Table 3—

Case-case analyses among subjects with current asthma: clinical and immunological characteristics in selected occupational groups, with adjusted odds ratios (OR) relative to office workers

OfficeCleaningHigh MWLow MW
Prevalence %Prevalence %OR#Prevalence %OR#Prevalence %OR#
Subjects n71810187213
Physician diagnosed asthma57.545.50.8449.40.7950.00.92
Adult onset asthma28.033.71.5325.31.2222.11.27
Bronchial hyperresponsiveness+46.457.11.6045.21.0039.71.01
Chest tight/wheezy at work26.348.42.71*47.63.11*45.53.25*
Chronic bronchitis9.120.82.14*19.52.19*15.61.22
COPD§9.47.31.2820.62.73*9.50.82
Atopyƒ60.938.30.51*57.80.8745.30.38*
  • MW: molecular weight

  • #: OR relative to office workers, adjusted for sex, age category, current smoking and study centre

  • : first asthma attack at age 15 or onwards

  • +: a fall of at least 20% in forced expiratory volume in one second (FEV1) associated with a methacholine dose of ≤1 mg, n=422+56+42+141

  • §: FEV1 <80% pred and FEV1/forced vital capacity ratio <0.7, n=543+82+63+179

  • ƒ: specific immunoglobulin E to common allergens, n=507+81+64+161

  • *: p<0.05