Epidemiology of drug exposure and adverse drug reactions in two Swiss departments of internal medicine

Abstract

Aims To explore drug exposure, frequency of adverse drug reactions (ADRs), types of ADRs, predisposing risk factors and ADR-related excess hospital stay in medical inpatients. Methods Structured data regarding patient characteristics, 'events' (symptoms, laboratory results), diagnoses (ICD10) and drug therapy were collected using a computer-supported data entry system and an interface for data retrieval from electronic patient records. ADR data were collected by 'event monitoring' to minimize possible bias by the drug monitor. The causality of each event was assessed in relation to disease(s) and drug therapy. Results The analysis included 4331 (100%) hospitalizations. The median observation period was 8 days. The median number of different drugs administered per patient and day was 6 and varied between 4 (Q 1 ) and 9 (Q 3 ) different drugs in 50% of all hospital days. In 41% of all hospitalizations at least one disease-unrelated event could be possibly attributed to drug therapy. Clinically relevant ADRs occurred in 11% of all hospitalizations. In 3.3% of all hospitalizations ADRs were the cause of hospital admission. The incidence of possibly ADR-related deaths was 1.4‰. Factors predisposing for clinically relevant ADRs were female gender and polypharmacy. ADR-related excess hospital stay accounted for 8.6% of hospital days. Conclusions These data demonstrate the feasibility of the developed 'event monitoring' system for quantitative analysis of ADRs in medical inpatients. With increasing numbers of recorded patients the pharmacoepidemiological database provides a valuable tool to study specific questions regarding drug efficacy and safety in hospitalized patients.

Incidence and Economic Burden of Adverse Drug Reactions among Elderly Patients in Ontario Emergency Departments

“…Consistent with previous work,[30–33] this study identified ADRs to be more common among females (60.7% of the overall ADR-related ED visits) than males. However, females appear to have a lower risk for experiencing severe ADRs.…”

Adverse drug events in hospitals: a systematic review

“…Interestingly, 62.1% of the studies (18/29) 6,7,8,9,12,13,15,16,19,20,21,22,25,26,27,31,33,34 involved university, academic, or teaching hospitals, i.e., presumably large-scale, high-complexity hospital units.…”

“…Forty-eight percent of the studies (14/29) 6,8,9,14,18,19,22,23,24,25,28,29,30,31 used a retrospective approach, i.e., the presence of ADEs was analyzed after the patient was discharged; 48.3% of the studies (14/29) 7,11,12,13,15,16,17,20,21,26,27,32,33,34 used a prospective approach, whereby the ADEs were identified during the hospital stay; and one study 10 was cross-sectional, where ADEs were identified using a survey. Among the studies with a prospective approach, two used retrospective strategies to complement the evaluation, based on an analysis of hospital discharge forms 16,21 .…”

“…Twenty-eight articles remained 6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33 for evaluation, plus one more article retrieved by manual search 34 . Table 1 describes the studies, conducted in 13 countries from North America, Europe, South America, and Asia.…”

“…Six were multi-center 6,9,22,23,24,29 and Figure 1 Flowchart of systematic article search and selection on in-hospital adverse drug events.…”