Psychometric testing of the health-related quality of life measurement, SF-36v2, in the general population of Thailand

ABSTRACT

Background: The SF-36v2 is commonly used instrument worldwide. Nevertheless, it lacks the evidence of psychometric testing and health-related quality of life (HRQoL) level among the general Thai population. Therefore, this study aimed to investigate the psychometric performance and to evaluate the HRQoL level and the factors associated with it in the general Thai population.

Methods: Cross-sectional research was conducted with 600 Thai subjects. Various psychometric properties were investigated including ceiling/floor effects, item-scale and scale levels validity using correlations, principal component analysis (PCA), and internal consistency. Multiple regression was used to assess the impact of demographic factors on the HRQoL level.

Results: Cronbach’s alpha ranged from 0.703 to 0.858. These eight SF-36v2 scales had a high ceiling effect while no floor effects were observed except for Bodily pain and General health. Correlations between the eight scales and two summary components, and item-scale correlations supported the hypotheses. Physical and Mental Health components were identified by PCA. Multiple regression revealed that having chronic diseases diminished HRQoL level.

Conclusions: These preliminary results confirmed that the Thai SF-36v2 was a valid and reliable instrument. Having chronic diseases diminished the HRQoL level. Further study investigating subjects in different severity and impact of other factors on HRQoL level is encouraged.

KEYWORDS:

• HRQoL Psychometrics Reliability SF36v2 Validity

Acknowledgments

We are so grateful to the National Statistical Office (NSO) in Thailand for their assistance with the sampling process. We are also thankful to all of the local village leaders for their facilitation during the data collection process and participants participating in this study.

Declaration in Interest

K Kangwanrattanakul received funding from the Royal Golden Jubilee Ph.D. Programme in Thailand to conduct this study. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Ethical approval and consent to participate

This study was reviewed and approved by the Mahidol University Institutional Review Board (MU-IRB), Thailand: MU-DT/PY-IRB 2015/016.1004. Written informed consent was obtained from individuals before the study commenced.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was fully funded through the Royal Golden Jubilee (RGJ) Ph.D. Programme in Thailand under Grant Number: PHD/0115/2556 provided by the Thailand Research Fund (TRF). However, the results and opinions in this study have not been endorsed by the grant.