Psychometric properties of the Polish version of SF-12v2 in the general population survey

This study aimed to assess the psychometric properties of the SF-12 questionnaire (in comparison to the EQ-5D questionnaire also), based on a survey conducted on a sample representing the general population of Poland. The respondents completed Polish versions of health-related quality of life (HRQoL) questionnaires: SF-12, EQ-5D-5L, EQ VAS, and EQ-5D-3L, together with demographic and socioeconomic characteristic items. The following psychometric properties were analyzed: informativity power, ceiling and floor effects, reliability, and construct validity. We also conducted an exploratory factor analysis. A total of 3,896 respondents (mean age 48.3 years, 53.2% female) were included in the analysis. The results showed exceptional informativity power of SF-12 items. We did not observe any ceiling and floor effects for the PCS and MCS components. The high values of the Cronbach’s alpha coefficients confirmed the reliability of SF-12. Our hypothesis about lower scores for the summary components among older respondents, females and patients having declared diabetes was confirmed. The results of factor analysis also provided evidence for a positive assessment of construct validity. Our results confirmed that the Polish version of the SF-12 questionnaire is a valid instrument for use in HRQoL assessment among the general population of Poland.