Study design
CARDIOPULMONARY, EVENTS
This is an ancillary study of the Cardiopulmonary outcomes and Household Air Pollution (CHAP) trial. Details of the CHAP trial have been published elsewhereIntervention participants received a three-burner LPG stove (Industrias SURGES, Juliaca, Peru), LPG refills delivered as needed (approximately every 2 weeks) for 12 months and behavioural reinforcement for exclusive LPG use. Control participants continued cooking with biomass. Before receiving their LPG stove, participants in the intervention group attended a demonstration in which field workers prepared a local dish with the LPG stove to teach participants about safe operation and maintenance of the LPG stove and logistical benefits of LPG on health. We monitored the use of both LPG and biomass stoves in control and intervention households during the entire 12-month period of the intervention using stove use monitors (Digit-TL, LabJack Corporation). These devices recorded temperature readings every minute throughout the 12-month post-randomisation period. These data were used to determine which stoves were used in the household and the frequency and duration of cooking events