Sex-specific performance of routine TB diagnostic tests
International Journal of Tuberculosis and Lung Disease
Center for Respiratory Diseases, Kenya Med. Res. Institute (KEMRI), Nairobi, Kenya; Department of Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, Netherlands; Centers for Dis. Contr. and Prev., Nairobi, Kenya; Department of Biomedical Research, Royal Tropical Institute (KIT), Meibergdreef 39, Amsterdam, Netherlands
SETTING: City Council Chest Clinic, Nairobi, Kenya. OBJECTIVE: To determine to what extent the performance of smear microscopy is responsible for sex differences in notification rates. METHODOLOGY: Three sputum samples from TB suspects were subjected to smear microscopy with Ziehl-Neelsen (ZN) and auramine (FM) staining. Löwenstein-Jensen culture was used as the gold standard. RESULTS: Of 998 suspects, 600 (60%) were men and 398 (40%) women. The odds of detecting culture-positive patients with ZN was lower for women (OR 0.67). By examining the first spot specimen, ZN detected 35% of culture-positive males and 26% of culture-positive females. These proportions increased to respectively 63% and 53% when examining three specimens, and to 79% and 74% when using FM. The sex difference reduced and became non-significant (P = 0.19) when adjusted for HIV; however, the numbers involved for HIV stratification were low. CONCLUSION: The performance of a diagnostic tool contributes to sex differences in notification rates and influences male/female ratios. Women were less likely to be diagnosed (P = 0.08), and when ZN was used they were less likely to be labelled as smear-positive TB (P < 0.01). The application of more sensitive diagnostic tools such as FM is to the advantage of women. © 2005 The Union.
adult; article; auramine stain; bacterium culture; controlled study; diagnostic accuracy; diagnostic test; female; human; Human immunodeficiency virus infection; Kenya; lowenstein jensen culture; major clinical study; male; priority journal; sensitivity and specificity; sex difference; sex ratio; sputum smear; staining; statistical significance; tuberculosis; ziehl neelsen stain; Adolescent; Adult; Aged; Bacteriological Techniques; Diagnostic Tests, Routine; Female; Humans; Male; Microscopy; Middle Aged; Mycobacterium tuberculosis; Regression Analysis; Sensitivity and Specificity; Sex Factors; Sputum; Tuberculosis, Pulmonary