Modifiable pathways from pain to functional status: Confirmatory baseline results from a randomised trial of African...

This study tested a model of cancer-related pain and functional status in African American patients, including beliefs about the ability to control pain as a key determinant of distress and functional status.

Baseline data from a randomised clinical trial consisting of clinical and patient-reported outcomes were used. Participants were 228 African American patients experiencing moderate to severe pain within the past 2 weeks. The model comprised four latent constructs: pain, perceived control over pain, pain-related distress and functional status. Confirmatory factor analysis was used to validate the factor structure of the measurement model. Structural equation modelling was used to estimate direct and mediated effects.

The measurement model fit well (RMSEA = 0.06, SRMR = 0.05) with all loadings significant (p < 0.05). The structural model also fit well (RMSEA = 0.04, SRMR = 0.05). The complex mediated pathway from pain to functional status through perceived control over pain and pain-related distress was strong and significant (specific indirect effect = -0.456, p = 0.004). Mediation by perceived control accounted for a 47% reduction of the effects of pain on functional status.

If these results hold up longitudinally, interventions to increase perceived control over pain have the potential to improve functional status by decreasing pain-related distress.