LAUSR

H Gyllensten, KM Hakkarianen, C Rehnberg, J Natanaelsson, K Andersson Sundell, M Petzold, S Svensson, S Hägg, A K Jönsson Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden EPID Research, Espoo, Finland Department of Learning, Informatics, Management and Ethics – LIME, Karolinska Institutet, Stockholm, Sweden Nordic School of Public Health NHV, Gothenburg, Sweden Department of Public Health and Community Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Health Metrics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Närhälsan Hjällbo Medical Centre, Gothenburg, Sweden Department of Drug Research/Clinical Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden National Board of Forensic Medicine, Department of Forensic Genetics and Forensic Toxicology, Linköping, Sweden Contact: [email protected] Background Adverse drug events (ADEs) cause considerable costs in hospitals. However, little is known about costs caused by ADEs outside hospitals and its effect on productivity. Moreover, no previous studies have explored how alternative methods for assigning resource use and costs to ADEs affects the cost estimate. The aim was thus to describe the direct and indirect costs caused by ADEs and how costs are affected by methodological decisions in assigning used resources to ADEs, and estimating costs for the assigned resources. Methods ADEs were identified from a random sample of 4970 Swedish adults, using medical records from primary care, other outpatient care and inpatient care. Prevalence-based costs for ADEs were calculated based on resource use judged to be caused by ADEs and identified in administrative registers, including direct costs (drugs and healthcare resource use) and indirect costs (estimated from lost productivity during healthcare contacts). For healthcare costs, a sensitivity analysis was conducted for the assignment of resource use and costs to ADEs, to account for resource use for which no cost was registered. Results The estimated cost for resource use caused by ADEs were EUR 505 per patient with ADEs (95% confidence interval: EUR 345665). Indirect costs corresponded to 38% of all costs. However, healthcare costs resulting from ADEs increased by up to 84% using alternative methods for assigning resource use and costs to ADEs. Conclusions The results adds to the evidence on the large economic impact of ADEs in society and although indirect costs were only estimated during ongoing healthcare contacts, it identifies indirect costs as an important component of the overall costs for ADE. Moreover, the estimated healthcare costs resulting from ADEs varied considerably based on alternative methods for assigning resource use and costs to ADEs.