Measurement instruments are utilized in quantitative research for the purposes of quantifying constructs, which lead to answering of research questions. Researchers know that inappropriate measures can lead to inaccurate data (DeVillis, 2011). As such, evaluation of measurements is essential. Although it might be time consuming, evaluation helps to prevent problems and errors that could result from the selection and use of inappropriate or psychometrically inadequate measures. (Waltz, Strickland, and Lenz, 2010). Therefore, the purpose of this paper is to analyze and critique the Multidimensional Fatigue Symptom inventory- Short Form (MFSI-SF), which is one of the instruments that measure fatigue. The MFSI-SF will be analyzed using the evaluation process provided in Waltz, Strickland, and Lenz (2010).
The Purpose and Stated Aim
The MFSI-SF was originally designed to measure fatigue symptoms in cancer patients (Stein, Martin, Hann, & Jacobsen, 1998). The MFSI- SF is useful when it comes to identifying patterns of fatigue within individual patients and across treatment modalities. Additionally, the measurement allows clinicians to develop, implement, and evaluate interventions that are targeted for different patterns of fatigue (Stein et al., 1998; Stein et al., 2004).
Development Procedures
A pool of 83 items describing the multidimensional nature of fatigue was generated to assess the principal manifestations of fatigue. These were based upon a review of the literature on cancer- related fatigue, discussions with treatment providers, and a survey of available measures of fatigue. The MFSI-SF consists of two subscales:
- The rationally derived subscales, which were developed based on experts’ assignment to categories. They are also designed to assess global, somatic, affective, cognitive, and behavioral manifestations of fatigue (Stein et al., 1998). The authors generated a first version that was distributed based on the validation of 15 breast cancer patients, 10 female friends, and relatives of breast cancer patients. Their feedback was taken into consideration, several were rewarded, and others were added accordingly. Generally, the patients felt that the MFSI-SF captured their experience of fatigue (Stein et al., 1998).
- The empirically derived subscales of MFSI-SF. These consist of 30-item short-form of the MFSI. The empirically derived subscales were developed using Exploratory Factor Analysis (EFA), which was used to reduce the pool of 83 items to a total of 30 items that produced five empirically derived subscales namely, general fatigue, physical fatigue, emotional fatigue, mental fatigue, and vigor (Stein et al., 1998). A panel of five judges assigned each item to one of the five dimensions to develop the MFSI-SF. This panel consisted of psychologists, nurses, and social workers (Stein et al., 1998).
History and Revisions
The original MFSI was developed by Stein et al., (1998). The purpose was to develop and validate a multidimensional measure of fatigue for use with cancer patients. The instrument was administered on three occasions to 275 women who had received or were undergoing treatment for breast cancer, and 70 women with no history of cancer. The results supported the validity of both the rationally and empirically derived scales. Concurrent validity was evaluated by computing correlations between MFSI and two established measures of fatigue such as the Profile of Mood States (POMS-F) and the Vitality subscale of the SF-36 Health Survey (SF-36 vitality scale)( Stein et al., 1998).
Results revealed moderate to high correlations, suggesting that the rationally and empirically derived scales measured constructs similar to those measured by the POMS-F and the SF-36. Convergent validity was evaluated by computing correlations between MFSI and measures of constructs related to fatigue such as the State Trait Anxiety Inventory (STAI) and the Center for Epidemiologic Studies Depression Scale (CES-D). There were significant positive correlations between both rationally and empirically derived MFSI scales, as well as, measures of anxiety and depression (Stein et al., 1998).
Furthermore, divergent validity was examined by computing the correlation between MFSI and Marlow-Crowne Social Desirability Scale (MC-20). However, the correlations were low, although, statistically significant. The researchers attributed that by the large sample size (Stein et al., 1998). Reliability of the rationally and the 5 empirically derived scales was excellent where alpha coefficients ranged from 0.87 to 0.96 (Stein et al., 1998).
The MFSI-SF was further validated by Stein et al. (2004). This was by the application of confirmatory factor analysis to evaluate the stability of the 5-factor structure of the MFSI-SF in a new sample of cancer patients. Additionally, they provided additional information regarding the reliability and validity of the MFSI-SF, and examined the performance of the MFSI-SF with a heterogeneous sample in terms of cancer type and gender different from the original validation sample. The sample consisted of 304 participants, the age mean was 54.9, and 80% of the sample were women. A range of cancer diagnoses was sampled to allow for heterogeneity in terms of cancer type; lung cancer (17%), ovarian cancer (7%), colon cancer (4%), lymphoma (3%), prostate cancer (2%), and endometrial cancer (2%) (Stein et al., 2004).
Construct validity was evaluated through comparisons of the MFSI-SF with other instruments administered. More specifically, concurrent validity was examined by computing correlations between the MFSI-SF and two established measures of fatigue, which are the Fatigue Symptom Inventory FSI (average fatigue severity rating) and the SF-36 Vitality Scale score. Results demonstrated moderate to high correlations, indicating that the five empirically- derived subscales measured constructs similar to those measured by FSI and the SF-36 Vitality Scale (Stein et al., 2004).
As for convergent validity, it was examined by computing correlations between the MFSI-SF and the SF-36 Physical Composite Score, a measure of physical health. Results demonstrated that, as expected, the correlations were in the moderate range but somehow lower than the correlations between the MFSI-SF and other measures of fatigue. The only exception to this pattern was the MFSI-SF Physical Fatigue Score, which, not surprisingly, yielded correlations with the SF- 36 Physical Component Score similar to this with other measures of fatigue (Stein et al., 2004).
The reliability of the MFSI-SF was evaluated by computing the internal consistency of each of the five empirically derived subscales. Alpha coefficients for the five subscales ranged from 0.87 to 0.96, all within acceptable limits (Stein et al., 2004). Reliability findings were consistent with previous estimates of internal consistency reported in the original validation study Stein et al. (1998). However, for the purposes of this paper, the MFSI-SF is what is critiqued in this paper.
Measurement Framework
The scoring Key for the MFSI-SF indicated that it is a norm-referenced measure. Norm-referenced measurements lack a threshold and they are designed to evaluate individual performance relative to the performance of a representative group (DeVellis, 2011).
Population, Setting, and Time Perspective
The MSFI-SF was developed to measure fatigue in cancer patients (breast cancer, gynecological cancer) and non-cancer patients. The results demonstrated that the MFSI-SF is sensitive to differences in fatigue between cancer patients and non-cancer controls. The MFSI-SF was translated to Spanish and Chinese (MFSI-SF-C). An examination of the psychometric properties of MFSI-SF-C was reported in the literature. However, the Spanish version was not reported. Pien et al. (2011) examined the psychometric properties of the Chinese version of the MFSI-SF-C for use in Chinese population. They compared cancer patients with people in the community and showed that the MFSI- SF-C had a well discriminating ability. In addition, it can be used to differentiate fatigue levels and fatigue dimensions among healthy and ill groups. Reliability was assessed by alpha coefficients for the subscales, which were all within acceptable limits, ranging from 0.83 to 0.84 Cronbach’s alpha of the Total measure 0.90. The Content validity index was 0.93. As for convergent validity, results indicated good convergent validity when comparing fatigue with depression and quality of life. In conclusion, the results revealed adequate internal consistency, appropriate content validity, and construct validity. These evidences of reliability and validity support the use of the Chinese version of the MFSI-SF as a measurement of fatigue in Chinese populations.
The MFSI-SF is a self-report instrument that is designed for use in a wide variety of settings, both the outpatient and inpatient. The time orientation for the instrument requires a recall time of one week (7-days). The instructions are concise, clear and indicate the period this tool is in use. The Completion time is 5 minutes, while the MFSI takes about 10 minutes to complete. Therefore, it is a suitable substitute for the MFSI when time constraints and scale length are of concern (Stein et al., 1998; Stein et al., 2004). However, recall time would only be a problem with geriatric patients and those memory deficits, or patients with decreased mental capacities.
Conceptual Basis
The theory base for this measurement is unspecified. However, there is correspondence between concepts and subscales. The researched indicated that fatigue could be manifested in a wide range of symptom domains. These included behavioral, cognitive, somatic, and affective. An advantage of the MFSI-SF is that it captures the full spectrum of the fatigue symptom profile and assesses a wider range of domains in which fatigue may be manifest (Stein et al., 1998; Stein et al., 2004).
Scoring
MFSI-SF is a 30-item self-report measure designed to assess the multidimensional nature of fatigue. The MFSI-SF consists of five subscales for different dimensions of fatigue and each subscale includes six items which are rated on a 5-point scale indicating how true the statement was during the last week (0 5 not at all, 4 =extremely). The General Fatigue subscale describes the experience of fatigue in a broad way. Emotional Fatigue pertains to affective symptoms. Physical Fatigue encompasses somatic symptoms. Mental Fatigue concerns cognitive symptoms.
Finally, the Vigor subscale includes items describing energy level. A total score is calculated by adding general, physical, emotional and mental fatigue together minus the vigor score (Stein et al., 1998; Stein et al., 2004). The range of scores for each subscale ranges from zero to 24, and for the MFSI-SF total fatigue score ranges from −24 to 96. Although, the MFSI-SF does not report cut-off scores for defining fatigue, MFSI-SF total scores > 0.85 are considered a significant indicator of fatigue. Additionally, a higher score means increased fatigue, except for the Vigor subscale, where a higher score means less fatigue (Stein et al., 1998; Stein et al., 2004).
Reference List
DeVellis, R. F. (2011). Scale development: Theory and applications. London: SAGE.
Pien, L., Chu, H., Chen, W., Chang, Y., Liao, Y., Chen, C., & Chou, K. (2011). Reliability and validity of a Chinese version of the multidimensional fatigue symptom inventory-short form (MFSI-SF-C). Journal of Clinical Nursing, 20(15), 2224-2232.
Stein, K. D., Martin, S. C., Hann, D. M., & Jacobsen, P. B. (1998). A multidimensional measure of fatigue for use with cancer patients. Cancer Practice, 6. 3, 143-152.
Stein, K. D., Jacobsen, P. B., Blanchard, C. M., Thors, C. T. (2004). Further validation of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF). Journal of Pain and Symptom Management, 27, 14-23.
Waltz, C., Strickland, O., & Lenz, E. (2010). Measurement in Nursing and Health Research. New York, NY: Springer Publishing Company.