Using inability to walk to predict in-hospital mortality in a high-income country - A comparison with the National Early Warning Score in a multicenter prospective cohort.

BACKGROUND

Inability to walk (IATW) has predicted mortality in emergency units and in low-income settings, but its value among inpatients in high-income countries is unknown.

AIM: To evaluate the predictive accuracy of IATW for 30-day in-hospital mortality among inpatients in a high-income country, compare its performance with NEWS CRITICAL (the threshold for urgent review), and assess whether IATW provides complementary risk stratification when combined with NEWS.

METHODS

All adult inpatients in four Swedish hospitals were prospectively examined in a multicenter point-prevalence assessment. IATW was defined as inability to walk five steps without physical assistance or walking aids. NEWS was calculated from contemporaneous vital signs. The primary outcome was 30-day in-hospital mortality. We computed sensitivity, specificity, predictive values, and likelihood ratios. Multivariable logistic regression assessed the association between IATW and mortality, adjusted for NEWS, age, and sex.

RESULTS

Of 1842 patients, 59.9% were IATW-positive and 22.3% met NEWS CRITICAL (≥5 or any single-parameter score of 3). Mortality was 4.6%. IATW had higher sensitivity (86.9% vs 66.7%) but lower specificity (41.4% vs 79.8%) than NEWS CRITICAL; NPV was high for both (98.5% vs 98.0%). IATW was independently associated with mortality after adjustment for NEWS (OR 2.43, 95% CI 1.24-4.76; p = 0.009). Patients that were both IATW-negative and with NEWS <5 (35.2% of the cohort) had 1.1% mortality.

CONCLUSIONS

Inability to walk (IATW) is a bedside assessment that when negative identifies patients with low 30-day in-hospital mortality and provides complementary information to NEWS. Its low complexity, high sensitivity and low negative likelihood ratios support its use in clinical risk assessments.