella D. Classical test theory and item response theory/ Rasch model to assess differences between patientreported fatigue using 7-day and 4-week recall periods. J Clin Epidemiol 2009;62:991e Butler L, Bacon M, Carey M, et al. Determining the relationship between toxicity and quality of life in an ovarian cancer chemotherapy clinical trial. J Clin Oncol 2004;22:2461e Stone AA, Shiffman S, Schwartz JE, Broderick JE, Hufford MR. Patient non-compliance with paper diaries. BMJ 2002;324:1193e1194.