Identifying and Validating Pediatric Hospitalizations for MIS-C Through Administrative Data.

BACKGROUND: Individual children's hospitals care for a small number of patients with multisystem inflammatory syndrome in children (MIS-C). Administrative databases offer an opportunity to conduct generalizable research; however, identifying patients with MIS-C is challenging. METHODS: We developed and validated algorithms to identify MIS-C hospitalizations in administrative databases. We developed 10 approaches using diagnostic codes and medication billing data and applied them to the Pediatric Health Information System from January 2020 to August 2021. We reviewed medical records at 7 geographically diverse hospitals to compare potential cases of MIS-C identified by algorithms to each participating hospital's list of patients with MIS-C (used for public health reporting). RESULTS: The sites had 245 hospitalizations for MIS-C in 2020 and 358 additional MIS-C hospitalizations through August 2021. One algorithm for the identification of cases in 2020 had a sensitivity of 82%, a low false positive rate of 22%, and a positive predictive value (PPV) of 78%. For hospitalizations in 2021, the sensitivity of the MIS-C diagnosis code was 98% with 84% PPV. CONCLUSION: We developed high-sensitivity algorithms to use for epidemiologic research and high-PPV algorithms for comparative effectiveness research. Accurate algorithms to identify MIS-C hospitalizations can facilitate important research for understanding this novel entity as it evolves during new waves.

Impact of the COVID-19 pandemic on hospitalizations of children with neurologic impairment.

INTRODUCTION: Children with neurologic impairment (NI) are frequently hospitalized for infectious and noninfectious illnesses. The early period of the COVID-19 pandemic was associated with overall lower pediatric hospitalization rates, particularly for respiratory infections, but the effect on utilization for children with NI is unknown. METHOD: This multicenter retrospective cohort study included hospitalizations of children 1-18 years of age with NI diagnosis codes from 49 children's hospitals. We calculated the percent change in the median weekly hospitalization volumes and the hospitalization resource intensity score (H-RISK), comparing the early-COVID era (March 15, 2020 to December 31, 2020) with the pre-COVID era (same timeframe of 2017-2019). Percent change was calculated over the entire study period as well as within three seasonal time periods (spring, summer, and fall/winter). Differences between infectious and noninfectious admission diagnoses were also examined. RESULTS: Compared with the pre-COVID era, there was a 14.4% decrease (interquartile range [IQR]: -33.8, -11.7) in the weekly median number of hospitalizations in the early-COVID era; the weekly median H-RISK score was 11.7% greater (IQR: 8.9, 14.9). Hospitalizations decreased for both noninfectious (-11.6%, IQR: -30.0, -8.0) and infectious (-35.5%, IQR: -51.1, -31.3) illnesses in the early-COVID era. This decrease was the largest in spring 2020 and continued throughout 2020. CONCLUSIONS: For children with NI, there was a substantial and significant decrease in hospitalizations for infectious and noninfectious diagnoses but an increase in illness severity during the early-COVID era compared with the pre-COVID era. Our data suggest a need to reconsider current thresholds for hospitalization and identify opportunities to support and guide families through certain illnesses without hospitalization.

Association Between Statewide School Closure and COVID-19 Incidence and Mortality in the US.

Importance: In the US, states enacted nonpharmaceutical interventions, including school closure, to reduce the spread of coronavirus disease 2019 (COVID-19). All 50 states closed schools in March 2020 despite uncertainty if school closure would be effective. Objective: To determine if school closure and its timing were associated with decreased COVID-19 incidence and mortality. Design, Setting, and Participants: US population-based observational study conducted between March 9, 2020, and May 7, 2020, using interrupted time series analyses incorporating a lag period to allow for potential policy-associated changes to occur. To isolate the association of school closure with outcomes, state-level nonpharmaceutical interventions and attributes were included in negative binomial regression models. States were examined in quartiles based on state-level COVID-19 cumulative incidence per 100 000 residents at the time of school closure. Models were used to derive the estimated absolute differences between schools that closed and schools that remained open as well as the number of cases and deaths if states had closed schools when the cumulative incidence of COVID-19 was in the lowest quartile compared with the highest quartile. Exposures: Closure of primary and secondary schools. Main Outcomes and Measures: COVID-19 daily incidence and mortality per 100 000 residents. Results: COVID-19 cumulative incidence in states at the time of school closure ranged from 0 to 14.75 cases per 100 000 population. School closure was associated with a significant decline in the incidence of COVID-19 (adjusted relative change per week, -62% [95% CI, -71% to -49%]) and mortality (adjusted relative change per week, -58% [95% CI, -68% to -46%]). Both of these associations were largest in states with low cumulative incidence of COVID-19 at the time of school closure. For example, states with the lowest incidence of COVID-19 had a -72% (95% CI, -79% to -62%) relative change in incidence compared with -49% (95% CI, -62% to -33%) for those states with the highest cumulative incidence. In a model derived from this analysis, it was estimated that closing schools when the cumulative incidence of COVID-19 was in the lowest quartile compared with the highest quartile was associated with 128.7 fewer cases per 100 000 population over 26 days and with 1.5 fewer deaths per 100 000 population over 16 days. Conclusions and Relevance: Between March 9, 2020, and May 7, 2020, school closure in the US was temporally associated with decreased COVID-19 incidence and mortality; states that closed schools earlier, when cumulative incidence of COVID-19 was low, had the largest relative reduction in incidence and mortality. However, it remains possible that some of the reduction may have been related to other concurrent nonpharmaceutical interventions.