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OP77 The prevalence and characteristics of adverse drug reaction-related hospital admissions in older patients
  1. CC Cahir1,
  2. CC Curran2,
  3. CW Walsh1,
  4. DW Williams2,
  5. KB Bennett1
  1. 1Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
  2. 2Department of Geriatric and Stroke Medicine, Royal College of Surgeons in Ireland and Beaumont Hospital, Dublin, Ireland


Background Older people experience greater morbidity with a corresponding increase in medication use resulting in a potentially higher risk of adverse drug reactions (ADRs).The aim of this study was to determine the prevalence and characteristics of ADR-related hospital admissions among older patients (≥ 65 years).

Methods A cross-sectional study of ADR prevalence in patients aged ≥ 65 years admitted acutely to a large tertiary referral hospital in Ireland over a 7 month period (November 2016- June 2017). A multifaceted review of each hospital admission was undertaken to assess the likelihood of an ADR being a reason for admission (cause of admission or contributing to admission) in the context of the patient’s medication, clinical condition, medical history, comorbidities and investigations. A number of decision aids were also applied by two independent reviewers to assess ADR causality (Naranjo criteria, WHO criteria, Liverpool Algorithm). The avoidability (Hallas criteria) and severity (Hartwig severity assessment scale) of the ADR were also assessed. Differences in causality, preventability and severity were reviewed by a third reviewer.

Results In total, 3760 hospital admission episodes (in 3091 patients) were screened and 377 admissions were ADR-related (10.02%, 95% CI 9.06%, 10.98%); 43 admissions were due to ≥2 ADRs (N=424 ADRs). 360 (11.64% 95% CI 10.51%, 12.77%) patients had at least one ADR with 50 (16.18%) patients experiencing ≥ 1 ADR-related admission. In summary, 219 (58.09%) admissions were caused by an ADR, while ADRs contributed to 158 (41.91%) admissions. For the majority of admissions (N=216, 57.60%) there was no other known acute medical issue that may have acted in synergy with the medication resulting in the ADR. Of the 377 ADR-related admissions, 43 (11.41%) were deemed definitely avoidable and 225 (59.68%) possibly avoidable and 350 (92.84%) were classified as moderate severity.

Conclusion One in ten hospital admissions were ADR-related, with approximately 70% potentially avoidable. Interventions are needed to reduce ADRs and improve medication management in older populations.

  • Adverse drug reaction
  • older people
  • prescribing

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