Prognostic significance of a prolonged international normalized ratio in elderly patients in an internal medicine ward.

PURPOSE: To investigate clinical characteristics and the prognostic significance of a prolonged international normalized ratio (INR) without obvious cause or anticoagulant treatment, in elderly inpatients.

METHODS: Demographic, clinical, and laboratory data, in-hospital death and 30day-mortality were prospectively registered for 100 consecutive patients aged ≥75years admitted to an internal medicine ward for a variety of acute medical disorders, and compared according to normal (≤1.15) and prolonged (>1.15) INR on admission. Exclusion criteria were: anticoagulant therapy, disseminated intravascular coagulopathy, acute bleeding, liver disease, active malignant disorder, and known coagulopathy.

RESULTS: Prolonged INR was found in 52% of patients. Patients with prolonged INR tended more likely to present with dementia and pressure sores than patients with normal INR. Moreover, patients with prolonged INR more often needed assisted feeding and presented lower mean levels of serum albumin on admission. In-hospital (21.2% vs. 6.2%) and 30-day (32.7% vs. 6.2%) mortality rates were significantly higher in patients with prolonged INR than those with normal INR. On stepwise logistic regression analysis, prolonged INR strongly predicted 30-day mortality (P=0.004, relative risk 1.67, 95% confidence interval 1.07-2.60).

CONCLUSIONS: Prolonged INR without obvious cause or anticoagulant treatment is common among elderly patients admitted to an internal medicine ward, and is associated with a severe clinical profile. Prolonged INR is a powerful predictor of 30-day mortality. Assessment of INR my improve risk stratification for elderly inpatients.