Improving the laboratory diagnosis of TB in Ghana: the impact of a quality assurance system
Loading...
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Tuberculosis Lung Disease
Abstract
SETTING: Greater Accra Region, Ghana.
OBJECTIVE: To establish a pilot quality assurance (QA)
system in sputum smear microscopy and to evaluate its
impact.
DESIGN: Quarterly supporting visits were paid to participating
laboratories between 2000 and 2002. Fifteen
examined slides were selected randomly from each laboratory
during the visits and blindly re-assessed. Feedback
was given promptly to the various laboratories.
Training and stakeholder workshops were organised
whenever necessary.
RESULTS: General improvements in smear preparation
and staining as well as the reading ability of the laboratory
personnel included in the study were observed. The
average marks for specimen quality, staining ability, smear
cleanness, thickness, size and evenness increased from
64%, 79%, 69%, 46%, 67% and 60% in the last quarter
of 2000 to 81%, 90%, 86%, 79%, 80% and 74%,
respectively, 24 months after the establishment of the
QA system. Within the same period, the rate of false positives
and -negatives decreased from respectively
14.8% and 20.5% to 0%, and agreements in positivity
grade increased from 74% to 95%. The performance of
the participating laboratories in keeping the laboratory
registers up to date also improved.
CONCLUSION: The QA system needs to be extended to
the rest of the country.
Description
Research Article
Keywords
quality assurance, pilot system, sputum smear microscopy, Ghana