Maternal, Perinatal and Pediatric Nutrition (Poster Session)
(P10-100-24) ‘Days of Gestation Lost’ May Inform Preterm Birth Intervention When the ‘Percent Preterm’ Is Unknown or Unreliable Due to Small Group or Sample Size
MCAH Senior Epidemiologist San Francisco Department of Public Health San Francisco, California, United States
Disclosure(s):
Jodi Stookey, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Timely, local data about preterm birth (PTB) prevalence, disparities, and trends are needed to inform essential public health services to prevent PTB. The count-based 'percent preterm' is frequently suppressed or unreliable due to privacy concerns in local jurisdictions and/or short time periods, because < 20 PTBs happened in the group and/or time interval. To address data gaps, a time-based indicator is proposed: days of gestation lost (DGL).
Methods: Sensitivity analyses explored the DGL range and confidence intervals associated with hypothetical best-case (only 1 least-severe PTB at 36 weeks gestation in the group) and worst-case (every birth in the group with most-severe PTB at 20 weeks gestation) scenarios for groups ranging in size from 10-1000. Pilot analyses then used DGL to check for significant disparities and/or trends in real birth record data from population groups (e.g. Native American (NA), Pacific Islander (PI)) and periods with < 20 PTBs in the city and county of San Francisco (SF). DGL was calculated as 1000*(sum of (7days*(37-gestational age in weeks for each birth) for all births in each population group in the period)/(7days*(37 possible weeks gestation*total births in group in period)). Within-period, race-ethnicity-specific DGL (95%CI) were compared to check for significant disparities. Within-group, period-specific DGL (95%CI) were compared to check for significant trends over time.
Results: In sensitivity analyses, DGL ranged from 0 to 460, regardless of group size. As group size increased from 10 to 1000, DGL 95%CIs ranged from 13 to 0 days lost per 1,000. In SF, in 2020-2021, the DGL for NA (7.1, 95%CI: 4.8-9.5) and PI (12.8, 95%CI: 11.1-14.6) were significantly higher than for White (95%CI: 4.5, 4.3-4.6) groups, and significantly higher than NA- and PI-specific, pre-pandemic DGL (2.5, 95%CI: 1.2-3.7 and 4.0, 95%CI: 3.1-4.8, respectively, in 2018-2019).
Conclusions: For population groups or periods with < 20 PTBs, when the percent preterm cannot be used for tracking, DGL may be used to detect disparities and trends and inform PTB intervention.
