The development and psychometric evaluation of the HIV-related Social Support Scale (HSSS): a health psychological measurement tool using the COSMIN methodology

Existing social support measures lack specificity for people with HIV (PWH), and fail to capture critical dimensions such as affiliational social and appraisal support under the context of HIV-related stigma. This methodological gap constrains research on the psychological mechanism linking social support to mental health outcomes, and hinders the development of targeted psychological interventions. This study aimed to develop and evaluate the psychometric properties of the HIV-related Social Support Scale (HSSS) following COSMIN methodology. The 25-item HSSS was developed from a realist synthesis and qualitative inquiry, and refined through a two-round Delphi process with 52 experts from 12 provinces in China. Three independent analytic samples were used for psychometric evaluation: validity and internal consistency ( N = 406), reliability and measurement error ( N = 63), and responsiveness ( N = 63). The five-factor model (informational, instrumental, emotional, affiliational social, and appraisal support) showed mixed structural validity (χ²/ df = 3.32, CFI = 0.95, TLI = 0.95, RMSEA = 0.075). Subscale-level internal consistency was excellent (Cronbach’s α = 0.976 for the full scale), test-retest reliability was satisfactory (ICC = 0.85), and measurement error was within an acceptable range (SEM% = 8.53%). Criterion validity was supported by a strong correlation with the MOS-SSS ( r = 0.731, p < 0.01). Both pre-specified construct validity hypotheses were confirmed: HSSS scores were negatively correlated with depression/anxiety symptoms ( r = -0.362, p < 0.01) and significantly lower in older adults ( p = 0.029). Responsiveness analysis showed that the HSSS was sensitive to changes in four dimensions (informational, emotional, affiliational social, and appraisal support). The HSSS is the first culturally tailored, multidimensional social support instrument for Chinese PWH that incorporates affiliational social and appraisal support. It shows promising and preliminary psychometric evidence to support its application in mental health risk screening and mechanism research of social support among PWH, and provide a standardized measurement tool for health psychology studies in stigmatized chronic disease populations.