Who's left? Symptoms of schizophrenia that predict clinical trial dropout

Abstract

A significant proportion of subjects drop out of medium to long-term clinical studies prior to trial completion. This may bias reported study outcomes and reduce the statistical power of analyses. There is therefore a need for researchers to better understand the characteristics of dropout populations to increase completion rates. Data from a set of participants recruited as part of a 24-week placebo-controlled trial were used to determine the relationship between the five Lindenmayer factors of positive, negative, cognitive, anxiety/depression and excitement symptoms and dropout at trial completion. Results indicated that the rate of trial dropout was significantly predicted by scores on the negative Lindenmayer factor (X² (6, N = 126) = 15.60, p < .05). By trial completion, participants with 'high' negative Lindenmayer scores dropped out at a rate of 64%, whereas 'medium' and 'low' groups dropped out at 43% and 30%, respectively. No other relationship between symptom severity scores and dropout across the remaining Lindenmayer factors was found. These findings reflect important considerations for the future design of clinical trials involving people with schizophrenia and may also provide clues into treatment compliance issues more generally.

D-Cycloserine in Neuropsychiatric Diseases: A Systematic Review

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Outcome of Youth with Early-Phase Schizophrenia-Spectrum Disorders and Psychosis Not Otherwise Specified Treated with Second-Generation Antipsychotics: 12 Week Results from a Prospective, Naturalistic Cohort Study

“…Also, 18.5% of the sample did not return for follow-up visits. High attrition is a well-known problem in psychiatric research (Martin et al 2006;Thompson et al 2011;Jorgensen et al 2014). Our attrition after baseline were rather low, and we were able to capture information on medication persistence and reasons for treatment discontinuation in 124 (95.4%) of 130 patients.…”

Negative symptoms in first‐episode psychosis: Clinical correlates and 1‐year follow‐up outcomes in London Early Intervention Services

“…The FEP sample was large and naturalistic, from different EIS within well-defined catchment areas, with minimal confounding effects of chronicity, institutionalization and prolonged exposure to antipsychotic treatment. Previous studies have indicated that FEP patients with higher NS might be at greater risk of dropping out (AlAqeel & Margolese, 2012;Thompson et al, 2011;Üçok & Ergül, 2014). Thus, although there was a considerable amount of missing data due to the naturalistic follow-up study design, MI was applied in order to correct for biases due to non-completion (Schafer & Graham, 2002).…”