Assessing the Incremental Value of Blood Oxygen Saturation (SpO2) in the miniPIERS (Pre-eclampsia Integrated Estimate of RiSk) Risk Prediction Model

Abstract Objective To assess the incremental value of blood oxygen saturation (SpO 2 ) as a predictor in the miniPIERS model, a risk prediction model for adverse outcomes among women with a diagnosis of hypertensive disorder of pregnancy (HDP) in low-resourced settings. Methods Using data from a prospective cohort including 852 women admitted to hospital for a HDP, the association between SpO 2 and adverse maternal outcome was assessed using logistic regression. The miniPIERS model was recalibrated and extended to include SpO 2 . The incremental value of adding SpO 2 to the model was measured using a net reclassification index (NRI), sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Results SpO 2 of 2 >97%. After recalibration and extension, the miniPIERS model including SpO 2 (vs. not including SpO 2 ) had improved sensitivity (32.8% vs. 49.6%) at the cost of minimally decreased specificity (91.5% vs. 96.2%) with a NRI of 0.122. Conclusion SpO 2 is a significant independent predictor of risk in women with a HDP. Adding SpO 2 to the miniPIERS model improved the model's ability to correctly identify high-risk patients who would benefit most from interventions.