(047) Characteristics and prevalence of potential inappropriate proton-pump-inhibitors users among older adults in Portugal: A nationwide retrospective study

Background: Proton pump inhibitors (PPI), commonly prescribed for acid-related disorders, are frequently used among older individuals, despite concerns about appropriateness. While short-term use seems safe, long-term use is associated with serious adverse drug events (ADEs). Except for severe acid-related disorders, clinical guidelines advise prescribing PPI at the lowest effective dose and for the shortest possible duration (4 to 8 weeks).

Objectives: To estimate the prevalence of potentially inappropriate PPIs (PIPPI) use among older adults in Portugal and its determinants.

Methods: Nationwide retrospective cohort study of people aged ≥65 years old using PPI (ATC/WHO: A02BC). Data on sociodemographic characteristics (sex, age), prescriber specialty and outpatient medication dispensed in the 2021 year were retrieved from an anonymized pharmacy population-based cohort, covering approximately 83% of Portuguese pharmacies. Days of medicine supply were calculated using the defined daily dose (DDD). PIPPI users were defined as those with a continuous covered period of over 8 weeks. Prevalence of PIPPI use (per 100 persons) was computed as the ratio of the estimated number of people ≥65 years old with at least 1-episode of PIPPI by the number of people ≥65 years living in Portugal for the same year. Characteristics such as sex, age, polypharmacy (use of ≥ 5 medicines), concurrent use of NSAID, oral anticoagulants (OA) and antiplatelet agents (AA) and, proportion of most frequent prescriber specialty, were compared between PIPPI and non-PIPPI users.

Results: A total of 533,869 PPI users aged ≥65 years were identified, with 82.2% classified as PIPPI users. Compared to non-PIPPI, PIPPI users were more likely to be female (64.6% vs 59.6%), older (76.7 (SD=7.8) vs 75.0 (SD=7.6)), and used on average more medicines (6.9 (SD=3.4) vs 5.4 (SD=3.1)) (p < 0.0001). Polypharmacy was found in 75.1% of PIPPI users compared to 55.6% in non-PIPPI users (p < 0.0001). Potentially inappropriate concurrente use with NSAIDs, OA or AA was higher in PIPPI users compared to non-PIPPI (52.7% vs. 28.8%, p< 0.0001). General practitioner was the most common PPI prescriber, accounting for 82.6% of PIPPI users compared to 61.1% in the non-PIPPI users (p < 0.0001). Overall, nationwide PIPPI prevalence among older adults was found to be 20.6%.

Conclusions: In Portugal, one in five older individuals are PIPPI-users, posing a significant risk of ADEs and contributing to unnecessary waste. The higher prevalence of inappropriate prescribing among females and older adults suggests potential disparities in prescription quality. Enhanced efforts are needed to improve prescribing and deprescribing practices.