Markov Chain-Based Acute Effect Estimation of Air Pollution on Elder Asthma Hospitalization

Table 1

Summary statistics of daily asthma hospital admission, air pollutant concentrations, and weather conditions from January 1, 2014, to December 31, 2014.

	N	Mean	SD	Min^a	Q1^a	Q2^a	Q3^a	Max^a	IQR^a
All elder	1567	4.29	2.30	0	4	3	6	13	3
Sex
Male	605	1.66	1.33	0	1	1	2	7	1
Female	962	2.64	1.76	0	2	13	10	2
Season^b
Warm	725	3.96	1.97	0	4	3	5	11	2
Cold	842	4.63	2.55	0	4	36	13	3
Air pollution concentrations (24 h average)
PM2.5 (μg/m^3)	—	72	52	10	38	55	88	396	50
PM10 (μg/m^3)	—	116	72	20	68	96	147	562	79
SO2 (μg/m^3)	—	17	10	3	11	15	21	61	10
NO2 (μg/m^3)	—	52	16	20	41	50	60	109	19
Meteorological measures
Min temperature	—	13	7	−2	7	15	20	24	13

PM2.5: particulate matter not greater than 2.5 mm in aerodynamic diameter; PM10: particulate matter not greater than 10 mm in aerodynamic diameter; SO₂: sulfur dioxide; NO₂: nitrogen dioxide; ^amin: minimum; Q1: 25th percentile; Q2: 50th percentile; Q3: 75th percentile; max: maximum; IQR: interquartile range (Q3–Q1). ^bCold season: from October to March; warm season: from April to September.