Via Dolorosa: impact of nociplastic pain on hospitalisation outcomes. A retrospective cohort study

OBJECTIVES: Nociplastic pain, characterised by altered central pain processing, is associated with increased healthcare utilisation. This study investigated the relationship between nociplastic pain, based on clinical diagnoses of fibromyalgia, chronic pain, or myofascial pain, and hospital outcomes in patients. METHODS: A retrospective cohort study was conducted using hospital records of hospitalised patients. Patients aged ≥18 years with a diagnosis of fibromyalgia, chronic pain, or myofascial pain were classified as the research group, while a comparison group of hospitalised patients without these diagnoses was selected. Outcomes included length of stay (LOS) for the index hospitalisation, recurrent hospitalisations within 6 months, Opioid use disorder (OUD), and 5-year mortality. Statistical analyses included t-tests, Wilcoxon tests, linear and Poisson regressions, adjusting for age and sex. RESULTS: Of 18,393 patients, 3,326 (18.1%) were in the research group. The research group was older (mean age 62.35 vs. 50.57 years, p<0.001) and had a higher proportion of females (72.7% vs. 56.6%). Adjusted analyses showed longer LOS in the research group (mean 6.89 vs. 5.59 days, p=0.002), higher recurrent hospitalisations (p<0.001), and increased OUD (87.5% of cases in the research group, p<0.001). Surprisingly, 5-year mortality risk was lower in the research group (HR 0.523, p<0.001). CONCLUSIONS: Nociplastic pain diagnoses are associated with prolonged hospitalisations, increased readmissions, and OUD, but lower long-term mortality. These findings highlight the need for targeted pain management strategies.