Table 4

Results of logistic regression for cough and phlegm in relation to environmental factors

Environmental factorOdds ratios (95% CI) for symptoms, adjusted for age, sex, region, and other factors shown
Cough without coldsPhlegm with coldsPhlegm without colds>3 colds per yearDry night cough without colds
Area (Metropolitan = 1.00) ** *** ***
 Non-metropolitan0.90 (0.83 to 0.96)0.95 (0.89 to 1.02)0.84 (0.78 to 0.91)1.03 (0.95 to 1.10)0.89 (0.83 to 0.95)
Pets (None = 1.00) *** **
 Furry pets0.97 (0.91 to 1.03)1.13 (1.07 to 1.20)1.01 (0.94 to 1.08)1.09 (1.02 to 1.16)1.01 (0.96 to 1.07)
 Other pets only1.07 (0.94 to 1.21)1.15 (1.02 to 1.29)1.02 (0.89 to 1.18)0.94 (0.82 to 1.07)1.08 (0.96 to 1.21)
Cooking fuel (Electricity only = 1.00)
 Gas1.04 (0.98 to 1.11)1.04 (0.99 to 1.10)1.07 (1.00 to 1.14)1.02 (0.96 to 1.09)1.07 (1.01 to 1.13)
 Other only0.94 (0.78 to 1.15)1.12 (0.94 to 1.35)0.92 (0.74 to 1.14)0.94 (0.78 to 1.14)1.05 (0.88 to 1.25)
Heating fuel (Electricity only = 1.00) 4-150 *** ** *** **
 Mains gas0.98 (0.92 to 1.05)1.26 (1.18 to 1.34)1.01 (0.94 to 1.09)1.07 (1.00 to 1.15)1.01 (0.95 to 1.08)
 Coal, wood, oil0.93 (0.85 to 1.02)1.35 (1.24 to 1.47)1.02 (0.92 to 1.13)1.08 (0.98 to 1.18)0.97 (0.89 to 1.06)
 Bottled gas, paraffin1.08 (0.95 to 1.22)1.33 (1.18 to 1.49)1.17 (1.02 to 1.33)1.27 (1.12 to 1.43)1.14 (1.01 to 1.28)
 Other1.23 (1.03 to 1.46)1.31 (1.11 to 1.56)1.40 (1.16 to 1.69)1.50 (1.26 to 1.78)1.29 (1.10 to 1.52)
Housing (Owned = 1.00) *** *** *** ** ***
 Council1.33 (1.24 to 1.43)0.82 (0.76 to 0.87)1.23 (1.14 to 1.33)1.11 (1.03 to 1.19)1.14 (1.07 to 1.22)
 Other rented1.18 (1.02 to 1.35)1.02 (0.89 to 1.16)1.11 (0.95 to 1.30)1.03 (0.89 to 1.19)1.04 (0.91 to 1.18)
 Other1.25 (1.08 to 1.44)0.87 (0.76 to 0.99)1.07 (0.91 to 1.26)1.19 (1.03 to 1.37)1.18 (1.03 to 1.34)
Passive smoking (Nobody = 1.00) *** *** *** ***
 Mother only1.23 (1.13 to 1.35)1.04 (0.96 to 1.14)1.24 (1.12 to 1.37)1.08 (0.99 to 1.19)1.23 (1.13 to 1.34)
 Father only1.23 (1.13 to 1.34)0.95 (0.88 to 1.03)1.26 (1.14 to 1.38)1.11 (1.02 to 1.21)1.14 (1.05 to 1.23)
 Both1.24 (1.14 to 1.36)1.05 (0.96 to 1.14)1.38 (1.25 to 1.53)1.07 (0.97 to 1.17)1.28 (1.17 to 1.39)
 Other1.52 (1.38 to 1.66)0.99 (0.90 to 1.08)1.46 (1.37 to 1.58)1.33 (1.21 to 1.46)1.46 (1.32 to 1.58)
Active smoking (Never = 1.00) *** *** *** *** ***
 Ex-smoker1.13 (1.06 to 1.21)1.46 (1.37 to 1.55)1.47 (1.37 to 1.58)1.15 (1.08 to 1.23)1.44 (1.36 to 1.53)
 <Once weekly1.11 (0.93 to 1.31)1.71 (1.45 to 2.03)1.60 (1.34 to 1.92)1.42 (1.20 to 1.67)1.68 (1.44 to 1.96)
 Weekly not daily1.38 (1.17 to 1.62)1.96 (1.66 to 2.33)2.03 (1.72 to 2.40)1.48 (1.26 to 1.74)1.82 (1.56 to 2.11)
 Daily2.07 (1.86 to 2.30)1.99 (1.78 to 2.22)2.68 (2.41 to 2.99)1.53 (1.37 to 1.70)2.22 (2.00 to 2.46)
  • 4-150 p<0.05, **p<0.01, ***p<0.001 for heterogeneity.