Using air-quality feedback to encourage disadvantaged parents to create a smoke-free home: Results from a randomised controlled trial

Objective To determine if low-cost air-quality monitors providing personalised feedback of household second-hand smoke (SHS) concentrations plus standard health service advice on SHS were more effective than standard advice in helping parents protect their child from SHS.
Design A randomised controlled trial of a personalised intervention delivered to disadvantaged mothers who were exposed to SHS at home. Changes in household concentrations of fine Particulate Matter (PM_2.5) were the primary outcome.
Methods Air-quality monitors measured household PM_2.5 concentrations over approximately 6 days at baseline and at one-month and six-months post-intervention. Data on smoking and smoking-rules were gathered. Participants were randomised to either Group A (standard health service advice on SHS) or Group B (standard advice plus personalised air-quality feedback). Group B participants received personalised air-quality feedback after the baseline measurement and at 1-month. Both groups received air-quality feedback at 6-months.
Results 120 mothers were recruited of whom 117 were randomised. Follow up was completed after 1-month in 102 and at 6-months in 78 participants. There was no statistically significant reduction in PM_2.5 concentrations by either intervention type at 1-month or 6-months, nor significant differences between the two groups at 1-month (p = 0.76) and 6-month follow-up (p = 0.16).
Conclusions Neither standard advice nor standard advice plus personalised air-quality feedback were effective in reducing PM_2.5 concentrations in deprived households where smoking occurred. Finding ways of identifying homes where air-quality feedback can be a useful tool to change household smoking behaviour is important to ensure resources are targeted successfully.