Table 1– Patients in the study characteristics
VariableCasesControls
Patients n192329
Age years median (range)/25–75 percentile70 (34–87)/61–7770 (43–90)/63.5–79
Sex
 Female153 (79.7)259 (78.7)
 Male39 (20.3)70 (21.3)
Education
 No formal studies49 (26.1)51 (15.5)
 Primary school114 (60.6)246 (74.7)
 High school13 (6.9)19 (5.8)
 University degree12 (6.4)13 (4.0)
Have worked in risk occupations for lung cancer#
 No163 (87.2)281 (87.3)
 Yes24 (12.8)41 (12.7)
Participant's habitat
 Urban77 (40.5)74 (22.6)
 Rural113 (59.5)254 (77.4)
Residential radon exposure Bq·m−3
 ≤10036 (20.3)73 (26.9)
 101–14724 (13.6)61 (22.4)
 148–19932 (18.1)58 (21.3)
 ≥20085 (48.0)80 (29.4)
Years living in the measured dwelling
median (25–75 percentiles)30 (17–44)36 (20–52)
Exposure to ETS at home in the last 20 years
 Yes81 (42.2)148 (45.1)
 No111 (57.8)180 (54.9)
Histological types
 Adenocarcinoma148 (77.5)
 Squamous cell carcinoma19 (10.0)
 Small cell carcinoma12 (6.3)
 Large cell carcinoma6 (3.1)
 Other histological types6 (3.1)
  • Data are presented as n (%) unless otherwise stated. ETS: environmental tobacco smoke. #: following the classification proposed by Ahrens and Merletti [19].