Table 1

Baseline characteristics of 386 subjects with COPD by follow up status

Characteristic at baseline	All (n = 386)		Re-interviewed (n = 267)		Not interviewed (n = 119)		p value
Characteristic at baseline	n	%	n	%	n	%
VGDF, vapours, gas, dusts, or fume reported at baseline on longest held employment.
*Includes subjects with a history of labour force participation and values for all key study variables (n = 234 for re-interviewed cohort; n = 108 of those not re-interviewed).
Total for income (n = 331) and education (n = 383) reflects missing responses to these items.
Age range (years)								0.59
55–59	111	29	74	28	37	31
60–64	100	26	73	27	27	23
65–75	175	45	120	45	55	46
Female	246	64	168	63	78	66	0.62
White, non-Hispanic	332	86	230	86	102	86	0.91
Highest educational level							0.92
High school or less	204	53	142	53	62	53
Some college	105	27	74	28	31	27
College graduate or above	74	19	50	19	24	21
Annual household income							0.49
<$20 000	144	44	107	44	37	42
$20 000–40 000	108	33	80	33	28	31
>$40–000	79	24	55	23	24	27
Chronic bronchitis alone	194	50	132	49	62	52	0.63
Cigarette smoking status							0.39
Never	75	19	48	18	27	23
Former	127	33	86	32	41	34
Current	184	48	133	50	51	43
Ever employed	352	91	242	91	110	92	0.56
Exposure to VGDF*	185	54	128	55	57	53	0.75
Exposure by job matrix*							0.94
Intermediate exposure	94	27	64	27	30	28
High exposure risk	36	11	25	11	11	10
Left work due to lung disease*	79	23	58	25	21	19	0.28