Table 5

Modelled changes in non-smokers. Figures are regression coefficients (95% confidence intervals) for cotinine concentrations and rate ratios (95% confidence intervals) for respiratory and sensory symptoms

Regression coefficient or rate ratio (95% Cl)P value
Cotinine concentrations (nmol/l) (n=131)
Region (Republic:Northern Ireland)0.022 (–1.56 to 1.61)0.978
Time period (follow-up:baseline)–1.99 (–3.64 to –0.36)0.017
Live with smoker (yes:no)1.62 (0.62 to 2.62)0.002
Hours worked in past 2 days0.07 (0.01 to 0.13)0.011
Age (years)–0.03 (–0.07 to 0.001)0.053
Sex (female:male)0.94 (–0.28 to 2.16)0.134
Interaction between region and time period–2.40 (–4.18 to –0.62)0.008
Constant6.19 (4.25 to 8.12)<0.001
Respiratory symptoms (n=158)
Region (Republic:Northern Ireland)1.96 (1.11 to 3.48)0.021
Time period (follow-up:baseline)1.22 (0.72 to 2.08)0.447
Age (years)1.00 (0.99 to 1.01)0.487
Sex (female: male)0.44 (0.28 to 0.69)<0.001
Interaction between region and time period0.60 (0.35 to 1.04)0.070
Sensory symptoms (n=158)
Region (Republic:Northern Ireland)1.14 (0.77 to 1.70)0.507
Time period (follow-up:baseline)0.57 (0.47 to 0.71)<0.001
Age (years)0.99 (0.98 to 1.00)0.063
Sex (female:male)0.86 (0.60 to 1.22)0.398
Hours worked in past week0.99 (0.98 to 1.00)0.089