Paramasivan C N, Venkataraman P, Vasanthan J S, Rahman F, Narayanan P R
Tuberculosis Research Centre, Chennai, Tamil Nadu, India.
Int J Tuberc Lung Dis. 2003 Jun;7(6):522-7.
Tuberculosis Research Centre, Chennai, India.
To undertake quality assurance studies in sputum smear microscopy at eight State-level laboratories in India using a panel of stained smears.
Coded panels of stained smears (100 slides in rounds I-IV and 50 slides in Round V), comprising different grades of positivity, were sent to each centre at 6-monthly intervals. The results obtained were analysed for consistency of positive and negative results and overall agreement, as well as discordance.
Consistency of positives ranged from 38% to 100%, indicating under-reading at some sites. The negative consistency was better, however, with only five of the total of 95 readers in all rounds yielding a consistency of less than 100%. Considering overall agreement, seven of the eight centres showed an agreement of over 90%. Four of the eight centres gave no false-positive result. For the remaining centres the false positivity rate varied from 2% to 7%. A wide variation was also observed in the proportion of false-negatives (3%-52%).
This study helped in the evaluation of the performance of individual laboratories and in identifying the drawbacks of this system of proficiency testing.
印度金奈结核病研究中心。
使用一组染色涂片对印度八个国家级实验室的痰涂片显微镜检查进行质量保证研究。
每隔6个月向每个中心发送编码的染色涂片组（第一轮至第四轮为100张玻片，第五轮为50张玻片），包括不同等级的阳性涂片。对获得的结果进行分析，以评估阳性和阴性结果的一致性、总体一致性以及不一致性。
阳性结果的一致性范围为38%至100%，表明一些检测点存在漏读情况。然而，阴性结果的一致性较好，在所有轮次的95名读者中，只有5人的一致性低于100%。考虑总体一致性，八个中心中有七个中心的一致性超过90%。八个中心中有四个中心没有给出假阳性结果。其余中心的假阳性率从2%到7%不等。假阴性比例也存在很大差异（3% - 52%）。
本研究有助于评估各个实验室的性能，并识别这种能力验证系统的缺点。
