Table 3. Demographic characteristics of students in the study sample, overall percentages, and percentages by mode.

ESPAD®Italy 2015: Comparison study (P&P vs computerized administration mode)
	Sample (%) N = 1555	P&P (%) N = 784	Computerized (%) N = 771	Pearson chi2 (df)	p-value
Gender
Male	59.0	61.4	56.5	3.7 (1)	0.06
Female	41.0	38.6	43.5
Age (years)
15	17.9	17.6	18.2	2.9 (4)	0.58
16	23.4	24.0	22.8
17	22.0	21.3	22.7
18	18.9	18.0	19.8
19	17.8	19.1	16.5