Medication histories and the identification of adverse drug event-related hosptial admissions
Cooke, Rachael Peart
BACKGROUND: Drug-related problems are a common cause of admission to hospital. Medication histories are traditionally taken in the Emergency Department but are seldom complete with OTC medications often not asked about. AIMS: To determine the accuracy of medication histories obtained during the admission process, identify and classify any discrepancies and medications involved and ascertain the value of a full medication history in the identification of an adverse drug event (ADE)-related admission. METHODS: A full medication history including all prescribed and over-the-counter (OTC) medication was obtained from patients admitted to an acute medical team over a three month period. The second history was compared with the history obtained during the admission process, discrepancies were classified and the drugs involved identified and classified according to British National Formulary (BNF) categories. Clarification of any doses or medications was obtained from the patient's community pharmacy. The histories of those patients with a positively identified ADE-related admission were analysed to determine any differences with the non-ADE-related admissions. RESULTS: A total of 320 interviews were obtained. Ninety two percent of patients had taken a prescribed medication in the two weeks prior to admission, 51.7% had taken an OTC/alternative medication. The average number of medications identified in the second history was significantly higher than that identified in the first history (5.6 ± 4.31 v 4.71 ± 3.93 items p< 0.001). A total of 669 discrepancies were found: 56.2% were omission errors, 13.4% wrong dose, 13% commission errors, 8.7% dose missing and 8.7% wrong or missing dose form. Forty five percent of histories contained one or more omissions. The BNF classifications of the drugs associated with discrepancies most commonly involved the gastrointestinal, respiratory system, cardiovascular system and central nervous systems. Ten percent of patients did not have any drug allergy or sensitivity data documented and the second interviews revealed 37 extra sensitivities to medication. Fifty one percent of patients interviewed had taken an OTC/alternative medication prior to admission. Only 29 items were identified at admission, the second interview revealed 335 items, most commonly analgesics, herbal supplements, cough and cold preparations and nine traditional medications. Thirty seven patients or 8.7% of total admissions were identified as an ADE-related admission. Patients associated with ADE-related admission were older than those with non-ADE-related admission (72±16.9 years v 62.8±20 years p< 0.01). They also took more medications than those with a non-ADE-related admission (7.35 ± 3.75 items v 5.38± 4.34 items p<0.01). There was no significant difference in the number of discrepancies or omissions in histories between the two groups. Extra information from the second interview revealed several cases of unintentional overdose, a warfarin interaction, drug allergy and a GI bleed associated with OTC purchased aspirin, all resulting in an ADE-related admission. CONCLUSIONS: Full medication histories can aid identification of ADE-related admission, ensure the patient receives all current medication and prevent ADEs occurring during the hospital stay.
Degree Name: Master of Clinical Pharmacy
Degree Discipline: Pharmacy
Publisher: University of Otago
Keywords: Hospital admissions
Research Type: Thesis
ix, 190 leaves ; 30 cm. Includes bibliographical references.