Table 2.

Comparison of urinary cotinine levels between the groups of the current study

Intervention groups	Pre-intervention urinary cotinine levels			Post-intervention urinary cotinine levels					Difference between pre- and post-intervention
	L4	L5	L6	L1	L2	L4	L5	L6	Mean ± SD	Median (IQR)
Group one	0	7	13	0	0	5	13	2	0.80 ± 0.6	1 (0–2)
Group two	0	12	8	1	0	4	13	2	0.70 ± 0.3	0 (0–4)
Group three	0	14	16	0	1	2	13	4	0.85 ± 0.3	1 (0–4)
Number of subjects	0	28	37	1	1	11	39	8	Kruskal-Wallis ANOVA value (P value)	6.08 (0.4)
Percentage of subjects	0	38	62	1.7	1.7	18.3	65	13.3
Chi-squared (P value)		6.91 (0.032)				6.27 (0.9)

SD = standard deviation; IQR = interquartile range; 0 = no detectable level of tobacco use; L1 (10–30 ng/mL) and L2 (30–100 ng/mL) = no use of tobacco products; L3 (100–200ng/mL) = cut-off level and positive for tobacco use; L4 (200–500 ng/mL), L5 (500–1000ng/mL) and L6 (>1000ng/ml) = use of tobacco product; group one = laser group; group two = counselling group; group three = laser + counselling group; ANOVA = analysis of variance.