Background Patient's proper dose is essential for an adequate treatment.

Purpose Checking the proper administration of prescribed treatments in a General Hospital.

Materials and methods The authors conducted a cross-sectional study about the detection of treatment administration errors, by means of two indicators: the treatment order signing before administration (preadministration signing) and the administration of a different pattern from the prescribed one by nursery (wrong pattern). Original treatment orders were reviewed in the unit dose dispensation area, and errors were reported in writing to the different services. Also, a data collecting sheet was designed, including medical service name, number of treatment orders, number of treatment lines and types of error.

Results 168 treatment orders were checked (1085 treatment lines) corresponding to nine hospital floors (traumatology, urology, two surgery services, two internal medicine services, haematology/ophthalmology/oncology, geriatrics/neurology and gynaecology) 48 management errors were detected, 86.33% of them caused by preadministration signing and 16.7% by wrong pattern. Attending to a classification of all these data, six errors (20 treatment orders) were detected in Traumatology, 83.3% of them by wrong pattern and 16.6% by preadministration signing; 1 wrong pattern out of 7 treatment orders in urology; 8 errors (27 orders) in right surgery and 11 errors (18 orders) in left surgery, all due to preadministration signing; 3 errors (27 orders) were detected by preadministration signing in right internal medicine; 11 errors (29 orders) in left internal medicine, 90.9% of them caused by preadministration signing and 9.1% by wrong pattern; in haematology/ophthalmology/oncology services, no administration errors were detected after checking 9 treatment orders; 4 errors (19 orders) were detected by preadministration signing in geriatrics/neurology; and 4 errors (12 orders) in gynaecology, 75% of them by preadministration signing and 25% by wrong pattern.

Conclusions Preadministration signing was the most common error, particularly within the surgery service. Apart from that, notifying the administration errors by the pharmacist helps to detect them on time so that they do not continue during hospitalisation.