Potentially inappropriate medications in geriatric outpatients with polypharmacy: application of six sets of published explicit criteria

Abstract

Aim: Our aim was to compare the practicability of six different potentially inappropriate medication (PIM) criteria in geriatric outpatients with polypharmacy.

Methods: We analysed baseline data from the Medication Safety Review Clinic in Taiwanese Elders (MSRC-Taiwan) study. The prevalence and correlates of PIMs were determined on the basis of criteria developed in the USA, Canada, France, Norway, Ireland and Thailand. The percentage of PIMs considered as drug-related problems and the problem-solving rate are reported.

Results: In the 193 participants, the prevalence of PIM varied from 24 to 73%. Application of the criteria revealed that a high number of chronic medications was a common risk factor for having at least one PIM. Of the 1713 medications reviewed, 5.6-14.8% were considered PIMs. Only 30-40% of the identified PIMs were reported as drug-related problems by the MSRC team experts. Criteria with a higher number of statements and a higher percentage of local market/institution drug availability tended to detect more PIMs.

Conclusions: The prevalence of PIM varied significantly when different criteria were applied. Caution should be exercised in applying PIM criteria developed in other regions when medication availability in the local market is limited.

Figure 1

Prevalence of potentially inappropriate medications from six sets of explicit criteria (total n = 193). Numbers of patients are shown above the bars. Abbreviations: NORGEP, Norwegian General Practice criteria; STOPP, the Screening Tool of Older Person's Prescriptions. No PIM (▪); 1 PIM (); 2 PIMs (□); >3 PIMS ()

Figure 2

Person-level analysis of prevalence, number of statements and availability (percentage) of potentially inappropriate medications in National Taiwan University Hospital (NTUH) based on six sets of criteria. Abbreviations: NORGEP, Norwegian General Practice criteria; STOPP, the Screening Tool of Older Person's Prescriptions. Statements (); Availability (%) (); Prevalence (%) ()