Eur J Clin Pharmacol (2003) 58: 707–714 DOI 10.1007/s00228-002-0535-5
P H A R M A C O E PI D E M I O L O G Y A N D PR E S C R I P T I O N
Annemie Somers Æ Mirko Petrovic Æ Hugo Robays Marc Bogaert
Reporting adverse drug reactions on a geriatric ward: a pilot project
Received: 6 May 2002 / Accepted: 19 September 2002 / Published online: 11 February 2003 Ó Springer-Verlag 2003
Abstract Objective: To test a method for registration of adverse drug reactions (ADRs) resulting in hospital admission and of ADRs occurring during hospital stay. Spontaneous reporting was compared with data from patient interview. Methods: Spontaneous reporting of ADRs by nurses and physicians, as well as patient interviews by pharmacists. This pilot project was carried out in the geriatric ward of the Ghent University Hospital over a period of 8 months in order to develop suitable registration forms and to test feasibility. Causality, severity, type and level of intervention of the reported ADRs were analysed. Reports from physicians and nurses were compared with the data obtained by patient interviews. Results: During the 8 months, for 168 patients, 12 spontaneous reports were received from physicians and nurses. Fifty-six of these patients were interviewed and 32 ADRs were reported. Only 2 ADRs detected by patient interview were also reported spontaneously. The interviews of the 56 geriatric patients indicated that 20% of them were admitted to the hospital because of an ADR. ADRs occurred during hospital stay in another 20% of those patients. Conclusion: Spontaneous reporting by physicians and nurses revealed considerably fewer ADRs than patient interview by pharmacists. Physicians and nurses reported the more serious ADRs that occurred during hospital stay, whereas the interviews revealed more ADRs that caused hospital
A. Somers (&) Æ H. Robays Department of Pharmacy, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium E-mail:
[email protected] Tel.: +32-9-2405373 Fax: +32-9-2404974 M. Petrovic Department of Internal Medicine, Ghent University Hospital, Ghent University, Belgium M. Bogaert Heymans Institute of Pharmacology, Ghent University, Belgium
admission. Our data confirm that ADRs are an important cause of hospital admission of geriatric patients and occur frequently during their hospital stay. Keywords Adverse drug events (ADE) Æ Adverse drug reactions (ADR) Æ Patient interview Æ Pharmacovigilance Æ Spontaneous reporting
Introduction Adverse drug reactions (ADRs) are a frequent cause for hospitalisation and occur often in hospitalised patients [1, 2, 3, 4, 5]. However, the frequency of ADRs leading to hospital admission or occurring during hospital stay differs markedly from study to study [6]. This is probably due in part to the use of different definitions for ADRs [7]. According to the World Health Organization (WHO) definition, an ADR is ‘‘a response to a drug which is noxious and unintended, and which occurs at doses normally used in man for the prophylaxis, diagnosis, or therapy of disease, or for the modification of physiological function’’. Some authors report, in fact, adverse drug events (ADEs), in accordance with the WHO definition ‘‘any untoward medical occurrence that may present during treatment with a pharmaceutical product but which does not necessarily have a causal relationship with this treatment’’. Other authors also include in their definition of ADRs medication errors, which are preventable events leading to inappropriate medication use or patient harm. The variation in reported incidence of ADRs can also be explained by different methods of investigation. Some studies involve only spontaneous reporting while others use active monitoring systems. Moreover, there are differences between stimulated versus non-stimulated reporting systems, as well as between manual and electronic active monitoring systems. In Belgium, a national ADR reporting system exists, organised by the Belgian Center for Pharmacovigilance. However, data show that the number of reports coming
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from hospital staff members is quite low [8]. In order to test the detection rate and the applicability of the methods, we compared the results of spontaneous reporting and of active observation of ADRs in the geriatric ward of our university hospital.
Methods Setting and study design The Drug and Therapeutics Committee of our hospital initiated the study. In Belgium, such a committee is in charge of developing the hospital formulary, formulating the procedures of drug handling, inspecting the drug distribution system and analysing the drug consumption. This prospective study was conducted in 1999, from 26 March until 24 November, at the geriatric ward of the Ghent University Hospital (27 beds). ADRs were collected by spontaneous reporting by nurses and physicians, and by interview of patients. Before the interview, the patients received an information sheet and gave written informed consent. The institutional ethics committee approved the study. Population and sampling Spontaneous reporting of ADRs was possible for all patients admitted to the geriatric ward (27 beds) during the study period. For patient interview, however, not all patients were eligible; exclusion criteria were dementia or confusion, severe illness, short hospital admission (
