OBJECTIVES: Treatment discontinuation is an important effectiveness measure for evaluating antipsychotic treatment, yet is typically assessed only on a high level (e.g., "lack of efficacy," "adverse event," or "patient decision"). The RAD-I was developed as a structured interview assessing patient's perspective regarding specific reasons for antipsychotic discontinuation and continuation and the RAD-Q as a questionnaire assessing clinician's perspective. This study assessed the validity of the RAD measures in a randomized clinical trial. METHODS: The RAD was assessed at baseline (referring to medications prior to the trial) and endpoint (referring to discontinuation/ continuation of study drug) in a 12-week schizophrenia clinical trial. To assess its psychometric properties, we examined content validity, discriminate validity, and agreement between RAD scales using endpoint data (N = 158). RESULTS: Of 29 potential primary reasons for medication discontinuation, the most common was insufficient improvement/worsening of positive symptoms (24%) followed by adverse events (22%). A high level of concurrent validity was observed, as 89% of patients discontinuing medication due to "lack of efficacy" (87%, "adverse events") per the standard trial form had lack of efficacy ("adverse events") as a primary or very important reason on the RAD. Patients indicating lack of improvement/worsening of positive symptoms as a primary reason for medication discontinuation on the RAD had significantly less improvement in PANSS positive score than patients not reporting this as a reason. Similar results were observed for the RAD mood items (per MADRS) and functional status (per QLS) as well as for corresponding analyses assessing reasons for continuation. Agreement between the clinician and patient scores was high (range 73% to 100%). CONCLUSIONS: This initial psychometric assessment suggests the RAD is a valid tool for gathering detailed information regarding reasons for antipsy chotic discontinuation and continuation from patients' and clinicians' perspectives. Further information is needed about the psychometric properties in usual care settings.
Faries, D., Ascher-Svanum, H., Nyhuis, A., Anderson, J., & Phillips, G. (2010). PMH15 THE VALIDATION OF TWO MEASURES ASSESSING REASONS FOR ANTIPSYCHOTIC DISCONTINUATION AND CONTINUATION FROM PATIENTS’ AND CLINICIANS’ PERSPECTIVES. Value in Health, 13(7), A555–A556. https://doi.org/10.1016/s1098-3015(11)73328-9