Impact of air pollutants on hospital admissions and economic losses of elderly patients with cardiovascular diseases in Southwestern China: A generalized additive model

Figures & data

Table 1. Information of air pollutant concentration, meteorological factors, and CVD in patients in Chengdu from 2014 to 2017

Variables	Mean ± SD	Value Range	Normal standard	Excess Days (%)
Air pollutants
AQI (ug/m^3)	99.927 ± 50.226	27 ~ 462	<100	559(39.09%)
PM2.5 (ug/m^3)	62.581 ± 44.567	6 ~ 396	<63	1038(38.53%)
PM10 (ug/m^3)	103.053 ± 65.669	16 ~ 562	<103	1180(39.65%)
SO2 (ug/m^3)	14.88 ± 7.239	4 ~ 61	<15	8(40.14%)
NO2 (ug/m^3)	52.038 ± 15.902	15 ~ 121	<52	78(51.05%)
CO (ug/m^3)	1079 ± 361	400 ~ 2800	<1079	0(43.22%)
O3 (ug/m^3)	92.706 ± 53.502	4 ~ 300	<93	568(45.73%)
Meteorological Factors
Temperature (°C)	16.793 ± 7.129	−1.9 ~ 29.8	< −5 and > 35	0(0%)
Air pressure (kPa)	95.104 ± 0.72	93.25 ~ 97.7	-	-
Humidity (%)	54.918 ± 15.493	15 ~ 96	<30 and > 80	161(11.26%)
Wind speed (m/s)	1.298 ± 0.455	0.3 ~ 3.4	-	-
Daily number of CVD Inpatient
Hypertension	109.269 ± 33.009	31 ~ 232	-	-
Coronary heart disease	104.658 ± 29.829	40 ~ 199	-	-
Myocardial ischemia	10.414 ± 4.398	0 ~ 27	-	-
Pulmonary heart disease	15.831 ± 5.511	3 ~ 39	-	-
Arrhythmia	12.305 ± 4.589	1 ~ 29	-	-

Table 2. Demographic, economic status, and the CVD inpatients’ costs in Chengdu by years

Variables	2014	2015	2016	2017
Elderly Population (age >60)	2492800	2598900	2995300	3039800
Daily GDP (yuan)	200.79	210.25	214.9	238.11
Average Medical Fee (yuan)	8329.471	8715.434	8803.879	8713.03
CHD	10068.864	10651.669	10533.948	10425.851
MI	5579.594	5360.809	5448.741	5081.868
PHD	5033.747	5932.459	6628.871	6572.663
hypertension	6810.467	7053.754	7247.005	7330.055
arrhythmia	8394.386	8887.796	9161.013	9374.628
Number of inpatients	89496	94407	93293	81075
CHD	34228	37906	39411	36734
MI	3244	4472	4069	2997
PHD	6162	6002	6115	4740
hypertension	42001	41490	38933	32333
arrhythmia	3861	4537	4765	4271
Hospitalization rate (%)	3.59	3.633	3.115	2.667

Table 3. The attributable risk and number, economic losses caused by air pollutants accounted for the CVD inpatients in Chengdu from 2014 to 2017

Diseases	Pollutants	AR	ARlower	ARupper	AN	Costs（million yuan）
CHD
	CO	0.09	0.06	0.13	61	0.64
	NO2	2.59	1.79	3.40	2042	21.28
	PM10	0.31	0.10	0.52	187	1.95
	SO2	6.54	4.65	8.46	4080	42.51
MI
	CO	0.16	0.09	0.23	11	0.06
	NO2	4.19	2.68	5.73	329	1.77
	O3	0.76	0.08	1.45	53	0.28
	PM10	0.79	0.39	1.19	48	0.26
	PM2.5	0.92	0.32	1.53	53	0.28
	SO2	7.49	3.96	11.14	477	2.56
PHD
	CO	0.14	0.07	0.21	16	0.1
	NO2	2.79	1.32	4.29	357	2.16
	PM10	0.75	0.39	1.11	78	0.47
	PM2.5	1.00	0.46	1.54	101	0.61
	SO2	3.86	0.54	7.28	400	2.42
Hypertension
	NO2	1.41	0.63	2.19	1149	8.17
	SO2	5.94	4.16	7.74	3996	28.41
Arrhythmia
	CO	0.09	0.03	0.16	7	0.06
	NO2	2.23	0.94	3.54	205	1.84
	PM10	0.36	0.02	0.71	25	0.22
	SO2	5.41	2.33	8.58	395	3.54

AR, Attributable risk; ARlower, Lower limit of AR’s 95% confidence interval; ARupper, Higher limit of AR’s 95% confidence interval; AN, Attributable number.

Figure 1. Correlation matrix between air pollutants, meteorological factors and CVD inpatients.

Figure 2. Percentage of change in the number of daily inpatients for CHD affected by air pollutants on the multi-day moving average lag line.

Figure 3. Percentage of change in the number of daily inpatients for hypertension affected by air pollutants on the multi-day moving average lag line.