Variables of Interest

The COVID-19 pandemic period was the treatment exposure and defined as March 10, 2020, through August 31, 2021. Encounter-level outcomes during this period were compared with those during the prepandemic period of January 1, 2018, to March 9, 2020. Outcomes of interest were boarding status, repeat visits, and discharge disposition. Boarding status was a binary outcome associated with a specific encounter. A visit was considered a repeat if the subsequent evaluation was performed by any BEST clinician within 30 days of the previous visit. Discharge disposition had 4 outcomes: IPU, CBAT facility, outpatient care, or NS. Covariates included demographic, encounter, and diagnostic data. Demographic data included age, gender identity, race and ethnicity (Asian/Pacific Islander, Black, Hispanic, White, and other [which included those who selected “other” or indicated American Indian/Alaska Native]), and zip code of residence. Race and ethnicity data were relevant to the study outcome because of known racial and ethnic disparities in mental health care.⁴³ Encounter data included referral source, location of encounter, and primary diagnosis. Primary psychiatric diagnoses were organized into categories using International Classification of Diseases, Tenth Revision codes and Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) criteria.³²

A secondary outcome of interest was boarding LOS, which was estimated by counting the hours between bed search start and end times and dividing that number by 24 to estimate the number of days. A total of 3624 encounters had a boarding flag; of those, only 1752 (48.3%) had bed search time stamps. We therefore conducted boarding LOS analyses using that subset of data. Sensitivity tests indicated that encounters without bed search data were more likely to result in discharge to outpatient care and less likely to result in discharge to IPUs than encounters with bed search data (eTable 3 in Supplement 1). For this reason, caution should be used when interpreting the boarding LOS findings.