Lone NI, et al. - Researchers analyzed the risk factors for unplanned 90-day readmission, developed a risk prediction model and evaluated its performance to screen for intensive care unit (ICU) survivors at highest readmission risk. They noted that unplanned 90-day hospital readmission was common. Compared to acute illness factors, pre-existing illness indices were better predictors of readmission. The risk prediction models could be improved by identifying additional patient-centered drivers of readmission. The clinical and cost-effectiveness of post-ICU care and rehabilitation could be improved with an improved understanding of risk factors that were amenable to intervention.

Methods

• Authors reviewed the population cohort study linking registry data for patients discharged from general ICUs in Scotland (2005–2013).
• Using multivariable logistic regression, independent risk factors for 90-day readmission and discriminant ability (c-index) of groups of variables were identified.
• They constructed derivation and validation risk prediction models using a time-based split.

Results

• As per the data, out of 55,975 ICU survivors, 24.1% (95%CI 23.7% to 24.4%) had unplanned 90-day readmission.
• Results demonstrated that pre-existing health factors were fair discriminators of readmission (c-index 0.63, 95% CI 0.63 to 0.64) but better than acute illness factors (0.60) or demographics (0.54).
• The acute illness factors (0.62) were better discriminators than pre-existing health factors (0.56) in a subgroup of those with no comorbidity.
• Findings suggested that in the validation cohort overall model performance and calibration was fair (0.65, 95% CI 0.64 to 0.66) but did not perform sufficiently well as a screening tool, suggesting high false-positive/false-negative rates at clinically relevant thresholds.