Table 1—

Summary of characteristics of the lung cancer cases and control smokers before and after matching

ParameterUnmatched cohortsMatched cohortsp-value#
Control smokersLung cancerControl smokersLung cancer
Subjects n654446301301
Males %57535353
Age yrs59±1069±1064±965±90.23
Height cm170±0.09167±0.08168±0.09168±0.080.58
Weight kg80±1669±1578±1571±16<0.001
Smoking history
 Age started smoking yrs18±417±418±418±40.62
 Cigarettes·day−117±920±1020±719±90.33
 Current smokers %24352239<0.001
 Pack-yrs35±2041±2538±1838±180.93
Lung function
 FEV1 L2.84±0.821.86±0.692.56±0.801.90±0.69<0.001
 FEV1 % pred97±1873±2396±2071±23<0.001
 FEV1/FVC %81±964±1380±1064±13<0.001
Prevalence of COPD %
 GOLD 1+10601565<0.001
 GOLD 2+651850<0.001
 GOLD 3+1.2141.315<0.001
History of comorbidities %
 Chronic bronchitis518616<0.001
 Asthma121211130.45
  • Data are presented as mean±sd, unless otherwise stated. FEV1: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity; COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease. #: comparison for matched cohorts only.