Background In the literature the authors find many types of reconciliation studies, only at admission, only at discharge or at discharge and later in primary care. The data on discrepancies can vary depending on the professionals performing the reconciliation.

Purpose Our objective was to create a team made up of hospital pharmacists, liaison sisters and primary care physicians to identify and classify the discrepancies at hospital admission, during and after discharge in patients with the same primary health area.

Materials and methods The authors performed a prospective observational study in polymedicated patients admitted to hospital. Patients were interviewed by the pharmacist at admission and discrepancies with treatment found at admission and after discharge were recorded. The discrepancies that required clarification (not justified) were classified depending on whether the drug had been withdrawn, added or modified with no apparent clinical justification regarding the patient's usual treatment. All discrepancies were reviewed later by the primary care physicians.

Results 55 patients were recruited, 48 patients had their medicines recorded at discharge but only 29 could be reviewed in primary care due to death or loss to follow-up. The patients took an average of 8 drugs, 669 drugs were recorded on admission and 480 at discharge. 31.84% (213) and 43.96% (211 drugs) of medicines required clarification at the time of admission and discharge respectively. The largest number of drugs in which discrepancies were found at admission was in the benzodiazepines group (17.58%) while it was proton pump inhibitors at discharge (16.09%).

Primary care disagreed with 4 (1.07%) of the discrepancies classified by hospital pharmacists at admission and 2 (0.75%) of discrepancies classified at discharge.

Conclusions It is necessary to implement measures in hospitals to reduce the number of unjustified discrepancies. These checks can be carried out by hospital pharmacists; reconciliation should be coordinated with primary care for follow-up of patients.