Analyzing Demographic Variabilities Associated With Age of Diagnosis of Schizophrenia Among Patients in Controlled Clinical Trials

Background Prior data suggest a multimodal distribution in the age of diagnosis of schizophrenia (AOD) for males and females, though these findings were based on small, geographically limited datasets. We used a big data approach to revisit this question by analyzing data from large, randomized controlled clinical trials. Methods Patient-level data from 9 clinical trials involving patients treated with paliperidone were obtained through the Yale Open Data Access Initiative (YODA). A two-sample t-test and an analysis of variance (ANOVA) were used for hypothesis testing. Results Our analysis included 6618 male (n = 3977) and female (n = 2641) patients. A two-sample t-test revealed a statistically significant difference between patient sex and AOD (t = 15.001, df = 4786.6, P < 0.0001). Histograms generated with the frequency of occurrences against AOD showed a unimodal distribution. The mean AODs for female and male patients were found to be 29.39 and 25.66 years old. Conclusion Our findings challenge previously long-held views and reveal that the AOD for male and female patients has a unimodal distribution, not multimodal. Our findings not only call for a re-evaluation of previous epidemiological findings of AOD but may support future efforts in understanding the typical clinical presentations of patients with newly developed symptomatology of schizophrenia.