Table 2. Univariable logistic regression analysis for low sensitivity of internet-based surveillance

Variable	Odds ratio	95% Confidence interval	p-value	N missing
Log (Population size)	0.843	0.669–1.059	0.140	0
Log (GDP per capita)	0.758	0.604–0.918	0.010	0
Income classification1)	0.076	0.004–0.384	0.013	0
Log (HDI)	0.038	0.005–0.236	0.001	0
Night-time light level2)	0.973	0.945–0.995	0.038	0
Health expenditure (2015 US$)	0.937	0.799–1.063	0.358	1
IHR score	0.970	0.951–0.989	0.003	3
Urban land use	0.779	0.435–1.041	0.251	0

Low sensitivity was defined as the number of unexplained death cases in the first reports were equal to ten or higher.
Income-based country classification by World Bank (4 categories; high income, upper middle income, lower income, low income). The odds ratio was for high and upper middle-income levels compared to low and lower middle-income levels as a reference.
Night-time light level values range from 0 to 255, and higher value indicates higher brightness form artificial light.
GDP, gross domestic product; HDI, human development index; IHR, International Health Regulation.