Relationship between emergency care utilization, ambient temperature, and the pollution standard index in Taiwan

Figures & data

Table 1. Variables descriptive analysis.

Variables	ECU	AT	PSI	TSP
Mean	2114.74	23.52	3.49	93.00
Median	2101.03	24.27	2.89	93.82
Maximum	3220.83	29.93	14.46	147.12
Minimum	1467.78	14.75	0.11	47.00
Standard Deviation	301.40	4.34	2.61	22.21
Observations	180	180	180	180

Notes:

ECU was emergency care utilization. AT was ambient temperature. PSI was pollution standard index. TSP was total suspended particulate (μg/m3).

Figure 1. Emergency care utilization (ECU), Ambient temperature (AT), pollution standard index (PSI) and Total suspended particulates (TSP) the from 1998 to 2012.

Notes: Emergency care utilization was ECU. Ambient temperature was AT. Pollution standard index was PSI. Total suspended particulates was TSP.

Table 2. ADF unit root test.

Variables	Level				1st difference				Order of integration
	Intercept		Trend and intercept		Intercept		Trend and intercept
	t-statistic	p-values	t-statistic	p-values	t-statistic	p-values	t-statistic	p-values
ECU	− 2.014	0.28	− 9.513	<0.01	− 5.82	<0.01	− 5.844	<0.01	I(1)
AT	− 3.003	0.04	− 3.406	0.05	− 10.327	<0.01	− 10.314	<0.01	I(1)
PSI	− 1.396	0.58	− 2.216	0.48	− 9.275	<0.01	− 9.237	<0.01	I(1)
TSP	0.309	0.978	− 6.267	<0.01	− 8.726	5.08E-13	− 8.701	<0.01	I(1)

Notes:

ECU was emergency care utilization. T was ambient temperature. PSI was pollution standard index. TSP was total suspended particulate (μg/m³).

Table 3. Johansen cointegration test.

Variables	Trace test		Max-eigenvalue test
	Statistic	Prob.**	Statistic	Prob.**
ECU-AT-PSI	72.640	0.00	64.778	0.00
ECU-AT-TSP	110.674	0.00	106.061	0.00

Note:

ECU was emergency care utilization. AT was ambient temperature. PSI was pollution standard index. TSP was total suspended particulate (μg/m3).

** denotes rejection of the hypothersis at the 5% significance level.

Table 4. VAC model results using ECU with AT and PSI.

	ECU	AT	PSI
Long-term equilibrium relationship
Cointegrating vector	1.000	1931.069 [14.556]	− 11.825 [− 0.110]
Adjustment factor	− 0.012 [− 1.816]	− 0.00045 [− 13.250]	0.00024 [3.095]
Cointegrating Equation	ECU = 47715.150 – 1931.06 × (AT) + 11.825 × (PSI) + residual
Short-run dynamics
D(ECU(-1))	− 0.498 [− 6.243]	0.001 [3.14]	− 0.000177 [− 0.183]
D(ECU(-2))	− 0.357 [− 4.108]	0.001 [2.218]	0.000455 [0.431]
D(ECU(-3))	− 0.298 [− 3.508]	0.001 [1.690]	− 0.000283 [− 0.274]
D(ECU(-4))	− 0.167 [− 2.353]	0.001 [2.200]	0.001 [1.068]
D(AT(-1))	− 35.498 [− 3.960]	0.414 [8.740]	− 0.401 [− 3.693]
D(AT(-2))	15.570 [1.517]	0.642 [11.848]	− 0.075 [− 0.605]
D(AT(-3))	27.095 [1.972]	0.536 [7.385]	− 0.262 [− 1.573]
D(AT(-4))	− 1.992 [− 0.134]	0.334 [4.268]	− 0.334 [− 1.862]
D(PSI(-1))	− 9.835 [− 1.515]	− 0.030 [− 0.870]	− 0.681 [− 8.654]
D(PSI(-2))	− 7.247 [− 0.948]	− 0.073 [− 1.825]	− 0.469 [− 5.061]
D(PSI(-3))	5.056 [0.653]	− 0.109 [− 2.669]	− 0.430 [− 4.590]
D(PSI(-4))	8.658 [1.317]	− 0.064 [− 1.832]	− 0.250 [− 3.144]
Constant term	6.167 [0.403]	− 0.123 [− 1.529]	− 0.017 [− 0.092]

Notes:

ECU was emergency care utilization. AT was ambient temperature. PSI was pollution standard index. [ ] is the z value, black fonts represent that the significance level of 5 % or better.

Table 5. VAC model results using ECU with AT and TSP.

	ECU	AT	TSP
Long-term equilibrium relationship
Cointegration vector	1.000	1698.664 [14.6643]	3.221 [0.33405]
Adjustment vector	− 0.008 [− 1.03]	− 0.000548 [− 13.631]	0.001621 [3.595]
Cointegrating Equation	ECU = 2561.88 – 1698.664 × (T) − 3.221 × (TSP) + residual
Short-run dynamics
D(ECU(-1))	− 0.506 [− 6.439]	0.001 [3.74460]	− 0.001 [− 0.29640]
D(ECU(-2))	− 0.363 [− 4.14369]	0.001 [1.84606]	0.007 [1.44998]
D(ECU(-3))	− 0.268 [− 3.10790]	0.000 [0.81391]	0.003 [0.60357]
D(ECU(-4))	− 0.148 [− 2.12168]	0.001 [1.91383]	0.004 [1.13443]
D(AT(-1))	− 39.795 [− 4.30690]	0.411 [8.86801]	− 4.575 [− 8.79286]
D(AT(-2))	− 0.386 [− 0.03258]	0.627 [10.5507]	− 3.085 [− 4.62878]
D(AT(-3))	15.376 [0.99524]	0.514 [6.62313]	− 1.772 [− 2.03717]
D(AT(-4))	− 1.003 [− 0.06431]	0.266 [3.40092]	− 2.203 [− 2.50830]
D(TSP(-1))	− 4.227 [− 3.05574]	− 0.004 [− 0.55444]	− 0.529 [− 6.78582]
D(TSP(-2))	− 1.900 [− 1.26853]	− 0.007 [− 0.89157]	− 0.347 [− 4.10795]
D(TSP(-3))	0.567 [0.39879]	− 0.034 [− 4.73215]	− 0.448 [− 5.59713]
D(TSP(-4))	0.499 [0.37793]	− 0.026 [− 3.99605]	− 0.211 [− 2.83667]
Constant term	5.685 [0.37799]	− 0.132 [− 1.75142]	− 0.383 [− 0.45190]

Notes:

ECU was emergency care utilization. AT was ambient temperature. TSP was total suspended particulate (μg/m3). [ ] is the z value, black fonts represent that the significance level of 5 % or better.