Multiple regression coefficient of sociodemographic factors affecting smoking.

Table 4: Multiple regression coefficient of sociodemographic factors affecting smoking.

Statistical indicator		Regression coefficients
*Excluded variables*	Predictive variables	Unstandardized Coefficients		Standardized Coefficients	t	Sig
Sleep Exercise Daily coffee consumption Working hours Age Nationality Occupation Specialty Specialty subgroups Health sector Monthly income	Predictive variables	B	Std. Error	Beta	t	Sig
	Constant	-0.513-	0.136		-3.766	0.000^**
	Presence of smoking among friends	0.249	0.061	0.229	4.092	0.000^**
	Presence of smoking among family	0.210	0.053	0.221	3.952	0.000^**
	Number of on-calls per month	0.050	0.018	0.151	2.688	0.008^**
*R²= 0.131 (13.1%), F = 14.098, P = 0.000*

R²: Square correlation; F for ANOVA; ^**significant at 0.01 level; ^*significant at 0.05 level.

N.B: Predictors: Gender, age, education, occupation and medical problems variables were excluded from the model.