Variation of the prevalence of pediatric polypharmacy: A scoping review

Purpose: To examine the range of prevalence of pediatric polypharmacy in literature through a scoping review, focusing on factors that contribute to its heterogeneity in order to improve the design and reporting of quality improvement, pharmacovigilance, and research studies. Methods: We searched Ovid Medline, PubMed, EMBASE, CINAHL, Ovid PsycINFO, Cochrane CENTRAL, and Web of Science Core Collection databases for studies with concepts of children and polypharmacy, along with a hand search of the bibliographies of six reviews and 30 included studies. We extracted information regarding study design, disease conditions, and prevalence of polypharmacy. Results: Two hundred eighty-four studies reported prevalence of polypharmacy. They were more likely to be conducted in North America (37.7%), published after 2010 (44.4%), cross-sectional (67.3%), in outpatient settings (59.5%). Prevalence ranged from 0.9% to 98.4%, median 39.7% (interquartile range [IQR] 22.0%-54.0%). Studies from Asia reported the highest median prevalence of 45.4% (IQR 27.3%-61.0%) while studies from North America reported the lowest median prevalence of 30.4% (IQR 14.7%-50.2%). Prevalence decreased over time: median 45.6% before 2001, 38.1% during 2001 to 2010, and 34% during 2011 to 2017. Studies involving children under 12 years had a higher median prevalence (46.9%) than adolescent studies (33.7%). Inpatient setting studies had a higher median prevalence (50.3%) than studies in outpatient settings (38.8%). Community level samples, higher number and duration of medications defining polypharmacy, and psychotropic medications were associated with lower prevalence. Conclusions: The prevalence of pediatric polypharmacy is high and variable. Studies reporting pediatric polypharmacy should account for context, design, polypharmacy definition, and medications evaluated.