Validation of the Mongolian version of the SF-36v2 questionnaire for health status assessment of Mongolian adults

BACKGROUND: Ulaanbaatar, Mongolia, is one of the world's worst air-polluted cities, but effects of this air pollution on the population health status have not yet been evaluated. Therefore, we developed a Mongolian version of the SF-36v2 questionnaire to investigate the health status of Mongolian population. METHODS: Health checkups were conducted in Ulaanbaatar and the health status was measured using a Mongolian translated version of the SF-36v2 questionnaire. The reliability and validity of the Mongolian SF-36v2 questionnaire, and the relationship between health status and respiratory condition were examined. RESULTS: Factor analysis of the Mongolian SF-36v2 questionnaire showed that the "Role-physical" and "Role-emotional" were classified into a single subscale. The "Mental health" and "Vitality" were each divided into two subscales. Cronbach's alpha and intraclass correlation coefficient (ICC) for reproducibility were >0.7, except for "General health perceptions" (Cronbach's alpha and ICC < 0.7), "Social functioning" (Cronbach's alpha < 0.7), and "Vitality" (ICC < 0.7). The SF-36v2 subscales and the corresponding items of the COOP/WONCA charts were correlated, and subjects with respiratory symptoms showed lower SF-36v2 scores compared to normal subjects, suggesting external validity. Subjects with respiratory symptoms showed significantly lower scores for the majority of the SF-36v2 subscales than those with normal lung function. In subjects with combined ventilatory impairment, "Physical functioning", "Role-physical", "Bodily pain", and "Vitality" scores were significantly lower than those with normal lung function. CONCLUSIONS: The Mongolian version of the SF-36v2 questionnaire provides substantial reliability and validity, and is useful for evaluating the health status of Mongolian adults with ventilatory impairment. Health status measured by SF-36v2 was significantly aggravated by combined ventilatory impairment when compared with normal lung function.