Table 2.
Work Ability Score, sick leave, respiratory symptom score and % of predicted FEV1, FVC and FEV1/FVC-ratio prebronchodilator and postbronchodilator by possible confounders: sex, smoking status, highest completed education and age category
| Outcome, summary statistics | Number | Sex | Smoking status | Highest completed education | Age category | |||||||||||
| Male | Female | P value | Never smoker | Former smoker | Daily smoker | P value | Elementary | Upper secondary | University | P value | 18–30 | 31–40 | 41–52 | P value | ||
| Work Ability Score <8, n/n total in group (%) | 261/1295 (20%) |
85/508 (17%) |
176/787 (22%) |
0.016 | 112/697 (16%) |
78/328 (24%) |
71/270 (27%) |
<0.001 | 52/168 (31%) |
130/525 (25%) |
79/602 (13%) |
<0.001 | 26/212 (12%) |
66/310 (21%) |
169/773 (22%) |
0.007 |
| Sick-leave in the last 12 months, n/n total in group (%) | 413/1143 (36%) |
113/453 (25%) |
300/690 (43%) |
<0.001 | 182/610 (30%) |
125/297 (42%) |
106/236 (45%) |
<0.001 | 44/116 (38%) |
180/464 (39%) |
189/563 (34%) |
0.203 | 47/156 (30%) |
108/237 (46%) |
258/714 (36%) |
0.148 |
| Sick leave >14 days, n/n total in group (%) | 199/1143 (17%) |
43/453 (9%) |
156/690 (23%) |
<0.001 | 78/610 (13%) |
63/297 (21%) |
58/236 (25%) |
<0.001 | 20/116 (17%) |
88/464 (19%) |
91/563 (16%) |
0.428 | 15/156 (10%) |
57/237 (24%) |
127/714 (18%) |
0.060 |
| Symptom score ≥3, n/n total in group (%) | 403/1317 (31%) |
120/515 (23%) |
283/802 (35%) |
<0.001 | 194/706 (27%) |
107/335 (32%) |
102/276 (37%) |
0.012 | 50/171 (29%) |
177/541 (33%) |
176/605 (29%) |
0.379 | 63/216 (29%) |
96/314 (31%) |
244/787 (31%) |
0.874 |
| Symptom score, n, mean (SEM) | 1317 | 515 1.87 (0.11) |
802 2.58 (0.10) |
<0.001 | 706 2.10 (0.10) |
335 2.37 (0.15) |
276 2.72 (0.18) |
0.004 | 171 2.26 (0.21) |
541 2.49 (0.12) |
605 2.14 (0.11) |
0.095 | 216 2.26 (0.18) |
314 2.26 (0.15) |
787 2.33 (0.10) |
0.911 |
| Pre-FEV1 % of predicted value, n, mean (SEM) | 1257 | 489 94.26 (0.67) |
768 96.00 (0.49) |
0.033 | 671 95.44 (0.52) |
322 96.57 (0.77) |
264 93.50 (0.99) |
0.031 | 158 93.12 (1.08) |
515 94.06 (0.63) |
584 97.02 (0.58) |
<0.001 | 199 94.45 (0.83) |
296 96.11 (0.81) |
762 95.25 (0.54) |
0.428 |
| Pre-FVC % of predicted value n, mean (SEM) | 1257 | 489 98.25 (0.44) |
768 98.25 (0.56) |
0.028 | 671 98.86 (0.46) |
322 100.14 (0.68) |
264 98.93 (0.82) |
0.284 | 158 97.37 (0.99) |
515 98.34 (0.54) |
584 100.46 (0.50) |
0.002 | 199 99.25 (0.81) |
296 99.91 (0.66) |
762 98.92 (0.47) |
0.498 |
| Pre-FEV1/FVC-ratio in %, n, mean (SEM) | 1257 | 489 0.79 (0.002) |
768 0.77 (0.003) |
<0.001 | 671 0.79 (0.002) |
322 0.77 (0.003) |
264 0.76 (0.005) |
<0.001 | 158 0.79 (0.006) |
515 0.77 (0.003) |
584 0.78 (0.003) |
0.093 | 199 0.81 (0.005) |
296 0.79 (0.004) |
762 0.77 (0.002) |
<0.001 |
| Post-FEV1 % of predicted value, n, mean (SEM) | 1091 | 425 96.79 (0.67) |
666 99.16 (0.50) |
0.004 | 588 98.22 (0.53) |
279 99.88 (0.76) |
224 96.25 (1.00) |
0.009 | 131 95.97 (1.16) |
442 97.10 (0.64) |
518 99.78 (0.57) |
<0.001 | 177 97.99 (0.84) |
264 99.10 (0.78) |
650 97.95 (0.55) |
0.478 |
| Post-FVC % of predicted value, n, mean (SEM) | 1091 | 425 98.57 (0.58) |
666 99.88 (0.46) |
0.077 | 588 98.78 (0.49) |
279 100.67 (0.70) |
224 99.28 (0.80) |
0.093 | 131 97.21 (1.12) |
442 98.85 (0.56) |
518 100.36 (0.51) |
0.012 | 177 98.92 (0.85) |
264 100.03 (0.69) |
650 99.23 (0.48) |
0.559 |
| Post-FEV1/FVC ratio in %, n, mean (SEM) | 1091 | 425 0.78 (0.004) |
666 0.81 (0.002) |
<0.001 | 588 0.81 (0.003) |
279 0.80 (0.003) |
224 0.78 (0.005) |
<0.001 | 131 0.81 (0.006) |
442 0.80 (0.003) |
518 0.81 (0.003) |
0.029 | 177 0.85 (0.005) |
264 0.81 (0.004) |
650 0.79 (0.003) |
<0.001 |
P values were calculated using Fisher’s exact, Pearson χ2 or one-way ANOVA. Statistically significant findings, p<0.05, are bolded
ANOVA, Analysis of variance; FEV, forced expiratory volume; FEV1, forced expiratory volume after 1 s; FVC, forced vital capacity.