Is Manchester (MTS) more than a triage system? A study of its association with mortality and admission to a large Portuguese hospital

Background: The Manchester Triage System (MTS) is a 5-point triage scale used to triage patients presenting to the emergency department. It was introduced in the UK in 1996 and is now widespread, especially in Europe, and has been in use in our hospital since 2000 via a computerised protocol. A study was undertaken to determine whether the subgroups created by the application of MTS have different propensities for indirect triage outcomes such as death in the A&E department or being admitted to hospital. Methods: A database of 321 539 patients triaged during a 30-month period (from January 2005 to June 2007) was used. MTS codes, death outcomes, admission and admission route were used to estimate the proportions and association between MTS codes and the remaining variables by chi(2) univariate analysis. Results: There was a clear association between the priority group and short-term mortality as well as with the proportion of patients admitted to hospital. Conclusions: The MTS provides information that extends beyond its immediate usefulness as a prioritisation mechanism. It is a powerful tool for distinguishing between patients with high and low unadjusted risk of short-term death as well as those who will stay in hospital for at least 24 h and those who will return home. Its discriminatory power is not equal for medical and surgical specialities, which may be linked to the nature of its inbuilt discriminators.