Development and validation of a prognostic model for COVID in-hospital
mortality in Mexican pregnant women: a national retrospective study
Abstract
Objective: Development of a prediction model for 90-day
in-hospital mortality in pregnant COVID-19 patients older or equal 18
years old. Design: Retrospective cohort study Setting:
Admissions from Mexican emergency services from April 2020 to November
2023 Population: Pregnant patients with a diagnosis of COVID,
confirmed by antigen or PCR, admitted in any Mexican health unit, and
older or equal eighteen years of age. Methods: The population
was divided in primary (2020-2022) and secondary cohorts (2023)
(external validation). 10-fold cross-validation was performed to create
training and testing subsets (internal validation). Association between
mortality and variables was assessed by Cox regression analyzes and the
least absolute shrinkage and selection operator (LASSO). A mortality
risk scale was also constructed. Discrimination was evaluated by area
under the receiver operating curve (AUC-ROC), calibration by
Hosmer-Lemeshow test and calibration slopes; and overall performance by
Brier scaled score. Results: 11,554 patients were included in
the study, of whom 372 died. The final model included six predictors:
intubation, pneumonia, diabetes, chronic kidney disease, time to care
and high-risk pregnancy. Similar discrimination and calibration
characteristics were observed between the training (AUC-ROC:0.873
[0.851-0.894]), Hosmer-Lemeshow test (X 2=6.38
[p=0.270]), calibration slope [R 2=0.409]) and
the test subset (0.884 [0.814-0.955]), X 2=1.64
[p=0.949] and R 2=0.472). Meanwhile, the external
validation showed mixed results (0.999 [0.996-1.000], X
2=0 [p=1.000], R 2=0.166).
Conclusions: The developed model may aid the analysis of
life-threatening cases and improve clinical decision-making to reduce
the burden on the healthcare system and decrease overall mortality.
Fundings: No funding sources are declared. Keywords:
Predictive model, mortality, COVID, pregnancy, Mexico