Prevalence and management of chronic nonmalignant pain in palliative care populations: A systematic review

Objectives. To investigate the prevalence and current approaches to clinical management of chronic nonmalignant pain in patients referred to palliative care services. Methods. A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered with PROSPERO (CRD42021205432). Six databases were searched on 25 August 2020 and again on 11 July 2022: PubMed and Ovid MEDLINE, Elsevier Scopus, PsychINFO, the Cochrane Library, and CINAHL. Search included prevalence or intervention studies with patients who had chronic nonmalignant pain and were referred to palliative care services. Screening was undertaken independently by 2 reviewers. Results. The searches returned 417 titles; subsequent screening identified 5 eligible studies, 4 from the USA and 1 from Hong Kong, including 2 cohort and 3 cross-sectional studies. Sample sizes ranged from 137 to 323, with a total of 1,056 patients. The prevalence of chronic nonmalignant pain ranged from 14% to 34% across different palliative care settings. There was significant crossover of pain types; 54% of patients with chronic no-malignant pain had additional cancer-related pain or cancer treatment-related pain. Opioids were used to manage stand-alone chronic nonmalignant pain for 39% of patients compared to 58% with mixed chronic nonmalignant pain and other pain diagnoses. Significance of results. Five studies have documented the prevalence of chronic nonmalignant pain of 14-34% in palliative care. Further research including prevalence and treatment studies would provide clearer evidence for best practice management of chronic nonmalignant pain in the palliative care setting.