Development and Validation of a PROMIS-based Measure to Assess Postpartum Sleep - Impaired postpartum sleep significantly impacts postpartum recovery, maternal health, and the maternal-infant dyad. Little is known about postpartum sleep as a construct, postpartum sleep disorders, or their association with mental health. Data are limited to small non-racially diverse cohorts using measures with inadequate content validity. Our pilot work demonstrates that one-third of patients with a postpartum sleep disorder have co-morbid postnatal depression, a leading cause of maternal suicide. We propose to test our overall hypothesis that postpartum sleep is inadequately assessed, and postpartum sleep disorders are underdiagnosed and linked to postnatal depression. The Structured Clinical Interview for Sleep Disorders (SCISD-R) diagnoses common DSM- 5 sleep disorders, including insomnia disorder. However, SCISD-R is impractical outside research settings. Wrist-worn actigraphy devices can also be used to measure sleep objectively. In contrast, patient-reported outcome measures (PROs) are inexpensive, self-reported tools, which can be used to assess postpartum well- being in large cohorts. Our recent work highlights that existing sleep PROs inadequately assess important postpartum sleep domains such as infant sleep, nocturnal feeding patterns, awakenings, and protected maternal sleep time. Clinicians currently lack robust PROs to assess postpartum sleep and screen for postpartum sleep disorders. We therefore propose developing, calibrating, and validating sensitive, context-specific, sleep PROs that capture the symptoms and dimensions of postpartum sleep, while screening for postpartum sleep disorders. To achieve this objective, we will implement novel Patient-Reported Outcomes Measurement Information System® (PROMIS®) ‘gap’ methodology to: (1) adapt existing PROMIS Sleep Disturbance and Sleep-Related Impairment PROs for postpartum use by identifying new PRO items, which improve their content validity, through qualitative interviews and focus group meetings with ≥75 stakeholders and cognitive debriefing interviews with ≥20 patients; (2) calibrate and finalize the adapted postpartum sleep PROs through psychometric evaluation in a racially and socioeconomically diverse cohort of 640 (160 White non-Hispanic, White Hispanic, Black and Asian) women recruited across two hospitals in Stanford, CA and Little Rock, AR. Women will complete sleep, global health and Edinburgh Postnatal Depression Scale PROs at 4 postpartum time points (inpatient, 3 and 6 weeks, 6 months). SCISD-R will also be conducted in 300 of these women at 6 weeks and 6 months, as a gold standard, to determine screening sensitivity and specificity of the adapted PROs. In 50 women, sleep data, (day, nocturnal and total awake time), will also be compared between actigraphy and the adapted PROs; and (3) characterize postpartum sleep and its association with postnatal depression using causal inference approaches. Rigorous validation of the sleep PROs will support their widespread use to assess postpartum sleep, screen for sleep disorders, identify disparities, explore links with postnatal depression, and to promote maternal health and well-being. As such the proposed study aligns well with Goals 3 and 4 of the 2021 NIH Sleep Research Plan.