P135 Intervention adherence and usefulness as predictors of the efficacy of Cognitive Behavioural Therapy for Insomnia during perinatal periods

INTRODUCTION: One third of birthing parents experience insomnia symptoms during perinatal periods. Cognitive Behavioural Therapy for Insomnia (CBT-I) is effective for perinatal insomnia. However, it is unclear how adherence to and perceived usefulness of individual CBT-I components predict treatment efficacy. METHODS: 76 nulliparous birthing parents (age M±SD=33.07±3.10) with prenatal insomnia received CBT-I from two randomised controlled trials. Insomnia symptoms, sleep-related impairment, dysfunctional beliefs and attitudes about sleep (DBAS), and adherence and usefulness were self-reported at 30 and 35-weeks gestation, and 2 and 6-months postpartum. Linear regressions assessed whether adherence and usefulness predicted sleep-related outcomes, controlling for age, mental health history and social support. RESULTS: Adherence and perceived usefulness decreased over time across all components. “Cognitive restructuring” and “sleep hygiene” had the highest usefulness and adherence ratings, while “relaxation and mindfulness” was the least useful and adhered to. Controlling for covariates, higher adherence to “sleep hygiene” predicted lower DBAS at 35-weeks gestation (p=.024). At 6-months postpartum, higher usefulness of “relaxation and mindfulness” predicted lower DBAS (p=.032), and higher usefulness/adherence to “managing sleep deprivation, sleepiness, and fatigue” predicted lower insomnia symptoms (usefulness p=.003; adherence p=.029) and lower sleep-related impairment (usefulness p=.007). No significant relationships were found between sleep-related outcomes and usefulness/adherence to other CBT-I components (i.e., psychoeducation, cognitive restructuring, and stimulus control). CONCLUSION: Individual CBT-I components play different roles in treatment efficacy as birthing parents navigate diverse sleep challenges in perinatal periods. Strategies to enhance adherence to and perceived usefulness of relevant treatment components for specific perinatal milestones may enhance efficacy.