Hospitalisations caused by adverse drug reactions (ADR): a meta-analysis of observational studies.
OBJECTIVE
To establish the percentage hospital admission related to adverse drug reactions (ADRs) from the data available in the literature.


METHODS
Literature search in the Medline database, meta-analysis.


RESULTS
From the literature it is revealed that a considerable part of all hospital admissions are related to adverse drug reactions. However, these data are not homogenous, i.e. larger studies display a lower percentage of ADR related hospital admission, while smaller studies display a higher percentage. Subgroup analysis showed that for elderly people the odds of being hospitalised by ADR related problems is 4 times higher than for younger ones (16.6% vs. 4.1%). A considerable part of these hospitalisations can be prevented. Subgroup analysis revealed that in the elderly up to 88% of the ADR related hospitalisations are preventable; for the non-elderly this is only 24%. Comparatively more elderly people are hospitalised than younger ones. Combining these findings, twice as much elderly people are hospitalised by ADR related problems than non-elderly, while preventability of ADR related hospitalisation might yield 7 times more people in the elderly than in the non-elderly. The estimation of the costs of ADR related hospitalisations in the Health Care system in The Netherlands is discussed.


CONCLUSIONS
Many elderly people are hospitalised by ADR related problems; an important part of these hospitalisations can be avoided.
Beijer
H J M
HJ
Scientific Institute Dutch Pharmacists (WINAp), P.O. Box 30460, 2500 GL The Hague, The Netherlands. h.j.m.beijer@winap.nl
de Blaey
C J
CJ
D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data; D000367:Age Factors; D000368:Aged; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D019370:Observation / Q000379:methods*