Table 1.

Age distribution of the overall study population and stratified by sex

	Controls	Provisional tic disorder	Tourette syndrome	P
Total
n	1460	230	535
Age, years (mean±SD)	7.4±3.2	7.0±2.3	9.4±2.8† *	<0.001‡
4–6 years	737 (50.5)	108 (47.0)	68 (12.7)
7–12 years	575 (39.4)	116 (50.4)	399 (74.6)
13–15 years	135 (9.2)	5 (2.2)	49 (9.2)
16–18 years	13 (0.9)	1 (0.4)	19 (3.6)
Boys
n	780	173	444
Age, years (mean±SD)	7.3±3.1	7.0±2.3	9.5±2.8†*	< 0.001‡
4–6 years	384 (49.2)	83 (48.0)	52 (11.7)
7–12 years	325 (41.7)	85 (49.1)	334 (75.2)
13–15 years	67 (8.6)	5 (2.9)	41 (9.2)
16–18 years	4 (0.5)	0 (0)	17 (3.8)
Girls
n	680	57	91
Age, years, (mean±SD)	7.4±3.3	7.1±2.3	8.9±2.8*†	< 0.001‡
4–6 years	353 (51.9)	25 (43.9)	16 (17.6)
7–12 years	250 (36.8)	31 (54.4)	65 (71.4)
13–15 years	68 (10.0)	0 (0)	8 (8.8)
16–18 years	9 (1.3)	1 (1.8)	2 (2.2)

Data are presented as n (%) for each age group.

*Statistically significant compared to controls.

†Statistically significant compared to the provisional tic disorder group.

‡Indicates significant difference between the three groups.