OBJECTIVES: To analyze the costs and discharge status for patients with prolonged mechanical ventilation undergoing tracheostomy (DRG code 483) in Spain and to examine the impact of age in terms of hospital outcome. METHODS: From the 2004 National Hospital Discharge Database records for all patients aged >16 years undergoing mechanical ventilation were retrieved. Demographic characteristics, clinical outcomes and hospital-resources utilization were examined. An exploratory logistic regression analysis and a multiple linear regression analysis were performed to identify factors associated with in-hospital mortality and LOS respectively. To depict the amount of resources spent to procure a given level of desired outcome (hospital survival) we also determined the cost per survivor based in the average National Health Service Charges for DRG 483 (€49,365.37). RESULTS: From a total of 33,416 cases undergoing mechanical ventilation during 2004, 4,277 cases (13%) with a final DRG code of 483 were selected and eligible for analysis. Median age was 65yr (p25:50; p75:73); 67% were men and 54% surgical patients. According to Charlson index, 56% of cases had no associated comorbidity. Overall in-hospital mortality was 41%. Total costs of hospitalizations exceeded € 211 million. An inverse relationship between survival rate and age was consistently observed after adjusting by other clinical variables, and this resulted in an age-related increased cost per survivor (€58,588 in patients aged <45 yrs; €75,1531 in those aged 45-64yrs; 99,720 in 65-74 yrs and €12,5903 in those older than 74 yrs). CONCLUSIONS: Patients who require tracheostomy for prolonged mechanical ventilation have high resource utilization and relatively poor outcomes. Age has a significant impact on outcomes in patients under DRG 483 both from clinical and economic perspectives. These analyses will help inform health care decision-making and resource planning in the face of an ageing population.