Adverse Drug Reaction-Related Hospitalisations: A Population-Based Cohort Study

Pharmacoepidemiol Drug Saf. 2008 Apr;17(4):365-71. doi: 10.1002/pds.1565.


Purpose: To evaluate the extent, characteristics and determinants of adverse drug reaction (ADR)-related hospitalisations on a population-based level in 2003.

Methods: We performed a cohort study in the Integrated Primary Care Information (IPCI) database, a general practitioners (GPs) research database with longitudinal data from electronic patient records of a group of 150 GP throughout the Netherlands. Hospital discharge letters and patient records were reviewed to evaluate ADR-related hospitalisations applying WHO causality criteria. The prevalence of ADR-related hospitalisations per total admissions and the incidence per drug group were calculated. Avoidability and seriousness of the ADRs causing admission were assessed applying the algorithm from Hallas.

Results: We identified 3515 hospital admissions, 1277 elective and 2238 acute. Of the acute admissions, 115 were caused by an ADR giving a prevalence of 5.1% (95% confidence intervals (CI): 4.3-6.1%). The prevalence of ADR-related acute admissions increased with age up to 9.8% (95%CI: 7.5-12.7) for persons >75 years. The ADRs that most frequently caused hospitalisations were gastro-intestinal bleeding with anti-thrombotics, bradycardia/hypotension with cardiovascular drugs and neutropenic fever with cytostatics. The incidence rate of ADR-related hospitalisations per drug group was highest for anti-thrombotics and anti-infectives and was relatively low for cardiovascular drugs. Fatality as a direct consequence of the ADR-related admission was 0.31%. In elderly patients 40% of the ADRs causing hospitalisation were judged to be avoidable.

Conclusions: The extent and potential avoidability of ADR-related hospitalisations is still substantial, especially in elderly patients. Measures need to be put into place to reduce the burden of ADRs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cohort Studies
  • Drug-Related Side Effects and Adverse Reactions*
  • Female
  • Hospitalization / statistics & numerical data*
  • Humans
  • Male
  • Medical Records Systems, Computerized
  • Middle Aged
  • Netherlands / epidemiology
  • Pharmacoepidemiology
  • Population Surveillance / methods*
  • Prevalence