Abstract:

Objective To understand the diagnosis status and influencing factors of smear negative pulmonary tuberculosis (PTB) in tuberculosis-designated hospitals at county level. Methods Convenient sampling method was used to select tuberculosis-designated hospitals at county level in Anhui province. A total of 6 counties (Qianshan city, Wangjiang county, Huoqiu county, Shucheng county, Taihe county and Linquan county) were selected (two counties in southern Anhui, central Anhui and northern Anhui respectively). Medical records, thoracic computed tomographic imaging and results of laboratory test of all smear negative PTB patients in the designated hospitals reported between 01 April and 31 May 2019 were retrospectively reviewed by an independent review board consisting of experts from provincial hospital. The consistency of diagnosis results was evaluated and the factors affecting the consistency of diagnosis were analyzed. Chi-square test was used to compare the categorical data, P<0.05 for the difference was statistically significant. Results A total of 280 patients were reviewed and the diagnoses of 237 cases (84.64%) were consistent with original diagnosis. Eight-one cases (28.93%) received biomolecular test. Univariate analysis showed that the diagnostic consistency rates of patients with qualified sputum specimens (92.31%, 72/78), initial treatment (87.40%, 215/246), pleural lesions (93.10%, 81/87), positive PPD (91.46%, 75/82), positive γ-interferon release test (100.00%, 46/46), and with local smear negative diagnosis team discussion (93.59%, 73/78) were significant high than those of the patients with unqualified sputum specimens (81.68%, 165/202), retreatment (64.70%, 22/34), without pleural lesions (80.83%, 156/193), negative PPD (70.83%, 17/24), negative γ-interferon release test (81.82%, 9/11) and without the smear negative diagnosis team discussion (81.19%,164/202), and χ² values were 4.887, 11.834, 6.951, 6.685, 9.987 and 6.658 respectively, and P values were all less than 0.05. Multivariate stepwise logistic regression analysis showed that the qualified sputum specimen (vs. unqualified, OR=2.944, 95%CI: 1.130-7.672, P=0.027), initial treatment (vs. retreatment, OR=2.465, 95%CI: 0.916-6.633, P=0.074), with pleural lesions (vs. without pleural lesions, OR=2.255, 95%CI: 0.924-5.499, P=0.074), PPD negative (vs. positive, OR=0.189, 95%CI: 0.052-0.692, P=0.012), with local diagnostic team discussion (without discussion, OR=2.244, 95%CI: 0.795-6.336, P=0.127) were the factors for the diagnosis consistency. Conclusion Diagnostic consistency for smear negative PTB between hospitals at county-level and provincial independent review board is not high, and the quality of sputum specimens, initial treatment, pleural lesions, PPD test result and local diagnostic team discussion are the main factors affecting the consistency of diagnosis results. The proportion of patients with molecular biological examination is low.

Key words: Tuberculosis, pulmonary, Diagnosis, Sampling studies, Data collection, Outcome assessment (health care), Factor analysis, statistical