Use of a laboratory only score system to define trajectories and outcomes of older people admitted to the acute hospital as medical emergencies.

AIM: Increasing numbers of older people are admitted to hospital as medical emergencies. They are a heterogeneous population with uncertain trajectories and outcomes. Our aim was to retrospectively characterize subgroups of older inpatients based on their acuity trajectories.

METHODS: This was a single-center patient series from St James's Hospital Dublin, Ireland (2002-2010). The Medical Admissions Risk System (MARS) score was used to classify a sample of 14,607 patients aged ≥ 65 years, from admission to end of episode, into four trajectory groups: (i) static high acuity (group 1); (ii) static low acuity (group 2); (iii) inpatient deterioration (group 3); and (iv) inpatient improvement (group 4). K-means cluster analysis was used for the classification.

RESULTS: Group 1 (4.1%): median length of stay (LOS) 7.4 days, 23.6% used intensive care, mortality rate 79.2%; sepsis and renal failure were the dominant features. Group 2 (76.6%): median LOS 8.0 days, 5.2% used intensive care, mortality rate 9.5%; younger age, low comorbidity and diseases of non-vital organs were predominant. Group 3 (7.6%): median LOS 17.2 days, 17.4% used intensive care, mortality rate 76.1%; high comorbidity and sepsis/respiratory disease featured. Group 4 (11.7%): median LOS 12.1 days, 12.8% used intensive care, mortality rate 22.7%; sepsis and renal/metabolic disease were frequent, and comorbidity levels were intermediate.

CONCLUSIONS: In older acute medical inpatients, the outcome seemed more driven by specific diagnoses (such as sepsis and renal failure) and comorbidity, than by age. Using the MARS score to retrospectively categorize older inpatients might help to understand their heterogeneity and promote the design of appropriate care pathways.