Incidence of Antipsychotic-Associated Side Effects: Impact of Clinician Versus Patient Ratings and Change Versus Absolute Scores

Objective This study aimed to compare (1) the detection rates of antipsychotic-associated side effects between clinician and patient ratings and (2) differences as a function of change and absolute score definitions. Methods: Data from phase 1 of the Clinical Antipsychotic Trials of Intervention Effectiveness (N = 1460) were analyzed. In this trial, 18 adverse events were systematically and concurrently assessed by clinicians and patients using a 4-point severity scale ranging from 0 (absent) to 3 (severe). The incidence of antipsychotic-associated side effects was calculated according to 2 definitions: change score (ie, higher score on the scale versus baseline) and absolute score (a score of 2 or 3 on the scale). In addition, patient and clinician concurrent detection rates were examined. Results The differences in incidence of antipsychotic-associated side effects between clinician and patient ratings were as small as 5.7% across the 2 definitions. The incidence of all side effects across clinician and patient ratings was approximately 2 times higher when using the change versus absolute score definition. Among the side effects detected by patients, 11 side effects were identified more frequently by clinicians, with 14.3% to 30.2% differences when using the change versus absolute score definition. Conversely, there was no difference of 10% or greater in patient or clinician concurrent detection rate on any item when using the absolute versus change score definition. Conclusions: Our findings suggest that patient ratings are in line with clinician ratings and that the change score definition may be superior for the assessment of antipsychotic-associated side effects in clinical studies.