Secondhand smoke in psychiatric units: patient and staff misperceptions

Background Mental health units have usually been exempted from complete smoke-free policies. The aim of this study was to compare the self-reported level of exposure to secondhand smoke (SHS) of patients and staff in psychiatric units to objective measures, and examine preference for different types of smoking bans. Methods Cross-sectional survey about ban preferences and self-reported exposure to SHS by means of a self-administered questionnaire administered to patients and staff from 65 inpatient psychiatric units in Catalonia (95.5% of all units). We measured air concentrations of particulate matter ≤2.5 μm (PM2.5 in µg/m3) as a marker of SHS in these units. Results 600 patients and 575 professionals completed the questionnaire. 78.7% of them were objectively exposed to SHS (PM2.5>10 μm/m3) but 56.9% of patients and 33.6% of staff believed they were not exposed at all and 41.6% of patients and 28.4% of staff believed the environment was not at all unhealthy. Nurses had a higher smoking prevalence than psychiatrists (35.8% vs 17.2%; p<0.001), and nurses had a higher perception of being moderately highly exposed to SHS (40.3% vs 26.2%; p<0.001). PM2.5 levels were significantly different depending on the type of smoking ban implemented but unrelated to the perception of SHS levels by both patients and staff. Only 29.3% of staff and 14.1% of patients strongly supported total smoking bans. Conclusions Patients and staff have substantial misperceptions about the extent of their exposure to SHS and low awareness about the harmful environment in which they stay/work. This might have an influence on the preference for less restrictive smoke-free bans. It is particularly noteworthy that less that one-third of mental health staff supported smoke-free units, suggesting an urgent need for further education about the harmful health effects of SHS.