Table 1

Demographic, clinical, spirometric, and allergological characteristics in 1994 for reevaluated and non-reevaluated farmers and control subjects

Reevaluated (n=325)Non-reevaluated (n=89)
FarmersControlsFarmersControls
SD, standard deviation; LY, last year; VC, vital capacity; FEV1, forced expiratory volume in one second; FEF25–75, forced mid-expiratory flow.
Reevaluated and non-reevaluated subjects were compared using χ2 tests for qualitative variables, and Student’s t tests for quantitative variables.
*p<0.05.
Demographic data n=215 n=110 n=50 n=39
Age (y), mean (SD)46.1 (11.5)38.3 (10.7)44.6 (10.0)36.7 (9.2)
Male, n (%)121 (56.3)51 (46.4)32 (64.0)20 (51.3)
Female, n (%)94 (43.7)59 (53.6)18 (36.0)19 (48.7)
Smoking status, n (%)
    Current smokers24 (11.2)30 (27.3)14 (28.0)9 (23.1)
    Ex-smokers29 (13.5)21 (19.1)3 (6.0)5 (12.8)
    Non-smokers162 (75.3)59 (53.6)33 (66.0)25 (64.1)
    Pack-years, mean (SD)16.4 (14.9)8.6 (9.4)21.3 (15.7)11.7 (15.9)
Altitude, n (%)
    Plain97 (45.1)48 (43.6)28 (56.0)17 (43.6)
    Tableland118 (54.9)62 (56.4)22 (44.0)22 (56.4)
Symptoms, n (%) n=214 n=110 n=50 n=39
Asthma12 (5.6)4 (3.6)4 (8.0)1 (2.6)
Wheezing, LY12 (5.6)03 (6.0)2 (5.1)
Wheezing with breathlessness, LY9 (4.2)02 (4.0)2 (5.1)
Wheezing apart from a cold, LY*7 (3.3)04 (8.0)2 (5.1)
Usual morning cough24 (11.2)4 (3.6)9 (18.0)2 (5.1)
Usual morning phlegm27 (12.6)2 (1.8)9 (18.0)1 (2.6)
Chronic bronchitis14 (6.5)1 (0.9)6 (12.0)0
Dyspnoea43 (20.1)12 (10.9)6 (12.0)7 (17.9)
Respiratory function, mean (SD) n=198 n=106 n=47 n=38
% VC102.7 (14.2)99.7 (13.0)101.0 (14.8)102.3 (13.5)
% FEV199.3 (14.9)98.0 (13.7)95.1 (11.6)98.4 (15.6)
% FEV1/VC96.3 (8.7)99.7 (16.6)95.0 (10.5)96.2 (11.3)
% FEF25–7585.8 (24.0)87.2 (27.2)79.8 (20.8)85.3 (23.8)
Immunological tests n=212 n=102 n=49 n=39
Total IgE, mean (SD)102.6 (468.3)69.1 (10.0)204.9 (459.5)56.8 (81.2)
Phadiatop +, n (%)30 (14.2)20 (19.4)11 (22.4)7 (17.9)
Skin prick tests +, n (%)78 (36.8)43 (40.2)16 (32)15 (39.5)