SciELO - Scientific Electronic Library Online

 
vol.16 issue46Characterization of patients with an ileostomy that are treated on a reference service for patients with an ostomyFactors associated with condom use among young men who have sex with men author indexsubject indexarticles search
Home Pagealphabetic serial listing  

My SciELO

Services on Demand

Journal

Article

Indicators

Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google

Share


Enfermería Global

On-line version ISSN 1695-6141

Enferm. glob. vol.16 n.46 Murcia Apr. 2017  Epub Apr 01, 2017

http://dx.doi.org/10.6018/eglobal.16.2.255821 

Originales

Factorial structure and internal consistency of the Fatigue Severity Scale in Colombian population with chronic diseases

Liliana Bernal-Vargas1  , Fernando Riveros-Munévar2  , Stefano Vinaccia-Alpi3  , Japcy-Margarita Quiceno-Sierra4 

1Universidad Cooperativa de Colombia, Villavicencio. Colombia. E-mail: liliana_bernal1@hotmail.com

2Universidad de San Buenaventura, Bogotá. Colombia

3Fundación Universitaria Sanitas, Bogotá. Colombia

4Universidad de Medellín, Colombia.

ABSTRACT

The present study has a psychometric design, with the objective of analyzing the factorial structure and the internal consistency for the Spanish version of the Fatigue Severity Scale (FSS) Questionnaire for Colombian population with chronic disease. Was applied the questionnaire to 52 people with chronic disease in Villavicencio city. The factorial Analysis indicates three factors: Factor 1 named physical affectation, Factor 2 named social affectation and Factor 3 named motivational affectation of the fatigue, where they explain the 76.324% of the total cumulative variance with .870 of Cronbach’s Alpha. The results present a high reliability and concordance for the factorial structure with the original version which indicates an adequate validity of the test for Colombian population with chronic disease.

Keywords: Fatigue; Fatigue Severity Scale (FSS); Colombia; Chronic disease people

INTRODUCTION

Fatigue can be defined as a subjective feeling a lack of physical and mental energy perceived by a person and interferes with the daily activities 1. Fatigue is a disabling symptom. Often co-varies with depression, anxiety and sleep deprivation symptoms and is associated with the poor state of subjective health perception and a low quality of life 1)(2)(3. There are not enough fatigue prevalence studies in the human population. But it has been found that women present 2 to 3 times more fatigue complaints than men, that occurs at all ages except for adolescence, that most chronic diseases have at some point in their development fatigue for sufferers and that various psychiatric disorders are associated with fatigue. 4

On the other hand, a large number of instruments have been developed to measure fatigue, see, among others, the Fatigue Severity Scale (FSS), the Brief Fatigue Inventory (BFI), the Fatigue Impact Scale (FIS) and the Multidimensional Fatigue Inventory (MFI-20) of which there is also a Colombian version validated with the general population 5)(6. The Fatigue Severity Scale (FSS) was designed by Krupp et al. 7 for the evaluation of this symptom in neurology. It has been validated psychometrically in different countries of the world, while major studies have been conducted in patients with diseases such as multiple sclerosis, systemic lupus erythematosus, poliomyelitis, hepatitis C, COPD, chronic pain, obesity, kidney failure among others 8)(9. The FSS scale has been validated in Latin America only in Brazil and there aren’t analyzed versions psychometrically in Spanish language. 10

Therefore, the purpose of this paper was to assess factorial structure and the reliability of the Fatigue Severity Scale (FSS) in Colombian patients with a diagnosis of chronic disease.

METHODS

Design

This is a cross-sectional study, with a descriptive scope and instrumental type. 11

Participants

52 persons with confirmatory medical diagnoses of chronic diseases (Hypertension, HIV, Myasthenia Gravis, Hemophilia, Lupus, Type 2 Diabetes and Cancer) with an illness time between 3 months to 14 years.

Instruments

The Fatigue Severity Scale was designed by Krupp et al. (7). Consist of 9 items with Likert response with 7 possibilities of increasing intensity and that score between 1 and 7. The total is the sum of all the items. This study use the Spanish version translated by Bulbena et al. 12.

Procedure

Before starting with the fieldwork phase of the research which involved the application of the Fatigue Severity Scale (FSS) questionnaire, the cultural evaluation of the instrument was carried out according to the Alexandre and Guirardello criteria 13. The cultural adaptation work consisted of applying the Fatigue Severity Scale questionnaire to a group of 10 chronic patients of both sexes. These after answering the questionnaire were interviewed to identify words or questions of difficult comprehension, evaluate the acceptability and to make general comments, also registering the necessary time to complete and comprehend the answering system for each item on the questionnaire. There were no major difficulties to justify changes, the patients reported understanding and comprehension of the items in all the psychometric instruments evaluated. After signing the informed consent was proceeded to perform the scale application to the participants. The obtained data was analyzed using the statistical package SPSS version 19.

RESULTS

In order to stablish if the sample size was sufficient to the factorial analysis, the Kaise-Mayer-Olkin statistics and the Bartlett’s sphericity test were generated. (Table 1)

Table 1 Kaiser - Meyer - Olkin (KMO) Index and Bartlett’s sphericity test. 

The data displayed in the Table 1 shows that there are enough participants to perform the factorial analysis. Therefore, the extraction of principal components with Varimax Rotation was performed, presenting on the first place the factorial loading for each reactant (Table 2) to determine if are eliminated or remain the same.

Table 2 Factor Loading for each reactant. 

Reactive Extraction
Fatigue1 ,891
Fatigue2 ,468
Fatigue3 ,734
Fatigue4 ,886
Fatigue5 ,707
Fatigue6 ,705
Fatigue7 ,885
Fatigue8 ,736
Fatigue9 ,858

Table 2 presents that all the factors in the scale have enough extraction (more than 0.3) to keep them all. Thus, determining the number of factors that are part of the scale of the applied sample (Table 3).

Table 3 Factor extraction of the Fatigue Severity Scale. 

Sum of square saturations of rotation
Component Total % of variance % accumulated
1 3,051 33,904 33,904
2 2,600 28,885 62,789
3 1,218 13,535 76,324

The results (Table 3) show that the 76.324% is explained in 3 factors of the total cumulative variance. With this number of factors, was proceeding to obtain the reactants to each factor. Table 4

Table 4 Reactants belonging to each factor. 

Ítem Component
1 2 3
Fatigue1 ,926
Fatigue2 ,674
Fatigue3 ,800
Fatigue4 ,910
Fatigue5 ,727
Fatigue6 ,627
Fatigue7 ,920
Fatigue8 ,725
Fatigue9 ,895

Note a: Principal components extraction, with Varimax rotation.

Note b: The rotation converged in 4 interactions.

The previous table presents that component 1 named as physical affectation of the fatigue consists of the reactant 2, 3, 4, 5, and 6, Component 2 named as social affectation of the fatigue consist of the reactant 7, 8, and 9, the third factor consists of item 1 named motivational affectation of the fatigue. Finally, on what implies to reliability, the data show a Cronbach’s Alpha of .870, and the internal consistency Analysis was conducted based on the inter element correlations and the corrected correlation analysis of the total elements (Table 5), where positive correlation between all reactants were found, as well as positive correlation over .30 in all the reactants of the scale facing the total score of the scale.

Table 5 Item correlations and total corrected correlation. 

Fatigue1 Fatigue2 Fatigue3 Fatigue4 Fatigue5 Fatigue6 Fatigue7 Fatigue8 Fatigue9 Correlation element-total corrected
Fatigue1 1,000 ,157 ,297 ,183 ,086 ,368 ,123 ,339 ,300 ,316
Fatigue2 --- 1,000 ,434 ,534 ,291 ,411 ,266 ,232 ,189 ,440
Fatigue3 --- --- 1,000 ,712 ,594 ,600 ,219 ,482 ,408 ,678
Fatigue4 --- --- --- 1,000 ,724 ,703 ,399 ,557 ,270 ,746
Fatigue5 --- --- --- --- 1,000 ,424 ,455 ,473 ,336 ,607
Fatigue6 --- --- --- --- --- 1,000 ,472 ,617 ,485 ,744
Fatigue7 --- --- --- --- --- --- 1,000 ,635 ,800 ,595
Fatigue8 --- --- --- --- --- --- --- 1,000 ,642 ,718
Fatigue9 --- --- --- --- --- --- --- --- 1,000 ,605

DISCUSSION

The fatigue is a feeling that can generate serious adaptative problematics both in the daily life as in clinical contexts, the reason why several studies 1)(2)(3)(4)(8)(9 highlight the need of evaluation. Against the scale, it is important to note that despite the fact that FSS has been widely used in the world, not enough studies have been done concerning its structure factor, by which is expected an important contribution through this research on how this test behaves on a psyhometric level.

Indeed, the present study examined the psychometric properties of the FSS questionnaire in a Colombian sample with a diagnosis of chronic disease. The results present a three factor scale: the factor 1 can be named as physical affectation, and contains the reactants 2, 3, 4, 5 and 6, the factor 2 known as social affectation and has the reactants 7, 8 and 9, and finally the factor 3 is composed by only the reactant 1 and evaluates the motivational affectation of the fatigue. Equally, the scale shows a proper index of internal consistency, appropriate correlations between corrected total element, as well as positive correlations between all the reactants.

The results found in the present research suggest that the scale can be used in Colombian population with chronic diseases, while the scale shows 3 factors with appropriate theoretical congruence with the reactants, and internally, show high data of reliability and internal consistency.

The above results are related to various studies developed in the validated FSS questionnaire with samples of people with chronic disease, see, among others, chronic hepatitis 8, stroke 14, COPD 10, fibromyalgia 15, however, none of those found in the review, carried out the factorial analysis of the scale, which may make this study a pioneer on the factor validity of this scale for Spanish language, to serve as a guide to continue in this fatigue research line with chronic patients.

In this research, there are certain limitations, therefore, the results may not be generalized without precautions given the sample size and that it was composed only by chronically ill. It would be important to analyze it for example with the general population.

CONCLUSIONS

The present study has been the first in Spanish language reporting the psychometric properties of the FSS, questionnaire that has been use abundantly in Ibero-America only based on the Spanish translation. The Colombian psychometric analysis of the FSS is the first step for future studies to know the validity and reliability of this instrument in population samples with and without chronic disease diagnosis.

REFERENCIAS

1. Font E, Rodriguez E, Buscemi V. Fatiga, expectativas y calidad de vida en cáncer. Psicooncologia. 2004; 1(2): 45-56. [ Links ]

2. Johansson S, Ytterberg C, Hillert J, Widen Holmqvist L, Von Koch LA. A longitudinal study of variations in and predictors of fatigue in multiple sclerosis. J Neurol Neurosurg Psychiatry. 2008; 79:454-457. [ Links ]

3. Stanton BR, Barnes F, Silber E. Sleep and fatigue in multiple sclerosis. Mult Scler. 2006; (12):481-486. [ Links ]

4. Lewis G, Wesseley S. The Epidemiology of fatigue: More questions than Answers. J Epidemiol Community Health. 1992; 46:92-97. [ Links ]

5. Hewlett S, Dures E, Almeida C. Measures of Fatigue Arthritis. Care Res. 2011; 63(S11):263-286. [ Links ]

6. Hinz A, Finck C, Barradas S, Korner A, Volker B, Singer S. Fatigue in the general population of Colombia: Normative values for the multidimensional Fatigue Inventory MFI-20. Onkologie. 2013; 36:403-407. [ Links ]

7. Krupp L, La Rocca N, Muir J, Steinberg A. The fatigue Severity Scale. Arch Neurol. 1992;46: 1121-1123. [ Links ]

8. Rosa K, Fu M, Gilles L, Cerri K, Peeters M, Bubb J, Scott J. Validation of the Fatigue Severity Scale in chronic hepatitis. Health Qual Life Outcomes. 2014; 11: 90. [ Links ]

9. Takasaki H, Treleaven J. Construct validity and test-retest reliability of the Fatigue Severity Scale in people with chronic neck pain. Arch Phys Med Rehabil. 2013; 94(7):1328-34. [ Links ]

10. Valderrama S, Camelier AA, Silva SA, Mallmann R, de Paulo HK, Rosa FW. Reliability of the Brazilian Portuguese version of the fatigue severity scale and its correlation with pulmonary function, dyspnea, and functional capacity in patients with COPD. J Bras Pneumol. 2013; 39(4):427-33. [ Links ]

11. Montero I, León O. Sistema de clasificación del método en los informes de investigación en Psicología.IJCHP 2005; 5(1): 115-127. [ Links ]

12. Bulbena A, Berrios GE, Fernández de Larrinoa P. Medición Clínica en Psiquiatría y Psicología. (1 ed.). Madrid: Masson; 2000. [ Links ]

13. Alexandre A, Guirardello EB. Adaptación cultural de instrumentos utilizados en salud ocupacional. Rev Panam Salud Publica. 2002; 11(2): 109-111. [ Links ]

14. Lerdal A, Kottorp A. Psychometric properties of the Fatigue Severity Scale-Rasch analyses of individual responses in a Norwegian stroke cohort. Int J Nurs Stud. 2011; 48(10):1258-65. [ Links ]

15. Mattsson M, Möller B, Lundberg Le, Gard G, Boström C. Reliability and validity of the Fatigue Severity Scale in Swedish for patients with systemic lupus erythematosus. Scand J Rheumatol. 2008; 37(4):269-77. [ Links ]

Received: April 05, 2016; Accepted: July 19, 2016

Creative Commons License Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons