Journal of Postgraduate Medicine
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ORIGINAL ARTICLE
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Year : 2008  |  Volume : 54  |  Issue : 4  |  Page : 273-275  

Quality of life in thalassemia major: Reliability and validity of the Persian version of the SF-36 questionnaire

H Jafari1, S Lahsaeizadeh1, P Jafari2, M Karimi1,  
1 Hematology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
2 Department of Biostatistics, Shiraz University of Medical Sciences, Shiraz, Iran

Correspondence Address:
M Karimi
Hematology Research Center, Shiraz University of Medical Sciences, Shiraz
Iran

Abstract

Aims: The objective of this study was to determine the reliability and validity of the eight-item Short Form Health Survey (SF-36) questionnaire translated into Persian for use in Iranian patients with thalassemia major. Materials and Methods: Using a standard «DQ»forward-backward«DQ» translation procedure, the English language version of the questionnaire was translated into Persian. Two hundred patients with thalassemia major following up at the Thalassemia Center, Dastgheib Hospital, Shiraz, Iran, were enrolled in this study. Statistical Analysis: The reliability and internal consistency of the questionnaire were assessed by Cronbach«SQ»s alpha coefficient and Spearman«SQ»s correlation, respectively. Validity was assessed using convergent and discriminant validity. Results: The mean age of 200 subjects enrolled in the study was 19.81+/-4.07 years. Reliability analysis showed satisfactory results (Cronbach«SQ»s a coefficient = 0.915). The factor analysis showed that all items were in the same groups as previous studies with the exception of role emotional and general health that had been substituted. Most of the patients were in lower range of normal for both mental and physical summary status. Conclusions: The study finding showed that the Persian version of SF-36 questionnaire has a good structural characteristic and is a reliable and valid instrument for measuring the quality of life of patients with thalassemia major.



How to cite this article:
Jafari H, Lahsaeizadeh S, Jafari P, Karimi M. Quality of life in thalassemia major: Reliability and validity of the Persian version of the SF-36 questionnaire.J Postgrad Med 2008;54:273-275


How to cite this URL:
Jafari H, Lahsaeizadeh S, Jafari P, Karimi M. Quality of life in thalassemia major: Reliability and validity of the Persian version of the SF-36 questionnaire. J Postgrad Med [serial online] 2008 [cited 2022 Jul 2 ];54:273-275
Available from: https://www.jpgmonline.com/text.asp?2008/54/4/273/41432


Full Text

Inadequately treated thalassemia major is a potentially fatal disorder . [1] It is a serious public health issue throughout the Mediterranean region, the Middle East, the Indian subcontinent and Southeast Asia [2],[3] and in several other countries due to migration. [4] In the last 30 years, introduction of regular blood transfusion therapy and effective iron chelating therapy with desferrioxamine have markedly improved the life expectancy of these patients. [5],[6],[7] However, these patients now face newer challenges in obtaining higher education, securing employment and raising their own families. They are also confronted with other problems like bone disease, infertility and increased prevalence of psychiatric distress. [8] The Quality of Life (QOL) of individuals with thalassemia major is influenced by the following factors: impact of the diagnosis and treatment, having a chronic condition, appearance, treatment components like frequent hospital visits for transfusion, nightly subcutaneous infusions, delayed or absent sexual development, complications of the disease and therapeutic interventions and uncertainties about the future. [9] Various studies have shown that culture and education play a vital role as Khurana et al. , showed that adverse impact of thalassemia was perceived in the domains of education and sports. Most thalassemics were not satisfied with their body image. The adolescents were anxious about their future health and education. They mainly depend on their parents for monetary and emotional support. [10] A study in India showed that thalassemia is extremely stressful, and patients face a variety of physical, psychological, and social problems. The findings also showed that culture and education play a major role in illness experiences. [11] Hence, as Iran has a high prevalence of thalassemic patients, a survey was conducted to determine the reliability and validity of the Short Form Health Survey (SF-36) Questionnaire in patients with thalassemia major in Iran.

 Materials and Methods



The standard "Forward-Backward" procedure was applied to translate the SF-36 questionnaire from English to Persian by a bilingual individual. The relevant cultural adaptation was also carried out (e.g. substituting golf and billiards into mild sports and changing mile to kilometer). The final form was administered by simple randomization to 200 patients amongst 810 individual thalassemic patients (from both rural and urban areas of Shiraz) aged over 15 years who came for blood transfusion to Dastgheib Hospital, Shiraz, south of Iran. The survey was carried out during 2004-05 in accordance with the ethical principles of the university hospital of Dastgheib (Shiraz, Iran) after the hospital's ethics committee's approval. The patients were requested to fill up the SF-36 questionnaire after obtaining written informed consent. Although the SF-36 is basically designed to be a self-administered questionnaire it can be completed through an interview in person, computerized administration or by telephone. [12] Hence, for illiterate individuals a trained person interviewed the patients face to face. There was no missing data. Age and sex of the patients were also recorded. Responses on the SF-36 form were scored according to the guidelines of the Clinical Outcome Evaluation System (COES) software.

Statistical analysis : All statistical analyses were carried out using the SPSS 13 for Windows. Reliability and the internal consistency of the questionnaire were assessed by Cronbach's alpha. Convergent and discriminant validity was checked using Spearman correlation. Construct Validity was checked by factor analysis. The correlation between sex and increase in age with the concepts of the QOL was also considered in our study.

 Results



The mean age of 200 patients (105 males, 52.5%) enrolled in the survey was 19.81+/- 4.07 years (range: 15-32 years). All the patients were on regular blood transfusion therapy (every two to four weeks) with poor chelation therapy due to painful injections. The reliability of the questionnaire was obtained by Cronbach's alpha coefficient (a= 0.915). In addition the Cronbach's alpha coefficient to indicate items internal consistency reliability for each measure is present and all measures but role emotional showed satisfactory results. All scales met or exceeded the 0.70 level recommendation for group comparison with the exception of the role emotional scale (Cronbach's α = 0.65) [Table 1]. The reliability obtained for both males and females was 0.90 and 0.93, respectively.

As shown in [Table 1], the convergent validity for each item ranged from 0.57-0.69 for physical functioning (PF) scales, 0.61-0.70 for role physical (RP) scale, 0.85-0.90 for bodily pain (BP) scales, 0.64-0.74 for general health (GH) scales, 0.62-0.75 for vitality (VT) scales, 0.77-0.88 for social functioning (SF) scales, 0.56-0.73 for role emotional (RE) scales and 0.69-0.77 for mental health (MH) scales. [Table 1] shows the results of item convergent, discriminant validity tests and internal consistency. The scaling success rates were 100% for convergent validity of each scale.

Factor analysis was performed to determine that the Persian version measures two dimensions: physical and mental parameters. As showed in [Table 2], all the items that should be in physical summary status (physical functioning, role physical, bodily pain) are in this group except general health that has been substituted with role emotional and the rest are in the mental summary status with the exception of role emotional.

From the collected data it was seen that, overall, most of the patients in both sexes and all ages were in the lower range for mental and physical summary dimensions and their scaling parameters [Table 3].

The analysis showed that there was no significant association between the gender and age with the questionnaire's eight scaling items and the physical and mental summary (all P values >0.05)

 Discussion



The SF-36 questionnaire is a well-known instrument for measuring QOL of normal population as well as of individuals with various disease states. The scale translated into Persian was used for obtaining the validity and reliability of the questionnaire in general population in Iran in two studies. [13],[14] However, there has been no research on patients with thalassemia major using this instrument in Iran or elsewhere.

This study reports data from a validation study of the eight-item questionnaire in thalassemic patients in Iran. In general, all psychometric tests of the SF-36 Iranian version showed satisfactory results. Reliability of the questionnaire as measured by the Cronbach's a coefficient for all eight scales except the RE scale exceeded the recommended level. The fact that the RE scale performed differently from other scales might reflect the difficulty encountered in translating its items from English to Persian. However, in translating the RE items it was decided to use very similar vocabularies to indicate what are exactly asked for.

The multi-item analysis of the SF-36 Iranian version of this study showed that the items related to each scale had a high correlation with its scale and low correlation with other scales. This reveals that the questionnaire has a high convergent validity and low discriminant validity for each scale and its items for thalassemic patients.

The factor analysis clearly indicated that the questionnaire includes two underlying factors, namely physical and mental components, although the findings were not exactly similar to the original hypothesized associations and the translated form done by Montazer et al . [13],[15] This might be due to the difference in the studied populations, as Tehran is a representative sample of urban population but the patients in this study came from both rural and urban areas of Shiraz. [13] The general health was strongly associated with the mental component and the RE scale with the physical component while one expects a weak association with physical component. It is discussed that these might be due to the strong impact of mental health on Iranians' QOL and the differences between the Asian culture and Western culture and it is not a structural defect since the validity of items and scales were satisfactory. [14],[16]

In conclusion, the first survey on thalassemia major patients with the Iranian version of the SF-36 questionnaire proved to be acceptable and has a good structured characteristic. Thus, it is a reliable and valid instrument that can be used to measure the effects of thalassemia on these patients' QOL and hence it is so important to promote a clear understanding of the disease and initiating intervention programs.

References

1Ismail A, Campbell MJ, Ibrahim HM, Jones GL. Health related quality of life in Malaysian children with thalassaemia. Health Qual Life Outcomes 2006;4:39.
2Angastiniotis M, Modell B. Global epidemiology of hemoglobin disorders. Ann N Y Acad Sci 1998;850:251-69.
3Weatherall D. The thalassemias: The role of molecular genetics in an evolving global health problem. Am J Hum Genet 2004;74:385-92.
4Mikelli A, Tsiantis J. Brief report: Depressive symptoms and quality of life in adolescents with β-thalassemia. J Adolescence 2004;27:213-6.
5Brittenham GM, Griffith PM, Nienhuis AW, McLaren CE, Young NS, Tucker EE, et al . Efficacy of deferoxamine in preventing complications of iron overload in patients with thalassemia major. N Engl J Med 1994;331:567-73.
6Telfer P, Coen PG, Christou S, Hadjigavriel M, Kolnakou A, Pangalou E, et al . Survival of medically treated thalassemia patients in Cyprus: Trends and risk factors over the period 1980-2004. Haematologica 2006;91:1187-92.
7Olivieri NF, Brittenham GM. Iron-chelating therapy and the treatment of Thalassemia. Blood 1997;89:739-761.
8Pakbaz Z, Treadwell M, Yamashita R, Quirolo K, Foote D, Quill L, et al . Quality of life in patients with thalassemia intermedia compared to thalassemia major. Ann N Y Acad Sci 2005;1054:457-61.
9Ware JE Jr, Sherbourne CD. The MOS 36-item short-form health survey (SF-36) I conceptual framework and item selection. Med Care 1992;30:473-83.
10Khurana A, Katyal S, Marwaha RK. Psychosocial burden in thalassemia. Indian J Pediatr 2006;73:877-80.
11Roy T, Chatterjee SC. The experiences of adolescents with thalassemia in West Bengal, India. Qual Health Res 2007;17:85-93.
12Ware JE Jr, Gandek B. Overview of the SF-36 health survey and the international quality of life assessment project. J Clin Epidemiol 1998;51:903-12.
13Montazeri A, Goshtasebi A, Vahdaninia M, Gandek B. The short form health survey: Translation and validation study of Iranian version. Qual Life Res 2005;14:875-82.
14Motamed N, Ayatollahi AR, Zare N, Sadeghi-Hassanabadi A. Validity and reliability of the Persian translation of the SF-36 version 2 questionnaire. East Med Health J 2005;11:349-57.
15Fukuhara S, Bito S, Green J, Hsiao A, Kurokawa K. Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan. J Clin Epidemiol 1998;51:1037-44.
16Sabbah I, Drouby N, Sabbah S, Retel-Rude N, Mercier M. Quality of Life in rural and urban populations in Lebanon using SF-36 Health Survey. Health Qual Life Outcomes 2003;1:30.

 
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