Exacerbations of Chronic Obstructive Pulmonary Disease (COPD): An Ecological Study in the Basque Country, Spain (2000–2011)

Figures & data

Table 1. Hospitalizations, mortality and hospital mortality.

	00/03	04/07	08/11	00/03	04/07	08/11	00/03	04/07	08/11	00/11
	Males			Females			Overall			Total
Hospitalizations
Number	18632	18630	15079	5509	5290	4263	24141	23920	19342	67403
Age(Avg ± SD)	72.9(10.6)	73.9(10.5)	74.3(11.3)	76.2(12.4)	75.9(13.3)	74.4(14.6)	73.7(11.1)	74.4(11.2)	74.3(12.1)	74.1(11.4)
Rates (per
<50	19.2	18.6	17.8	8.8	10.4	8.3	14.1	14.6	13.1	13.9
50–64	315.4	288.1	241.7	57.1	72.6	89.5	184	178.5	164.3	175.6
65–74	1713.4	1451.3	1044.4	303.2	225.9	164.5	952.7	790	569.5	770.7
>74	3203.7	3044.4	3056	710.1	700.9	528.5	1631.8	1718.6	1462.7	1604.4
Overall^*	311.4	298.6	250.3	63.1	60.3	52.8	283.4	274.9	227.1	261.8
Mortality
Number	2430	2368	2099	957	891	796	3387	3259	2895	9541
Age(Avg ± SD)	79.6(8.7)	79.9(8.9)	81.2(9.1)	83.7(8.9)	85.3(8.9)	85.4(10)	80.8(9)	81.4(9.2)	82.3(9.5)	81.4(9.2)
Rates (per
<50	0.6	0.5	0.6	0.1	0.2	0.2	0.27	0.25	0.3	0.2
50–64	13	15.4	13.8	3.1	2.4	4.7	7.7	8.5	8.8	8.7
65–74	133.1	106.8	63.7	21.8	15.6	10.6	68.4	52.8	33.6	55.2
>74	632.5	638.8	604.6	170.1	163.2	144.4	342.9	338.5	314.8	331.5
Overall^*	39.8	38.3	34.7	8.5	7.6	7	20.1	19	16.7	18
Hospital
Number	1061	1059	667	394	304	191	1455	1363	858	3676
Age(Avg ± SD)	77.7(9.1)	78.6(8.4)	79.6(8.1)	81.7(9.4)	82.6(8.9)	82(10.7)	78.8(9.4)	79.5(8.7)	80.2(8.8)	79.3(9)
Rates (per
<50	2.7	1	0.5	2.2	1.4	1.5	2.5	1.1	0.9	1.6
50–64	3	3.2	2.2	2.6	0.8	2	2.9	2.6	2.2	2.6
65–74	6	6.6	4	5.2	5.6	1.9	5.8	6.4	3.7	5.5
>74	11.1	10.8	7.9	11.2	9.2	7.2	11.2	10.4	7.8	9.9
Overall	8	8.3	5.9	8.7	7.1	5.1	8.2	8	5.8	7.4

* European age-standardized rate.

Table 2. Hospitalization and mortality trends.

	Hospitalization rates				Mortality rates
	Man		Woman		Man		Woman
	Beta	p-values	Beta	p-values	Beta	p-values	Beta	p-values
<50	−1	0.4	−0.11	0.89	−0.15	0.42	0.07	0.52
50–64	−18	0.002^***	7.8	<0.0001^***	−0.14	0.69	0.37	0.16
65–74	−77	<0.0001^***	−17	<0.0001^***	−8.32	<0.0001^***	−1.4	0.001^***
>74	−7.8	0.72	−27	0.01^**	−3.42	0.31	−4.54	0.048^*
Total	−26.17	0.477^***	−9.342	0.461	−3.867	0.582^***	−1.986	0.586

^***<0.001;

^**<0.005;

^*<0.01.

Figure 1. Distribution of risk of hospitalizations (posterior probability).

Table 3. Correlation between variables.

	EPOC	CO	NO	NO2	O3	PM10	PM2.5	SO2	Temperature	Humidity	InfluenzaRate Rate
EPOC	1	0.54^***	0.47^***	0.49^****	−0.37^***	0.14^**	0.09	0.52^***	−0.61^***	0.02	0.57^***
CO		1	0.79^***	0.77^***	−0.60^***	0.56^***	0.53^***	0.75^***	−0.44^***	0.15^**	0.18^***
NO			1	0.83^***	−0.81^***	0.50^***	0.46^***	0.63^***	−0.55^***	0.18^***	0.29^***
NO2				1	−0.62^***	0.55^***	0.55^***	0.66^***	−0.58^***	0.08	0.23^***
O3					1	−0.23^***	−0.18^***	−0.38^***	0.43^***	−0.26^***	−0.32^***
PM10						1	0.90^***	0.57^***	0.09	−0.10^*	0.01
PM2.5							1	0.48^***	0.03	0.08	0
SO2								1	−0.40^***	−0.01	0.12^*
Temper									1	−0.25^***	−0.30^***
Humidity										1	0.03
Influenza Rate											1

^{*** <0.001;}

^** <0.005;

^*<0.01.

Table 4. Comparison between Cold and Warm season.

	Warm Av.	Warm SD	Cold Av.	Cold SD	p-value
Hospitalizations	79.28	20.1	125.5	46.1	<0.005
Mortality (Rate)	4.33	2.3	7.19	4.8	<0.005
Hospital mortality (Rate)	12.52	4.1	17.8	7.4	<0.005
CO (mg/m^3)	278.7	58.48	363	102.20	<0.005
NO (μg/m^3)	13.97	2.85	29.67	14.63	<0.005
NO2 (μg/m^3)	27.62	5.54	37.75	7.8	<0.005
O3 (μg/m^3)	50.79	7.7	33.08	11.65	<0.005
PM10 (μg/m^3)	23.16	5.87	24.13	8.43	0.17
PM2.5 (μg/m^3)	14.1	4.24	14.55	5.12	0.32
SO2 (μg/m^3)	5.77	1.26	6.69	1.88	<0.005
Temperature (°C)	17.25	3.52	10.64	4.44	<0.005
Humidity (%)	75.79	7.84	76.27	6.94	0.40
Influenza (Rate)	6.27	20.37	72.09	121.45	<0.005

Av – Average; SD – Standard deviation.

Table 5. Relationships between each principal component (Comp) and their original pollutants variables: assumed variance in % (AsVar), significant pair-wise correlation coefficient (r) (P < 0.05) and overall proportions of explained variance.

	Comp1 Av.		Comp2		Comp3
Variable	AsVar	R	AsVar	R	AsVar	r
CO	49.3	0.87	6.65	0.07	16.71	0.13
NO2	51.01	0.90	−28.25	−0.26	−17.32	−0.13
O3	−42.39	−0.75	64.8	0.59	7.56	0.05
PM10	38.02	0.61	58.15	0.46	−66.65	−0.40
SO2	41.54	0.74	39.71	0.36	70.15	0.51
Overall%	62.11		16.93		11.12

Table 6. Output of the multivariable Poisson regression model predicting COPD cases with environmental factors.

Variable	Coefficient	Standard error	z	P-value	Lower 95% CI	Upper 95% CI
Intercept	3.22	0.018	178.44	<0.005***	3.18	3.25
Trend	−0.000	0.000	−13.41	<0.005***	−0.001	−0.000
City
Bilbao	Ref
Donostia	−1.21	0.022	−54.28	<0.005***	−1.257	−1.170
Gasteiz	−0.46	0.001	−26.57	<0.005***	−0.494	−0.427
Lag1_PC1	0.029	0.005	6.08	<0.005***	0.02	0.04
Mean Temp.	−0.161	0.009	−18.18	<0.005***	−0.178	−0144
Rate Influenza	0.114	0.006	18.59	<0.005***	0.102	0.126