Table 2 Mortality from lung cancer in relation to length of employment in carding and other jobs: observed (O) and expected (E) cases, standardised mortality ratio (SMR), and 95% CI
Length of employment (months)Carding (n = 1045)*Other jobs (n = 2916)
6.5–70O/E6/3.27/5.6
SMR1.881.25
95% CI0.68 to 4.080.50 to 2.58
71–147O/E3/3.011/7.0
SMR1.011.57
95% CI0.20 to 2.940.78 to 2.82
148–476O/E1/4.58/11.6
SMR0.220.69
95% CI0.00 to 1.240.30 to 1.35

  • *χ2 trend = 5.45 (p<0.05).