How Accurate Are we as Clinicians and Pharmacists In Obtaining and Documenting Complete Drug Histories?

Over the counter medication, medication documentation errors and potential adverse drug reactions: A survey of an acute medical unit

Background: Medication errors cause adverse drug events and negative patient outcomes. One important contributory factor to this is incomplete or inaccurate drug history. Over counter medications and herbal remedies are commonly missed in this process and are known to interact with prescribed drugs. No data is available in acute medical admission units to evaluate magnitude of errors arising as result of inaccurate/incomplete medication history.

Aims: To evaluate the accuracy and completeness of drug history taking and documentation by doctors and pharmacists on an acute medical unit with particular emphasis on over the counter (OTC) medication.

Methods: A cross-sectional study was carried out on a 58 bedded acute medical unit. Patients were invited to participate in the study, providing their drug history from repeat prescriptions, their own written account of their drug history, or their blister pack/boxes. Three steps were involved 1) an independent medication history separate from the initial admission was obtained from each participant. Direct enquiry regarding intake of any concurrent OTC +/- non-prescription medication and the reasons for their use was made 2) the documented medical clerking notes and drug history were reviewed 3) medicines reconciliation section of the participant’s prescription chart was reviewed and sources of informants were noted. At each step full doses, route and frequency of use were documented. Any incomplete, inaccurate or omission in the documentation of the drugs, dose or frequency was classed as “Error in documentation” for the purposes of our analysis. Finally the working diagnosis and reason for admission were also studied to evaluate if any of the admission medications may have directly or indirectly contributed to the index admission.

Results: The study included 46 patients. There was 40% “Errors in documentation” for prescribed medications in medical notes at the time of admission compared with medicines reconciliation. Alarmingly 10% errors in documentation remained after medicines reconciliation was carried out. 17 (37%) out of 46 patients were taking some OTC and 64% of these patients did not have their OTC documented anywhere in medical notes or medicines reconciliation section of the drug charts. There were 9% and 11% admissions that were directly and indirectly related to the prescribed medication respectively.

Out of all the OTC supplements, ingredients in 3 had potentials for interactions with the prescribed medications.

Conclusion: In a large acute admission unit drug histories were inaccurate and incomplete both by busy clerking doctors and pharmacists during their medicines reconciliation rounds. More than half of the patients who were on OTC did not have these documented anywhere in their medical or prescription charts. A tenth of all admission were either directly or indirectly related to prescribe medications, which may have been avoided.