Ontario Study Identifies 24 Common Prescribing Cascades in Older Adults

The study used ICES population data linked to a consensus list of 65 PIPCs developed by 12 international experts. Researchers scored each cascade on prevalence of the index drug, frequency of the second prescription within a defined window, and strength of the causal link. This produced a ranked set of 24 cascades most likely to occur at scale and generate harm or cost. Statins, NSAIDs, and iron supplements ranked among the leading triggers.

Prescribing cascades arise when a drug side effect is misread as a new condition. Older adults face elevated risk because polypharmacy rates exceed 40 percent and symptom attribution becomes harder with multiple prescribers. The Ontario findings align with earlier U.S. and European observational work showing similar NSAID-blood-pressure and diuretic-gout sequences, yet add population-level frequency estimates that prior single-center studies lacked.

Next steps include embedding automated alerts in electronic records and routine medication reviews that query indication and start date. Without such tools, the pattern will persist as chronic-disease guidelines continue to recommend additional agents without deprescribing protocols.

Evidence quality remains observational; randomized trials testing cascade-prevention interventions are still required to quantify net clinical benefit.