Impact of a Novel Strategy for Critical Values Communication for the Management of Patients Treated with Clozapine

Clozapine is an antipsychotic drug used to treat resistant schizophrenia and other disorders. Based on the actual Spanish legislation, patients treated with clozapine must undergo periodical haematological examinations and treatment should be reviewed when the haemogram shows either a leukocyte count of ≤ 3500/mm³ or neutrophil count < 2000/mm³. An automatic notification system has been developed to optimize patient management and it's utility was assessed following the implementation of the new system.

When clozapine (CLO) laboratory test request was made, a reflex complete blood count test was also done. An automatic e-mail was sent by the laboratory information system to the physician when a CLO was ordered and low leukocyte or neutrophil counts were detected, or when a patient with an ordered CLO test did not attend the laboratory for blood drawing.

For patients with haemogram alterations, the time to take clinical action was significantly decreased from 23 to 7 days (p = 0.02). Moreover, the adherence to Spanish Agency of Drugs and Sanitary Devices recommendations significantly increased from 45% to 76% (p = 0.02). For not attending patients, the days out of control decreased from 29 to 12 days, although it was not statistically significant (p = 0.06).

This strategy has allowed the compliance of legal requirements, the improvement of patient safety, and the optimisation of clinical and laboratory procedures.