Stratifying mortality risk in hypotension using outcome-oriented clustering of vital sign trajectories

Figures

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  Figure 1. The overall framework of the clustering strategy and analysis method

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  Figure 2. Normalized total SHAP values for the time series of vital signs in each model The variables in the figure are arranged in ascending order of the mean normalized total SHAP values on the five models. Notes: RR, respiratory rate; SpO2, pulse oxygen saturation; HR, heart rate; MAP, mean arterial pressure; SAP, systolic arterial pressure; DAP, diastolic arterial pressure.

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  Figure 3. The standard deviation of subgroup mortality for each combination of variables at each effective number of clusters The x axis represents various variable combinations, accumulated sequentially from RR onward. Clusters with a population size of less than 5% of the total or whose survival curves did not show significant differences (p < 0.05) from those of any other clusters were considered invalid, and the standard deviation of subgroup mortality was not calculated for these clusters.

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  Figure 4. Survival curves for subgroups based on 12-h and 2-h RRs from the three cohorts (A, D) Survival curves for subgroups identified within the 12-h and 2-h time windows, respectively, from MIMIC IV. (B, E) Survival curves for the 12-h and 2-h windows from eICU. (C, F) Survival curves for the 12-h and 2-h windows from Xiangya. Limited by data availability, in-hospital survival curves were drawn and ended at 90 days. The number at risk at every 10-day interval is annotated on the corresponding coordinates. 90-day survival curves for MIMIC IV were shown in Figure S8. Notes: RR, respiratory rate.

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  Figure 5. Trajectories of vital signs in subgroups based on the 12-h time window (A) Trajectories of vital signs in subgroups from MIMIC IV, (B) Corresponding trajectories from eICU, (C) Corresponding trajectories from Xiangya. Upon testing, none of the vital signs at each time step follow a normal distribution. Therefore, the trajectory is composed of the median vital signs at each time step within each subgroup. The shaded area represents the interquartile range (IQR). Notes: RR, respiratory rate; SpO2, pulse oxygen saturation; HR, heart rate; MAP, mean arterial pressure; SAP, systolic arterial pressure; DAP, diastolic arterial pressure.

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  Figure 6. Critical mortality influences across subtypes in MIMIC IV based on 12-h RRs Notes: max, maximum; min, minimum; bun, blood urea nitrogen; pt, prothrombin time; po2, arterial partial pressure of oxygen; abs, absolute; ph, potential of hydrogen; ptt, partial thromboplastin time.

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  Figure 7. Independent prognostic factors associated with survival outcome identified by multivariate Cox regression analysis The analysis was conducted across all clusters derived from the 2-h RRs, with a specific focus on the septic shock subgroup. The forest plot presents the adjusted hazard ratios and 95% confidence intervals of variables that retained independent statistical significance (p < 0.05).