Self-reported alcohol intake and risk of acute exacerbations of chronic obstructive pulmonary disease: a prospective cohort study

Figures & data

Figure 1 Alcohol use questionnaire.

Table 1 Baseline characteristics*

	All (n=1,082)	Alcohol intake category			P-value**
		Minimal to none (n=645)	Light-to-moderate (n=363)	Heavy (n=74)
Age, years	65.2±8.7	64.9 ±8.7	65.4±8.5	66.8±9.0	0.189
Female sex, %	41	44	40	16	<0.0001
Race or ethnicity, %
White	81	79	84	89	0.086
African-American	14	17	12	4
Asian	0.9	1	0.2	1
Native American	0.4	0.5	0.2	0
More than one	3	3	3	5
Hispanic	2	2	4	1	0.139
Post-bronchodilator FEV1, L	1.11±0.51	1.08±0.49	1.14±0.52	1.27±0.55	0.003
Post-bronchodilator FEV1 %	39.6 ±15.7	39.1 ±15.5	40.2±16.1	41.3±15.4	0.357
predicted FEV1/FVC, %	42.6±12.8	42.9±12.9	41.7±12.7	44.4±12.4	0.163
Smoking history, pack-years	58.6±32.3	58.3±32.3	56.9±29.7	70.4±41.0	0.004
Current smokers, %	22	21	22	31	0.111
Medication use, %
ICS only	5	6	4	3	0.256
LAMA only	7	8	7	1	0.116
LABA only	2	2	2	0	0.416
ICS + LABA	20	20	20	27	0.322
ICS + LAMA	5	5	5	4	0.939
LABA + LAMA	5	4	6	4	0.612
ICS + LABA + LAMA	48	46	49	50	0.648
None	9	10	8	10	0.518
Oxygen use, %	60	62	59	43	0.007
Chronic bronchitis, %	55	56	53	64	0.223
SGRQ total (mean ± SD)	50.6±16.5	52.0±16.5	48.6±16.7	48.1±14.2	0.003
GERD, %	43	44	43	38	0.612
HAD anxiety scale	5.4±3.7	5.6±3.9	5.2±3.6	4.5±3.3	0.019
HAD depression scale	4.9±0.2	5.1±3.3	4.6±3.0	4.5±3.0	0.030
AECOPD previous year	88	90	83	91	0.007
Randomized to azithromycin/placebo	50%/50%	60%/59%	33%/34%	7%/7%	0.660

Notes:

* Data are presented as mean ± standard deviation or frequency (%).

** P-values calculated by chi-square (categorical) and t-test (continuous).

Abbreviations: AECOPD, acute exacerbation of chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GERD, gastroesophageal reflux disease; HAD, hospital anxiety and depression; LABA, long-acting β₂ agonist; LAMA, long-acting muscarinic antagonist; SGRQ, St George’s Respiratory Questionnaire; ICS, inhaled corticosteroid; SD, standard deviation.

Table 2 Time to first AECOPD by alcohol consumption pattern

	Total (n=1,082)	Alcohol intake			P-value
		Minimal (n=645)	Light-to moderate (n=363)	Heavy (n=74)
Median time to first exacerbation, days (95% CI)	216 (190–241)	195 (163–225)	241 (205–302)	288 (164–372)	0.1113
Crude HR (95% CI)	NA	(Referent)	0.87 (0.74–1.03) P=0.097	0.78 (0.56–1.07) P=0.123	–
Adjusted HR (95% CI)*	NA	(Referent)	0.89 (0.75–1.05) P=0.155	0.93 (0.70–1.29) P=0.656	–

Notes:

* Covariates included in final stepwise model: treatment group, age, sex, smoking status, bronchitis, oxygen, FEV₁/FVC ratio, exacerbation in past year, SGRQ.

Abbreviations: AECOPD, acute exacerbation of chronic obstructive pulmonary disease; CI, confidence interval; HR, hazard ratio; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; NA, not applicable; SGRQ, St George’s Respiratory Questionnaire.

Figure 2 Proportion free from AECOPD for 1 year, according to alcohol consumption pattern.

Abbreviation: AECOPD, acute exacerbation of chronic obstructive pulmonary disease.

Table 3 AECOPD event rates by alcohol consumption pattern

	Alcohol intake
	Total (n=1,082)	Minimal (n=645)	Light-to-moderate (n=363)	Heavy (n=74)
Mean exacerbation rate, exacerbations per year (95% CI)	1.66 (1.51–1.80)	1.62 (1.53–1.94)	1.44 (1.31–1.71) P=0.095	1.68 (1.17–2.19) P=0.796

Note: P-values comparing to referent group of minimal alcohol intake.

Abbreviations: AECOPD, acute exacerbation of chronic obstructive pulmonary disease; CI, confidence interval.