Clinical factors associated with increased length of stay and readmission in patients with medication-related hospital admissions: a retrospective study

Ilsa R. Wojt, Rose Cairns, Isabelle Gillooly, Asad E. Patanwala, Edwin C.K. Tan

Research output: Contribution to journalArticlepeer-review


Background: Adverse drug events (ADEs) remain a key contributor to hospitalisations, resulting in long hospital stays and readmissions. Information pertaining to the specific medications and clinical factors associated with these outcomes is limited. Hence, a better understanding of these factors and their relationship to ADEs is required. Objectives: To investigate medications involved, clinical manifestations of ADE-related hospitalisations, and their association with length of stay and readmission. Methods: A retrospective medical record review of patients admitted to a major, tertiary referral hospital in NSW, Australia, from January 2019 to August 2020 was conducted. ADEs were identified using Australian Refined Diagnosis Related Group (AR-DRG) codes: X40, X61, X62 and X64. Medications were classified per the Anatomical Therapeutic Chemical (ATC) classification system and clinical symptoms were classified per the International Classification of Disease (ICD) 9-CM. Logistic regression was performed to assess the relationship between medication and presentation classes with length of stay (≥2 days vs <2 days) and readmission. Results: There were 125 patients who met inclusion criteria (median age = 64 [interquartile range, 45–75] years; 53.6% male). Anti-thrombotic agents, opioids, antidepressants, antipsychotics, insulins and NSAIDs were the most implicated pharmacological classes. Neurological medications and falls were associated with a length of stay ≥2 days (adjusted odds ratio [aOR] 3.92, 95% confidence interval [CI] 1.48–10.33 and aOR 3.24, 95% CI 1.05–10.06, respectively). Neurological medications and neurological and cognitive disorders were associated with an increased likelihood of 90-day readmission (aOR 2.63, 95% CI 1.05–6.57 and aOR 3.20, 95% CI 1.17–8.75, respectively). Conclusion: This study identified neurological medications as high-risk for increased length of stay and readmission in those hospitalised due to ADEs. This highlights the need for judicious prescribing and monitoring of these medications.

Original languageEnglish (US)
JournalResearch in Social and Administrative Pharmacy
StateAccepted/In press - 2021


  • Adverse drug events
  • Length of stay
  • Medication safety
  • Medication-related hospitalisation
  • Neurological medicines
  • Readmission

ASJC Scopus subject areas

  • Pharmacy
  • Pharmaceutical Science


Dive into the research topics of 'Clinical factors associated with increased length of stay and readmission in patients with medication-related hospital admissions: a retrospective study'. Together they form a unique fingerprint.

Cite this