A Community-Based Validation Study of the Short-Form 36 Version 2 Philippines (Tagalog) in Two Cities in the Philippines

Nina T Castillo-Carandang,Hwee-Lin Wee,Mary Lenore Grefal,Rody G Sy,Felix Eduardo R Punzalan,Paul Ferdinand M Reganit,Allan Wilbert G Gumatay,Oliver C Alix,Elmer Jasper B Llanes,Olivia T Sison,E Shyong Tai,Felicidad V Velandria,Noel Christopher Barengo

doi:10.1371/journal.pone.0083794

Abstract

ObjectiveTo evaluate the validity and reliability of the Philippines (Tagalog) Short Form 36 Health Survey version 2 (SF-36v2®) standard questionnaire among Filipinos residing in two cities.Study Design and SettingThe official Philippines (Tagalog) SF-36v2 standard (4-week recall) version was pretested on 30 participants followed by formal and informal cognitive debriefing. To obtain the feedback on translation by bilingual respondents, each SF-36v2 question was stated first in English followed by Tagalog. No revisions to the original questionnaire were needed except that participants thought it was appropriate to incorporate "po" in the instructions to make it more polite. Face-to-face interviews of 562 participants aged 20-50 years living in two barangays (villages) in the highly urbanized city of Makati City (Metro Manila) and in urban and rural barangays in Tanauan City (province of Batangas) were subsequently conducted. Content validity, item level validity, reliability and factor structure of the SF-36v2 (Tagalog) were examined. ResultsContent validity of the SF-36v2 was assessed to be adequate for assessing health status among Filipinos. Item means of Philippines (Tagalog) SF-36v2 were similar with comparable scales in the US English, Singapore (English and Chinese) and Thai SF-36 version 1. Item-scale correlation exceeded 0.4 for all items except the bathing item in PF (correlation: 0.31). In exploratory factor analysis, the US two-component model was supported. However, in confirmatory factor analysis, the Japanese three-component model fit the Tagalog data better than the US two-component model. ConclusionsThe Philippines (Tagalog) SF-36v2 is a valid and reliable instrument for measuring health status among residents of Makati City (Metro Manila) and Tanauan City (Province of Batangas).

Highlights

The Short Form 36 (SF-36) Health Survey is a generic instrument which assesses “functional health and well-being from the patient’s perspective”.[1]
Content validity of the Social Functioning (SF)-36v2 was assessed to be adequate for assessing health status among Filipinos
Item means of Philippines (Tagalog) SF-36 version 2 (SF-36v2) were similar with comparable scales in the US English, Singapore (English and Chinese) and Thai SF-36 version 1

Summary

Introduction

The Short Form 36 (SF-36) Health Survey is a generic instrument which assesses “functional health and well-being from the patient’s perspective”.[1] It is a 36-item questionnaire which has been translated to over 140 languages and is used globally to assess changes in health status as well as comparing the burden of illness in a population. In SF-36v2, the following revisions were made: (1) simpler instructions and improved layout for questions and answers to improve clarity, (2) improved phrasing of some items to provide greater comparability with translations and cultural adaptations widely-used in the U.S and in other countries and (3) revision of response options from dichotomous to five-level response choices for the role physical and role emotional items to improve sensitivity and from sixlevel to five-level response choices for the vitality and mental health items for simplification[5]. As any revisions to the SF-36v1 may be expected to alter its psychometric properties, we seek to perform a socio-cultural validation of the Philippines (Tagalog) SF-36v2 among urban and rural adults living in two cities in the Philippines

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Results

Conclusion