New medical diagnoses and length of stay of acutely unwell older patients: Implications for funding models.

Aim: To examine the relationship between newly made medical diagnoses and length of stay (LOS) of acutely unwell older patients.

Methods: Consecutive patients admitted under the care of four geriatricians were randomly allocated to a model development sample (n = 937) or a model validation sample (n = 855). Cox regression was used to model LOS. Variables considered for inclusion in the development model were established risk factors for LOS and univariate predictors from our dataset. Variables selected in the development sample were tested in the validation sample.

Results: A median of five new medical diagnoses were made during a median LOS of 10 days. New diagnoses predicted an increased LOS (hazard ratio 0.90, 95% confidence interval 0.88-0.92). Other significant predictors of increased LOS in both samples were malnutrition and frailty.

Conclusions: Identification of new medical diagnoses may have implications for Diagnosis Related Groups-based funding models and may improve the care of older people.