Table 5: Multiple regression analysis of different factors.

BETA 𝑡 𝑃 -level

Age−0.020−0.2850.777
BMI0.0590.8110.422
Vitamine deficiency−0.022−0.3140.755
Duration of smoking−0.025−0.2190.827
Number of cigarettes per day0.3373.2510.002
Cotinine−0.119−0.4170.679
Cotinine/creatinine ratio0.7862.9160.005

𝑅 = 0 . 9 0 9 , 𝑅 2 = 0 . 8 2 7 , Adjusted 𝑅 2 = 0 . 7 9 6 , 𝐹 = 2 6 . 6 3 8 , 𝑃 < 0 . 0 0 0 0 0 , sd. error of estimate: 0.469.
BMI: body mass index.