Objectives: Injury Severity Score (ISS) is the most widely used method of assessing severity of injury in blunt trauma. It has been recognized that, by only allowing the score to consider the worst injury for each body system, ISS underestimates the problems of multiple musculoskeletal injuries. The New ISS (NISS) allows the three most severe injuries to be scored, irrespective of region affected, and may give better prediction of functional recovery in these patients.
Methods: A prospective cohort study of 200 patients with musculoskeletal injuries, examining the predictive value of ISS and NISS on functional recovery as measured by patient-derived outcome measures (Short Form-36, Sickness Impact Profile, and Musculoskeletal Function Assessment).
Results: NISS was greater than ISS in 34 patients (17%). NISS showed closer correlation with total scores and subscores of the outcomes measures than did ISS (Spearman's rho ranked test, P < 0.05).
Conclusions: NISS, a simple modification from ISS, better predicts functional outcomes in survivors of musculoskeletal trauma, and offers an improvement in the assessment of effectiveness of trauma care delivery.