Table 1.

Negative binomial regression models used to analyse factors associated with HRSV occurrence in Japan

		Model 1		Model 2		Model 3		Model 4
		Coeff.*	(95% CI)	Coeff.	(95% CI)	Coeff.	(95% CI)	Coeff.	(95% CI)
Variables
Temperature, °C
<23·3		Reference				Reference		Reference
⩾23·3 and <26·0		−0·04	(–0·13 to 0·05)			−0·09	(–0·18 to 0)	NS†
⩾26·0 and <28·2		0·43	(0·34 to 0·51)			0·43	(0·34 to 0·52)	NS
⩾28·2		0·80	(0·72 to 0·89)			0·88	(0·79 to 0·96)	NS
Relative humidity, %
<69				Reference		Reference		Reference
⩾69 and <73				0·05	(–0·04 to 0·13)	0·13	(0·04 to 0·22)	NS
⩾73 and <79				0·06	(–0·02 to 0·15)	0·26	(0·17 to 0·35)	NS
⩾79				0·05	(–0·04 to 0·14)	0·36	(0·27 to 0·45)	NS
T (°C) × H (%) (interaction term)
T < 23·3 × H < 69								Reference
23·3 ⩽ T < 26·0 × 69 ⩽ H < 73								0·04	(–0·27 to 0·35)
23·3 ⩽ T < 26·0 × 73 ⩽ H < 79								0·12	(–0·18 to 0·41)
23·3 ⩽ T < 26·0 × 79 ⩽ H								0·08	(–0·19 to 0·36)
26·0 ⩽ T < 28·2 × 69 ⩽ H < 73								−0·17	(–0·43 to 0·10)
26·0 ⩽ T < 28·2 × 73 ⩽ H < 79								−0·13	(–0·39 to 0·13)
26·0 ⩽ T < 28·2 × 79 ⩽ H								0·51	(0·25 to 0·77)
T ⩾ 28·2 × 69 ⩽ H < 73								0·26	(0·03 to 0·50)
T ⩾ 28·2 × 73 ⩽ H < 79								0·70	(0·44 to 0·95)
T ⩾ 28·2 × 79 ⩽ H								1·57	(1·23 to 1·90)
Year
2007		Reference		Reference		Reference		Reference
2008		0·26	(0·14 to 0·37)	0·34	(0·22 to 0·45)	0·25	(0·14 to 0·37)	NS
2009		0·16	(0·04 to 0·27)	0·14	(0·03 to 0·26)	0·16	(0·04 to 0·27)	NS
2010		−0·08	(–0·19 to 0·04)	0·08	(–0·03 to 0·20)	−0·11	(–0·23 to 0)	NS
2011		0·99	(0·87 to 1·1)	1·16	(1·05 to 1·28)	0·93	(0·81 to 1·04)	NS
2012		1·18	(1·06 to 1·29)	1·36	(1·24 to 1·47)	1·10	(0·99 to 1·22)	NS
2013		1·36	(1·25 to 1·48)	1·55	(1·44 to 1·67)	1·32	(1·21 to 1·44)	NS
Akaike's Information Criterion		11·36		11·48		11·35		11·31
Bayesian Information Criterion		−20 377·90		−19 891·03		−20 419·00		−20 519·60

CI, Confidence interval; T, temperature; H, relative humidity.

^*Coefficient of the variables.

^†NS, data not shown because model used the interaction term.