[Prognosis of patients with tuberculosis]

The global incidence of tuberculosis peaked around the year 2003 and is currently declining gradually. However, the worldwide incidence of new tuberculosis cases is still estimated to be 8.8 million/year, with 1.5 million deaths occurring per year. Considering that previous studies have determined the risk factors for death due to tuberculosis, we aimed at reviewing the literature to collectively evaluate these risk factors. According our literature review of 12 articles published in English language and 7 articles published in Japanese, the risk factors for death due to tuberculosis are age, human immunodeficiency virus (HIV) co-infection, multi-drug resistant tuberculosis (MDR-TB), malnutrition, low activities of daily living, co-morbidities, unemployment, and drug injection. We developed a scoring system to calculate the Tuberculosis Prognostic Score using 4 risk factors, namely, age, serum albumin level, oxygen requirement, and activities of daily living, after assessing several cohorts in Japan, in which HIV co-infection and MDR-TB are rare and their associations with mortality due to tuberculosis patients are unclear. This scoring system was successfully able to estimate life prognosis of inpatients with newly diagnosed, smear-positive, lung tuberculosis without MDR-TB and/or HIV virus co-infection.