Tuberculosis patients learning about second-hand smoke (TBLASS): results of a pilot randomised controlled trial

N Safdar, R Zahid, S Shah, R Fatima, I Cameron, K Siddiqi

Research output: Contribution to journalArticlepeer-review


BACKGROUND: Passive smoking is associated with tuberculosis (TB). Measures are required to protect non-smoking TB patients from second-hand smoke (SHS).

SETTING: We developed a behavioural intervention to encourage TB patients to implement smoking restrictions at home in Pakistan.

OBJECTIVES: To assess the likelihood of such an intervention being successful and to inform a definitive trial in future.

DESIGN: This was a pilot randomised controlled trial in which non-smoking TB patients were randomised to receive either individual-based support or individual-based support combined with family reminders. We recruited patients living with at least one smoker in their homes. Our primary outcome was urinary cotinine level as a measure of SHS exposure 2 months post-randomisation.

RESULTS: Of 273 patients assessed for eligibility, 150 (56%) patients were recruited and all but one were retained throughout the trial. A statistically significant absolute reduction was observed in non-smoking participants' exposure to SHS based on urinary cotinine levels in both Arm 1 (71%, 95%CI 61-79) and Arm 2 (76%, 95%CI 67-83) between baseline and follow-up at 2 months.

CONCLUSIONS: The recruitment and retention rates for trial participants make it feasible to conduct a definitive trial in future. The observed effect size makes it worthwhile to conduct such a trial.

Original languageEnglish
Pages (from-to)237-43
Number of pages7
JournalThe international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease
Issue number2
Publication statusPublished - 1 Feb 2015


  • Passive smoking
  • Smoke-free homes
  • Tobacco
  • Tuberculosis

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