Abstract: Objective To evaluate and analyze the results of nationwide anti-tuberculosis drug susceptibility proficiency testing from 2009 to 2013, and improve the capability of tuberculosis laboratories in China. Methods Natio-nal tuberculosis reference laboratory issued 30 Mycobacterium tuberculosis isolates for the DST to each participating laboratories yearly from 2009 to 2013. The laboratories performed DST for isoniazid(H), streptomycin(S), ethambutol(E), rifampicin(R), kanamycin(Km), amikacin(Am), capreomycin(Cm) and ofloxacin (Ofx) using the proportion method in Lowenstein-Jensen medium, the World Health Organization guideline was strictly followed. All 508 laboratories participated the proficiency testing and reported the results of first line DST, and 445 laboratories reported the results of second line DST. The reported results were checked and compared with the judicial results by national tuberculosis reference laboratory. The evaluation index is sensitivity, specificity, reproducibility and efficiency. The Chi-square test was be used to analyze the results, and the Cochran-Armitage trend test was be used to describe the trend results, significant difference was defined as P<0.05.  Results The overall value of sensitivity, specificity, reproducibility and efficiency for each drug was respectively as following: H: 91.88%－97.62%, 92.01%－98.33%, 86.55%－95.27% and 91.40%－97.60%；S: 88.79%－94.14%, 87.59%－91.36%, 77.37%－93.13% and 88.20%－92.45%；E：66.24%－85.17%, 83.22%－97.87%, 63.46%－89.76% and 75.78%－90.80%；R: 78.54%－96.34%, 96.19%－98.07%, 79.11%－95.66% and 90.72%－97.21%；Km: 81.12%－95.46%, 95.35%－98.86%, 94.12%－96.84% and 90.23%－97.77%；Am: 93.14%－98.94%, 96.16%－99.00%, 93.52%－97.94% and 95.59%－98.19%；Cm:52.45%－95.68%, 89.68%－97.85%, 89.48%－92.99% and 89.08%－95.61%；Ofx: 84.75%－94.38%, 96.21%－98.90%, 88.01%－94.41% and 93.01%－96.90%. Except for the specificity of S, reproducibility of Km and Cm was not statistically significant difference between each year(χ² value of 8.49, 4.1, 7.78, respectively, P>0.05）,the difference of overall sensitivity for each drug between each year was statistically significant(H:χ²=134.76；S:χ²=44.12；E:χ²=266.22；R:χ²=256.35；Km:χ²=197.46；Am:χ²=12.16；Cm:χ²=433.50；Ofx:χ²=47.38，P<0.05); the difference of overall specificity for other drug between each year was statistically significant(H:χ²=67.69； E:χ²=439.39；R:χ²=16.61；Km:χ²=94.97；Am:χ²=52.96；Cm:χ²=139.51；Ofx:χ²=11.66，P<0.05);the difference of overall reproducibility for other drug between each year was statistically significant(H:χ²=61.82；S:χ²=127.15；E:χ²=246.49；R:χ²=180.03；Am:χ²=21.65；Ofx:χ²=28.49，P<0.05); the difference of overall efficiency for each drug between each year was statistically significant(H:χ²=162.05；S:χ²=36.58；E:χ²=369.11；R:χ²=152.30；Km:χ²=233.69；Am:χ²=32.55；Cm:χ²=168.79；Ofx:χ²=36.97，P<0.05). While, except for the overall sensitivity of Am and Cm, the overall specificity of Ofx and the overall reproducibility of Km, Am and Cm（Z value of 0.46, 0.99, －0.30, －0.85, 0.09 and －0.27, respectively, P>0.05), the overall sensitivity for other drug showed a trend of increase by year (H:Z=－11.06；S: Z=－6.39；E: Z=－12.39；R: Z=－11.17；Km: Z=－12.60；Ofx: Z=－4.40，P<0.05);the overall specificity for other drug showed a trend of increase by year(H:Z=－3.85；S: Z=－2.14；E: Z=－12.30；R: Z=－3.31；Km: Z=－5.05；Am: Z=－5.43；Cm: Z=－8.90，P<0.05); the overall reprodu-cibility for other drug showed a trend of increase by year(H:Z=－5.36；S: Z=－9.11；E: Z=－7.76；R: Z=－8.52；Ofx: Z=－3.44，P<0.05)；the overall efficiency for each drug showed a trend of increase by year (H:Z=－10.95；S: Z=－5.95；E: Z=－11.87；R: Z=－9.70；Km: Z=－14.11；Am: Z=－3.32；Cm: Z=－5.71；Ofx: Z=－3.40，P<0.05).  Conclusion Proficiency testing was an efficient method to improve the capacity and performance of DST, PT has made a great contribution to increase the ability of DST in Chinese TB laboratory network, and continuously conducting the laboratory internal quality control and carrying out personnel training to perform proficiency testing could increase the laboratory capabilities of DST year by year.

Key words: Mycobacterium tuberculosis, Microbial sensitivity tests,  , Sensitivity and specificity