Comparison of syndromic surveillance and hospital discharge data for unintentional drowning in metropolitan Houston, Texas, USA.

Abstract

Background: Syndromic surveillance, which provides real-time data, may provide timely drowning surveillance compared with hospital discharge data where the release of data may be delayed. We compared data on hospital visits for unintentional drowning identified in hospital discharge and syndromic surveillance data sets for accuracy and completeness.

Methods: We compared data for hospital visits for unintentional drowning identified in the Texas Health Care Information Collection hospital discharge and syndromic surveillance data sets for metropolitan Houston, Texas, USA from 2019 to 2021. Hospital visits included emergency department-only visits and hospital admissions. We compared time-series visualisation of hospital visits between data sets. Injury burden, demographics and intercounty distribution of drowning patients were compared using the Pearson correlation coefficient for continuous data and the Pearson χ² goodness-of-fit test for categorical data.

Results: We identified 860 hospital discharge visits and 929 syndromic surveillance visits (quarterly median (IQR): 64.0 (26.8-117.5); 54.5 (28.0-132.3), respectively) for unintentional drowning. Time-series visualisation showed a high correlation between syndromic surveillance and hospital discharge visits (correlation coefficient: 0.93 (95% CI: 0.77 to 0.98)). There were small differences by race, ethnicity and county for all ages and for paediatrics and large differences by sex for all ages in the number of unintentional drowning hospital visits identified within the data sets.

Conclusions: Regional unintentional drowning burden and trends are highly correlated between syndromic surveillance and hospital discharge data. Small differences by race, ethnicity and county and large differences by sex in the number of unintentional drowning hospital visits were identified between data sets. Syndromic surveillance is useful for real-time surveillance of unintentional drowning.