Effect of medication-related factors on adherence in people with schizophrenia: a European multi-centre study.
OBJECTIVE
To investigate the relation between medication-related factors and adherence in people with schizophrenia in outpatient treatment.


METHODS
The sample comprised 409 outpatients (ICD-10 diagnosis of schizophrenia) with clinician-rated instability in four European cities (Amsterdam, The Netherlands; Verona, Italy; Leipzig, Germany; London, Great Britain). Adherence was assessed using the Medication Adherence Questionnaire (patient perspective), and the Clinician Rating Scale (clinician perspective). Examined medication-related factors were type (atypical vs. typical), application (oral vs. depot), daily dose frequency of antipsychotic medication (Medication History Scale), number of side effects (Liverpool University Neuroleptic Side Effect Rating Scale), and patient attitudes toward medication (Drug Attitude Inventory). Multiple regression analysis was used to identify predictors of adherence by medication-related factors.


RESULTS
Adherence, as rated by patient and clinician, was predicted by patient attitude towards medication, but was unrelated to type of drug, formulation or side effects of antipsychotic medication. A high daily dose frequency was associated with better adherence, but only when rated by the patient.


CONCLUSIONS
In order to improve adherence there is a need to seriously consider and attempt to improve patient attitude toward medication. However, type of antipsychotic and other medication-related factors may not be as closely related to adherence as it has often been suggested.
Department of Psychiatry II, Ulm University, Ulm, Germany.
Johanna
J
Meier
Thomas
T
Becker
Anita
A
Patel
Debbie
D
Robson
Aart
A
Schene
Martijn
M
Kikkert
Corrado
C
Barbui
Lorenzo
L
Burti
Bernd
B
Puschner
D000328:Adult; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000188:drug therapy*; D016903:Drug Monitoring