Risk factors for mortality in 600 patients in vegetative and minimally conscious states

A significant proportion of patients who survive traumatic or nontraumatic severe acquired brain injuries experiences disorders of consciousness. The vegetative state and the minimally conscious state may have different prognoses, and while some patients regain awareness, others have negative outcomes and die. The aim of this work is to identify age-related, medical and behavioural risk factors for mortality in those patients. Participants were enrolled from June 2009 to March 2012 in 107 Italian health care institutions. Univariate and multivariate Cox proportional hazard models were adopted to screen and test candidate risk factors. The study enrolled 600 subjects in vegetative and minimally conscious states for an overall mortality rate of 180.1 per 1,000 person-years. The following traits were associated with a significantly lower chance of survival: age at the acute event higher than 51 years, disease duration less than 1 year, post-anoxic aetiology, absence of visual fixation, and the presence of endocrine, nutritional, and metabolic diseases, and immunity disorders. Clinical history, behavioural assessment, and age-related factors provide important prognostic information on negative outcomes that helps clinicians and researchers to predict patients who are at higher risk of mortality. This knowledge has important clinical, managerial, and ethical implications.