Anti-psychotics adherence among out-patients with schizophrenia in Hong Kong.

Objective: Adherence to antipsychotic treatment is an important aspect of long term management of schizophrenia and other related psychotic disorders. The evaluation of adherence is often difficult in clinical settings. This study compared patients self-reports and clinician judgment of adherence behavior and explored their relationship with attitudes toward taking medication.

Methods: Clinician rated questionnaire and matching patient self rated questionnaires were administered to 508 consecutive outpatients and their clinicians in four hospital clinic sites in Hong Kong. Items in the questionnaires address adherence behaviors as well as attitudes toward medication. In addition, clinicians also estimate the presence of factors unfavorable to adherence such as substance abuse, cognitive impairments etc.

Results: Non-adherence was reported in at least 26% of patients. Clinician's detection of non-adherence behaviors achieved relative high specificity (0.84) but has low sensitivity (0.33). A logistic regression analysis on patients' decision to stop medication revealed that significant predictors include patients' reported lack of perception from the benefits of medication, patients' reported negative feelings associated with regular medication and younger age.

Conclusion: Non-adherence is a widespread phenomenon affecting a significant proportion of outpatients under treatment. Clinicians have relatively low sensitivity in detecting which patients are non-adherent. Non-adherence behavior is predicted by level of awareness of illness, perceived benefits of medication, negative feelings toward medication and age.