Background: In several settings, women with suspected tuberculosis are less likely to test smear positive than are men. Submission of poor-quality sputum specimens by women might be one reason for the difference between the sexes. We did a pragmatic randomised controlled trial to assess the effect of sputum-submission instructions on female patients.
Methods: 1494 women and 1561 men with suspected tuberculosis attending the Federal Tuberculosis Centre in Rawalpindi, Pakistan, were randomly assigned between May and July, 2005 either to receive sputum-submission guidance before specimen submission or to submit specimens without specific guidance, according to prevailing practice. Of enrolled patients, 133 (4%) declined to participate. The primary outcome measure was the proportion of instructed and non-instructed women testing smear positive. Intention-to-treat analysis was undertaken on the basis of treatment allocation. This study is registered with the International Standard Randomised Controlled Trial number 34123170.
Findings: Instructed women were more likely to test smear positive than were controls (Risk ratio 1.63 [95% CI 1.19-2.22]). Instructions were associated with a higher rate of smear-positive case detection (58 [8%] in controls vs 95 [13%] in the intervention group; p=0.002), a decrease in spot-saliva submission (p=0.003), and an increase in the number of women returning with an early-morning specimen (p=0.02). In men, instructions did not have a significant effect on the proportion testing smear positive or specimen quality.
Interpretation: In the Federal Tuberculosis Centre in Rawalpindi, lower smear positivity in women than in men was mainly a function of poor-quality specimen submission. Smear positivity in women was increased substantially by provision of brief instructions. Sputum-submission guidance might be a highly cost-effective intervention to improve smear-positive case detection and reduce the disparity between the sexes in tuberculosis control in low-income countries.