A Person-Centered Mixed-Methods Analysis of Third-Party Disability Among Family Caregivers of Post-Stroke Disabled Older Adults: Identifying Modifiable Determinants for Tailored Support

Background Long-term care for post-stroke disabled older adults places family caregivers at high risk of severe third-party disability (TPD). Prior research has predominantly used single quantitative or qualitative designs, with a lack of integrated mixed-methods studies. This study explored TPD determinants in these caregivers to inform evidence-based personalized interventions. Methods A convergent mixed-methods design was used. From January to November 2025, 796 caregiver-patient dyads were conveniently sampled from two tertiary hospitals in Shanghai. Data were collected using a sociodemographic and caregiving-related questionnaire, the Third-Party Disability Assessment Scale for Family Caregivers of Post-Stroke Disabled Older Adults (TPDAS-FCPSD), the Simplified Coping Style Questionnaire (SCSQ), the Social Support Rating Scale (SSRS), the General Self-Efficacy Scale (GSES), the 10-item Connor-Davidson Resilience Scale (CD-RISC-10), the 7-item Generalized Anxiety Disorder scale (GAD-7), and the Patient Health Questionnaire-9 (PHQ-9). Multivariate stepwise linear regression was performed for quantitative data analysis. In December 2025, 23 caregivers were purposively selected for semi-structured interviews, with thematic analysis for coding. From January to February 2026, a joint display approach integrated quantitative and qualitative findings. Results Caregivers had a mean age of 56.1 ± 14.4 years (57.5% female) and post-stroke disabled older adults 68.0 ± 8.2 years (68.8% male); nearly 70% of the latter had moderate-to-severe disability. The mean TPDAS-FCPSD score was 34.76 ± 18.15. Quantitative analyses identified two independent TPD risk factors (disability severity among post-stroke disabled older adults, caregiver depressive symptoms) and three key protective factors (number of co-caregivers, social support, resilience); Caregiver demographics and simplified coping style showed no significant associations. Qualitative analyses further revealed unmeasured contributors: combined physical-speech dysfunction burden, environmental barriers, inadequate health services and person-care demand mismatch. Integrated findings confirmed qualitative results expanded quantitative observations by clarifying social support structure, physical-speech impairment synergies and care fitness mismatch. Co-caregivers protected all four TPD dimensions; social support influenced all dimensions, depressive symptoms and total disability affected the first three, and sibling number only impacted environmental adaptation. Conclusions TPD in family caregivers of post-stroke disabled older adults stems from complex multidimensional interactions of caregiver traits, clinical status of post-stroke disabled older adults, social support and environmental factors. This mixed-methods study fully identifies TPD’s influencing factors and mechanisms, providing theoretical and practical evidence to reduce caregiver burden, optimize home-based care models and advance healthy aging.