# Psychological and functional predictors of chronic pain outcomes in youth with Duchenne muscular dystrophy

## TL;DR

The study found that psychological distress and physical function are key factors influencing chronic pain in children with Duchenne muscular dystrophy over a year.

## Contribution

The study identifies psychological distress and physical function as independent predictors of chronic pain outcomes in youth with DMD.

## Key findings

- Psychological distress and reduced physical function independently predict chronic pain in DMD.
- Psychological distress mediates the effects of fatigue and HRQoL on pain outcomes.
- Physical function is primarily linked to pain severity, while psychological distress and fatigue affect broader pain burden.

## Abstract

This study aimed to characterize 1-year pain trajectories in children with Duchenne muscular dystrophy (DMD) and identify predictors across physical, psychosocial, and quality-of-life domains.

We conducted a 1-year prospective cohort study involving young males with genetically confirmed DMD. Baseline assessments included sociodemographic characteristics, clinical history, chronic pain profile, fatigue, psychological distress, and health-related quality of life (HRQoL). Follow-up assessments were completed approximately 1 year later through structured telephone interviews with participants and their primary caregivers. Outcomes at follow-up included the presence of chronic pain, pain intensity, and pain interference.

A total of 73 participants (median age = 10.6 years; range = 8–16 years) completed the 1-year follow-up assessment. Multivariable logistic regression analysis indicated that physical function (p = 0.028; OR = 0.929, 95% CI [0.586, 0.988]) and psychological distress (OR = 1.502, 95% CI [1.157, 5.508], p = 0.004) were significant independent predictors of chronic pain. Physical function also demonstrated a modest indirect effect through psychological distress (indirect effect = −0.048, 95% CI [−0.369, −0.0004]). Fatigue (indirect effect = −0.116, 95% CI [−0.567, −0.038]) and HRQoL (indirect effect = −0.064, 95% CI [−0.428, −0.022]) influenced pain outcomes only indirectly via psychological distress. Multivariable linear regression further showed that both psychological distress (severity: B = 0.208, p < 0.001; 95% CI [0.105, 0.307]; interference: B = 0.193, p < 0.001; 95% CI [0.100, 0.279]) and fatigue (severity: B = −0.054, p = 0.037; 95% CI [−0.107, −0.006]; interference: B = −0.047, p = 0.020; 95% CI [−0.085, −0.008]) were associated with increased pain burden. Physical function predicted pain severity (B = −0.036, p = 0.001; 95% CI [−0.057, −0.012]) but not pain interference, whereas HRQoL did not show a significant effect in either model.

This prospective study identifies psychological distress and reduced physical function as independent contributors to chronic pain outcomes in DMD, with psychological distress mediating the effects of fatigue and HRQoL. Physical function was primarily associated with pain severity, whereas psychological distress and fatigue predicted the broader pain burden, including functional interference. These findings support a biopsychosocial model in which psychosocial factors translate underlying biological vulnerability into clinically significant pain.