The side effects of antipsychotic drugs and patients' quality of life: patient education and preference assessment with computers and multimedia.

Determining the relative value of novel antipsychotics such as clozapine requires measures of the utility of their different side-effect profiles. Many of these side effects (SE) are complex and difficult to describe adequately. Schizophrenic patients are also difficult to interview reliably. Even in normal subjects, utility assessment can be tedious, inconsistent, and difficult for subjects to understand. We addressed these challenges by developing a multimedia patient education and utility assessment tool. SE were described using short video sequences accompanied by digitized voice descriptions. Patients' preferences were assessed using visual analog scales, pairwise comparisons, and standard gambles. These assessment techniques were carefully explained and logically integrated. Instructions were presented both by digitized voice and in print, and, if necessary, were clarified by a moderator. Animated displays were used to graphically display probability. Reminder pictures, comprehension tests and validation questions were used throughout the survey. Thirty-three patients from VA and public clinic inpatient and outpatient settings took the survey. Five psychiatrists were surveyed as a reference group. Patients understood the SE and the survey (92% mean comprehension) and their answers were internally valid and consistent (74% internal consistency). The standard gamble disutilities for the SE were substantial, ranging from 12-20% decrease in their quality of life. Computer-based, multimedia techniques are useful in conducting utility assessment and evaluating its validity. They allow effective patient education and elicitation of useful values, even in subjects with cognitive impairments.