Impact of Social Factors on Visual Analog Scale Pain in Patients With Spondyloarthritis: A Propensity Score Matching Analysis
Year: 2025
Type: article
Abstract: OBJECTIVE: Pain in spondyloarthritis reflects not only inflammatory activity but also social context. We quantified the association between a composite Social Factors Index (SFI) and patient-reported pain severity on the Visual Analog Scale (VAS). METHODS: We analyzed 2,042 patients from REGISPONSER (N = 1,514) and RESPONDIA (N = 528). Missing data were handled with multiple imputation (m = 20). The SFI combined education, employment, housing, income source, and Graffar class using penalized regression (sparse-group lasso). Mutual information (MI) quantified the SFI's relative importance. Propensity scores (logistic regression) supported 1:1 caliper matching (0.2 SD on the logit), comparing the highest (Q4) and lowest (Q1) SFI quartiles. RESULTS: Before matching, Q1 and Q4 included on average 918 and 829 patients per imputation, differing mainly in race (White 80.8% vs 86.8%; standardized mean difference [SMD] = -0.16) and country (Spain 66.2% vs 78.2%; SMD = -0.27). After matching, a mean of 745 pairs (range 731-761) were retained with excellent covariate balance (all |SMD| < 0.10). In the matched sample, patients in Q4 reported higher pain (average treatment effect on the treated +0.38 VAS points; 95% confidence interval [CI] 0.05-0.71; P = 0.023). Postmatching regression yielded an identical estimate (β = +0.37; 95% CI 0.04-0.70; P = 0.030). MI indicated the SFI carried more information about VAS than any single social variable. Stratified analyses suggested heterogeneity: Spain +0.31 (95% CI 0.08-0.71) and Latin America +0.62 (95% CI -0.22 to 1.45). CONCLUSION: Social disadvantage, summarized by the SFI, is independently associated with greater pain severity in spondyloarthritis after adjustment. These findings support incorporating social determinants into clinical assessment and pain management.
Source: Arthritis Care & Research
DOI: 10.1002/acr.25675
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W4415279856