title: A cleaner burning biomass-fuelled cookstove intervention to prevent pneumonia in children under 5 years old in rural Malawi (the Cooking and Pneumonia Study): a cluster randomised controlled trial.
abstract: WHO estimates exposure to air pollution from cooking with solid fuels is associated with over 4 million premature deaths worldwide every year including half a million children under the age of 5 years from pneumonia. We hypothesised that replacing open fires with cleaner burning biomass-fuelled cookstoves would reduce pneumonia incidence in young children.
  
  
  
  We did a community-level open cluster randomised controlled trial to compare the effects of a cleaner burning biomass-fuelled cookstove intervention to continuation of open fire cooking on pneumonia in children living in two rural districts, Chikhwawa and Karonga, of Malawi. Clusters were randomly allocated to intervention and control groups using a computer-generated randomisation schedule with stratification by site, distance from health centre, and size of cluster. Within clusters, households with a child under the age of 4·5 years were eligible. Intervention households received two biomass-fuelled cookstoves and a solar panel. The primary outcome was WHO Integrated Management of Childhood Illness (IMCI)-defined pneumonia episodes in children under 5 years of age. Efficacy and safety analyses were by intention to treat. The trial is registered with ISRCTN, number ISRCTN59448623.
  
  
  
  We enrolled 10 750 children from 8626 households across 150 clusters between Dec 9, 2013, and Feb 28, 2016. 10 543 children from 8470 households contributed 15 991 child-years of follow-up data to the intention-to-treat analysis. The IMCI pneumonia incidence rate in the intervention group was 15·76 (95% CI 14·89-16·63) per 100 child-years and in the control group 15·58 (95% CI 14·72-16·45) per 100 child-years, with an intervention versus control incidence rate ratio (IRR) of 1·01 (95% CI 0·91-1·13; p=0·80). Cooking-related serious adverse events (burns) were seen in 19 children; nine in the intervention and ten (one death) in the control group (IRR 0·91 [95% CI 0·37-2·23]; p=0·83).
  
  
  
  We found no evidence that an intervention comprising cleaner burning biomass-fuelled cookstoves reduced the risk of pneumonia in young children in rural Malawi. Effective strategies to reduce the adverse health effects of household air pollution are needed.
  
  
  
  Medical Research Council, UK Department for International Development, and Wellcome Trust.
authors.affiliation: Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi; Liverpool School of Tropical Medicine, Liverpool, UK. Electronic address: Kevin.mortimer@lstmed.ac.uk.
authors.forename: Kevin
authors.initials: K
authors.lastname: Mortimer
authors.affiliation: Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi.
authors.forename: Chifundo B
authors.initials: CB
authors.lastname: Ndamala
authors.affiliation: Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Naunje
authors.affiliation: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi.
authors.forename: Jullita
authors.initials: J
authors.lastname: Malava
authors.affiliation: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Katundu
authors.affiliation: Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi; Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: William
authors.initials: W
authors.lastname: Weston
authors.affiliation: Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Havens
authors.affiliation: University of Liverpool, Liverpool, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pope
authors.affiliation: University of Liverpool, Liverpool, UK.
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Bruce
authors.affiliation: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi; London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Moffat
authors.initials: M
authors.lastname: Nyirenda
authors.affiliation: Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Duolao
authors.initials: D
authors.lastname: Wang
authors.affiliation: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi; London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Amelia
authors.initials: A
authors.lastname: Crampin
authors.affiliation: Queen Mary University of London, London, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Grigg
authors.affiliation: University of California, Berkeley, CA, USA; University of California, San Francisco, CA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Balmes
authors.affiliation: Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi; Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Gordon
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000517:prevention & control*; D018533:Biomass; D002675:Child, Preschool; D003296:Cooking / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D005390:Fires; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008295:Malawi / Q000453:epidemiology; D008297:Male; D011014:Pneumonia / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D012423:Rural Health / Q000706:statistics & numerical data; D016037:Single-Blind Method; D012906:Smoke / Q000009:adverse effects; D014934:Wood
chemical_list: D012906:Smoke