Risk Factors for Potentially Unsuccessful Results and Mortality during Duberculosis Treatment in Spain

Background: Successful result of treatment in 85% of cases is the target of a Tuberculosis (TB) Control Programme. The aim of this study is to determine the risk factors for unsuccessful completion of treatment and deaths of TB cases in Spain. Methods: Data from the National Surveillance Epidemiological Network. Retrospective study including 5,880 TB cases reported in 2012. Outcomes were classified as: successful (S: cured and treatment completed), potentially unsuccessful (PU: failed, transferred, defaulted, still on treatment and unknown) and deaths. Logistic regression analysis was used to explore the association between epidemiological and clinical factors with PU and deaths as outcome variables. Two different models for nationals and foreigners were adjusted. Results: Successful outcome was 81% in nationals and 79% in foreigners. Spanish TB cases had higher mortality rates than foreigners (8% vs. 2%), and lower percentage of transfers (2% vs. 6%). At multivariate level the risk factors for PU in nationals were: HIV coinfection (OR 1.6 CI95% 1.09-2.29) and previous treatment (OR 2.4 CI95% 1.67-3.53); and HIV coinfection (OR 1.7 CI95% 1.15-2.60), male sex (OR 1.4 CI95% 1.11-1.83) and pulmonary TB (OR 1.6 CI95% 1.22-2.09) in foreigners. Risk factors for death in nationals were: HIV coinfection (OR 2.7 CI95% 1.63-4.54), male sex (OR 1.4 CI95% 1.09-1.89), pulmonary TB (OR 1.5 CI95% 1.13-1.95) and an increasing risk with age (OR 8.9 CI95% 5.16-15.67 in over 45 years group.).; and HIV coinfection (OR 3.2 CI95% 1.53-6.76), male sex (OR 2.2 CI95% 1.01-4.60) and older age(OR 3.4 CI95% 1.81-6.48 in over 45 years group.) in foreigners. Conclusion: The rate of successful treatment in Spain does not meet the international target, especially in foreigners. To reduce unsuccessful treatment and deaths it is necessary to improve management in TB-HIV co-infected cases, and those with previous treatment story, pulmonary TB, males and older age.