Prioritising interventions against medication errors: the importance of a definition

Marianne Lisby, Louise Pape-Larsen, Ann Lykkegaard Sørensen, Lars Peter Nielsen, Jan Mainz

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Authors: Lisby M, Larsen LP, Soerensen AL, Nielsen LP, Mainz J

Prioritising interventions against medication errors – the importance of a definition

Objective: To develop and test a restricted definition of medication errors across health care settings in Denmark

Medication errors constitute a major quality and safety problem in modern healthcare. However, far from all are clinically important. The prevalence of medication errors ranges from 2-75% indicating a global problem in defining and measuring these [1]. New cut-of levels focusing the clinical impact of medication errors are therefore needed.

Development of definition: A definition of medication errors including an index of error types for each stage in the medication process was developed from existing terminology and through a modified Delphi-process in 2008. The Delphi panel consisted of 25 interdisciplinary experts appointed by 13 healthcare-, professional- and scientific organisations in Denmark.

Test of definition: The definition was applied to historic data from a somatic hospital (2003; 64 patients) [2] and further, prospectively tested in comparable studies of medication errors in a psychiatric hospital (2010; 67 patients) and in nursing homes (2009; 33 patients). Finally, it was tested in a study of prescribing errors in a somatic hospital (2010; 108 patients) The same data collection methods (chart review; review of electronic drug order system; direct observation; unannounced control visit), denominator (opportunities for errors) and the same severity scale to assess the potential clinical consequences (potential fatal, -serious, -significant and non-significant) were used in all four studies[2] to measure prevalences reflecting the impact of the definition. The overall prevalence of medication errors was compared between the somatic hospital (2003), the nursing homes and the psychiatric hospital whereas comparison of prescribing errors included all four clinical settings.

Definition: The expert panel reached consensus of the following definition “An error in the stages of the medication process - ordering, transcribing, dispensing, administering and monitoring the effect - causing harm or implying a risk of harming the patient”. In addition, consensus for 60 of 76 error types covering all stages in the medication process was achieved.

Test of definition: The definition of medication errors corresponded to the levels potential fatal and potential serious in the severity scale [2]. After application of the definition the overall prevalence of medication errors was 144/1.942 (7.4%) in the retrospective test and in the prospective studies 100/1.249 (8.0%) in the psychiatric hospital and 83/1.134 (7.3%) in nursing homes. Similar patterns were seen when comparing the occurrence of prescribing errors: 52/991 (5.3%:CI95%: 3.9-6.8) retrospective test; 23/510 (4.5%: CI95%: 2.9-6.7) psychiatric hospital; 100/872 (11.4%:CI95%: 9.4-13.8) and finally 53/1.437 (3.7%:CI95%: 2.8-4.8) in the somatic hospital. Further analysis of prescribing errors in the somatic hospital indicated paracetamol, opioids and antibiotics as the most frequently involved drugs and ordering an unnecessary drug or an inappropriate drug as well as discrepancies between drug orders constituted the majority of prescribing errors when defined as errors with potential for harm.

Conclusion: A definition restricted to the potential clinical impact of medication errors appears to be a reproducible method across healthcare settings detecting almost identical prevalence’s in overall studies of medication errors and in studies of prescribing errors. In addition, it contributes to identify medication errors related to high-risk processes and drugs. The definition can therefore be considered as a relevant tool for decision makers in modern healthcare to prioritise interventional strategies.

1) Lisby M, Nielsen LP, Brock B, Mainz J: How are medication errors defined? A systematic literature review of definitions and characteristics. Int J Qual Healthcare 2010; Vol. 22 (6) pp. 507-518

2) Lisby M, Nielsen LP, Mainz J. Errors in the medication process: frequency type and potential Int J Qual Healthcare 2005; Vol. 17 (1) pp.15-22
Original languageDanish
Publication date2011
Publication statusPublished - 2011
EventISQua's 28th international Conference, Hong Kong 2011 - Hong Kong, China
Duration: 14 Sept 201117 Sept 2011


ConferenceISQua's 28th international Conference, Hong Kong 2011
CityHong Kong

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