Use of a structured medication history to establish medication use at admission to an old age psychiatric clinic: a prospective observational study.

OBJECTIVE: Medication reconciliation results in fewer adverse drug events. The first step in medication reconciliation is to carry out a structured interview about medication use. It is not known whether such an interview is useful in inpatient old age psychiatry. The object of this study was to determine at admission the number of discrepancies in medication use, comparing the structured history of medication use (SHIM) procedure with the usual procedure for taking the medication history.

METHODS: A prospective observational study was conducted. All consecutive patients aged 55 years and older admitted from January until April 2011 to the inpatient old age psychiatric clinic of a large psychiatric teaching hospital in The Hague, the Netherlands, were eligible for inclusion; 50 patients were included. In every patient, the usual procedure (medication history-taking at admission by the treating physician) was compared with the SHIM procedure administered by the researcher. The SHIM procedure consists of a structured interview with the patient about the actual use of medication, incorporating the information from the community pharmacy and the patient's medications brought to the interview. The main outcome was the number of discrepancies in recorded medication use between the SHIM and the usual procedure.

RESULTS: In total, 100 discrepancies (median 2 per patient, range 0-8) in medication use were identified; 78 % (n = 39) of the patients had at least one discrepancy. Of the discrepancies, 69 % were drug omissions, and 31 % were drug additions or discrepancies in the frequency or dosage of medications. Eighty-two percent of all discrepancies were potentially clinically relevant. In 24 % of the patients, the discrepancies had clinical consequences.

CONCLUSION: The number of discrepancies that were found suggests that the usual procedure for taking the medication history can be improved. The SHIM procedure enables a comprehensive and accurate overview of the medication used by older patients admitted to a psychiatric hospital, and contributes to the prevention of clinically relevant adverse drug events.