Lung Diseases LD13, 2017 – 2017

Muslim Communities Learning About Second-hand Smoke (MCLASS II): An effectiveness-Implementation hybrid study

Funding amount



3.5 Years


SHS contains 4,000 toxic chemicals and is a serious health hazard to non-smokers. Every year, an estimated 600,000 people die and 10·9 million disability-adjusted life years (DALYs) are lost due to SHS exposure, worldwide.1 A significant proportion of this disease burden (40% deaths and 70% DALYs lost) is due to lung diseases i.e. asthma, chest infections and lung cancer. Women and children are worst affected; 47% of deaths from SHS exposure occur in female adults and 28% in children. SHS increases children’s risk of acquiring lower respiratory tract infections, tuberculosis, and incident cases, recurrent episodes, and increased severity of asthma. Parental smoking is also associated with their children’s admissions to hospital. Children living in smoking households are at high risk of becoming adult smokers later.


Our overall aim is to reduce the burden of disease due to Second Hand Smoke in LMICs by discovering innovative community-based approaches to behaviour change. Our specific objectives, some of which relate to the effectiveness question (1, 2) and others (3-8) to the implementation question, are as follows

  • To assess the effect of a community-based intervention – Smoke Free Homes (SFH), with or without Indoor Air Quality (IAQ) feedback on;
    • non-smokers’ exposure to SHS in the home (primary outcome),
    • the frequency and severity of respiratory symptoms,
    • healthcare service use, and
    • quality of life.
  • To assess the cost-effectiveness of SFH, with or without IAQ feedback in reducing nonsmokers’ exposure to SHS in the home.
  • To identify the modifications required in SFH and IAQ feedback in order to make it culturally appropriate, feasible, and acceptable for families and Imams in Bangladesh.
  • To assess what competencies and organisational capacity are required for Imams and in mosques, respectively, to deliver SFH.
  • To identify the mechanism (e.g. participants’ level of engagement, acceptability and perceived benefits/harms) and the contextual factors (social, economic, environmental and political) that are likely to influence the impact of SFH and IAQ feedback.
  • To estimate the likely costs and effects of scaling up SFH with or without IAQ feedback
  • To develop a simple monitoring framework, which could be efficiently employed as the intervention (s) are scaled up.
  • To identify the likely obstacles to and opportunities for implementing and scaling up the intervention (s) and how best to work with communities and policy makers to overcome the obstacles and maximise the opportunities.

Principal Investigator

Kamran Siddiqi, York University, United Kingdom

Funding organisations

  • Lung Diseases LD13
  • Bangladesh
  • 2017 – 2017