Shah, Jay D.

BACKGROUND: Complex regional pain syndrome (CRPS) is a debilitating and painful condition accompanied by sensory, autonomic, trophic, and/or motor abnormalities. Although CRPS is rare in the general population, the prevalence among individuals at higher risk, particularly posttraumatic and postsurgical patients, remains unknown. This study aims to provide a benchmark that quantifies CRPS prevalence in high-risk groups, and offers insights on potential predictors of developing CRPS. METHODS: We conducted a systematic review and meta-analysis to identify studies reporting prevalence of CRPS after an inciting event (eg, fracture, surgery), specifically 12-month and 24-month prevalence (primary outcomes), as well as 3-month and 6-month prevalence (secondary outcomes). Estimates from individual studies were transformed using double-arcsine transformation, and the resulting estimates with 95% confidence interval (CI) were pooled in a meta-analysis using a random-effects model. RESULTS: We included 214 articles with data from 2491,378 participants worldwide (35 countries), of which 16,873 had CRPS. The pooled 12-month and 24-month global prevalence was 3.04% (95% CI, 2.64–3.48) and 6.46% (95% CI, 5.46–7.53), respectively. Subgroup analysis and meta-regression were performed to understand the impact of population-dependent (mechanism of injury, type of CRPS), contextual-dependent (socioeconomic status), and methodological-dependent (study design, publication year) factors. The 12-month prevalence was higher in countries with a high human development index (HDI) compared to those with a medium or very high HDI, was higher in participants with a traumatic inciting injury only versus those with surgical injury only or traumatic/surgical injury, and was higher in prospective versus retrospective studies. Meta-regression analysis showed that publication year was a significant moderator, with more recent articles reporting lower 12-month prevalence. CONCLUSIONS: This study provides a benchmark of the global prevalence of CRPS, which anesthesiologists and pain specialists can use to prioritize early diagnosis and identify those at the highest risk for CRPS.