Predicting the Physical and Mental Health Status of Individuals With Chronic Musculoskeletal Pain From a Biopsychosocial Perspective: A Multivariate Approach.

Objectives: Chronic pain is theoretically conceptualized from a biopsychosocial perspective. However, research into chronic pain still tends to focus on isolated, biological, psychological, or social variables. Simultaneous examination of these variables in the prediction of outcomes is important because communalities between predictors exist. Examination of unique contributions might help guide research and interventions in a more effective way.

Methods: The participants were 114 individuals with chronic pain (mean age=58.81, SD=11.85; 58.8% women and 41.2% men) who responded to demographics (age and sex), pain characteristics (duration and sensory qualities), psychological (catastrophizing and perceived injustice), and social (marital adjustment) measures. Multivariate analyses were conducted to investigate their unique contributions to pain-related health variables pain severity, pain interference, disability, anxiety, and depressive symptoms.

Results: Bivariate analyses evidenced significant associations between pain sensory qualities, catastrophizing, perceived injustice, and all health variables. In multivariate analyses, pain sensory qualities were associated with pain severity (β=0.10; 95% confidence interval [CI]=0.05, 0.14; t=4.28, P<0.001), while perceived injustice was associated with pain interference (β=0.08; 95% CI=0.03, 0.12; t=3.59, P<0.001), disability (β=0.25; 95% CI=0.08, 0.42; t=2.92, P=0.004), anxiety (β=0.18; 95% CI=0.08, 0.27; t=3.65, P<0.001), and depressive symptoms (β=0.14; 95% CI=0.05, 0.23; t=2.92, P=0.004). Age, sex, pain duration, and marital adjustment were not associated with health variables either in bivariate or in multivariate analyses (all P>0.010).

Discussion: As expected, communalities between biopsychosocial variables exist, which resulted in a reduced number of unique contributions in multivariate analyses. Perceived injustice emerged as a unique contributor to variables, which points to this psychological construct as a potentially important therapeutic target in multidisciplinary treatment of pain.