Clinical Characteristics of People in Randomized Clinical Trials of First Episode Schizophrenia Spectrum Disorders

Abstract

Clinical Characteristics Of People In Randomized Clinical Trials Of First Episode Schizophrenia Spectrum Disorders: Attrition Versus Non-Attrition Groups Submitted by Joanne D. Wojcik PhD, RN Dissertation Advisor Judith Shindul-Rothschild, PhD, RN Abstract Background: Early identification of psychosis and intensive treatment has been the focus of the treatment of people with a first episode (FE) schizophrenia spectrum disorder (SSD). Attrition rates in studies of people in the first episode are high, which makes it difficult to understand the meaning of the study outcomes. High attrition rates affect the validity of a study by decreasing its power and the study's ability to detect differences between treatment groups. Additionally, the people who leave a study may be different from those who stay in demographic, illness and treatment characteristics. Method: This study is a secondary analysis of a group of FE SSD participants enrolled in one of three separate double-blind, randomized, drug trials. The variables were first analyzed across the three drug study data sets to determine if the patient populations are comparable across the three studies to allow for the merging of the data. Exploratory and descriptive statistics of study participants were conducted in a comparison of the three studies, for the merged group, and for the attrition and non-attrition groups. Effect sizes (Cohen's d) were calculated for each variable in the individual studies and in the merged dataset for the magnitude of difference between the attrition and non-attrition groups. Results: The three studies were merged after analysis found no consistent difference in demographic and illness characteristics between the three studies. There was no significant difference between the attrition and non-attrition groups in the merged data in demographic and illness characteristics. Treatment characteristics consistently found lack of efficacy and patient withdrawal of consent to be the two most frequent reasons for attrition from the studies. In addition, participants receiving a typical agent were less likely to complete the study. Effect size calculations found attrition group to more likely be Caucasian, with a lower median income. The attrition group had more years of education, but was not in school in the year previous to hospitalization. Conclusion: Historically, attrition is a major problem in clinical trials of people in a first episode of schizophrenia spectrum disorders. People receiving typical antipsychotic medication are more likely to leave a study. Most common reasons for attrition include lack of efficacy and withdrawal of consent