Eighteen studies that assessed the consequences of polypharmacy were included, as were five studies of interventions to reduce polypharmacy (numbers of patients were not reported for most studies).
Consequences of polypharmacy (18 studies): Reduced adherence, inappropriate prescribing, adverse drug reactions, increased incidence of geriatric syndromes, decline in physical and instrumental activities of daily living were detailed.
Interventions to reduce polypharmacy (five RCTs): Three studies assessed the impact of prescriber education on reducing polypharmacy. All studies reported reductions in medication use among patients involved in the studies. In one study, 12.5% of potentially inappropriate medications were stopped. In another, 20% of the 42% of patients who had a review had a medication stopped. In the third study the polypharmacy event rate (five or more medications) dropped from 7.99 to 4.1 per 1,000 patients. Statistical significance of these reductions was not reported.
One study assessed use of a medication grid by hospital residents and found that the number of medications taken by patients in the intervention group reduced by 0.92 per patient compared with an increase of 1.65 for the control group. This difference was statistically significant (p<0.001). There was also a reduction in the number of doses per day, although it was not clear whether this was statistically significant.
The use of inpatient geriatric evaluation and management was found by one RCT (n=834) to result in a statistically significant reduction in unnecessary drug use (defined by the MAI) compared with usual care (p < 0.05).