Patient preference effects in a randomized comparative effectiveness study of electroconvulsive therapy and ketamine...

Previous studies have shown patient preference can have large effects on treatment adherence and patient satisfaction. However, the direct effects of matching treatment with patient preference on efficacy and safety outcomes remain unclear. We aimed to evaluate the effects of patient preference and preference-matching on efficacy, adverse events, and adherence to electroconvulsive therapy (ECT) and intravenous (IV) ketamine treatments in a randomized clinical trial.

Data were collected during the Patient-Centered Outcomes Research Institute (PCORI) funded ECT vs. Ketamine in Patients with Treatment Resistant Depression (ELEKT-D) study, which randomized patients to treatment with either ECT or IV ketamine across five U.S. sites. We performed post hoc-analyses on 255 patients who provided responses to a patient preference survey following treatment phase completion, which allowed us to explore the relationships between treatment preference and several treatment outcome measures.

Our analysis showed that (1) Ketamine was preferred by more trial participants than ECT; (2) Preference for ketamine was associated with higher likelihood of treatment response for all patients regardless of treatment assignment; (3) Preference-matching (patients receiving the treatment they indicated a moderate or strong preference for on the survey) was associated with greater likelihood of treatment response to ketamine but not ECT; (4) Preference-matching was associated with reduced rates of adverse events in ECT-treated patients. There was a trend for preference-matching potentially influencing treatment adherence.

Our findings suggest treatment preference-matching affects treatment effectiveness, adverse event reporting and possibly adherence. However, these associations may be contextual, modality dependent, and complex.