Prevalence of breakthrough cancer pain: a systematic review and a pooled analysis of published literature.

ABSTRACT

CONTEXT Despite the large body of literature on breakthrough cancer pain (BTcP), an accurate estimate of BTcP prevalence is still not available. OBJECTIVES: To provide an estimate of BTcP prevalence and investigate the association between different prevalence rates and possible determinants. METHODS: We conducted MEDLINE and EMBASE searches for studies published from 1990 to 2012 reporting data on BTcP prevalence in adult cancer populations. Pooled prevalence rates from observational studies with an acceptable methodological quality were computed. The association between BTcP prevalence and possible predictors was investigated using subgroup analyses and meta-regression. RESULTS: Twenty-seven observational studies were identified. When quality criteria were applied, only 19 studies were included in the pooled analysis. The overall pooled prevalence was 59.2%, with high heterogeneity. The lowest prevalence rates were detected in studies conducted in outpatient clinics (39.9%), and the highest prevalence was reported in studies conducted in hospice (80.5%). The association between BTcP prevalence and other determinants such as publication year, age, gender, metastatic disease prevalence, or baseline pain intensity did not reach statistical significance. CONCLUSION: In the context of a large between-studies heterogeneity, more than one in two patients with cancer pain also experiences BTcP, with some variability according to clinical and organizational variables.