Table 3.

Age and sex standardised prevalences (numbers of participants) of respiratory illness by smoking status, and prevalence ratios in 1996 compared with 1972–6 in men and women aged 45–54 years

1972-61996Prevalence ratio adjusted for age and sexPrevalence ratio adjusted for all covariates*
Never smokersn=540n=495
Hay fever5.8 (34)19.9 (110)4.17 (2.75 to 6.32)3.53 (2.30 to 5.43)
Asthma:
In those without hay fever1.8 (12)†6.3 (23)†2.54 (1.21 to 5.33)2.86 (1.36 to 6.02)
In those with hay fever18.1 (8)‡13.0 (19)‡0.65 (0.24 to 1.77)0.76 (0.25 to 2.36)
All3.0 (20)8.2 (42)2.38 (1.34 to 4.23)2.60 (1.41 to 4.80)
Wheeze4.6 (24)1.1 (6)0.31 (0.12 to 0.80)0.32 (0.11 to 0.90)
Chronic sputum5.1 (26)5.1 (28)1.03 (0.60 to 1.79)1.11 (0.60 to 2.04)
Breathlessness8.3 (55)6.3 (32)0.68 (0.42 to 1.09)0.92 (0.55 to 1.53)
Asthma and/or wheeze6.4 (37)8.5 (44)1.33 (0.83 to 2.15)1.40 (0.83 to 2.36)
Ever smokersn=1168n=629
Hay fever5.4 (64)15.5 (97)3.21 (2.28 to 4.53)2.76 (1.91 to 3.98)
Asthma:
In those without hay fever1.0 (13)†3.4 (18)†3.17 (1.57 to 6.42)2.92 (1.37 to 6.23)
In those with hay fever11.6 (7)‡15.9 (16)‡1.46 (0.54 to 3.95)0.95 (0.33 to 2.76)
All1.6 (20)5.3 (34)3.36 (1.94 to 5.82)2.69 (1.49 to 4.84)
Wheeze14.2 (173)8.1 (49)0.53 (0.37 to 0.76)0.79 (0.53 to 1.17)
Chronic sputum23.9 (285)14.2 (88)0.50 (0.38 to 0.66)0.73 (0.55 to 0.97)
Breathlessness12.0 (140)8.8 (57)0.75 (0.54 to 1.05)0.85 (0.59 to 1.22)
Asthma and/or wheeze15.1 (184)12.0 (75)0.77 (0.57 to 1.04)1.04 (0.76 to 1.43)
  • Standardisation for age differences means that percentages differ from estimates based on raw numerators and denominators.

  • * Age, sex, and social class in never smokers; and age, sex, social class, pack years, and former or current status in ever smokers.

  • † Denominator is those without hay fever.

  • ‡ Denominator is those with hay fever.