title: Quality indicators in a mycobacteriology laboratory supporting clinical trials for pulmonary tuberculosis.
abstract: BACKGROUND
  Documentation of structured quality indicators for mycobacteriology laboratories supporting exclusively controlled clinical trials in pulmonary tuberculosis (PTB) is lacking.
  
  
  OBJECTIVE
  To document laboratory indicators for a solid (Lowenstein-Jensen medium) culture system in a mycobacteriology laboratory for a period of 4years (2007-2010).
  
  
  METHODS
  The sputum samples, collected from PTB suspects/patients enrolled in clinical trials, were subjected to fluorescence microscopy, culture and drug sensitivity testing (DST). Data was retrospectively collected from TB laboratory registers and computed using pre-formulated Microsoft Office Excel. Laboratory indicators were calculated and analyzed.
  
  
  RESULTS
  The number of samples processed in a calendar year varied from 6261 to 10,710. Of the samples processed in a calendar year, specimen contamination (4.8-6.9%), culture positives (78.4-85.1%) among smear positives, smear positives (71.8-79.0%) among culture positive samples, smear negatives among culture negative samples (95.2-96.7%), and average time to report DST results (76-97days) varied as shown in parentheses.
  
  
  CONCLUSIONS
  Values of quality indicators in mycobacteriology laboratories supporting exclusively clinical trials of PTB have to be defined and used for meaningful monitoring of laboratories.
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India. Electronic address: selvakumar.nagamiah@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Selvakumar
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: K
authors.initials: K
authors.lastname: Silambuchelvi
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: M
authors.initials: M
authors.lastname: Gomathi Sekar
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: A
authors.initials: A
authors.lastname: Syam Sunder
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: S
authors.initials: S
authors.lastname: Anbarasu
authors.affiliation: Department of Clinic, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: V
authors.initials: V
authors.lastname: Banu Rekha
authors.affiliation: Department of Statistics, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: C
authors.initials: C
authors.lastname: Ponnuraja
authors.affiliation: Department of Mycobacteriology, National Institute for Research in Tuberculosis (ICMR), Chetpet, Chennai 600031, India.
authors.forename: Vanaja
authors.initials: V
authors.lastname: Kumar
keywords: Laboratory indicator; Mycobacterium tuberculosis; Pulmonary tuberculosis; Quality assurance