Prevalence and impact of prescribing cascades in community‐dwelling adults: Longitudinal analysis of the Irish longitudinal study on ageing (TILDA)

Prescribing cascades occur when medication is prescribed to prevent/treat the adverse effects of another medication and may be intentional/unintentional. This study examines the prevalence of nine prescribing cascades (ThinkCascades) in The Irish Longitudinal StuDy on Ageing (TILDA). A prospective cohort study examined those aged ≥50 years with three consecutive data collection waves (N = 6118) recorded between Wave 1 (2009/2011) and Wave 5 (2018). Nine separate analysis sets were created, representing each ThinkCascade. Exposure was the incident use of Drug A at wave x. A prescribing cascade was defined as the incident use of Drug B at wave x + 1, with continued use of Drug A. Five out of nine ThinkCascades were identified over 9 years of follow-up. Overall, 24 participants experienced at least one ThinkCascade, representing a 2.1% prevalence (n = 1153 eligible). This low prevalence may indicate prescribers' awareness of prescribing cascades. Higher event rates are required to examine any association with adverse health outcomes.