Associations of Self-Reported Cigarette Smoking with Chronic Obstructive Pulmonary Disease and Co-Morbid Chronic Conditions in the United States

Figures & data

Table 1.  Distribution of  selected characteristics among adults aged ≥ 18 years, by chronic obstructive pulmonary disease (COPD) status and cigarette smoking status: Behavioral Risk Factor Surveillance System, 2011

Characteristic	Number of Respondents	No COPD [N = 372,498] % (95% CI)	COPD [N = 33,088] % (95% CI)	Never Smoker [N = 218,356] % (95% CI)	Former Smoker [N = 126,784] % (95% CI)	Current Smoker [N = 60,446] % (95% CI)
Age group, years,
18–24	8,271	6.9 (6.6, 7.1)	3.0 (2.4, 3.7)	8.8 (8.5, 9.2)	1.6 (1.4, 1.9)	7.6 (7.0, 8.2)
25–44	79,574	33.2 (32.8, 33.5)	15.6 (14.6, 16.6)	35.3 (34.9, 35.8)	21.9 (21.4, 22.5)	37.4 (36.5, 38.2)
45–64	177,092	39.8 (39.5, 40.1)	44.4 (43.3, 45.5)	37.4 (37.0, 37.8)	42.7 (42.2, 43.3)	44.5 (43.7, 45.3)
≥65	140,649	20.1 (19.9, 20.3)	37.1 (36.1, 38.1)	18.4 (18.2, 18.7)	33.7 (33.2, 34.2)	10.5 (10.2, 10.9)
Gender,
Men	155,240	47.6 (47.3, 47.9)	40.0 (38.9, 41.2)	41.9 (41.5, 42.4)	54.5 (54.0, 55.1)	51.3 (50.5, 52.1)
Women	250,346	52.4 (52.1, 52.7)	60.0 (58.8, 61.1)	58.1 (57.6, 58.5)	45.5 (44.9, 46.0)	48.7 (47.9, 49.5)
Race/ethnicity,
White, non-Hispanic	326,032	69.4 (69.1, 69.7)	76.4 (75.3, 77.5)	65.7 (65.2, 66.1)	77.7 (77.1, 78.2)	70.7 (69.8, 71.5)
Black, non-Hispanic	32,004	11.1 (10.8, 11.3)	10.7 (9.9, 11.5)	12.1 (11.8, 12.5)	7.4 (7.0, 7.7)	13.4 (12.8, 14.0)
Asian	6,534	3.9 (3.7, 4.1)	1.1 (0.8, 1.4)	5.1 (4.9, 5.4)	2.2 (1.9, 2.4)	1.8 (1.5, 2.1)
Native Hawaiian or Pacific Islander	641	0.2 (0.2, 0.3)	0.2 (0.1, 0.4)	0.2 (0.2, 0.3)	0.2 (0.2, 0.3)	0.2 (0.1, 0.3)
American Indian or Alaskan Native	5,062	0.9 (0.9, 1.0)	1.7 (1.4, 2.0)	0.7 (0.7, 0.8)	1.1 (1.0, 1.2)	1.6 (1.4, 1.8)
Other race, non-Hispanic	2,154	0.4 (0.3, 0.4)	0.4 (0.2, 0.6)	0.4 (0.3, 0.4)	0.4 (0.3, 0.4)	0.4 (0.3, 0.5)
Multiracial, non-Hispanic	6,601	1.3 (1.2, 1.3)	2.6 (2.2, 3.0)	1.1 (1.0, 1.2)	1.4 (1.3, 1.6)	2.1 (1.9, 2.3)
Hispanic	26,558	12.8 (12.5, 13.1)	7.0 (6.3, 7.8)	14.6 (14.2, 14.9)	9.7 (9.3, 10.2)	9.8 (9.2, 10.4)
Marital status,
Married	226,900	57.4 (57.0, 57.7)	45.2 (44.1, 46.3)	58.3 (57.8, 58.7)	62.4 (61.8, 62.9)	41.8 (41.0, 42.6)
Previously married	124,897	20.3 (20.1, 20.5)	38.4 (37.4, 39.4)	17.9 (17.6, 18.2)	24.5 (24.1, 24.9)	28.2 (27.6, 28.9)
Never married	52,789	22.3 (22.0, 22.7)	16.4 (15.4, 17.5)	23.8 (23.4, 24.2)	13.2 (12.7, 13.6)	30.0 (29.2, 30.8)
Educational attainment,
Did not graduate high school	31,713	11.7 (11.4, 12.0)	23.0 (22.0, 24.1)	10.0 (9.7, 10.3)	13.1 (12.6, 13.6)	19.2 (18.4, 19.9)
Graduated high school	116,123	27.8 (27.5, 28.1)	34.3 (33.3, 35.4)	24.9 (24.5, 25.3)	30.0 (29.5, 30.5)	35.9 (35.2, 36.7)
Some college or technical school	109,389	30.1 (29.7, 30.4)	29.8 (28.8, 30.8)	29.0 (28.6, 29.5)	30.9 (30.4, 31.4)	31.8 (31.1, 32.6)
Graduated college or technical school	148,361	30.5 (30.2, 30.8)	12.8 (12.2, 13.4)	36.1 (35.7, 36.5)	26.1 (25.6, 26.5)	13.1 (12.6, 13.6)
Annual Household Income,
<$25 000	99,613	22.7 (22.4, 23.0)	43.5 (42.4, 44.6)	21.1 (20.7, 21.5)	22.2 (21.8, 22.7)	36.6 (35.8, 37.4)
$25 000–$49 999	94,694	22.2 (21.9, 22.5)	23.4 (22.5, 24.4)	20.8 (20.5, 21.2)	23.9 (23.4, 24.3)	24.3 (23.6, 25.0)
≥$50 000	159,790	43.6 (43.3, 44.0)	20.5 (19.6, 21.4)	46.0 (45.6, 46.4)	42.8 (42.2, 43.3)	28.5 (27.8, 29.3)
Missing	51,489	11.5 (11.2, 11.7)	12.6 (11.9, 13.4)	12.1 (11.8, 12.3)	11.1 (10.8, 11.4)	10.6 (10.1, 11.1)
Health insurance coverage	372,163	87.9 (87.6, 88.1)	87.5 (86.5, 88.3)	89.1 (88.8, 89.4)	91.2 (90.9, 91.6)	78.7 (77.9, 79.4)
Other chronic conditions
Arthritis,	146,781	26.4 (26.1, 26.6)	59.2 (58.1, 60.3)	23.5 (23.1, 23.8)	37.1 (36.6, 37.6)	31.2 (30.5, 32.0)
Asthma,	51,877	11.2 (11.0, 11.4)	43.6 (42.5, 44.7)	12.4 (12.1, 12.7)	13.4 (13.0, 13.8)	16.5 (15.9, 17.2)
Cancer,
	41,469	6.9 (6.8, 7.1)	15.9 (15.1, 16.6)	6.1 (5.9, 6.3)	10.8 (10.5, 11.1)	7.0 (6.6, 7.3)
Coronary heart disease,	40,071	4.3 (4.2, 4.4)	18.1 (17.3, 18.9)	3.4 (3.3, 3.6)	8.7 (8.4, 9.0)	5.5 (5.2, 5.8)
Depression,	74,234	15.7 (15.4, 15.9)	38.1 (37.0, 39.2)	13.1 (12.8, 13.4)	18.2 (17.8, 18.6)	28.3 (27.6, 29.0)
Diabetes,	55,227	10.9 (10.7, 11.1)	23.0 (22.1, 23.9)	10.0 (9.8, 10.3)	15.7 (15.3, 16.1)	10.7 (10.3, 11.2)
High blood pressure,	175,037	35.0 (34.7, 35.3)	58.1 (57.0, 59.2)	32.3 (31.9, 32.7)	45.6 (45.1, 46.1)	35.7 (35.0, 36.5)
High cholesterol,	175,875	36.8 (36.5, 37.1)	57.9 (56.8, 59.0)	33.8 (33.4, 34.2)	46.8 (46.3, 47.4)	38.7 (37.9, 39.5)
Kidney disease,	13,513	2.5 (2.4, 2.6)	7.3 (6.8, 7.9)	2.4 (2.3, 2.5)	3.7 (3.5, 3.9)	2.8 (2.6, 3.1)
Stroke,	17,362	2.8 (2.7, 2.9)	9.7 (9.2, 10.3)	2.3 (2.1, 2.4)	4.6 (4.4, 4.8)	4.2 (4.0, 4.5)
(Continued on next page)
Table 1.( Continued)
Characteristic	Number of Respondents	No COPD [N = 372,498] % (95% CI)	COPD [N = 33,088] % (95% CI)	Never Smoker [N = 218,356] % (95% CI)	Former Smoker [N = 126,784] % (95% CI)	Current Smoker [N = 60,446] % (95% CI)
Number of chronic conditions,
0	90,144	30.8 (30.5, 31.1)	5.2 (4.7, 5.8)	34.9 (34.5, 35.4)	19.7 (19.2, 20.2)	25.5 (24.8, 26.2)
1	95,683	26.4 (26.1, 26.7)	12.6 (11.8, 13.4)	26.7 (26.3. 27.1)	23.2 (22.7, 23.7)	25.1 (24.4, 25.8)
2	84,435	19.3 (19.0, 19.5)	17.7 (16.9, 18.6)	17.8 (17.5, 18.2)	21.5 (21.1, 22.0)	19.5 (18.9, 20.2)
3	63,927	12.6 (12.4, 12.8)	20.0 (19.2, 20.9)	11.0 (10.8, 11.2)	16.8 (16.4, 17.2)	14.1 (13.6, 14.6)
4	39,321	6.8 (6.6, 6.9)	18.6 (17.7, 19.4)	5.8 (5.6, 6.0)	10.4 (10.1, 10.7)	8.6 (8.2, 9.1)
5	19,735	2.9 (2.8, 3.0)	13.4 (12.7, 14.1)	2.5 (2.3, 2.6)	5.3 (5.1, 5.6)	4.4 (4.1, 4.7)
6	8,470	1.0 (0,9, 1.0)	7.5 (7.0, 8.1)	0.9 (0.9, 1.0)	2.1 (2.0, 2.3)	1.9 (1.7, 2.1)
7	2,840	0.3 (0.2, 0.3)	3.5 (3.2, 3.9)	0.3 (0.2, 0.3)	0.7 (0.6, 0.8)	0.7 (0.6, 0.8)
≥8	1,031	0.1 (0.1, 0.1)	1.4 (1.2, 1.6)	0.1 (0.1, 0.1)	0.2 (0.2, 0.3)	0.2 (0.2, 0,3)
Cigarette smoking
Never smoker	218,356	57.0 (56.7, 57.3)	24.1 (23.2, 25.1)	–	–	–
Former smoker	126,784	27.0 (26.7, 27.2)	39.2 (38.1, 40.2)	–	–	–
Current smoker	60,446	16.0 (15.8, 16.3)	36.7 (35.6, 37.8)	–	–	–

^aRespondents who smoked fewer than 100 cigarettes during their lifetime were considered never smokers.

^bRespondents who smoked at least 100 cigarettes and reported smoking not at all at the time of interview were considered former smokers.

^cRespondents who smoked at least 100 cigarettes and reported smoking every day or on some days at the time of interview were considered current smokers.

^dDifference in distribution by COPD status determined to be statistically significant (chi-square p≤0.05).

^eDifference in distribution by smoking status determined to be statistically significant (chi-square p≤0.05).

^fPreviously married includes those divorced, widowed, or separated.

^gNever married includes those never married or members of unmarried couples.

Figure 1. Age-adjusted  percentages of chronic conditions among adults aged ≥18 years, by cigarette smoking status: Behavioral Risk Factor Surveillance System, 2011.

Table 2.  Relationship of  cigarette smoking status to other chronic conditions among adults aged ≥18 years, by chronic obstructive pulmonary disease (COPD) status: Behavioral Risk Factor Surveillance System, 2011

Chronic Disease	No COPD	COPD
	Age-adjusted% (95% CI)	Multivariable PR (95% CI)	Age-adjusted% (95% CI)	Multivariable PR (95% CI)^a
Arthritis
Never Smoker	20.5 (20.2, 20.8)	1.0 (referent)	45.0 (42.3, 47.8)	1.0 (referent)
Former Smoker	24.5 (24.0, 25.1)	1.2 (1.2, 1.2)	51.0 (45.7, 56.3)	1.0 (1.0, 1.1)
Current Smoker	26.1 (25.4, 26.8)	1.2 (1.2, 1.3)	50.8 (48.3, 53.2)	1.0 (1.0, 1.1)
Asthma
Never Smoker	11.5 (11.2, 11.9)	1.0 (referent)	52.3 (48.8, 55.8)	1.0 (referent)
Former Smoker	12.5 (11.7, 13.3)	1.1 (1.1, 1.2)	51.8 (46.7, 56.9)	0.9 (0.8, 0.9)
Current Smoker	12.6 (12.0, 13.4)	1.1 (1.0, 1.1)	44.3 (41.2, 47.4)	0.8 (0.8, 0.9)
Cancer
Never Smoker	5.4 (5.2, 5.6)	1.0 (referent)	11.1 (9.4, 13.1)	1.0 (referent)
Former Smoker	6.8 (6.4, 7.2)	1.3 (1.2, 1.3)	13.4 (11.1, 16.0)	1.3 (1.2, 1.5)
Current Smoker	6.0 (5.7, 6.4)	1.2 (1.1, 1.3)	13.8 (12.3, 15.5)	1.2 (1.1, 1.4)
Coronary heart disease
Never Smoker	4.2 (4.0, 4.3)	1.0 (referent)	14.6 (13.1,16.3)	1.0 (referent)
Former Smoker	6.8 (6.5, 7.1)	1.4 (1.4, 1.5)	16.6 (14.8, 18.5)	1.1 (1.0, 1.2)
Current Smoker ^d	6.9 (6.5, 7.3)	1.4 (1.3, 1.5)	19.1 (17.2, 21.2)	1.0 (0.9, 1.2)
Depression
Never Smoker	12.2 (11.9, 12.6)	1.0 (referent)	34.3 (31.2, 37.5)	1.0 (referent)
Former Smoker ^c	18.0 (17.1, 18.9)	1.4 (1.3, 1.4)	39.4 (34.9, 44.2)	1.1 (1.0, 1.2)
Current Smoker ^d	24.3 (23.5, 25.1)	1.7 (1.6, 1.8)	49.2 (46.1, 52.2)	1.2 (1.1, 1.3)
Diabetes
Never Smoker	8.8 (8.6, 9.1)	1.0 (referent)	19.5 (17.0, 22.2)	1.0 (referent)
Former Smoker	10.6 (10.2, 11.1)	1.2 (1.1, 1.2)	17.8 (15.7, 20.0)	1.0 (0.9, 1.1)
Current Smoker	9.2 (8.7, 9.6)	0.9 (0.8, 0.9)	16.6 (15.0, 18.3)	0.8 (0.7, 0.9)
High blood pressure
Never Smoker	29.1 (28.9, 29.5)	1.0 (referent)	48.5 (45.1, 52.1)	1.0 (referent)
Former Smoker	33.1 (32.4, 33.8)	1.1 (1.1, 1.1)	49.3 (43.3, 55.3)	1.0 (0.9, 1.0)
Current Smoker	33.0 (32.1, 33.8)	1.0 (1.0, 1.0)	44.2 (41.8, 46.7)	0.9 (0.8, 0.9)
High cholesterol
Never Smoker	31.0 (30.7, 31.4)	1.0 (referent)	45.6 (42.3, 48.9)	1.0 (referent)
Former Smoker ^c	35.6 (34.9, 36.4)	1.1 (1.1, 1.2)	49.0 (42.9, 55.1)	1.1 (1.0, 1.1)
Current Smoker ^d	34.5 (33.8, 35.3)	1.1 (1.1, 1.1)	51.4 (48.4, 54.4)	1.1 (1.0, 1.1)
Kidney disease
Never Smoker	2.1 (2.0, 2.3)	1.0 (referent)	6.3 (5.3, 7.5)	1.0 (referent)
Former Smoker ^c	2.5 (2.2, 2.8)	1.2 (1.1, 1.3)	7.6 (5.1, 11.0)	0.9 (0.8, 1.1)
Current Smoker	2.4 (2.1, 2.6)	1.0 (0.9, 1.2)	5.6 (4.5, 6.8)	0.7 (0.6, 0.9)
Stroke
Never Smoker	1.9 (1.8, 2.0)	1.0 (referent)	6.4 (5.3, 7.7)	1.0 (referent)
Former Smoker	2.7 (2.5, 2.9)	1.4 (1.3, 1.4)	6.1 (4.8, 7.7)	1.0 (0.9, 1.2)
Current Smoker	3.3 (3.1, 3.6)	1.5 (1.3, 1.6)	8.9 (7.7, 10.3)	1.2 (1.0, 1.5)

^a Prevalence ratio (PR) and 95% confidence interval (CI) obtained from separate multivariable log-linear regression models that included age, gender, race/ethnicity, marital status, educational attainment, household income, and health insurance coverage as covariates.

^b Respondents who smoked fewer than 100 cigarettes during their lifetime were considered never smokers.

^cRespondents who smoked at least 100 cigarettes and reported smoking not at all at the time of interview were considered former smokers.

^dRespondents who smoked at least 100 cigarettes and reported smoking every day or on some days at the time of interview were considered current smokers.

Figure 2. Age-adjusted  percentages of chronic conditions among adults aged ≥18 years, by chronic obstructive pulmonary disease (COPD) status: Behavioral Risk Factor Surveillance System, 2011.

Table 3.  Relationship of chronic  obstructive pulmonary disease (COPD) to other chronic conditions among adults aged ≥ 18 years, by cigarette smoking status: Behavioral Risk Factor Surveillance System, 2011

Chronic Disease	Never Smoker		Former Smoker		Current Smoker
	Age-adjusted % (95% CI)	Multivariable PR (95% CI)	Age-adjusted % (95% CI)	Multivariable PR (95% CI)	Age-adjusted % (95% CI)	Multivariable PR (95% CI)
Arthritis
No COPD	20.5 (20.2, 20.8)	1.0 (referent)	24.5 (24.0, 25.1)	1.0 (referent)	26.1 (25.4, 26.8)	1.0 (referent)
COPD	45.0 (42.3, 47.8)	1.7 (1.6, 1.8)	51.0 (45.7, 56.3)	1.3 (1.3, 1.4)	50.8 (48.3, 53.2)	1.6 (1.5, 1.7)
Asthma
No COPD	11.5 (11.2, 11.9)	1.0 (referent)	12.5 (11.7, 13.3)	1.0 (referent)	12.6 (12.0, 13.4)	1.0 (referent)
COPD	52.3 (48.8, 55.8)	4.6 (4.3, 4.8)	51.8 (46.7, 56.9)	4.0 (3.8, 4.2)	44.3 (41.2, 47.4)	3.6 (3.3, 3.8)
Cancer
No COPD	5.4 (5.2, 5.6)	1.0 (referent)	6.8 (6.4, 7.2)	1.0 (referent)	6.0 (5.7, 6.4)	1.0 (referent)
COPD	11.1 (9.4, 13.1)	1.5 (1.4, 1.7)	13.4 (11.1, 16.0)	1.3 (1.2, 1.4)	13.8 (12.3, 15.5)	1.8 (1.6, 2.0)
Coronary heart disease
No COPD	4.2 (4.0, 4.3)	1.0 (referent)	6.8 (6.5, 7.1)	1.0 (referent)	6.9 (6.5, 7.3)	1.0 (referent)
COPD	14.6 (13.1, 16.3)	2.8 (2.6, 3.1)	16.6 (14.8, 18.5)	1.9 (1.8, 2.0)	19.1 (17.2, 21.2)	2.4 (2.2, 2.6)
Depression
No COPD	12.2 (11.9, 12.6)	1.0 (referent)	18.0 (17.1, 18.9)	1.0 (referent)	24.3 (23.5, 25.1)	1.0 (referent)
COPD	34.3 (31.2, 37.5)	2.2 (2.1, 2.4)	39.4 (34.9, 44.2)	1.7 (1.6, 1.8)	49.2 (46.1, 52.2)	1.6 (1.6, 1.7)
Diabetes
No COPD	8.8 (8.6, 9.1)	1.0 (referent)	10.6 (10.2, 11.1)	1.0 (referent)	9.2 (8.7, 9.6)	1.0 (referent)
COPD	19.5 (17.0, 22.2)	1.7 (1.5, 1.8)	17.8 (15.7, 20.0)	1.3 (1.2, 1.4)	16.6 (15.0, 18.3)	1.6 (1.5, 1.8)
High blood pressure
No COPD	29.1 (28.8, 29.5)	1.0 (referent)	33.1 (32.4, 33.8)	1.0 (referent)	33.0 (32.1, 33.8)	1.0 (referent)
COPD	48.5 (45.1, 52.1)	1.4 (1.3, 1.4)	49.3 (43.3, 55.3)	1.2 (1.2, 1.2)	44.2 (41.8, 46.7)	1.3 (1.3, 1.4)
High cholesterol
No COPD	31.0 (30.7, 31.4)	1.0 (referent)	35.6 (34.9, 36.4)	1.0 (referent)	34.5 (33.8, 35.3)	1.0 (referent)
COPD	45.6 (42.3, 48.9)	1.3 (1.3, 1.4)	49.0 (42.9, 55.1)	1.2 (1.1, 1.2)	51.4 (48.4, 54.4)	1.4 (1.3, 1.4)
Kidney disease
No COPD	2.1 (2.0, 2.3)	1.0 (referent)	2.5 (2.8, 2.8)	1.0 (referent)	2.4 (2.1, 2.6)	1.0 (referent)
COPD	6.3 (5.3, 7.5)	2.4 (2.1, 2.8)	7.6 (5.1, 11.0)	2.0 (1.7, 2.2)	5.6 (4.5, 6.8)	1.8 (1.5, 2.2)
Stroke
No COPD	1.9 (1.8, 2.0)	1.0 (referent)	2.7 (2.5, 2.9)	1.0 (referent)	3.3 (3.1, 3.6)	1.0 (referent)
COPD	6.4 (5.3, 7.7)	2.2 (1.9, 2.5)	6.1 (4.8, 7.7)	1.6 (1.5, 1.8)	8.9 (7.7, 10.3)	2.0 (1.8, 2.4)

^a Respondents who smoked fewer than 100 cigarettes during their lifetime were considered never smokers.

^b Respondents who smoked at least 100 cigarettes and reported smoking not at all at the time of interview were considered former smokers.

^c Respondents who smoked at least 100 cigarettes and reported smoking every day or on some days at the time of interview were considered current smokers.

^d Prevalence ratio (PR) and 95% confidence interval (CI) obtained from separate multivariable log-linear regression models that included age, gender, race/ethnicity, marital status, educational attainment, household income, and health insurance coverage as covariates.

Table 4.  Relationship of all  possible combinations of chronic obstructive pulmonary disease (COPD) and cigarette smoking status categories to other chronic conditions among adults aged ≥ 18 years: Behavioral Risk Factor Surveillance System, 2011

COPD × Smoking Status	Chronic Disease Multivariable PR (95% CI)	COPD × Smoking Status	Chronic Disease Multivariable PR (95% CI)
	Arthritis		Diabetes
No COPD/Never Smoker	1.0 (referent)	No COPD/Never Smoker	1.0 (referent)
No COPD/Former Smoker	1.2 (1.2, 1.2)	No COPD/Former Smoker	1.2 (1.1, 1.2)
No COPD/Current Smoker	1.2 (1.2, 1.2)	No COPD/Current Smoker	0.9 (0.8, 0.9)
COPD/Never Smoker	1.8 (1.7, 1.8)	COPD/Never Smoker	1.7 (1.6, 1.9)
COPD/Former Smoker	1.6 (1.5, 1.6)	COPD/Former Smoker	1.5 (1.4, 1.6)
COPD/Current Smoker	1.8 (1.7, 1.9)	COPD/Current Smoker	1.4 (1.3, 1.5)
	Asthma		High blood pressure
No COPD/Never Smoker	1.0 (referent)	No COPD/Never Smoker	1.0 (referent)
No COPD/Former Smoker	1.1 (1.0, 1.1)	No COPD/Former Smoker	1.1 (1.1, 1.1)
No COPD/Current Smoker	1.1 (1.0, 1.1)	No COPD/Current Smoker	1.0 (1.0, 1.0)
COPD/Never Smoker	4.5 (4.3, 4.8)	COPD/Never Smoker	1.4 (1.4, 1.5)
COPD/Former Smoker	4.3 (4.1, 4.6)	COPD/Former Smoker	1.3 (1.2, 1.3)
COPD/Current Smoker	3.7 (3.5, 3.9)	COPD/Current Smoker	1.2 (1.2, 1.3)
	Cancer		High cholesterol
No COPD/Never Smoker	1.0 (referent)	No COPD/Never Smoker	1.0 (referent)
No COPD/Former Smoker	1.3 (1.2, 1.4)	No COPD/Former Smoker	1.1 (1.1, 1.2)
No COPD/Current Smoker	1.1 (1.1, 1.2)	No COPD/Current Smoker	1.1 (1.0, 1.1)
COPD/Never Smoker	1.5 (1.4, 1.7)	COPD/Never Smoker	1.3 (1.3, 1.4)
COPD/Former Smoker	1.7 (1.6, 1.8)	COPD/Former Smoker	1.3 (1.3, 1.4)
COPD/Current Smoker	2.0 (1.8, 2.2)	COPD/Current Smoker	1.4 (1.4, 1.5)
	Coronary heart disease		Kidney disease
No COPD/Never Smoker	1.0 (referent)	No COPD/Never Smoker	1.0 (referent)
No COPD/Former Smoker	1.5 (1.4, 1.5)	No COPD/Former Smoker	1.2 (1.1, 1.3)
No COPD/Current Smoker	1.4 (1.3, 1.5)	No COPD/Current Smoker	1.0 (0.9, 1.2)
COPD/Never Smoker	3.0 (2.7, 3.3)	COPD/Never Smoker	2.5 (2.2, 2.9)
COPD/Former Smoker	2.7 (2.5, 2.9)	COPD/Former Smoker	2.2 (1.9, 2.5)
COPD/Current Smoker	3.1 (2.9, 3.4)	COPD/Current Smoker	2.8 (1.6, 2.1)
	Depression		Stroke
No COPD/Never Smoker	1.0 (referent)	No COPD/Never Smoker	1.0 (referent)
No COPD/Former Smoker	1.4 (1.3, 1.4)	No COPD/Former Smoker	1.4 (1.3, 1.5)
No COPD/Current Smoker	1.7 (1.6, 1.8)	No COPD/Current Smoker	1.5 (1.3, 1.6)
COPD/Never Smoker	2.3 (2.1, 2.4)	COPD/Never Smoker	2.3 (2.0, 2.7)
COPD/Former Smoker	2.3 (2.2, 2.4)	COPD/Former Smoker	2.2 (1.9, 2.4)
COPD/Current Smoker	2.6 (2.5, 2.8)	COPD/Current Smoker	2.9 (2.6, 3.2)

^aPrevalence ratio (PR) and 95% confidence interval (CI) obtained from separate multivariable log-linear regression models for each chronic condition that included all possible combinations of COPD and status smoking categories as a predictor when entered simultaneously with age, gender, race/ethnicity, marital status, educational attainment, household income, and health insurance coverage as covariates.

^bRespondents who smoked fewer than 100 cigarettes during their lifetime were considered never smokers.

^cRespondents who smoked at least 100 cigarettes and reported smoking not at all at the time of interview were considered former smokers.

^dRespondents who smoked at least 100 cigarettes and reported smoking every day or on some days at the time of interview were considered current smokers.