Should household air quality monitoring be considered in selected patients with asthma and COPD?

Background Indoor air quality (IAQ) is a well demonstrated actionable determinant of health status. Low-cost sensors (LCS) could enable patient-centred assessments, but real-world clinical utility is uncertain. Objective Evaluate the feasibility, usability and clinical indications of home IAQ monitoring with LCS. Methods We conducted a cohort study involving household continuous IAQ monitoring with LCS of 205 adults with chronic obstructive pulmonary disease, bronchiectasis or asthma. Household IAQ was profiled prospectively over a 2-month period registering concentrations of carbon dioxide, particulate matter 2.5 µm (PM 2.5 ) and formaldehyde every 10 min. For each pollutant, dwellings were classified as good, moderate or unhealthy according to the Global Open Air Quality Standards thresholds. Pulmonary exacerbations requiring unplanned hospitalisations and all-cause emergency department (ED) visits over the preceding 12 months were registered and potential relationships with household IAQ results were explored. Results Of the 205 participants, 178 were included in the final analysis after excluding dropouts and cases with insufficient monitoring data. More than half of homes (51.7%) had at least one pollutant in an at-risk category. The burden was mostly generated by PM 2.5 : 40.1% of dwellings were classified as at risk (32.8% moderate; 7.3% unhealthy). Formaldehyde exceeded the low-risk threshold in 22 homes (12.4%). Tobacco smoking, either active or passive, was significantly associated with PM 2.5 levels (p