Improvement of tuberculosis case detection and reduction of discrepancies between men and women by simple sputum-submission instructions: a pragmatic randomised controlled trial.

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.