Does COPD risk vary by ethnicity? A retrospective cross-sectional study

Figures & data

Table 1 Characteristics of the whole population (age, sex, smoking status, IMD score, COPD diagnosis, and spirometry-confirmed COPD) by ethnic group

Ethnic group	N (%)	Mean age (years)	Male (%)	Current smoker (%)	Ex-smoker (%)	Never smoker (%)	Smoker status unknown (%)	Mean IMD score	Recorded COPD diagnosis (%)	Spirometry-confirmed COPD (%)
White group	170,632 (48)	37	49	22	24	43	11	30	1.55	0.77
Black or black British	71,836 (20)	35	47	14	14	51	20	34	0.58	0.26
Asian or Asian British	18,770 (5)	36	53	13	13	59	15	27	0.78	0.34
Mixed	16,803 (5)	28	46	18	14	40	28	32	0.50	0.17
Chinese/other	13,650 (4)	35	47	15	16	55	15	32	0.34	0.13
Unknown	57,107 (16)	33	55	17	13	39	32	31	0.41	0.15
Not stated	9,816 (3)	30	51	15	15	36	34	31	0.65	0.29
All	358,614	35	49	18	19	45	18	31	1.01	0.48

Abbreviation: IMD, index of multiple deprivation.

Table 2 Characteristics of COPD patients (age, sex, smoking status, IMD score, and spirometry-confirmed COPD) by ethnic group

Ethnic group	N (%)	Mean age (years)	Male (%)	Current smoker (%)	Ex-smoker (%)	Never smoker (%)	Smoker status unknown (%)	Mean IMD score	Spirometry-confirmed COPD (%)
White group	2,637 (73)	68	52	43	52	5	0.1	32	50
Black or black British	416 (11)	69	69	31	52	16	0.5	34	44
Asian or Asian British	146 (4)	67	75	35	46	19	0.0	31	44
Mixed	84 (2)	66	57	40	43	17	0.0	34	33
Chinese/other	47 (1)	65	70	21	51	28	0.0	30	38
Unknown	236 (7)	68	60	40	47	11	1.7	32	36
Not stated	64 (2)	70	69	30	56	14	0.0	30	44
All	3,630	68	56	41	51	8	0.2	32	48

Abbreviation: IMD, index of multiple deprivation.

Table 3 Comparison of likelihood of COPD diagnosis and spirometry-confirmed COPD diagnosis between ethnic groups and subgroups, with white and white British as baseline

Ethnic group	COPD diagnosis OR	95% confidence interval	Spirometry-confirmed COPD OR	95% confidence interval	Ethnic subgroup	COPD diagnosis OR	95% confidence interval
White	1		1		White British/mixed	1
					Irish white	1.35	1.13–1.62
					Other white	0.55	0.46–0.67
Black or black British	0.44	0.39–0.51	0.42	0.36–0.49	Caribbean	0.45	0.38–0.52
					African	0.32	0.25–0.41
					Other black	0.26	0.18–0.39
Asian or Asian British	0.82	0.68–0.98	0.74	0.57–0.96	Indian/British Indian	0.65	0.47–0.90
					Pakistani/British Pakistani	0.95	0.61–1.50
					Bangladeshi	0.63	0.37–1.07
					Other Asian	0.76	0.60–0.97
Mixed	0.70	0.49–0.98	0.49	0.32–0.74	White and black Caribbean	0.76	0.47–1.25
					White and black African	0.21	0.09–0.51
					White and Asian	0.61	0.28–1.36
					Mixed other	0.67	0.49–0.91
Chinese/other	0.41	0.28–0.60	0.34	0.16–0.70	Chinese	0.34	0.21–0.58
					Other ethnic group	0.38	0.23–0.63

Notes: Multiple logistic regression controlling for age, sex, smoking status, deprivation, and practice clustering. Excludes people with no recording of ethnicity (n=247,939). Bold indicates significance, P<0.05.

Abbreviation: OR, odds ratio.

Table 4 Comparison of smoking history in COPD patients between ethnic groups (n=3,330)

Ethnic group	Frequency	% currently smoking	OR for currently smoking	95% CI	% never smoked	OR for never smoked	95% CI
White	2,637	43.2	1		4.8	1
Black	416	31.5	0.56	0.44–0.71	15.6	4.9	3.4–7.1
Asian	146	34.9	0.69	0.47–1.02	19.2	6.5	3.7–11.4
Mixed	84	40.5	0.79	0.53–1.18	16.7	4.7	2.3–9.6
Chinese/other	47	21.3	0.28	0.15–0.52	27.7	10.6	4.6–24.3

Notes: Current smokers were compared with current nonsmokers and never smokers were compared with ever smokers using multiple logistic regression, controlling for age, sex, deprivation score, and practice clustering. Excludes people with no recording of ethnicity. Bold indicates statistical significance, P<0.05.

Abbreviations: OR, odds ratio; CI, confidence interval.

Table 5 Comparison of COPD severity (% predicted FEV₁) between ethnic groups among all COPD patients (n=2,824) and spirometry-confirmed COPD patients (n=1,509)

Ethnic group	% predicted FEV1 (ECSC-derived predicted values)			% predicted FEV1 (ethnicity-specific predicted values)
	B coefficient	95% CI	Standardized β	B coefficient	95% CI	Standardized β
All COPD patients (n=2,824)
White
Black or black British	−7.59	−10.0 to −5.2	−0.111	−1.09	−1.6 to 3.8	0.016
Asian or Asian British	−4.23	−7.1 to −1.3	−0.038	0.37	−2.7 to 3.4	0.003
Mixed	−4.95	−10.0 to 0.1	0.033	−4.95	−10.1 to 0.1	−0.032
Chinese/other	−3.08	−9.7 to 3.5	0.016	−3.10	−9.7 to 3.5	−0.016
Spirometry-confirmed COPD (n =1,509)
White
Black or black British	−8.99	−12.00 to −5.97	−0.140	−1.63	−5.02 to 1.76	0.016
Asian or Asian British	−5.12	−10.22 to −0.02	−0.050	−1.14	−6.58 to 4.30	0.003
Mixed	−7.48	−15.27 to 0.31	0.050	−7.46	−15.27 to 0.34	−0.032
Chinese/other	−2.46	−9.61 to 4.69	0.012	−2.48	−9.63 to 4.67	−0.016

Notes: A sensitivity analysis using ethnicity-specific predicted FEV₁ values is included. Multiple linear regression controlling for age, sex, smoking status, deprivation, and practice clustering. Excludes people with no recording of ethnicity. Bold indicates statistical significance, P<0.05.

Abbreviations: ECSC, European Coal and Steel Community; FEV₁, forced expiratory volume in 1 second; CI, confidence interval.