Daily Meteorological Parameters Influence the Risk of Intracerebral Hemorrhage in a Subtropical Monsoon Basin Climate

Figures & data

Table 1 Statistical Descriptions of Meteorological Parameters and Air Pollutants Between December 30, 2013, and December 31, 2019, in Chengdu

Variables	Units	Min	P25	P50	P75	Max	IQR
Daily meteorological parameters
Daily mean TEM	°C	−1.9	9.8	17.3	22.9	29.8	13.1
Daily max TEM	°C	3.1	14.3	22.0	28.0	36.7	13.7
Daily min TEM	°C	−6.5	7.3	14.2	19.7	25.9	12.4
Daily mean PRE	hPa	932.5	944.9	950.9	956.9	977.0	12.0
Daily max PRE	hPa	936.3	946.9	953.6	959.5	980.4	12.6
Daily min PRE	hPa	928.7	942.2	948.2	953.8	973.3	11.6
Daily mean RHU	%	42.0	77.0	83.0	89.0	99.0	12.0
Daily SSD	h	0.0	0.0	1.1	5.4	12.6	5.4
Meteorological parameters fluctuation
Diurnal variation of TEM	°C	0.7	4.8	7.6	10.9	20.0	6.1
Diurnal variation of PRE	hPa	1.7	3.9	4.9	6.2	16.7	2.3
Day-to-day variation of TEM	°C	0.0	0.4	0.9	1.7	5.6	1.3
Day-to-day variation of PRE	hPa	0.0	0.8	1.8	3.2	16.0	2.4
Day-to-day variation of RHU	%	0.0	2.0	5.0	9.0	43.0	7.0
Day-to-day variation of SSD	h	0.0	0.1	1.8	4.4	12.6	4.3
Air Pollutants
PM2.5	μg/m^3	4.0	30.0	46.0	73.0	396.0	43.0
NO2	μg/m^3	12.0	38.0	48.0	59.0	121.0	21.0
O3	μg/m^3	4.0	49.0	78.0	124.0	300.0	75.0

Abbreviations: TEM, temperature; PRE, atmospheric pressure; RHU, relative humidity; SSD, sunshine duration; PM_2.5, particulate matter with aerodynamic diameter ≤2.5μm; NO₂, nitrogen dioxide; O₃, ozone; IQR, interquartile range.

Figure 1 Spearman correlation analysis of meteorological parameters and air pollutants. The correlation coefficient of two variables marked as “×” is greater than 0.9.

Abbreviations: TEM, temperature; PRE, atmospheric pressure; RHU, relative humidity; SSD, sunshine duration; PM_2.5, particulate matter with aerodynamic diameter ≤2.5μm; NO₂, nitrogen dioxide; O₃, ozone; Corr, correlation coefficient.

Figure 2 The forest diagram shows the effect of daily meteorological parameters on intracerebral hemorrhage (ICH) occurrence risk in the single-factor model. The red line represents daily meteorological parameters, and the blue line represents meteorological parameters fluctuation. (A) Odds ratios of ICH onset risk in all study months. (B) Odds ratios of ICH onset risk in cold months. (C) Odds ratios of ICH onset risk in warm months. *P<0.05; **P<0.01.

Abbreviations: TEM, temperature; PRE, atmospheric pressure; RHU, relative humidity; SSD, sunshine duration.

Table 2 The Effect of Daily Meteorological Parameters on the ICH Onset Risk for All Study Months in the Two-Factor Model (or, 95% CI)

Variables	Adjusted for Daily Mean TEM	Adjusted for Daily Mean PRE	Adjusted for Daily Mean RHU	Adjusted for Daily SSD
Lag0
Daily mean TEM	—	0.953 (0.916, 0.991) *	0.941 (0.911, 0.971) **	0.942 (0.912, 0.973) **
Daily mean PRE	1.010 (0.991, 1.030)	—	1.025 (1.009, 1.041) **	1.023 (1.008, 1.040) **
Daily mean RHU	0.998 (0.987, 1.009)	1.001 (0.990, 1.012)	—	0.999 (0.988, 1.010)
Daily SSD	1.007 (0.976, 1.038)	1.009 (0.979, 1.041)	1.017 (0.986, 1.048)	—
Lag1
Daily mean TEM	—	0.978 (0.940, 1.018)	0.963 (0.933, 0.995) *	0.957 (0.926, 0.989) **
Daily mean PRE	1.013 (0.994, 1.032)	—	1.018 (1.002, 1.035) *	1.022 (1.006, 1.038) **
Daily mean RHU	0.995 (0.984, 1.005)	0.997 (0.986, 1.008)	—	0.993 (0.982, 1.004)
Daily SSD	0.967 (0.938, 0.998) *	0.967 (0.938, 0.998) *	0.971 (0.942, 1.002)	—
Lag2
Daily mean TEM	—	0.990 (0.951, 1.029)	0.982 (0.951, 1.015)	0.976 (0.944, 1.009)
Daily mean PRE	1.006 (0.987, 1.026)	—	1.009 (0.993, 1.025)	1.014 (0.997, 1.030)
Daily mean RHU	0.997 (0.986, 1.008)	0.998 (0.987, 1.009)	—	0.994 (0.983, 1.005)
Daily SSD	0.956 (0.926, 0.986) **	0.954 (0.925, 0.985) **	0.956 (0.927, 0.986) **	—

Notes: *P<0.05; **P<0.01.

Abbreviations: TEM, temperature; PRE, atmospheric pressure; RHU, relative humidity; SSD, sunshine duration; OR, odds ratio; CI, confidence interval.

Table 3 The Effect of Day-to-Day Variation of Meteorological Parameters on the ICH Onset Risk for All Study Cases in the Two-Factor Model (or, 95% CI)

Variables	Adjusted for Day-to-Day Variation of TEM	Adjusted for Day-to-Day Variation of PRE	Adjusted for Day-to-Day Variation of RHU	Adjusted for Day-to-Day Variation of SSD
Lag0
Day-to-day variation of TEM	—	1.064 (0.989, 1.146)	1.073 (0.997, 1.156)	1.076 (1.000, 1.157) *
Day-to-day variation of PRE	1.028 (0.993, 1.064)	—	1.032 (0.998, 1.068)	1.033 (0.999, 1.069)
Day-to-day variation of RHU	1.002 (0.988, 1.016)	1.003 (0.990, 1.017)	—	1.005 (0.991, 1.018)
Day-to-day variation of SSD	0.998 (0.971, 1.025)	1.001 (0.975, 1.028)	0.999 (0.972, 1.026)	—
Lag1
Day-to-day variation of TEM	—	1.014 (0.944, 1.089)	1.042 (0.970, 1.120)	1.026 (0.955, 1.101)
Day-to-day variation of PRE	1.032 (0.996, 1.068)	—	1.036 (1.001, 1.072) *	1.033 (0.998, 1.069)
Day-to-day variation of RHU	0.987 (0.973, 1.001)	0.988 (0.974, 1.001)	—	0.988 (0.974, 1.002)
Day-to-day variation of SSD	1.001 (0.975, 1.028)	1.004 (0.978, 1.030)	1.008 (0.982, 1.036)	—
Lag2
Day-to-day variation of TEM	—	0.977 (0.906, 1.053)	0.974 (0.903, 1.051)	0.975 (0.905, 1.050)
Day-to-day variation of PRE	1.009 (0.975, 1.044)	—	1.006 (0.973, 1.041)	1.008 (0.974, 1.042)
Day-to-day variation of RHU	1.005 (0.991, 1.019)	1.004 (0.990, 1.017)	—	1.002 (0.988, 1.016)
Day-to-day variation of SSD	1.022 (0.996, 1.050)	1.021 (0.995, 1.049)	1.021 (0.994, 1.048)	—

Note: *P<0.05.

Abbreviations: TEM, temperature; PRE, atmospheric pressure; RHU, relative humidity; SSD, sunshine duration; OR, odds ratio; CI, confidence interval.

Figure 3 Summary of the relationship between daily meteorological parameters and intracerebral hemorrhage (ICH) onset risk in a subtropical monsoon basin climate. The blue solid line indicates that the parameter negatively correlated with the ICH occurrence, and the red solid line represents a positive correlation between the parameter and ICH onset. The black solid circle means the parameter is an independent risk factor, and the black dotted circle shows the parameter is a non-independent risk factor.

Abbreviations: TEM, temperature; PRE, atmospheric pressure; SSD, sunshine duration.