Quality control of sputum smear examination in Cebu Province.

SETTING

Rural Health Units (RHUs) in Cebu Province, Philippines.

OBJECTIVE

To assess and improve the on-going quality control of tuberculosis activities in Cebu Province.

METHODS

During the period of the study, from January 1996 to December 1997, positive slides (100% in 1996 and 20% or 100% in 1997) and 20% of negative slides selected from all of the slides examined at the RHUs were assessed on the quality of smear preparation. The readings were blindly cross-checked by the provincial assessors.

RESULTS

In 1997, 1) 90% of RHUs participated in the quality control activity; 2) the proportion of good quality smears increased markedly; and 3) the false positive and false negative rates did not change during the period, but most of the false positives were observed among the scanty positives of the field reading, and no false negatives were noted among the heavily positive slides.

CONCLUSION

Although the false positive and negative rates did not decrease during the period, the quality control procedure resulted in marked improvements in smear preparation, a high participation of RHUs in the quality control programme and the elimination of large discrepancies between readers on positive slides in 1997. It is considered to have significantly improved the NTP's smear microscopy service in Cebu Province.