- Email: [email protected]
Validity and Reliability of the Indonesian Version of the Brief Fatigue Inventory in Cancer Patients
Accepted Manuscript Validity and Reliability of Brief Fatigue Inventory (BFI)-Indonesian Version in Cancer Patients dr. Nurul Paramita, MBiomed, SpKFR, Dr. dr. Nury Nusdwinuringtyas, MEpid, SpKFR(K), dr. Siti Annisa Nuhonni, SpKFR(K), DR. dr. Tubagus Djumhana Atmakusuma, SpPD-KHOM, DR. Dr. R. Irawati Ismail, MEpid, SPKJ(K), Prof., Tito R. Mendoza, PhD, MS, MEd, Charles S. Cleeland, PhD PII:
S0885-3924(16)30300-1
DOI:
10.1016/j.jpainsymman.2016.04.011
Reference:
JPS 9191
To appear in:
Journal of Pain and Symptom Management
Received Date: 8 September 2015 Revised Date:
3 February 2016
Accepted Date: 11 April 2016
Please cite this article as: Paramita N, Nusdwinuringtyas N, Annisa Nuhonni S, Atmakusuma TD, Ismail RI, Mendoza TR, Cleeland CS, Validity and Reliability of Brief Fatigue Inventory (BFI)-Indonesian Version in Cancer Patients, Journal of Pain and Symptom Management (2016), doi: 10.1016/ j.jpainsymman.2016.04.011. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Validity and Reliability of Brief Fatigue Inventory (BFI)-Indonesian Version in Cancer Patients Authors
TE D
M AN U
SC
RI PT
1. dr. Nurul Paramita, MBiomed, SpKFR Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia Department of Medical Physiology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 2. Dr. dr. Nury Nusdwinuringtyas, MEpid, SpKFR(K) Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 3. dr. Siti Annisa Nuhonni, SpKFR(K) Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 4. DR. dr. Tubagus Djumhana Atmakusuma, SpPD-KHOM Department of Internal Medicine, Hemology-Oncology Division, Cipto Mangunkusumo Hospital-Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 5. Prof. DR. Dr. R. Irawati Ismail, MEpid, SPKJ(K) Department of Psychiatry, Cipto Mangunkusumo Hospital-Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 6. Tito R. Mendoza, PhD, MS, MEd Department of Symptom Research Division of Internal Medicine, The University of Texas, MD Anderson Cancer Center, Houston, Texas 7. Charles S. Cleeland, PhD Department of Symptom Research Division of Internal Medicine, The University of Texas, MD Anderson Cancer Center, Houston, Texas
AC C
EP
Contact person Nurul Paramita Komp. Bona Indah B3 No.25 Jakarta, Indonesia Phone number: +62217513456 Mobile phone number: +6281281839593 Email address: [email protected] List of Tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7.
Descriptive characteristics of study subjects Factor Analysis of Indonesian BFI (1 factor extraction) (n=121) Spearman’s rho coefficient correlation between Indonesian BFI with Indonesian MOS SF-36 subscales Mean rank Indonesian BFI score and ECOG-PS score Reliability with Cronbach’s Alpha and Alpha If Item Deleted Inter-item correlation coefficients for the nine items of the Indonesian BFI Descriptive Statistics of Indonesian BFI (n=121) 1
ACCEPTED MANUSCRIPT List of Figure Figure 1.
Plot of mean Indonesian BFI interference score against fatigue severity measured by “Worst Fatigue” on Indonesian BFI
RI PT
References
AC C
EP
TE D
M AN U
SC
1. World Health Organization. Cancer-Key facts. 2015. Available from: http://www.who.int./mediacentre/factsheets/fs297/en/. Accessed August 30, 2015. 2. Hofman M, Ryan JL, Figueroa-Moseley CD, Jean-Pierre P, Morrow GR. Cancer-related fatigue: the scale of the problem. Oncologist 2007;12 Suppl 1:4-10. 3. Yeh ET, Lau SC, Su WJ, et al. An examination of cancer-related fatigue through proposed diagnostic criteria in a sample of cancer patients in Taiwan. BMC Cancer 2011;11:387. 4. Wang XS. Pathophysiology of cancer-related fatigue. Clin J OncolNurs 2008;12(5 Suppl):11-20. 5. Gupta D, Lis CG, Grutsch JF. The relationship between cancer-related fatigue and patient satisfaction with quality of life in cancer. J Pain Symptom Manage 2007;34(1):40-47. 6. Mendoza TR, Wang XS, Cleeland CS, et al. The rapid assessment of fatigue severity in cancer patients: use of the Brief Fatigue Inventory. Cancer 1999;85(5):1186-1196. 7. Okuyama T, Wang XS, Akechi T, et al. Validation study of Japanese version of the brief fatigue inventory. J Pain Symptom Manage 2003;25(2):106-117. 8. Smets EM, Garssen B, Bonke B, De Haes JC. The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Pschosom Res 1995;39(3):315-325. 9. Yellen SB, Cella DF, Webster K, Blendowski C, Kaplan E. Measuring fatigue and other anemia-related symptoms with the Functional Assessment of Cancer Therapy (FACT) measurement system. J Pain Symptom Manage 1997;13(2):63-74. 10. Schwartz AL. The Schwartz Cancer Fatigue Scale: testing reliability and validity. OncolNurs Forum 1998;25(4):71-7. 11. 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(4):301-310. 12. Piper BF, Dibble SL, Dodd MJ, et al. The revised Piper Fatigue Scale: psychometric evaluation in women with breast cancer. OncolNurs Forum 1998;25(4):677-684. 13. Okuyama T, Akechi T, Kugaya A, et al. Development and validation of the cancer fatigue scale: a brief, three-dimensional, self-rating scale for assessment of fatigue in cancer patients. J Pain Symptom Manage 2000;19(1):5-14. 14. Yun YH, Wang XS, Lee JS, et al. Validation study of the korean version of the brief fatigue inventory. J Pain Symptom Manage 2005;29(2):165-172.
2
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
15. Wang XS, Hao XS, Wang Y, et al. Validation study of the Chinese version of the Brief Fatigue Inventory (BFI-C). J Pain Symptom Manage 2004;27(4):322-332. 16. Catania G, Bell C, Ottonelli S, et al. Cancer-related fatigue in Italian cancer patients: validation of the Italian version of the Brief Fatigue Inventory (BFI). Support Care Cancer 2013;21(2):413-419 17. Radbruch L, Sabatowski R, Elsner F, et al. Validation of the German version of the brief fatigue inventory. J Pain Symptom Manage 2003;25(5):449-458. 18. McHorney CA, Ware JE, Jr., Lu JF. Sherbourne CD. The MOS 36-item ShortForm Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Med Care 1994;32(1):40-66. 19. Perwitasari DA. Development the validation of Indonesian version of SF-36 questionnaire in cancer disease. Indonesian J Pharm 2012;23(4):248-253. 20. Perwitasari DA, Atthobari J, Dwiprahasto I, et al. Translation and validation of EORTC QLQ-C30 into Indonesian version for cancer patients in Indonesia. Jpn J ClinOncol 2011;41(4):519-529. 21. Oken MM, Creech RH, Tormey DC, et al. Toxicity and response criteria of the Eastern Cooperative Oncology Group. Am J Clin Oncol 1982;5(6):649655. 22. Taylor AE, Olver IN, Sivanthan T, Chi M, Purnell C. Observer error in grading performance status in cancer patients. Support Care Cancer 1999;7(5):332-335. 23. Roila F, Lupattelli M, Sassi M, et al. Intra and interobserver variability in cancer patients’ performance status assessed according to Karnofsky and ECOG scales. Ann Oncol 1991;2(6):437-439. 24. Test Reliability. 2006. Available from: http://www.proftesting.com/test_topics/pdfs/test_quality_reliability.pdf. Accessed June 27, 2014. 25. Streiner DL, Norman GR. Health Measurement Scales: A practical guide to their development and use, 3rd ed. New York: Oxford University Press, 2003. 26. Campos MP, Hassan BJ, Riechelmann R, Del Giglio A. Cancer-related fatigue: a review. Rev Assoc Med Bras 2011;57(2):211-219. 27. Vainio A, Auvinen A. Prevalence of symptoms among patients with advanced cancer: an international collaborative study. J Pain Symptom Manage 1996;12(1):3-10. 28. Teunissen SC, Wesker W, Kruitwagen C, de Haes HC, Voest EE, de Graeff A. Symptom prevalence in patients with incurable cancer: a systematic reveiw. J Pain Symptom Manage 2007;34(1):94-104.
3
ACCEPTED MANUSCRIPT Abstract
M AN U
SC
RI PT
CONTEXT. Cancer-related Fatigue (CRF) is one of the most commonly reported symptoms in cancer patients. Short but good assessment is essential to detect and manage this symptom. Brief Fatigue Inventory (BFI) is a valid and reliable short instrument to assess CRF. OBJECTIVES. To examine the validity and reliability of the Indonesian BFI. METHODS. Forward and backward translation approach, followed by cognitive debriefing process was done to develop Indonesian BFI. One hundred and twenty one consecutive adult outpatients with cancer who are willing to participate in this study filled in Indonesian BFI along with the Medical Outcome Study Quality of Life Short Form 36 (MOS SF-36). Demographic and health data were collected. RESULTS. The Indonesian BFI had an overall Cronbach alpha for the 9 items of 0.956. The results of the factor analysis suggested a 1-factor solution, supporting the hypothesis of unidimentionality of the Indonesian BFI. The Indonesian BFI score was compared to MOS SF-36 subscale to evaluate convergent validity. An expected inverse correlation between Indonesian BFI and all domains of MOS SF-36 was observed (r= -0.388 to -0.676; p<0.0000). Discriminant validity analysis showed the Indonesian BFI mean score significantly increased with increasing Eastern Cooperative Oncology Group Performace Status (ECOG-PS) values (p=0.000). CONCLUSIONS. Indonesian BFI is a reliable, valid instrument for Indonesian cancer patients. KEYWORDS: CRF; fatigue; assessment; validity; reliability; Indonesia
AC C
EP
TE D
Running Title: Validation Study of Indonesian BFI
4
ACCEPTED MANUSCRIPT Introduction Until now, cancer is still a health problem throughout the world. In 2012, worldwide, there were 14.1 million new cancer cases and 32.6 million people living with cancer (over 5 years of diagnosis).(1) Improved medical technology in terms of screening and treatment of cancer has increased the life expectancy of cancer patients.
RI PT
This situation led to increasing realization of various symptoms and problems that accompany cancer and its treatment. Fatigue is one of the most common symptoms complained by cancer patients. Fatigue is also the most common side effects arise on the treatment of cancer. In one of their study, Hoffman et.al find that 95 % of cancer
SC
patients are predicted to experience fatigue as a result of the chemotherapy or radiotherapy they received. Fatigue felt by the majority of patients with various types of cancer. Cancer-related fatigue (CRF) is one of the most disturbing complaints
M AN U
compared to various other complaints reported by patients.(2,3)
It is thought that CRF arising due to various factors. Several factors that had already been known to play a role in CRF include the cancer itself, cancer treatment, and chronic conditions such as anemia, pain, depression, anxiety, cachexia, sleep disturbance and immobilization.(4)
TE D
The impact of CRF on patient’s quality of life, particularly in relation to physical functioning and ability to perform daily activities is very real and substantial.(2,5) Given the magnitude of the impact of CRF in patients’ functional activity and fairly high frequency of CRF, researches on CRF continue to be developed. In order for
EP
CRF to be studied and managed effectively, a valid and reliable fatigue assessment tools is needed. CRF, like pain, is a subjective symptom, so the instrument that
AC C
assesses fatigue has to be based on the respective patient’s report. A good CRF assessment tools needs to allow for doctors and medical personnel to evaluate the symptoms of CRF without bias.(6,7) There have been many studies constructing an instrument to assess CRF, but until
now not a single instrument can be considered as the "gold standard" to measure CRF. Several CRF assessment tools have been developed in various countries around the world, in English language. Multidimensional Fatigue Inventory (MFI)(8), Functional Assesment of Cancer Therapy-Fatigue (FACT-F)(9), Schwartz Cancer Fatigue Scale (SCFS)(10), Fatigue Symptom Inventory (FSI)(11) and Piper Fatigue Scale (PFS)(12) are several examples of CRF assessment tools. The main characteristics of all of these 5
ACCEPTED MANUSCRIPT measuring tools are multidimensional. These tools usually consist of several subscales that allow evaluation of various aspects of fatigue and are especially useful in a descriptive study of fatigue. However, for patients with cancer who experience fatigue, multidimensional measurement tools are sometimes felt too long and too difficult for the patient to complete. Expressive description of the multidimensional
RI PT
measurement tools also led to a higher degree of difficulty in the process of translation into other languages.
Brief Fatigue Inventory (BFI) is a unidimensional questionnaire that was originally developed in the United States, to assess the level of fatigue in cancer patients. BFI
SC
consist of 3 questions that measure the severity of fatigue, and 6 questions to determine the impact of fatigue on daily activities. There are 3 important characteristics of this measure, which are: 1) short and easy to answer 2) easily
M AN U
translated into other languages, and 3) include interference (impact) assessment. Usually the term used to describe fatigue is often difficult to translate, but BFI conduct assessment of the intensity of fatigue and its impact on daily activities by using simple words. Selection of the numerical scale of 0-10 and not words to describe the level of fatigue also facilitate the process of translating the
TE D
questionnaire.(6,7)
BFI has been translated into various languages through the linguistic validation process. Some already test the psychometric properties of the BFI translations and the results already published in international journals.(13-17) All of validity and
EP
reliability tests of the translation had showed good results. There is an increasing need to assess the fatigue experienced by patients as a result
AC C
of cancer and its treatment in Indonesia, but no easily administered instrument has been available. The purpose of this study was to create an Indonesian version of the BFI for Indonesian cancer patients, and thus produce an instrument that is reliable and valid for use in future clinical trials assessing CRF in Indonesia. This study will be the foundation to evaluate the effectiveness of intervention strategies in reducing CRF and the impact it has on the patients’ daily functioning.
Methods Study Design This is a cross-sectional study, which involves the collection of data at one point in time. 6
ACCEPTED MANUSCRIPT Patients and Data Collection The subjects of this study were cancer patients at the outpatient clinics of the Dr. Cipto Mangunkusumo National Centre Hospital, Department of Internal Medicine, Hematology-Oncology Division, Indonesia. The study was conducted between November and December 2014. Subjects were recruited on specified days from all
RI PT
patients who met eligibility criteria using consecutive sampling method. Patients who met all the following inclusion criteria were considered eligible for this validation study: (1) a pathological diagnosis of cancer, (2) were older than 18 years, (3) gave their informed consent to participate, and (4) were able to understand and complete
SC
the questionnaires. The subjects were asked to complete the questionnaires either by self-administered or through an interview. The study was approved by the Institutional Review Board of the Dr. Cipto Mangunkusumo National Center Hospital
M AN U
and Faculty of Medicine, Universitas Indonesia. Each subject gave written consent after being fully informed with the study. Research staff collected patient data including age, gender, education, performance status and treatments received. The collection of data was taken in a comfortable and quiet room, apart from the waiting
Measurements
TE D
area, to provide comfort and privacy for the patients.
Brief Fatigue Inventory (BFI). The BFI was originally developed specifically to assess CRF. It is a brief questionnaire, which consists only 9 items, using numerical rating scale of 0 - 10. The first 3 items ask patients about their level of fatigue on 3
EP
occasions : right now; at its usual level within the past 24 hours; at its worst level within the past 24 hours − using extreme points “no fatigue” as “0” and “fatigue as
AC C
bad as you can imagine” as “10”. The next 6 items ask patients to describe how much fatigue has interfere with different aspects of their life within the past 24 hours. The aspects assessed are general activity, mood, walking ability, normal work (both work outside the home and daily chores), relations with other people, and enjoyment of life. These interference scales range from “0” as “does not interfere” and “10” as “completely interferes”. The global score for the BFI is the mean value of all these 9 items. The validity and reliability of the original BFI has been established.(6) Indonesian BFI. The Indonesian BFI was developed using the standard forwardbackward translation process according to the translation guidelines from University of Texas, M.D. Anderson Cancer Center. In the translation process, the original 7
ACCEPTED MANUSCRIPT English version of the BFI was first translated into Indonesian by two independent translators and then back-translated into English by another independent translator who had not seen the original English version. All the translators are Indonesian native who is fluent in English. Next, the English back-translated versions were compared with the originals. If a back-translated item did not agree with the original,
RI PT
the first two translators performed a second translations and the second two translators performed second back-translations. This process was repeated until agreement was reached. The final Indonesian version of the BFI was sent to the University of Texas, M.D. Anderson Cancer Center. After minimal changes, the center approved the
SC
Indonesian BFI. The process was then followed by the cognivitive debriefing process to 30 eligible cancer patients. The final revised version of the translation was adjusted in accordance to the result of cognitive debriefing interviews. The final revised
Center and was approved.
M AN U
version of the translation was sent to the University of Texas, M.D. Anderson Cancer
The medical outcome study quality of life SF36 (MOS SF-36). The MOS SF-36 is one of the most widely used health-related quality of life instruments. Thirty-six questions address 8 domains: physical functioning; social functioning; role limitation
TE D
due to physical problems; pain; vitality; role limitation due to emotional problems; mental health; and general health. The scores are transformed to a 0-100 scale with lower values representing a lower functioning level. The MOS SF-36 has been validated with internal consistency for each domain between 88 – 95%.(18)
EP
The MOS SF-36 has been translated into numerous languages, including Indonesian. Internal consistency of Indonesian MOS SF-36 showed Cronbach’s alpha
AC C
> 0.7 for physical functioning, social functioning, physical pain, role limitation due to physical problems and role limitation due to emotional problem.(19,20) The Eastern Cooperative Oncology Group performance status (ECOG-PS). The
ECOG-PS scale is rated on five levels from 0 -5. Level 0 indicates “fully active” to level 4 “cannot carry on any self-care” and completely bedridden, level 5 indicating “dead”. The ECOG-PS scale is used to assess how a patient’s disease is progressing, how the disease affect the patient’s ability to perform activities of daily living, and to determine appropriate treatment and prognosis.(21) The ECOG-PS is a well-accepted measure of a patient’s health status in clinical setting with good reliability and validity.(22,23) Patients’ performance status was clinically evaluated on the same day as assessment by attending oncologist. 8
ACCEPTED MANUSCRIPT Sociodemographic Information. The subject’s education level, age, sex, marital status and religion were obtained using a questionnaire. Clinical Data Checklist. Subject’s medical information was obtained by research staff members from their medical records and interview, which included cancer site and stage, presence of metastatic lesions, treatment status (including history of cancer
RI PT
treatment), performance status, prescribed medication, Visual Analog Scale for pain, and recent laboratory data. Statistical Analysis
The reliability and validity of Indonesian BFI was evaluated as follows. The
SC
reliability was evaluated by calculating the Cronbach’s alpha coefficient, which is a measure of the internal consistency of responses – the extent to which the scores of
M AN U
each item are correlated with the scores of all other items.(24) This coeficcient ranges from 0 to 1, with higher values indicating good reliability. A low alpha value suggest that some items either have very high variability or that the items are not all measuring the same thing. A value of 0.70 or greater is considered an adequate level of correlation between items. Factor analysis was used to determine the underlying construct and to test the hypothesis of unidimensionality of the Indonesian BFI, as
TE D
proposed by the original BFI validation. We examine whether Indonesian BFI reproduced the same factor loading pattern seen in the original scale, and the fit of the factor model was evaluated based on the results of the scree test, interpretability, and examinations of the residuals. Convergent validity – the extent to which an instrument
EP
is correlated with similar instrument(25) – was evaluated by calculating correlation coefficient between the Indonesian BFI and the MOS SF-36 subscale and global
AC C
health status. The hypothesis tested was that the Indonesian BFI overall score was more highly correlated with vitality domain score as compared to the others domain score. Discriminant validity – the extent to which a measure diverges from other measures from which it is theoretically distinct(25) – was examined using KruskalWallis test, to compare the Indonesian BFI mean rank scores in patients having different ECOG-PS; it was hypothesized that patients having poor performance status have an increased level of fatigue score. Statistical analysis was performed with the statistical package SPSS® version 22 (SPSS Inc., Chicago, IL)
9
ACCEPTED MANUSCRIPT Results Study Subjects Overall, 125 eligible patients were recruited. Four of these patients were excluded: 2 for refusal to participate, 2 for excessive illness. The remaining 121 patients agreed to participate in the study and completed the questionnaires. Of the 121 subjects,
RI PT
56.2% were female. The majority of subjects (39.7%) had primary education. Fifty five point four percent (55.4%) of the subjects had a good functional status (performance status of 0 and 1). The subjects were diagnosed with various types of cancer. The top 3 were nasopharyngeal carcinoma (25.6%), lymphoma maligna non
characteristics of the subjects are shown in Table 1.
SC
hodgkin (17.4%), and breast cancer (14%). The sociodemographic and clinical
We found that there were no missing responses to all the questions of the
M AN U
Indonesian BFI.
Psychometric properties of Indonesian BFI
Construction of Indonesian BFI was confirmed using factor analysis. The KMO measure of sampling adequacy is 0.909, showing that factor analysis can be used in
TE D
this group of data. Principal axis factor analysis with oblimin rotation supported the 1factor solution for all 9 items in the Indonesian BFI by model fitting and consideration of clinical interpretability. The eigenvalue was 6.731 for the first factor, followed by 0.58 and 0.51 for the second and the third factor. The first factor explained 76% of the
EP
variability in the data. The eigenvalues and amount of explained variability shows that most of the data can be explained by a single construct. A scree plot also identified 1
AC C
construct to explain the majority of variance. The factor loadings in each group were equally high, ranging from 0.648 to 0.837 as can be seen in Table 2. This patterns of factor loadings indicated the association of the 9 items with a single factor. Because the Indonesian BFI measures a single construct, the mean of the 9 Indonesian BFI items can be used as a global Indonesian BFI score. Convergent validity was demonstrated by calculating correlation coefficient between the Indonesian BFI score and the MOS SF-36 subscale and global health status. An expected inverse correlation was observed between the Indonesian BFI mean score and the vitality subscale of the MOS SF-36 (r=-0.676, p<0.000). The correlation with the other subscales of the MOS S-F36 ranged between -0.388 and 10
ACCEPTED MANUSCRIPT 0.623 (Table 3). The results supported the hypothesis that the Indonesian BFI scales would correlate significantly with the fatigue-related constructs of the MOS SF-36. The discriminant validity was assessed using Kruskal-Wallis test, to compare the Indonesian-BFI mean rank scores in patients having different ECOG performance statuses. An expected increase in BFI mean rank scores with an increase in ECOG –
RI PT
PS score was observed. (Table 4 ). To measure the reliability of the Indonesian BFI, we measure the internal consistency of the instrument. Cronbach’s alpha was calculated for the 9 items in the scale. The overall alpha was 0.956. The fact that the reliability coefficient of the scale
SC
is high emphasized the increased internal consistency and reliability of the scale. The alpha coefficient if item deleted was also measured to determine how each item individually contributes to the reliability of the questionnaire. The result shows that
M AN U
all of the items have similar strong contribution to the overall Cronbach’s alpha coefficient (Table 5). The inter-item mean correlation was 0.715, and coefficients correlation ranged from 0.570 – 0.886 for the 9 items of the Indonesian BFI (Table 6). Prevalence and Severity of Fatigue
TE D
The current study showed that 64.5% of the subjects was feeling unusual fatigue (Table 1). The mean of the 9 Indonesian BFI items is 3.61+2.75 and the mean of “fatigue at its worst” is 4.93+ 3.11 with mode value is 8 (Table 7). Figure 1 shows the relationship between Indonesian BFI mean of the 6 interference items and the worst
EP
fatigue. The slope in the graph illustrates the steep increases in interference with increases in fatigue level.
AC C
Discussion
CRF is increasingly recognized as a considerable issue for cancer patients and
health-care providers, yet there is still no universally accepted standard for measurement of CRF. Consequently, it is frequently underdiagnosed and under assessed, and not treated properly. Several problems in the management of CRF are known to be associated with patients, health-care providers and health systems. Clinical intervention model programs aiming to eliminate these problems have already been developed in some countries. Good assessment tools to identified CRF is one of the key component in the programs. In this study, we developed and validated an Indonesian version of the 11
ACCEPTED MANUSCRIPT BFI, one of the tools to assess CRF. We were not only investigated the reliability and validity of the Indonesian BFI, but we also generated a CRF profile based on responses from the subjects. The current study demostrates that the Indonesian BFI is an excellent assessment tool for use in both research and clinical fields. The small number of items, using
RI PT
straighforward sentences that is easily understood, and using numerical rating scale that is easy for patients to use, has made the subjects to be able to complete the instrument in an average of 5 minutes, and the longest was 10 minutes. It proves that this instrument is suitable enough (will not overly tiring) for fatigue cancer patients to
SC
complete. All of the subjects in this study able to complete the questionnaire. Forty nine subjects (40%) completed the questionnaire through an interview instead of filling the questionnaire by themselves. We can not rule out the education level as the
M AN U
cause because only around half of the subjects surpass the secondary education. We do not think the functional status to be the main reason because 81% of the subjects had good functional status. This result should be of particular attention in the subsequent studies, but the fact that they still could complete the instrument, whether by themselves or through an interview, had proved that Indonesian BFI can be used
TE D
for patients of all education level and social statuses.
As seen in the original version, the result of this study support the Indonesian BFI as a valid and reliable tool for measuring CRF in cancer patients. The factor solution for the Indonesian BFI produced one factor with an eigenvalue over one; all items
EP
loaded on a single factor. The high scores highlighted by factor analysis indicated the association of 9 Indonesian BFI items that can be used as a global Indonesian BFI
AC C
score.
As seen in the original version(6), Japanese(7), Korean(14), Taiwanese(15),
Italian(16) and German(17) BFI validation studies, most of our study subjects had a good performance status. Subjects in our study were outpatients which may have influenced both the score of the subject’s fatigue perception and the validation result. Because only 5 subjects had an ECOG-PS 4, it was not possible to correlate the BFI mean scores with the performance status of the subjects. However, the increase of the Indonesian BFI scores with the worsening of performance status was a significant discriminant validity. The subjects in this study relate fatigue more with the vitality subscales of the MOS SF-36 than with other subscales. This result is similar to the Italian and German 12
ACCEPTED MANUSCRIPT version of BFI.(16,17) This result shows that, as expected, the Indonesian BFI captures the fatigue dimension included in the vitality subscale of the MOS SF-36. The Cronbach’s alpha coefficient and inter-item correlation coefficient were high, indicating good internal consistency of this questionnaire. The current study shows that fatigue was highly prevalent in the Indonesian cancer
RI PT
patients (64.5% of the subjects was feeling unusual fatigue). This finding is consistent with results from other studies that show the prevalence of CRF between 50 – 90%.(26-28)
The mean total score of Indonesian BFI is 3.61+2.75. This value is lower than the
SC
value obtained in validity study of the original BFI by Mendoza TR, et al. (4.7+2.8); German version by Radbruch L, et al. (4.5+2.1); and Korean version by Yun YH, et al. (4.7 for severity of fatigue composite and 4.3 for effect of fatigue composite);
M AN U
which conducted the study in both outpatients and hospitalized patients.(6,14,17) Approximately the same value obtained in validity study of the Japanese version of the BFI by Okuyama T, et al. (3.1+2.4) and the Italian version by Catania G, et al. (3.8+2.4), which also conducted the study on only outpatients.(7,16) Further studies in Indonesian hospitalized cancer patients can reveal more about the fatigue profile in
TE D
Indonesia’s cancer population.
One interesting finding is that the mode value is much higher in the item "worst fatigue" compared with the “fatigue right now” and the “average fatigue (8, 0 and 3, respectively) as seen in Table 7. This shows a very fluctuating nature of fatigue, even
EP
within 24 hours. Further research is needed to explore factors that contribute to the fluctuating nature of fatigue and its effects on physical functioning.
AC C
According to the fatigue classification described in the original BFI study, fatigue can be categorized as not severe (BFI score <7) and severe (BFI score 7-10). Based on this classification, 17.4% of the subjects in this study had severe fatigue. Moreover, 19% of the subjects experienced limited functional performance (measured using ECOG-PS scale). Given this study subjects were outpatients, these results reveal that fatigue is a critical problem even in ambulatory patients with cancer, and it should be explored and treated comprehensively. Further study will be needed to explore the prevalence and severity of fatigue in hospitalized Indonesian cancer patients. Subjects of this study experienced more severe interference for higher fatigue level. To improve the management of fatigue, health care professional working in oncology should be familiar with patients who are disabled by their fatigue. Further 13
ACCEPTED MANUSCRIPT studies are needed to explore factors related to fatigue, which type of cancer or cancer treatments causes fatigue and to evaluate the effectiveness of different therapeutic regimens or to compare the side effect of different drugs. This study had 3 major limitations. First, we did not do a test-retest reliability procedure. Second, this is a cross-sectional study and we did not measure fatigue over
RI PT
time. Therfore, the responsiveness to change of the Indonesian BFI could not be estimated. Future studies with longitudinal design can help to further evaluate the Indonesian BFI’s responsiveness and test-retest reliability. Third, this study did not have a control group to differentiate between severity of CRF and typical fatigue in
SC
Indonesian general population. Future large-scale epidemiology studies using Indonesian BFI across diseases and age groups of Indonesian population could provide more data on the nature of fatigue.
M AN U
In conclusion, the results from this study are consistent with the other BFI validation studies that support the use of Indonesian BFI as a valid and reliable tool for measuring fatigue in Indonesian cancer population. The Indonesian BFI could become a good and valid tool for further study of fatigue etiology, pathophysiology and managements trials. In addition, because the BFI has been translated into many
TE D
other languages, the use of Indonesian BFI can simplify fatigue epidemiology and etiology study comparisons between countries. Acknowledgments
AC C
EP
We would like to thank the patients who cooperated so willingly.
14
ACCEPTED MANUSCRIPT Table 1 Descriptive characteristics of study subjects Sample size, n=121 51; 20 - 73 53 (43.8%) 68 (56.2%)
RI PT
8 (6.6%) 48 (39.7%) 38 (31.4%) 27 (22.3%)
SC
31 (25.6%) 21 (17.4%) 17 (14%) 16 (13.2%) 36 (29.8%)
AC C
EP
TE D
M AN U
Characteristics Median age; range Sex - Male - Female Education - Do not go to school/do not finish elementary school - Primary Education - Secondary Education - Higher Education Types of cancer - Nasopharyngeal Carcinoma - Lymphoma Maligna Non Hodgkin - Breast Cancer - Cervical Cancer - Other Cancer Staging - Already staged - Staging I - Staging II - Staging III - Staging IV - Not yet staged Feeling Unusual Fatigue - Yes - No ECOG-PS score - 0 : fully active - 1 : Restricted but ambulatory - 2 : Ambulatory; capable of self-care - 3 : Capable of only limited self care - 4 : Completely disabled Mean MOS SF-36 (Mean; SD) - Mental Component Summary - Physical Component Summary BFI Score (Mean; SD) Level of fatigue - Not Severe ( BFI mean score < 7) - Severe (BFI mean score >7)
1
96 (79.3%) 4 (4.2%) 20 (20.9%) 26 (27%) 46 (47.9%) 25 (20.7%) 78 (64.5%) 43 (35.5%)
30 (24.8%) 37 (30.6%) 31 (25.6%) 18 (14.9%) 5 (4.1%)
49.78 ; 11.86 36.05 ; 9.99 (3.61 ; 2.75) 100 (82.6%) 21 (17.4%)
ACCEPTED MANUSCRIPT
Table 2 Factor Analysis of Indonesian BFI (1 factor extraction) (n=121) Factor analysis factor 1 0.802
Usual fatigue
0.801
Worst fatigue
0.805
Activity
0.837
Mood
0.684
Walking
0.648
Working
0.734
Relation to others
0.675
Enjoyment of life
0.744
M AN U
SC
Fatigue right now
RI PT
BFI items
Table 3 Spearman’s rho coefficient correlation between Indonesian BFI with Indonesian MOS SF-36 subscales Indonesian BFI
< 0.000
Role-Physical Limitation
- 0.547
< 0.000
Bodily Pain
- 0.538
< 0.000
- 0.491
< 0.000
Vitality
- 0.676
< 0.000
Social Functioning
- 0.521
< 0.000
Role-Emotional Limitation
- 0.388
< 0.000
Mental Health
- 0.528
< 0.000
Physical Component Summary
- 0.623
< 0.000
Mental Component Summary
- 0.491
< 0.000
TE D
Spearman’s rho coefficient correlation - 0.588
Physical Functioning
AC C
EP
General Health
2
P
ACCEPTED MANUSCRIPT Table 4 Mean rank Indonesian BFI score and ECOG-PS score Subjects 30 37 31 18 5
BFI mean rank 43.73 49.80 68.37 88.33 103.40
RI PT
ECOG-PS 0 1 2 3 4
Table 5 Reliability with Cronbach’s Alpha and Alpha If Item Deleted
SC
Subjects (n = 121) 0.956
Alpha Alpha if item deleted
Usual Fatigue Worst Fatigue Activity Mood Walking
TE D
Working
0.950
M AN U
Fatigue right now
0.950 0.949 0.948 0.953 0.954 0.951 0.953
Enjoyment of life
0.951
AC C
EP
Relation to others
3
ACCEPTED MANUSCRIPT
2
3
A
B
C
D
E
F
1
1.000
-
-
-
-
-
-
-
-
2
0.886
1.000
-
-
-
-
-
-
-
3
0.869
0.863
1.000
-
-
-
-
-
-
A
0.764
0.819
0.806
1.000
-
-
-
-
-
B
0.719
0.707
0.670
0.711
1.000
-
-
-
-
C
0.682
0.617
0.714
0.697
0.570
1.000
-
-
-
D
0.716
0.680
0.695
0.823
0.642
0.733
1.000
-
-
E
0.632
0.688
0.665
0.715
0.655
0.604
0.672
1.000
F
0.676
0.677
0.678
0.764
0.772
0.669
0.710
0.780
M AN U
1= fatigue right now 2= usual fatigue 3= worst fatigue
RI PT
1
SC
Table 6 Inter-item correlation coefficients for the nine items of the Indonesian BFI
A=general activity B=mood C=walking ability
1.000
D=normal work E=relation to others F=enjoyment of life
TE D
Table 7 Descriptive Statistics of Indonesian BFI (n=121) Minimum
Fatigue right now
Maximum Mode Mean
Std. Deviation
0
10
0
3.85
2.96
0
10
3
3.70
2.66
0
10
8
4.93
3.11
0
10
0
3.81
3.29
0
10
0
2.95
3.18
0
10
0
3.33
3.33
Working
0
10
0
3.99
3.47
Relation to others
0
10
0
2.91
3.35
Enjoyment of life
0
10
0
3.02
3.30
BFI total score
0
10
0
3.61
2.75
Usual fatigue
Activity Mood
AC C
Walking
EP
Worst fatigue
4
SC
RI PT
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
Figure 1. Plot of mean Indonesian BFI interference score against fatigue severity measured by “Worst Fatigue” on Indonesian BFI.
1
S0885-3924(16)30300-1
DOI:
10.1016/j.jpainsymman.2016.04.011
Reference:
JPS 9191
To appear in:
Journal of Pain and Symptom Management
Received Date: 8 September 2015 Revised Date:
3 February 2016
Accepted Date: 11 April 2016
Please cite this article as: Paramita N, Nusdwinuringtyas N, Annisa Nuhonni S, Atmakusuma TD, Ismail RI, Mendoza TR, Cleeland CS, Validity and Reliability of Brief Fatigue Inventory (BFI)-Indonesian Version in Cancer Patients, Journal of Pain and Symptom Management (2016), doi: 10.1016/ j.jpainsymman.2016.04.011. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Validity and Reliability of Brief Fatigue Inventory (BFI)-Indonesian Version in Cancer Patients Authors
TE D
M AN U
SC
RI PT
1. dr. Nurul Paramita, MBiomed, SpKFR Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia Department of Medical Physiology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 2. Dr. dr. Nury Nusdwinuringtyas, MEpid, SpKFR(K) Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 3. dr. Siti Annisa Nuhonni, SpKFR(K) Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 4. DR. dr. Tubagus Djumhana Atmakusuma, SpPD-KHOM Department of Internal Medicine, Hemology-Oncology Division, Cipto Mangunkusumo Hospital-Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 5. Prof. DR. Dr. R. Irawati Ismail, MEpid, SPKJ(K) Department of Psychiatry, Cipto Mangunkusumo Hospital-Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia 6. Tito R. Mendoza, PhD, MS, MEd Department of Symptom Research Division of Internal Medicine, The University of Texas, MD Anderson Cancer Center, Houston, Texas 7. Charles S. Cleeland, PhD Department of Symptom Research Division of Internal Medicine, The University of Texas, MD Anderson Cancer Center, Houston, Texas
AC C
EP
Contact person Nurul Paramita Komp. Bona Indah B3 No.25 Jakarta, Indonesia Phone number: +62217513456 Mobile phone number: +6281281839593 Email address: [email protected] List of Tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7.
Descriptive characteristics of study subjects Factor Analysis of Indonesian BFI (1 factor extraction) (n=121) Spearman’s rho coefficient correlation between Indonesian BFI with Indonesian MOS SF-36 subscales Mean rank Indonesian BFI score and ECOG-PS score Reliability with Cronbach’s Alpha and Alpha If Item Deleted Inter-item correlation coefficients for the nine items of the Indonesian BFI Descriptive Statistics of Indonesian BFI (n=121) 1
ACCEPTED MANUSCRIPT List of Figure Figure 1.
Plot of mean Indonesian BFI interference score against fatigue severity measured by “Worst Fatigue” on Indonesian BFI
RI PT
References
AC C
EP
TE D
M AN U
SC
1. World Health Organization. Cancer-Key facts. 2015. Available from: http://www.who.int./mediacentre/factsheets/fs297/en/. Accessed August 30, 2015. 2. Hofman M, Ryan JL, Figueroa-Moseley CD, Jean-Pierre P, Morrow GR. Cancer-related fatigue: the scale of the problem. Oncologist 2007;12 Suppl 1:4-10. 3. Yeh ET, Lau SC, Su WJ, et al. An examination of cancer-related fatigue through proposed diagnostic criteria in a sample of cancer patients in Taiwan. BMC Cancer 2011;11:387. 4. Wang XS. Pathophysiology of cancer-related fatigue. Clin J OncolNurs 2008;12(5 Suppl):11-20. 5. Gupta D, Lis CG, Grutsch JF. The relationship between cancer-related fatigue and patient satisfaction with quality of life in cancer. J Pain Symptom Manage 2007;34(1):40-47. 6. Mendoza TR, Wang XS, Cleeland CS, et al. The rapid assessment of fatigue severity in cancer patients: use of the Brief Fatigue Inventory. Cancer 1999;85(5):1186-1196. 7. Okuyama T, Wang XS, Akechi T, et al. Validation study of Japanese version of the brief fatigue inventory. J Pain Symptom Manage 2003;25(2):106-117. 8. Smets EM, Garssen B, Bonke B, De Haes JC. The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Pschosom Res 1995;39(3):315-325. 9. Yellen SB, Cella DF, Webster K, Blendowski C, Kaplan E. Measuring fatigue and other anemia-related symptoms with the Functional Assessment of Cancer Therapy (FACT) measurement system. J Pain Symptom Manage 1997;13(2):63-74. 10. Schwartz AL. The Schwartz Cancer Fatigue Scale: testing reliability and validity. OncolNurs Forum 1998;25(4):71-7. 11. 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(4):301-310. 12. Piper BF, Dibble SL, Dodd MJ, et al. The revised Piper Fatigue Scale: psychometric evaluation in women with breast cancer. OncolNurs Forum 1998;25(4):677-684. 13. Okuyama T, Akechi T, Kugaya A, et al. Development and validation of the cancer fatigue scale: a brief, three-dimensional, self-rating scale for assessment of fatigue in cancer patients. J Pain Symptom Manage 2000;19(1):5-14. 14. Yun YH, Wang XS, Lee JS, et al. Validation study of the korean version of the brief fatigue inventory. J Pain Symptom Manage 2005;29(2):165-172.
2
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
15. Wang XS, Hao XS, Wang Y, et al. Validation study of the Chinese version of the Brief Fatigue Inventory (BFI-C). J Pain Symptom Manage 2004;27(4):322-332. 16. Catania G, Bell C, Ottonelli S, et al. Cancer-related fatigue in Italian cancer patients: validation of the Italian version of the Brief Fatigue Inventory (BFI). Support Care Cancer 2013;21(2):413-419 17. Radbruch L, Sabatowski R, Elsner F, et al. Validation of the German version of the brief fatigue inventory. J Pain Symptom Manage 2003;25(5):449-458. 18. McHorney CA, Ware JE, Jr., Lu JF. Sherbourne CD. The MOS 36-item ShortForm Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Med Care 1994;32(1):40-66. 19. Perwitasari DA. Development the validation of Indonesian version of SF-36 questionnaire in cancer disease. Indonesian J Pharm 2012;23(4):248-253. 20. Perwitasari DA, Atthobari J, Dwiprahasto I, et al. Translation and validation of EORTC QLQ-C30 into Indonesian version for cancer patients in Indonesia. Jpn J ClinOncol 2011;41(4):519-529. 21. Oken MM, Creech RH, Tormey DC, et al. Toxicity and response criteria of the Eastern Cooperative Oncology Group. Am J Clin Oncol 1982;5(6):649655. 22. Taylor AE, Olver IN, Sivanthan T, Chi M, Purnell C. Observer error in grading performance status in cancer patients. Support Care Cancer 1999;7(5):332-335. 23. Roila F, Lupattelli M, Sassi M, et al. Intra and interobserver variability in cancer patients’ performance status assessed according to Karnofsky and ECOG scales. Ann Oncol 1991;2(6):437-439. 24. Test Reliability. 2006. Available from: http://www.proftesting.com/test_topics/pdfs/test_quality_reliability.pdf. Accessed June 27, 2014. 25. Streiner DL, Norman GR. Health Measurement Scales: A practical guide to their development and use, 3rd ed. New York: Oxford University Press, 2003. 26. Campos MP, Hassan BJ, Riechelmann R, Del Giglio A. Cancer-related fatigue: a review. Rev Assoc Med Bras 2011;57(2):211-219. 27. Vainio A, Auvinen A. Prevalence of symptoms among patients with advanced cancer: an international collaborative study. J Pain Symptom Manage 1996;12(1):3-10. 28. Teunissen SC, Wesker W, Kruitwagen C, de Haes HC, Voest EE, de Graeff A. Symptom prevalence in patients with incurable cancer: a systematic reveiw. J Pain Symptom Manage 2007;34(1):94-104.
3
ACCEPTED MANUSCRIPT Abstract
M AN U
SC
RI PT
CONTEXT. Cancer-related Fatigue (CRF) is one of the most commonly reported symptoms in cancer patients. Short but good assessment is essential to detect and manage this symptom. Brief Fatigue Inventory (BFI) is a valid and reliable short instrument to assess CRF. OBJECTIVES. To examine the validity and reliability of the Indonesian BFI. METHODS. Forward and backward translation approach, followed by cognitive debriefing process was done to develop Indonesian BFI. One hundred and twenty one consecutive adult outpatients with cancer who are willing to participate in this study filled in Indonesian BFI along with the Medical Outcome Study Quality of Life Short Form 36 (MOS SF-36). Demographic and health data were collected. RESULTS. The Indonesian BFI had an overall Cronbach alpha for the 9 items of 0.956. The results of the factor analysis suggested a 1-factor solution, supporting the hypothesis of unidimentionality of the Indonesian BFI. The Indonesian BFI score was compared to MOS SF-36 subscale to evaluate convergent validity. An expected inverse correlation between Indonesian BFI and all domains of MOS SF-36 was observed (r= -0.388 to -0.676; p<0.0000). Discriminant validity analysis showed the Indonesian BFI mean score significantly increased with increasing Eastern Cooperative Oncology Group Performace Status (ECOG-PS) values (p=0.000). CONCLUSIONS. Indonesian BFI is a reliable, valid instrument for Indonesian cancer patients. KEYWORDS: CRF; fatigue; assessment; validity; reliability; Indonesia
AC C
EP
TE D
Running Title: Validation Study of Indonesian BFI
4
ACCEPTED MANUSCRIPT Introduction Until now, cancer is still a health problem throughout the world. In 2012, worldwide, there were 14.1 million new cancer cases and 32.6 million people living with cancer (over 5 years of diagnosis).(1) Improved medical technology in terms of screening and treatment of cancer has increased the life expectancy of cancer patients.
RI PT
This situation led to increasing realization of various symptoms and problems that accompany cancer and its treatment. Fatigue is one of the most common symptoms complained by cancer patients. Fatigue is also the most common side effects arise on the treatment of cancer. In one of their study, Hoffman et.al find that 95 % of cancer
SC
patients are predicted to experience fatigue as a result of the chemotherapy or radiotherapy they received. Fatigue felt by the majority of patients with various types of cancer. Cancer-related fatigue (CRF) is one of the most disturbing complaints
M AN U
compared to various other complaints reported by patients.(2,3)
It is thought that CRF arising due to various factors. Several factors that had already been known to play a role in CRF include the cancer itself, cancer treatment, and chronic conditions such as anemia, pain, depression, anxiety, cachexia, sleep disturbance and immobilization.(4)
TE D
The impact of CRF on patient’s quality of life, particularly in relation to physical functioning and ability to perform daily activities is very real and substantial.(2,5) Given the magnitude of the impact of CRF in patients’ functional activity and fairly high frequency of CRF, researches on CRF continue to be developed. In order for
EP
CRF to be studied and managed effectively, a valid and reliable fatigue assessment tools is needed. CRF, like pain, is a subjective symptom, so the instrument that
AC C
assesses fatigue has to be based on the respective patient’s report. A good CRF assessment tools needs to allow for doctors and medical personnel to evaluate the symptoms of CRF without bias.(6,7) There have been many studies constructing an instrument to assess CRF, but until
now not a single instrument can be considered as the "gold standard" to measure CRF. Several CRF assessment tools have been developed in various countries around the world, in English language. Multidimensional Fatigue Inventory (MFI)(8), Functional Assesment of Cancer Therapy-Fatigue (FACT-F)(9), Schwartz Cancer Fatigue Scale (SCFS)(10), Fatigue Symptom Inventory (FSI)(11) and Piper Fatigue Scale (PFS)(12) are several examples of CRF assessment tools. The main characteristics of all of these 5
ACCEPTED MANUSCRIPT measuring tools are multidimensional. These tools usually consist of several subscales that allow evaluation of various aspects of fatigue and are especially useful in a descriptive study of fatigue. However, for patients with cancer who experience fatigue, multidimensional measurement tools are sometimes felt too long and too difficult for the patient to complete. Expressive description of the multidimensional
RI PT
measurement tools also led to a higher degree of difficulty in the process of translation into other languages.
Brief Fatigue Inventory (BFI) is a unidimensional questionnaire that was originally developed in the United States, to assess the level of fatigue in cancer patients. BFI
SC
consist of 3 questions that measure the severity of fatigue, and 6 questions to determine the impact of fatigue on daily activities. There are 3 important characteristics of this measure, which are: 1) short and easy to answer 2) easily
M AN U
translated into other languages, and 3) include interference (impact) assessment. Usually the term used to describe fatigue is often difficult to translate, but BFI conduct assessment of the intensity of fatigue and its impact on daily activities by using simple words. Selection of the numerical scale of 0-10 and not words to describe the level of fatigue also facilitate the process of translating the
TE D
questionnaire.(6,7)
BFI has been translated into various languages through the linguistic validation process. Some already test the psychometric properties of the BFI translations and the results already published in international journals.(13-17) All of validity and
EP
reliability tests of the translation had showed good results. There is an increasing need to assess the fatigue experienced by patients as a result
AC C
of cancer and its treatment in Indonesia, but no easily administered instrument has been available. The purpose of this study was to create an Indonesian version of the BFI for Indonesian cancer patients, and thus produce an instrument that is reliable and valid for use in future clinical trials assessing CRF in Indonesia. This study will be the foundation to evaluate the effectiveness of intervention strategies in reducing CRF and the impact it has on the patients’ daily functioning.
Methods Study Design This is a cross-sectional study, which involves the collection of data at one point in time. 6
ACCEPTED MANUSCRIPT Patients and Data Collection The subjects of this study were cancer patients at the outpatient clinics of the Dr. Cipto Mangunkusumo National Centre Hospital, Department of Internal Medicine, Hematology-Oncology Division, Indonesia. The study was conducted between November and December 2014. Subjects were recruited on specified days from all
RI PT
patients who met eligibility criteria using consecutive sampling method. Patients who met all the following inclusion criteria were considered eligible for this validation study: (1) a pathological diagnosis of cancer, (2) were older than 18 years, (3) gave their informed consent to participate, and (4) were able to understand and complete
SC
the questionnaires. The subjects were asked to complete the questionnaires either by self-administered or through an interview. The study was approved by the Institutional Review Board of the Dr. Cipto Mangunkusumo National Center Hospital
M AN U
and Faculty of Medicine, Universitas Indonesia. Each subject gave written consent after being fully informed with the study. Research staff collected patient data including age, gender, education, performance status and treatments received. The collection of data was taken in a comfortable and quiet room, apart from the waiting
Measurements
TE D
area, to provide comfort and privacy for the patients.
Brief Fatigue Inventory (BFI). The BFI was originally developed specifically to assess CRF. It is a brief questionnaire, which consists only 9 items, using numerical rating scale of 0 - 10. The first 3 items ask patients about their level of fatigue on 3
EP
occasions : right now; at its usual level within the past 24 hours; at its worst level within the past 24 hours − using extreme points “no fatigue” as “0” and “fatigue as
AC C
bad as you can imagine” as “10”. The next 6 items ask patients to describe how much fatigue has interfere with different aspects of their life within the past 24 hours. The aspects assessed are general activity, mood, walking ability, normal work (both work outside the home and daily chores), relations with other people, and enjoyment of life. These interference scales range from “0” as “does not interfere” and “10” as “completely interferes”. The global score for the BFI is the mean value of all these 9 items. The validity and reliability of the original BFI has been established.(6) Indonesian BFI. The Indonesian BFI was developed using the standard forwardbackward translation process according to the translation guidelines from University of Texas, M.D. Anderson Cancer Center. In the translation process, the original 7
ACCEPTED MANUSCRIPT English version of the BFI was first translated into Indonesian by two independent translators and then back-translated into English by another independent translator who had not seen the original English version. All the translators are Indonesian native who is fluent in English. Next, the English back-translated versions were compared with the originals. If a back-translated item did not agree with the original,
RI PT
the first two translators performed a second translations and the second two translators performed second back-translations. This process was repeated until agreement was reached. The final Indonesian version of the BFI was sent to the University of Texas, M.D. Anderson Cancer Center. After minimal changes, the center approved the
SC
Indonesian BFI. The process was then followed by the cognivitive debriefing process to 30 eligible cancer patients. The final revised version of the translation was adjusted in accordance to the result of cognitive debriefing interviews. The final revised
Center and was approved.
M AN U
version of the translation was sent to the University of Texas, M.D. Anderson Cancer
The medical outcome study quality of life SF36 (MOS SF-36). The MOS SF-36 is one of the most widely used health-related quality of life instruments. Thirty-six questions address 8 domains: physical functioning; social functioning; role limitation
TE D
due to physical problems; pain; vitality; role limitation due to emotional problems; mental health; and general health. The scores are transformed to a 0-100 scale with lower values representing a lower functioning level. The MOS SF-36 has been validated with internal consistency for each domain between 88 – 95%.(18)
EP
The MOS SF-36 has been translated into numerous languages, including Indonesian. Internal consistency of Indonesian MOS SF-36 showed Cronbach’s alpha
AC C
> 0.7 for physical functioning, social functioning, physical pain, role limitation due to physical problems and role limitation due to emotional problem.(19,20) The Eastern Cooperative Oncology Group performance status (ECOG-PS). The
ECOG-PS scale is rated on five levels from 0 -5. Level 0 indicates “fully active” to level 4 “cannot carry on any self-care” and completely bedridden, level 5 indicating “dead”. The ECOG-PS scale is used to assess how a patient’s disease is progressing, how the disease affect the patient’s ability to perform activities of daily living, and to determine appropriate treatment and prognosis.(21) The ECOG-PS is a well-accepted measure of a patient’s health status in clinical setting with good reliability and validity.(22,23) Patients’ performance status was clinically evaluated on the same day as assessment by attending oncologist. 8
ACCEPTED MANUSCRIPT Sociodemographic Information. The subject’s education level, age, sex, marital status and religion were obtained using a questionnaire. Clinical Data Checklist. Subject’s medical information was obtained by research staff members from their medical records and interview, which included cancer site and stage, presence of metastatic lesions, treatment status (including history of cancer
RI PT
treatment), performance status, prescribed medication, Visual Analog Scale for pain, and recent laboratory data. Statistical Analysis
The reliability and validity of Indonesian BFI was evaluated as follows. The
SC
reliability was evaluated by calculating the Cronbach’s alpha coefficient, which is a measure of the internal consistency of responses – the extent to which the scores of
M AN U
each item are correlated with the scores of all other items.(24) This coeficcient ranges from 0 to 1, with higher values indicating good reliability. A low alpha value suggest that some items either have very high variability or that the items are not all measuring the same thing. A value of 0.70 or greater is considered an adequate level of correlation between items. Factor analysis was used to determine the underlying construct and to test the hypothesis of unidimensionality of the Indonesian BFI, as
TE D
proposed by the original BFI validation. We examine whether Indonesian BFI reproduced the same factor loading pattern seen in the original scale, and the fit of the factor model was evaluated based on the results of the scree test, interpretability, and examinations of the residuals. Convergent validity – the extent to which an instrument
EP
is correlated with similar instrument(25) – was evaluated by calculating correlation coefficient between the Indonesian BFI and the MOS SF-36 subscale and global
AC C
health status. The hypothesis tested was that the Indonesian BFI overall score was more highly correlated with vitality domain score as compared to the others domain score. Discriminant validity – the extent to which a measure diverges from other measures from which it is theoretically distinct(25) – was examined using KruskalWallis test, to compare the Indonesian BFI mean rank scores in patients having different ECOG-PS; it was hypothesized that patients having poor performance status have an increased level of fatigue score. Statistical analysis was performed with the statistical package SPSS® version 22 (SPSS Inc., Chicago, IL)
9
ACCEPTED MANUSCRIPT Results Study Subjects Overall, 125 eligible patients were recruited. Four of these patients were excluded: 2 for refusal to participate, 2 for excessive illness. The remaining 121 patients agreed to participate in the study and completed the questionnaires. Of the 121 subjects,
RI PT
56.2% were female. The majority of subjects (39.7%) had primary education. Fifty five point four percent (55.4%) of the subjects had a good functional status (performance status of 0 and 1). The subjects were diagnosed with various types of cancer. The top 3 were nasopharyngeal carcinoma (25.6%), lymphoma maligna non
characteristics of the subjects are shown in Table 1.
SC
hodgkin (17.4%), and breast cancer (14%). The sociodemographic and clinical
We found that there were no missing responses to all the questions of the
M AN U
Indonesian BFI.
Psychometric properties of Indonesian BFI
Construction of Indonesian BFI was confirmed using factor analysis. The KMO measure of sampling adequacy is 0.909, showing that factor analysis can be used in
TE D
this group of data. Principal axis factor analysis with oblimin rotation supported the 1factor solution for all 9 items in the Indonesian BFI by model fitting and consideration of clinical interpretability. The eigenvalue was 6.731 for the first factor, followed by 0.58 and 0.51 for the second and the third factor. The first factor explained 76% of the
EP
variability in the data. The eigenvalues and amount of explained variability shows that most of the data can be explained by a single construct. A scree plot also identified 1
AC C
construct to explain the majority of variance. The factor loadings in each group were equally high, ranging from 0.648 to 0.837 as can be seen in Table 2. This patterns of factor loadings indicated the association of the 9 items with a single factor. Because the Indonesian BFI measures a single construct, the mean of the 9 Indonesian BFI items can be used as a global Indonesian BFI score. Convergent validity was demonstrated by calculating correlation coefficient between the Indonesian BFI score and the MOS SF-36 subscale and global health status. An expected inverse correlation was observed between the Indonesian BFI mean score and the vitality subscale of the MOS SF-36 (r=-0.676, p<0.000). The correlation with the other subscales of the MOS S-F36 ranged between -0.388 and 10
ACCEPTED MANUSCRIPT 0.623 (Table 3). The results supported the hypothesis that the Indonesian BFI scales would correlate significantly with the fatigue-related constructs of the MOS SF-36. The discriminant validity was assessed using Kruskal-Wallis test, to compare the Indonesian-BFI mean rank scores in patients having different ECOG performance statuses. An expected increase in BFI mean rank scores with an increase in ECOG –
RI PT
PS score was observed. (Table 4 ). To measure the reliability of the Indonesian BFI, we measure the internal consistency of the instrument. Cronbach’s alpha was calculated for the 9 items in the scale. The overall alpha was 0.956. The fact that the reliability coefficient of the scale
SC
is high emphasized the increased internal consistency and reliability of the scale. The alpha coefficient if item deleted was also measured to determine how each item individually contributes to the reliability of the questionnaire. The result shows that
M AN U
all of the items have similar strong contribution to the overall Cronbach’s alpha coefficient (Table 5). The inter-item mean correlation was 0.715, and coefficients correlation ranged from 0.570 – 0.886 for the 9 items of the Indonesian BFI (Table 6). Prevalence and Severity of Fatigue
TE D
The current study showed that 64.5% of the subjects was feeling unusual fatigue (Table 1). The mean of the 9 Indonesian BFI items is 3.61+2.75 and the mean of “fatigue at its worst” is 4.93+ 3.11 with mode value is 8 (Table 7). Figure 1 shows the relationship between Indonesian BFI mean of the 6 interference items and the worst
EP
fatigue. The slope in the graph illustrates the steep increases in interference with increases in fatigue level.
AC C
Discussion
CRF is increasingly recognized as a considerable issue for cancer patients and
health-care providers, yet there is still no universally accepted standard for measurement of CRF. Consequently, it is frequently underdiagnosed and under assessed, and not treated properly. Several problems in the management of CRF are known to be associated with patients, health-care providers and health systems. Clinical intervention model programs aiming to eliminate these problems have already been developed in some countries. Good assessment tools to identified CRF is one of the key component in the programs. In this study, we developed and validated an Indonesian version of the 11
ACCEPTED MANUSCRIPT BFI, one of the tools to assess CRF. We were not only investigated the reliability and validity of the Indonesian BFI, but we also generated a CRF profile based on responses from the subjects. The current study demostrates that the Indonesian BFI is an excellent assessment tool for use in both research and clinical fields. The small number of items, using
RI PT
straighforward sentences that is easily understood, and using numerical rating scale that is easy for patients to use, has made the subjects to be able to complete the instrument in an average of 5 minutes, and the longest was 10 minutes. It proves that this instrument is suitable enough (will not overly tiring) for fatigue cancer patients to
SC
complete. All of the subjects in this study able to complete the questionnaire. Forty nine subjects (40%) completed the questionnaire through an interview instead of filling the questionnaire by themselves. We can not rule out the education level as the
M AN U
cause because only around half of the subjects surpass the secondary education. We do not think the functional status to be the main reason because 81% of the subjects had good functional status. This result should be of particular attention in the subsequent studies, but the fact that they still could complete the instrument, whether by themselves or through an interview, had proved that Indonesian BFI can be used
TE D
for patients of all education level and social statuses.
As seen in the original version, the result of this study support the Indonesian BFI as a valid and reliable tool for measuring CRF in cancer patients. The factor solution for the Indonesian BFI produced one factor with an eigenvalue over one; all items
EP
loaded on a single factor. The high scores highlighted by factor analysis indicated the association of 9 Indonesian BFI items that can be used as a global Indonesian BFI
AC C
score.
As seen in the original version(6), Japanese(7), Korean(14), Taiwanese(15),
Italian(16) and German(17) BFI validation studies, most of our study subjects had a good performance status. Subjects in our study were outpatients which may have influenced both the score of the subject’s fatigue perception and the validation result. Because only 5 subjects had an ECOG-PS 4, it was not possible to correlate the BFI mean scores with the performance status of the subjects. However, the increase of the Indonesian BFI scores with the worsening of performance status was a significant discriminant validity. The subjects in this study relate fatigue more with the vitality subscales of the MOS SF-36 than with other subscales. This result is similar to the Italian and German 12
ACCEPTED MANUSCRIPT version of BFI.(16,17) This result shows that, as expected, the Indonesian BFI captures the fatigue dimension included in the vitality subscale of the MOS SF-36. The Cronbach’s alpha coefficient and inter-item correlation coefficient were high, indicating good internal consistency of this questionnaire. The current study shows that fatigue was highly prevalent in the Indonesian cancer
RI PT
patients (64.5% of the subjects was feeling unusual fatigue). This finding is consistent with results from other studies that show the prevalence of CRF between 50 – 90%.(26-28)
The mean total score of Indonesian BFI is 3.61+2.75. This value is lower than the
SC
value obtained in validity study of the original BFI by Mendoza TR, et al. (4.7+2.8); German version by Radbruch L, et al. (4.5+2.1); and Korean version by Yun YH, et al. (4.7 for severity of fatigue composite and 4.3 for effect of fatigue composite);
M AN U
which conducted the study in both outpatients and hospitalized patients.(6,14,17) Approximately the same value obtained in validity study of the Japanese version of the BFI by Okuyama T, et al. (3.1+2.4) and the Italian version by Catania G, et al. (3.8+2.4), which also conducted the study on only outpatients.(7,16) Further studies in Indonesian hospitalized cancer patients can reveal more about the fatigue profile in
TE D
Indonesia’s cancer population.
One interesting finding is that the mode value is much higher in the item "worst fatigue" compared with the “fatigue right now” and the “average fatigue (8, 0 and 3, respectively) as seen in Table 7. This shows a very fluctuating nature of fatigue, even
EP
within 24 hours. Further research is needed to explore factors that contribute to the fluctuating nature of fatigue and its effects on physical functioning.
AC C
According to the fatigue classification described in the original BFI study, fatigue can be categorized as not severe (BFI score <7) and severe (BFI score 7-10). Based on this classification, 17.4% of the subjects in this study had severe fatigue. Moreover, 19% of the subjects experienced limited functional performance (measured using ECOG-PS scale). Given this study subjects were outpatients, these results reveal that fatigue is a critical problem even in ambulatory patients with cancer, and it should be explored and treated comprehensively. Further study will be needed to explore the prevalence and severity of fatigue in hospitalized Indonesian cancer patients. Subjects of this study experienced more severe interference for higher fatigue level. To improve the management of fatigue, health care professional working in oncology should be familiar with patients who are disabled by their fatigue. Further 13
ACCEPTED MANUSCRIPT studies are needed to explore factors related to fatigue, which type of cancer or cancer treatments causes fatigue and to evaluate the effectiveness of different therapeutic regimens or to compare the side effect of different drugs. This study had 3 major limitations. First, we did not do a test-retest reliability procedure. Second, this is a cross-sectional study and we did not measure fatigue over
RI PT
time. Therfore, the responsiveness to change of the Indonesian BFI could not be estimated. Future studies with longitudinal design can help to further evaluate the Indonesian BFI’s responsiveness and test-retest reliability. Third, this study did not have a control group to differentiate between severity of CRF and typical fatigue in
SC
Indonesian general population. Future large-scale epidemiology studies using Indonesian BFI across diseases and age groups of Indonesian population could provide more data on the nature of fatigue.
M AN U
In conclusion, the results from this study are consistent with the other BFI validation studies that support the use of Indonesian BFI as a valid and reliable tool for measuring fatigue in Indonesian cancer population. The Indonesian BFI could become a good and valid tool for further study of fatigue etiology, pathophysiology and managements trials. In addition, because the BFI has been translated into many
TE D
other languages, the use of Indonesian BFI can simplify fatigue epidemiology and etiology study comparisons between countries. Acknowledgments
AC C
EP
We would like to thank the patients who cooperated so willingly.
14
ACCEPTED MANUSCRIPT Table 1 Descriptive characteristics of study subjects Sample size, n=121 51; 20 - 73 53 (43.8%) 68 (56.2%)
RI PT
8 (6.6%) 48 (39.7%) 38 (31.4%) 27 (22.3%)
SC
31 (25.6%) 21 (17.4%) 17 (14%) 16 (13.2%) 36 (29.8%)
AC C
EP
TE D
M AN U
Characteristics Median age; range Sex - Male - Female Education - Do not go to school/do not finish elementary school - Primary Education - Secondary Education - Higher Education Types of cancer - Nasopharyngeal Carcinoma - Lymphoma Maligna Non Hodgkin - Breast Cancer - Cervical Cancer - Other Cancer Staging - Already staged - Staging I - Staging II - Staging III - Staging IV - Not yet staged Feeling Unusual Fatigue - Yes - No ECOG-PS score - 0 : fully active - 1 : Restricted but ambulatory - 2 : Ambulatory; capable of self-care - 3 : Capable of only limited self care - 4 : Completely disabled Mean MOS SF-36 (Mean; SD) - Mental Component Summary - Physical Component Summary BFI Score (Mean; SD) Level of fatigue - Not Severe ( BFI mean score < 7) - Severe (BFI mean score >7)
1
96 (79.3%) 4 (4.2%) 20 (20.9%) 26 (27%) 46 (47.9%) 25 (20.7%) 78 (64.5%) 43 (35.5%)
30 (24.8%) 37 (30.6%) 31 (25.6%) 18 (14.9%) 5 (4.1%)
49.78 ; 11.86 36.05 ; 9.99 (3.61 ; 2.75) 100 (82.6%) 21 (17.4%)
ACCEPTED MANUSCRIPT
Table 2 Factor Analysis of Indonesian BFI (1 factor extraction) (n=121) Factor analysis factor 1 0.802
Usual fatigue
0.801
Worst fatigue
0.805
Activity
0.837
Mood
0.684
Walking
0.648
Working
0.734
Relation to others
0.675
Enjoyment of life
0.744
M AN U
SC
Fatigue right now
RI PT
BFI items
Table 3 Spearman’s rho coefficient correlation between Indonesian BFI with Indonesian MOS SF-36 subscales Indonesian BFI
< 0.000
Role-Physical Limitation
- 0.547
< 0.000
Bodily Pain
- 0.538
< 0.000
- 0.491
< 0.000
Vitality
- 0.676
< 0.000
Social Functioning
- 0.521
< 0.000
Role-Emotional Limitation
- 0.388
< 0.000
Mental Health
- 0.528
< 0.000
Physical Component Summary
- 0.623
< 0.000
Mental Component Summary
- 0.491
< 0.000
TE D
Spearman’s rho coefficient correlation - 0.588
Physical Functioning
AC C
EP
General Health
2
P
ACCEPTED MANUSCRIPT Table 4 Mean rank Indonesian BFI score and ECOG-PS score Subjects 30 37 31 18 5
BFI mean rank 43.73 49.80 68.37 88.33 103.40
RI PT
ECOG-PS 0 1 2 3 4
Table 5 Reliability with Cronbach’s Alpha and Alpha If Item Deleted
SC
Subjects (n = 121) 0.956
Alpha Alpha if item deleted
Usual Fatigue Worst Fatigue Activity Mood Walking
TE D
Working
0.950
M AN U
Fatigue right now
0.950 0.949 0.948 0.953 0.954 0.951 0.953
Enjoyment of life
0.951
AC C
EP
Relation to others
3
ACCEPTED MANUSCRIPT
2
3
A
B
C
D
E
F
1
1.000
-
-
-
-
-
-
-
-
2
0.886
1.000
-
-
-
-
-
-
-
3
0.869
0.863
1.000
-
-
-
-
-
-
A
0.764
0.819
0.806
1.000
-
-
-
-
-
B
0.719
0.707
0.670
0.711
1.000
-
-
-
-
C
0.682
0.617
0.714
0.697
0.570
1.000
-
-
-
D
0.716
0.680
0.695
0.823
0.642
0.733
1.000
-
-
E
0.632
0.688
0.665
0.715
0.655
0.604
0.672
1.000
F
0.676
0.677
0.678
0.764
0.772
0.669
0.710
0.780
M AN U
1= fatigue right now 2= usual fatigue 3= worst fatigue
RI PT
1
SC
Table 6 Inter-item correlation coefficients for the nine items of the Indonesian BFI
A=general activity B=mood C=walking ability
1.000
D=normal work E=relation to others F=enjoyment of life
TE D
Table 7 Descriptive Statistics of Indonesian BFI (n=121) Minimum
Fatigue right now
Maximum Mode Mean
Std. Deviation
0
10
0
3.85
2.96
0
10
3
3.70
2.66
0
10
8
4.93
3.11
0
10
0
3.81
3.29
0
10
0
2.95
3.18
0
10
0
3.33
3.33
Working
0
10
0
3.99
3.47
Relation to others
0
10
0
2.91
3.35
Enjoyment of life
0
10
0
3.02
3.30
BFI total score
0
10
0
3.61
2.75
Usual fatigue
Activity Mood
AC C
Walking
EP
Worst fatigue
4
SC
RI PT
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
Figure 1. Plot of mean Indonesian BFI interference score against fatigue severity measured by “Worst Fatigue” on Indonesian BFI.
1