Six-month outcomes of the CODES randomised controlled trial of cognitive behavioural therapy for dissociative seizures: A secondary analysis. (March 2022)

• Record Type: Journal Article
• Authors: Goldstein, Laura H.; Robinson, Emily J.; Chalder, Trudie; Reuber, Markus; Medford, Nick; Stone, Jon; Carson, Alan; Moore, Michele; Landau, Sabine
• Is Part Of: Seizure. Volume 96(2022)
• Page Start: 128
• Page End: 136
• Publication Date: 2022-03
• Subjects: Dissociative seizures -- Cognitive behavioural therapy -- Randomised controlled trial -- Outcomes; Epilepsy -- Periodicals; Epilepsy -- Periodicals; Seizures -- Periodicals; Épilepsie -- Périodiques; Electronic journals; Electronic journals; 616.853
• DOI: 10.1016/j.seizure.2022.01.016
• Languages: English
• ISSNs: 1059-1311

Abstract

Highlights: We report an unplanned secondary analysis of 6-month outcomes in the CODES trial. 13/14 outcomes were better following CBT plus standardised medical care (SMC). Monthly seizure frequency was significantly lower at 6 months in the CBT+SMC group. Treatment effect sizes across outcomes were moderate-to-large at 6-month follow-ups. Short- and longer-term evaluations are necessary to understand treatment effectiveness. Abstract: Purpose: The CODES Trial for adults with dissociative seizures had a predesignated 12-month post-randomisation follow-up point for outcome evaluation. We undertook an exploratory, unplanned, secondary analysis to evaluate the effectiveness of cognitive behavioural therapy plus standardised medical care (CBT+SMC) compared to SMC alone at 6 months post-randomisation, i.e., closer to the end of treatment. Methods: The analysis of 6-month data followed our previous method of using multiple imputation and an intention-to-treat approach to analyse variables 12 months post-randomisation. Results: The original trial primary outcome of monthly seizure frequency showed greater benefit from CBT+SMC than SMC-alone at 6 months (at p < 0.05). Of 13 comparable previously-defined secondary outcomes, 12 showed a significant between group effect ( p < 0.05) in favour of the CBT intervention at 6 months. The average effect size of the comparable previously-defined primary and secondary continuous outcomes was 0.33 at 6 months vs 0.26 at 12 months. The estimated Incidence Rate Ratio (IRR) quantifying monthly seizure reduction was IRR = 0.72 (95%CI from 0.55 to 0.93) at 6 months compared to IRR = 0.78 at 12 months. Conclusion: DS-specific CBT (plus SMC) produced evidence of significant benefits at 6 months post- randomisation (around which time CBT was complete) compared to SMC alone; for the majority of these outcomes, better results following CBT (plus SMC) had previously been reported at 12 months. Our pattern of results suggests that short- and longer-term follow-ups are necessary to understand treatment effects in this disorder. Studies only providing short-term follow-up data should be interpreted with caution.