Abstract
Background Transition of care on admission to the hospital and between clinical areas are risk points for medication errors. All type of medication errors can be reduced by improving communication at each transition point of care. Objectives This study examines the impact of pharmacist obtained best possible medication histories on medication errors at admission due to unintentional medication discrepancies in older patients. Setting This was a prospective, single-center study conducted in an Internal Medicine Department of a tertiary care teaching hospital in Saudi Arabia. Methods Patients >= 65 years with an existing drug therapy on admission were eligible. The best possible medication history taken by the pharmacist from different sources of medication information was compared to the admission medication order to identify and correct unintentional discrepancies. The discrepancies were classified according to the type of errors. An independent multidisciplinary team adjudicated the potential for harm of each type of medication error. Main outcome measure Number and proportion of unintentional medication discrepancies upon admission and associated medication errors. Secondary outcomes included clinical significance and drug classes involved in the discrepancies and risk factors for the occurrence of these discrepancies. Results A total of 375 evaluable patients were identified. Among 375 medication histories, 609 discrepancies were detected of which 226 were recorded as unintentional. 151 patients (42.4%) had >= 1 unintended discrepancy. Drug omission (37%) was the most frequent type of error. Nervous system (24.5%), and cardiovascular system (21.2%) were the most common drug classes involved in medication errors. Three-fifths of the UMD had the potential to cause temporary harm with initial or prolonged hospitalization. The number of medications prescribed upon admission (OR 1.32, 95% CI 1.09-1.54, p<0.034), number of sources consulted for the best possible medication history(OR 1.53, 95% CI 1.38-1.76, p<0.01) and the completion of medication review process within 24h (OR 0.89, 95% CI 0.86-0.94, p<0.03) of the admission were the 3 most significant predictors of the discrepancies. Conclusions In elderly patients, medication histories are often recorded inaccurately by physicians at the time of hospital admission, this creates the potential for medication errors starting at admission. In older adults, best possible medication histories are also useful in detecting drug related pathology or drug-drug interactions.