Nosocomial infections impact in a hospital in Bogota, Colombia:effects on mortality and hospital costsBackground: Nosocomial infections (NI) are events associated with high impact on hospital costs and mortality.Aim: To evaluate from the health provider's perspective the costs and mortality attributable to NI. Methods: We selected a sample of patients with and without NI matched by age and diagnosis at admission.Costs were calculated and converted from Colombian pesos to US dollars using the average exchange rate of 2008.We evaluated the mortality rate in both groups.Results: We collected data on 187 patients with NI and 276 without NI.Median total hospitalization cost was US$ 6,329 (95% CI US$5,527-7,934) in NI patients, while in non-infected patients this median was US$1,207 (95% CI US$ 974-1,495).Mortality was higher in the NI group (31.6% versus 5.1%).Patients with NI had longer hospital stays (median 21 days, 95% CI 18-24 days) than non-infected patients (median 5 days, 95% CI 5-6 days).Mortality was also markedly higher in the NI group than in the non-infected group (31.6% versus 5.1%).Conclusion: NI are adverse and costly events related to patient attention that affect adversely the quality of attention.