Early detection of COPD in general practice

Figures & data

Table 1 Characteristics of the enrolled subjects

	Males (n = 1503)	Females (n = 1594)
Age (years)	58 (36–90)	57 (36–88)
BMI (kg/m^2)	27 (15–49)	26 (14–55)
Pack-years (n)	38 (0.5–175)	29 (0.1–172)*

* Note: P < 0.05.

Abbreviation: BMI, body mass index.

Table 2 Distribution of FEV₁/FVC < 70 stratified on gender, smoking status, age, and BMI

Risk factor	FEV1/FVC < 70 N (%)	FEV1/FVC ≥ 70 N (%)	95% CI for OR	P-value
Gender
Female	527 (33.1)	1063 (66.9)
Male	551 (36.6)	954 (63.4)	[1.01–1.38]	0.039
Smoking		1290 (64.5)
Smoker	713 (35.5)
Ex-smoker	343 (34.6)	647 (65.4)	[0.64–0.91]	0.002
Never smoker	22 (21.5)	80 (78.5)	[0.27–0.74]	0.001
Age (years)
36–48	144 (17.9)	657 (82.1)
49–58	262 (31.6)	566 (68.4)
59–66	312 (41.7)	436 (58.3)
67–90	360 (50.0)	358 (50.0)	[2.20–2.84]	<0.001
BMI (kg/m^2)
14.4–23.1	327 (42.2)	447 (57.8)
23.2–25.6	301 (39.3)	464 (60.7)
25.7–28.7	231 (30.1)	536 (69.9)
28.8–55.0	219 (27.7)	570 (72.3)	[0.64–0.78]	<0.001

Notes: The grouping of age and body mass index (BMI) is based on quartiles. The 95% confidence intervals (CI) and P-values for odds ratios (OR) were obtained from multivariate logistic regression. Female smokers were set as reference levels for the OR. The OR for age and BMI correspond to an increase in interquartile range.

Figure 1 Estimated age and gender specific prevalence of FEV₁/FVC ratio ≤ 70%.

Figure 2 Nomogram used for predicting the probability of FEV₁/FVC ≤ 70%. The model reported in Table 2 has been used in constructing the nomogram.

Figure 3 Distribution of enrolled subjects with airway obstruction (FEV₁/FVC ≤ 70%) (n = 1078) according to severity of COPD (based on FEV₁% predicted).