Validation of the Chinese version of the Oslo-3 Social Support Scale among nursing students: a study based on Classical Test Theory and Item Response Theory models

Background Nursing students are encountering a range of health issues. Assessing social support is a key component in most questionnaire surveys related to health status, aiming to investigate the relationships and mechanisms between health status and social support to enhance overall health. Therefore, it is essential to seek out appropriate instruments to evaluate social support for nursing students. The Oslo-3 Social Support Scale (OSSS-3) is a reliable and concise instrument for evaluating social support. To date, there have been no studies validating the OSSS-3 based on Item Response Theory (IRT) models. Also, an officially validated Chinese version has not been found. The current research intended to verify the Chinese version of the OSSS-3.Methods The OSSS-3 was translated into Chinese and culturally adapted. Subsequently, the OSSS-3 was validated by employing the Classical Test Theory (CTT) and IRT models.Results The split-half reliability was 0.622. The Cronbach's alpha coefficient was 0.687. The correlations between each item and total scores varied from 0.723 to 0.835. The retest coefficient was 0.907. The content validity index was 0.933. A single common factor was extracted and accounted for 61.559% of the variance. The item loading values on the single factor were between 0.743 and 0.814. The communalities were between 0.552 and 0.663. There was no variance between males and females (P = 0.055). The difference in scores between the top (30%) and bottom (30%) groups attained significance. IRT models results revealed that the discrimination parameters ranged from 1.39 to 2.33 and difficulty parameters increased monotonically.Conclusion The OSSS-3 demonstrates satisfying psychometric properties and is a proper instrument for measuring social support in Chinese nursing students.