Validity of a Revised Short Form-12 Health Survey Version 2 in Different Ethnic Populations

<p><b>INTRODUCTION</b>The Short Form-12 version 2 (SF-12v2) is a shorter version of the Short Form-36 version 2 (SF-36v2) for assessing health-related quality of life. As the SF-12v2 could not be resolved into the physical- and mental-component summary score (PCS and MCS, respectively) in the general population of Singapore, this study aims to determine and validate the Singapore SF-12 version 2 (SG-12v2).</p><p><b>MATERIALS AND METHODS</b>The SG- 12v2 was generated using the same methodology as the SF-12v2. Bootstrap analysis was used to determine if the SG-12v2 were significantly different from the SF-12v2. Content validity was assessed using percentage of variance (R²) of the Singapore version of SF-36v2 PCS and MCS explained by the SG-12v2 items. Agreement between the SF-36v2 and the SG-12v2 was assessed using Bland-Altman diagrams. Criterion validity was demonstrated if effect size differences between SF-36v2 and SG-12v2 were small (Cohen's criteria). Known-group validity of SG-12v2 was reported for participants with and without chronic diseases.</p><p><b>RESULTS</b>Five items differed between the SG-12v2 and SF-12v2. Bootstrap analysis confirmed that SG-12v2 and SF-12v2 were significantly different. The SG12v2 explained 94% and 79% of the R² of the SF-36v2 PCS and MCS, respectively. Agreement was good and effect size differences were small (<0.3). Participants with chronic diseases reported lower SG-12v2 scores compared to participants without chronic diseases.</p><p><b>CONCLUSION</b>The SG-12v2 offers advantage over the SF-12v2 for use in the general population of Singapore. The SG-12v2 is a valid measure and will be particularly useful for large population health surveys in Singapore.</p>

Diabetes Health Profile-18 is Reliable, Valid and Sensitive in Singapore

<p><b>INTRODUCTION</b>The Diabetes Health Profile-18 (DHP-18) measures diabetes-related psychological well-being in patients with type 2 diabetes mellitus (T2DM). It includes 3 subscales: psychological distress (PD), barriers to activity and disinhibited eating. The psychometric properties of the DHP have not been evaluated in Asia. The aim of this study was to determine the psychometric properties of the DHP in multiethnic Singapore.</p><p><b>MATERIALS AND METHODS</b>Patients between the ages of 18 to 65 diagnosed with diabetes (either type 1 or type 2) for at least 1 year were recruited from a diabetes outpatient clinic in a tertiary hospital. They completed a set of self-administered questionnaires including sociodemographic information and the DHP. Validity of the DHP was evaluated using confirmatory factor analysis (CFA) and exploratory factor analysis (EFA). Reliability was assessed with internal consistency and sensitivity was determined by effect size, associated with detecting a statistically significant and clinically important difference between various patient subgroups.</p><p><b>RESULTS</b>A total of 204 patients with mean age 45.4 (11.9) years, comprising 64% males and 50% Chinese, 27% Indian and 12% Malay were studied. In CFA, model fit was poor. Forced 3-factor EFA supported the original 3-factor structure of the DHP. Convergent and discriminant validity was demonstrated (100% scaling success). DHP was sensitive across majority of social demographic, clinical and social-functioning determinants (i.e., effect size >0.3). Cronbach's alpha exceeded 0.70 for all subscales. Ceiling effects were negligible but large floor effects were seen for the PD subscale (23%).</p><p><b>CONCLUSION</b>The DHP is valid, reliable and sensitive for measuring well-being in Asian patients with T2DM.</p>