Socioeconomic status and social relationships in persons with spinal cord injury from 22 countries: Does the countries’ socioeconomic development moderate associations?

Background: Social relationships are powerful determinants of health and inequalities in social relationships across socioeconomic status (SES) groups may contribute to social inequalities in health. This study investigates inequalities in social relationships in an international sample of persons with spinal cord injury and explores whether social gradients in relationships are moderated by the countries’ socioeconomic development (SED). Methods: Data from 12,330 participants of the International SCI Community Survey (InSCI) performed in 22 countries were used. We regressed social relationships (belongingness, relationship satisfaction, social interactions) on individual SES (education, income, employment, financial hardship, subjective status) and countries’ SED (Human Development Index) using multi-level models (main effects). To test potential moderation of the SED, interaction terms between individual SES and countries’ SED were entered into multi-level models. Results: Paid work, absence of financial hardship and higher subjective status were related to higher belongingness (OR, 95% CI: 1.50, 1.34–1.67; 1.76, 1.53–2.03; 1.16, 1.12–1.19, respectively), higher relationship satisfaction (OR, 95% CI: 1.28, 1.15–1.42; 1.97, 1.72–2.27; 1.20, 1.17–1.24, respectively) and fewer problems with social interactions (Coeff, 95% CI: 0.96, 0.82–1.10; 1.93, 1.74–2.12; 0.26, 0.22–0.29, respectively), whereas associations with education and income were less consistent. Main effects for countries’ SED showed that persons from lower SED countries reported somewhat higher relationship satisfaction (OR, 95% CI: 0.97, 0.94–0.99) and less problems with social interactions (Coeff, 95% CI: -0.04, -0.09- -0.003). Results from moderation analysis revealed that having paid work was more important for relationships in lower SED countries, while education and subjective status were more important for relationships in higher SED countries (interaction terms p