Predictors of 1-Year Mortality from a Subacute Geriatric Ward in Singapore

Background/Purpose: Older patients have multiple comorbidities that result in adverse health outcomes. However, factors predicting mortality in subacute geriatric population is lacking. The study aims to identify factors and develop a scoring system to predict 1 year all-cause mortality of older patients in subacute geriatric unit. Methods: This was a prospective study carried out from June 2018 to June 2019. 290 consecutive patients admitted to the subacute unit in a Singapore community hospital were recruited. Patient data collected included demographics, laboratory markers, length of stay in acute and subacute unit, readmissions rates, medications, geriatric survey instruments. Logistic regression was performed to identify factors associated with 1 year all-cause mortality. Risk score was calculated for each identified factor and a scoring system that stratified patient into 3 risk groups with corresponding mortality percentages was developed. Results: Our study showed a 1 year all-cause mortality of 15.8% post subacute unit discharge. Predictors of mortality included eGFR <60ml/ min/1.73m2 (OR 6.30; 95% CI 2.34, 16.92), 1 year readmission (OR 4.58; 95% CI 1.28, 16.38), hypoalbuminemia <35mmol/L (OR 4.10; 95% CI 1.68, 10.01), dysnatremia (<135 or >145 mmol/L) (OR 3.49; 95% CI 1.07, 11.44) and MMSE <24 (OR 2.66; 95% CI 0.55, 12.90). Our scoring system stratified patients into 3 groups with the following 1 year mortality risk: Low: 3.2%, Moderate: 7.7%, and High: 45.2%. Conclusion: Readmission within 1 year, dysnatremia, low eGFR, hypoalbuminemia and lower MMSE scores were significant predictors of 1 year mortality post discharge from a subacute unit.