Abstract:

Objective: To explore the clinical characteristics and anti-tuberculosis treatment outcomes of elderly patients with pulmonary tuberculosis complicated with anemia to provide a reference for the prevention, control and treatment of pulmonary tuberculosis complicated with anemia. Methods: Elderly pulmonary tuberculosis patients aged 60 and above who visited Shanghai Pulmonary Hospital from 2018 to 2020 were selected and divided into anemia group and non-anemia group to compare their clinical characteristics and treatment outcomes. Further stratified analysis was conducted based on patients' severity of anemia, and Kaplan-Meier method was used to evaluate their survival difference. Cox regression model and restricted cubic spline were used to analyze the association between anemia and treatment outcomes, and subgroup analysis was performed. Results: A total of 904 elderly patients with pulmonary tuberculosis were included, among whom 316 were anemic and 588 were non-anemic. With the increase of severity of anemia (non-anemia, mild anemia, moderate to severe anemia), the proportion of patients with ≥3 lung fields involved (72.28% (425/588) vs. 78.32% (224/286) vs. 96.67% (29/30); H=8.028, P=0.005), cavities (22.11% (130/588) vs. 38.81% (111/286) vs. 46.67% (14/30); H=31.651, P<0.001), and positive sputum culture (41.84% (246/588) vs. 61.19% (175/286) vs. 86.67% (26/30); H=42.564, P<0.001) increased. Compared with non-anemia patients, the treatment success rate of anemia patients decreased by 14.88% (84.18% (495/588) vs. 69.30% (219/316); χ²=28.154, P<0.001), and the cumulative survival rate of patients with moderate to severe anemia within 36 months was the lowest (99.66% (586/588) vs. 96.85% (277/286) vs. 86.67% (26/30); χ²=24.290, P<0.001). Cox regression analysis and trend test results showed that after adjusting for confounding factors, anemia was one of the risk factors for poor prognosis (HR=1.515, 95%CI: 1.091-2.104), and the risk of adverse outcomes increased with the severity of anemia (HR=1.449, 95%CI: 1.115-1.883). The restricted cubic spline results showed that there was a linear dose-response relationship between anemia and adverse outcomes (χ²=35.040, P_{overall trend}<0.001; χ²=1.700, P_nonlinearity=0.191). Further subgroup analysis results were still robust, and there was no significant interaction between anemia and prognosis in terms of gender (P_interaction=0.219), age (P_interaction=0.151), and drug resistance (P_interaction=0.810). Conclusion: Elderly pulmonary tuberculosis patients with anemia have more severe lung damage, lower treatment success rate and cumulative survival rate, especially those with moderate to severe anemia. In clinical treatment, attention should be paid to the screening and intervention of anemia in elderly pulmonary tuberculosis patients to further reduce the occurrence of adverse outcomes.

Key words: Tuberculosis, Anemia, Aged, Disease attributes, Treatment outcome