Table 3

Exposure to secondhand smoke in non-smokers* at baseline and follow-up surveys in the Republic of Ireland (n=138) and Northern Ireland (n=20). Values are medians (interquartile ranges) unless stated otherwise

BaselineFollow-upP valueDifference (95% CI)
Republic of Ireland
Secondhand smoke exposure:
Salivary cotinine (nmol/l)§29.0 (18.2-43.2)5.1 (2.8-13.1)<0.001–22.7 (–26.7 to –19)
Self reported exposure:
Hours exposed at work (pub or bar) during past 7 days40 (39-50)0<0.001–40 (–47 to –41.5)
Hours exposed outside work (domestic or social) during past 7 days4 (0-10)0 (0-2)<0.001–1.25 (–4 to –1.5)
No (%) living with smoker37 (26.8)36 (26.1)0.79–0.7 (–6.9 to 5.5)
Hours worked in past 2 days13 (9-19.5)13 (7.1-18)0.01–2 (–3 to –0.5)
Northern Ireland
Secondhand smoke exposure:
Salivary cotinine (nmol/l)§25.3 (10.4-59.2)20.4 (13.2-33.8)0.05–5.7 (–21.3 to –3.7)
Self reported exposure:
Hours exposed at work (pub or bar) during past 7 days42 (15-55)40 (6.5-45)0.02–3 (–11.5 to –0.5)
Hours exposed outside work (domestic or social) during past 7 days0 (0-10)2.5 (0-18)0.410 (–2.5 to 7.5)
No (%) living with smoker6 (30)6 (31.6)1.000 (–19.9 to 19.9)
Hours worked in past 2 days12 (0-19)10 (4-14)0.63–1.25 (–6 to 3.3)
  • IQR=interquartile range.

  • * Non-smokers defined as participants who said they did not smoke or had given up and had salivary cotinine concentrations <113.6 nmol/l at both baseline and follow-up surveys.

  • † P value for comparison of medians (Wilcoxon signed rank test) and categorical variables (McNemar χ2 test) at baseline and follow-up.

  • ‡ Differences refer either to medians or percentages

  • § Values are for 131 participants (111 in the Republic of Ireland and 20 in Northern Ireland) with cotinine concentrations at both baseline and follow-up survey.