MedicalResearch.com Interview with:
Katja M Hakkarainen, M.Sc.Pharm.
Doctoral researcher Nordic School of Public Health NHV
Guest teacher, Doctoral studentSection for Social Medicine
Department of Public Health and Community Medicine, Institute of Medicine Sahlgrenska Academy, University of Gothenburg
MedicalResearch.com: What are the main findings of the study?
Answer: In total 12% of the adult general public was found to experience harm from medicines, i.e. adverse drug events (ADEs), when we scrutinised the medical and dispensing records of 4970 adults in Sweden during three months, including 29 inpatient care departments in three hospitals, 110 specialised outpatient clinics, and 51 primary care units. Most ADEs were adverse drug reactions (also called side effects) and sub-therapeutic effects. Commonly used drugs caused most ADEs, with a high frequency of adverse drug reactions from antidepressants and cardiovascular drugs as well as sub-therapeutic effects of analgesics and cardiovascular drugs. Of all ADEs, 39% were potentially preventable, because the drug therapy or use was judged suboptimal.
MedicalResearch.com: Were any of the findings unexpected?
Answer: The 12% ADE prevalence for the general public, corresponding to 25% of all persons with outpatient and inpatient healthcare encounters, was high compared to previous estimates of approximately 5% of inpatients suffering from ADEs. Thus, most ADEs occur in outpatient settings. We were also surprised to find sub-therapeutic effects equally common to adverse drug reactions, as adverse drug reactions have gained much more attention in previous literature on ADEs.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: For preventing ADEs more efficiently, large-scale efforts to improve the quality and safety of healthcare at organisational level are needed. This requires the commitment of clinicians and care units, collaboration with patients, researchers and safety experts, and strong political will and leadership. Because ADEs occur across care settings and are caused by widely used drugs, the burden of ADEs is unlikely to decrease considerably through exclusively focusing on specific events, patient groups, or care units.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: Firstly, actions to prevent ADEs must be further studied (previous question). Secondly, definitions and classifications for ADEs shall be improved. Because existing definitions and classifications were partially inconsistent, we developed our own categorisation, dividing ADEs into adverse drug reactions, sub-therapeutic effects, intoxications, dependence and misuse, and morbidities due to untreated indications. This was found informative because associated drugs, affected organs, preventability, and seriousness differed for these sub-categories of ADEs. Therefore, we recommend future research on preventing, detecting, and mitigating ADEs to categorise these events. In the future, a consensus on a standard definition and classification of ADEs should be reached.
Prevalence, nature and potential preventability of adverse drug events – A population-based medical record study of 4970 adults
British Journal of Clinical Pharmacology