Reliability and validity of the Turkish version of short form 36 (SF-36) in patients with rheumatoid arthritis

Abstract

Aim: Investigating reliability and validity of the Turkish version of short form-36 (SF-36) in patients with rheumatoid arthritis

Methods: Demographic data of the patients with rheumatoid arthritis were recorded. Health Assessment Questionnaire (HAQ) and Short Form 36 (SF-36) were filled out. Disease activities were computed using Disease Activity Score 28 (DAS-28). Patients were recalled after three months and were asked to state how they felt compared to their first visit, and the same tests were repeated. 

Results: 141 patients were admitted (9.9% male, 90.1% female). In the reliability study of SF-36, the Cronbach alpha value of the subscales varied in the range 0.792-0.992, hence SF-36 was found to be highly reliable. The item total score correlations were computed for each subscale and were found to be in the ranges: 0.436-0.840 for physical functioning, 0.887-0.895 for role function (physical), 0.861-0.958 for pain, 0.564-0.892 for general health perception, 0.702-0.841 for vitality (energy/fatigue), 0.949-0.952 for social functioning, 0.396-0.473 for role function (emotional) and 0.456-0.824 for mental health. The SF-36 scores from two consecutive visits spaced 3 months apart were compared and the p values were found to be greater than 0.05. The validity study was conducted for the 63 patients whose reported conditions did not change between two visits. The test-retest relation was evaluated using intra-class correlation coefficients, which ranged from 0.51 to 0.78 and the correlations of the two tests were found to be statistically significant. The comparison of SF-36 scores from two consecutive visits, all with p>0.05, showed no statistically significant changes.  

Conclusions: The Turkish version of SF-36 was found to be reliable and valid in patients with rheumatoid arthritis.

Keywords

• Reliability,Validity,Rheumatoid arthritis,SF-36

Romatoid artritli hastalarda Türkçe kısa form 36’nın (SF-36) güvenilirlik ve geçerliliği

Öz

Amaç: Romatoid artritte Türkçe SF-36’nın güvenilirlik ve geçerliliğini araştırmak.

Yöntemler: Çalışmaya alınan Romatoid artritli hastaların demografik özellikleri kayıt edildi. Sağlık değerlendirme anketi (HAQ) ve SF-36 formları dolduruldu. Hastalık aktiviteleri DAS-28 kullanılarak hesaplandı. Hastalar 3 ay sonra tekrar çağırılarak kendilerini ilk gelişlerine göre nasıl hissettikleri soruldu ve ilk gelişlerinde yapılan testler tekrarlandı.

Bulgular: Çalışmadaki 141 hastanın  %9,9’u erkek; %90,1’i kadındır. SF-36’nın güvenilirlik çalışmasında ölçek alt boyutlarının Cronbach alfa değerleri 0,792-0,992 arasında değişmekte olup, bunun sonucunda SF-36 yüksek düzeyde güvenilir bulunmuştur. Madde-toplam puan korelasyon katsayıları da her bir alt ölçek için ayrı ayrı hesaplanmıştır. Fiziksel fonksiyonda 0,436-0,840, fiziksel rol güçlüğünde 0,887-0,895; ağrıda 0,861-0,958, sağlığın genel olarak algılanmasında 0,564-0,892; vitalite (enerji)’de 0,702-0,841; sosyal fonksiyonda 0,949-0,952; emosyonel rol kısıtlamasında 0,396-0,473 ve mental sağlıkta 0,456-0,824 arasında bulunmuştur. Daha sonra her iki SF-36 ölçümü karşılaştırılmış ve p>0,05 olduğu için ikinci ölçümlerde ilk ölçümlere göre bir farklılık saptanmamıştır.

SF 36 geçerlilik çalışması, beyana dayalı durumları ikinci gelişlerinde ilkine göre değişmeyen 63 olgu üzerinde yapılmış olup; test tekrar test arasındaki korelasyon, intra-class korelasyon katsayıları ile değerlendirildiğinde her iki uygulama arasında istatistiksel olarak anlamlı ilişki görülmektedir.  Bu çalışmada korelasyon katsayıları 0,51 ile 0,78 arasında değişmektedir. SF-36 puanlarının ilk ve ikinci ölçümleri arasında istatistiksel olarak anlamlı farklılık görülmemektedir  (p>0,05).

Sonuç: Sonuç olarak Türkçe SF-36 Romatoid artritli hastalarda güvenilir ve geçerli bulunmuştur.

Anahtar Kelimeler

• Güvenilirlik,Geçerlilik,Romatoid artrit,SF-36

Kaynakça

1. 1. Fries JF, Spitz P, Kraines RG, Holman HR Measurement of patient outcome in arthritis. Arthritis Rheum 1980;23(2):137–45
2. 2. Kucukdeveci AA, Sahin H, Ataman S et al. Issues in crosscultural validity: example from the adaptation, reliability and validity testing of a Turkish version of the Standford Health Assessment Questionnaire. Arthritis & Rheumatism; Arthritis Care & Research. 2004;51(1):14-19.
3. 3. Kirwan JR, Reeback JS Stanford Health Assessment Questionnaire modified to assess disability in British patients with rheumatoid arthritis. Br J Rheumatol 1986;25(2):206-9.
4. 4. Leigh JP, Fries JF, Parikh N Severity of disability and duration of disease in rheumatoid arthritis. J Rheumatol 1992;19(12):1906-11.
5. 5. Buchbinder R, Bombardier C, Yeung M, Tugwell P. Which outcome measure should be used in rheumatoid arthritis clinical trials? Clinical and quality-of-life measures’ responsiveness to treatment in a randomised controlled trial. Arthritis Rheum 1995;38(11):1568-80.
6. 6. Carr A, Thompson P, Young A. Do health status measures (HSM) have a role in rheumatology? A survey of the use of and attitudes towards health status measures in the UK. Arthritis Rheum 1996; ACR Abstracts S261.
7. 7. Wolfe F, Cathey MA. The assessment and prediction of functional disability in rheumatoid arthritis. J Rheumatol 1991;18(11):1774.
8. 8. Leigh JP, Fries JF. Predictors of disability in a longitudinal sample of patients with rheumatoid arthritis. Ann Rheum Dis 1992;51(5):581-7.

9. 9. Young A. Short-term outcomes in recent-onset rheumatoid arthritis. Br J Rheumatol 1995;34(suppl. 2):79-86.
10. 10. Fitzpatrick R, Ziebland S, Jenkinson C, Mowat A, Mowat A. Importance of sensitivity to change as a criterion for selecting health status measures. Quality Health Care 1992;1(2):89-93.
11. 11. Liang MH, Jette AM. Measuring functional ability in chronic rheumatoid arthritis. A critical review. Arthritis Rheum 1981;24(1):80-6.
12. 12. Ware JE, Sherbourne CD. The MOS 36-item short-form health status survey (SF-36). 1. Conceptual framework and item selection. Med Care 1992;30(6):473-83.
13. 13. Koçyiğit H, Aydemir Ö, Ölmez N et al. SF-36’nın Türkçe için güvenilirliği ve geçerliliği. İlaç ve tedavi 1999;12:102-6.
14. 14. Küçükdeveci A, Şahin H, Ataman Ş, Griffiths B, Tennant A. Issue in cross-cultural validity: example from the adaptation, reliability, and validity testing of a Turkish version of thr Stanford Health Assessment Questionnaire. Arthritis & Rheum 2004;51(1):14-9.
15. 15. Aletaha D, Ward MM, Machold KP, Nell VPK, Stamm T, Smolen JS. Remission and active disease in rheumatoid arthritis. Defining criteria for disease activity states. Arthritis Rheum. 2005;52(9):2625-36.
16. 16. Coronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika 1951;16(3):297-334.
17. 17. Jenkinson C, Peto V, Coulter A. Making sense of ambiguity: evaluation of internal reliability and face validity of SF-36 questionnaire in women presenting with menorrhagia. Qual Health Care 1996;5(1):9-12.
18. 18. Hurst NP, Kind P, Ruta DA, Hunter M, Stubbings A. Measuring health-related quality of life in rheumatoid arthritis: validity, responsiveness and reliability of EuroQol (EQ-5D). Br J Rheumatol 1997;36(5):551-9.
19. 19. Kosinski M, Keller SD, Ware JE, Hatoum HT, Kong SX. The SF-36 health survey (SF-36) as a generic outcome measure in clinical trials of patients with osteoarthritis and rheumatoid arthritis: relative validity of scales in relation to clinical measures of arthritis severity. Med Care 1999;37(5 suppl):23-39.
20. 20. Talamo J, Frater A, Gallivan S, Young A. Use of the short form 36 (SF-36) for health status measurement in rheumatoid arthritis. Br J Rheumatol 1997;36(4):463-9.
21. 21. Kvein TK, Smestad LM, Uhlig T. The responsiveness of generic and disease specific health health status measures in 759 patients with rheumatoid arthritis (RA). Arthritis Rheum 1996;39(suppl.):260.
22. 22. Streiner DL, Norman GR. Health measurement scales. A practical guide to their development and use. New York: Oxford University Press; 1989.
23. 23. Ware JE, Snow KK, Kosinski M, Gandek B. SF-36 Health Survey: Manual and interpretation guide. Boston: The Health Institute. New England Medical Center, 1993.
24. 24. Brazier JE, Harper R, Jones NMB et al. Validating the SF-36 health survey questionnaire: new outcome measure for primary care. BMJ 1992;305(6846):160-4.
25. 25. Jenkinson C, Coulter A, Wright L: Short Form-36 (SF-36) health survey questionnaire: Normative data for adults of working age. BMJ 1993;306(6890):1437-1440.
26. 26. Husted JA, Gladman DA, Farewell VT et al. Validating the SF-36 health survey questionnaire in patients with psoriatic arthritis. J Rheumatol 1997;24(3):511-7.
27. 27. Stoll T, Gordon C, Seifert B et al. Consistency and validity of patient administered assessment of quality of life by the MOS SF-36; its association with disease activity and damage in patients with systemic lupus erythematosus. J Rheumatol 1997;24(8):1608-14.
28. 28. Birrell FN., Hassell AB., Jones PW., Dawes PT. How does the short form 36 health questionnaire (SF-36) in rheumatoid arthritis (RA) relate to RA outcome measures and SF-36 population values? A cross-sectional study. Clin Rheumatol. 2000;19(3):195-9.
29. 29. Russell AS, Conner-Spady B, Mintz A, Maksymowych WP. The responsiveness of generic health status measures as assessed in patients with rheumatoid arthritis receiving infliximab. J Rheumatol 2003;30(5):941–7.