Social Support Modifies the Pain-Disability Relationship in Degenerative Spine Disease: Evidence From the PROGRES Study.

BACKGROUND

Low back pain from degenerative spine disease is the main contributor to years lived with disability globally. Although social support is a multifaceted construct with both health-promoting and potentially deleterious effects on chronic pain, whether perceived social support modifies the pain-disability relationship in lumbar degenerative spine disease remains unclear. We hypothesised that social support level would modify the pain-disability association, with distinct predictor patterns of disability emerging for low- versus high-support patients.

METHODS

In this cross-sectional analysis of baseline data from the PROGRES cohort study, 156 pre-operative patients with lumbar degenerative disease (mean age 60.0 years; 58.3% female) completed validated measures of pain (Visual Analog Scale [VAS] for radicular and axial pain, supplemented by the pain/discomfort item of the EuroQol EQ-5D-5L [EQ-5D pain]), disability (Oswestry Disability Index [ODI]), health-related quality of life (EQ-5D-5L), and perceived social support (Multidimensional Scale of Perceived Social Support [MSPSS]). Participants were stratified by median MSPSS score into low- (n = 83) and high-support (n = 73) groups. The primary outcome was the between-group difference in pain-disability correlations, tested with Fisher's z-transformation and Benjamini-Hochberg false discovery rate (FDR) correction. The robustness of dichotomisation was confirmed using moderation analysis with MSPSS as a continuous variable.

RESULTS

After FDR correction, the correlation between EQ-5D pain severity and the ODI daily-activities item was significantly stronger in the high-support group than in the low-support group (ρ = 0.69 vs. 0.25; Δρ = 0.44; PFDR = 0.005). Multiple regression models explained more variance of disability in the high-support group (R2 = 31.5%) than in the low-support group (R2 = 16.6%). Depression was a significant predictor of disability in both groups; in the low-support group, it was the sole significant predictor (p = 0.037), whereas in the high-support group, radicular (leg) pain emerged as the dominant predictor (B = 1.45; β = 0.50; p < 0.001) alongside depression (B = 1.83; β = 0.31; p = 0.007). Higher perceived social support showed a small positive correlation with radicular pain intensity (ρ = +0.18; p = 0.026), with no significant association with axial pain.

CONCLUSIONS

Perceived social support appears to influence which factors are most strongly associated with disability rather than uniformly buffering against it. The positive pain-support correlation, restricted to radicular pain, is consistent with operant models of social support in chronic pain, in which clinically unambiguous symptoms may preferentially mobilise support. Brief screening of perceived social support may help inform individualised treatment planning in degenerative spine disease.