Table 2.

Participant information and current identity at last visit before January 1, 2021 Overall, for those with recent visits only, and by initial social transition and gender.

	Total Sample	Recent Sample (with visits in 2019 or 2020)	Sample who initially socially transitioned before age 6	Sample who initially socially transitioned at 6 or later	Transgender girls (at recruitment)	Transgender boys (at recruitment)
Sample Size	317	291	124	193	208	109
% assigned male at birth	65.6%	65.3%	73.4%	60.6%	100%	0%
Mean age at first transition	6.5 years old	6.4 years old	4.3 years old	7.9 years old	6.2 years old	7.1 years old
Mean age at start of study	8.1 years old	8.0 years old	5.9 years old	9.5 years old	7.7 years old	8.7 years old
Average time since start of study	3.8 years	4.1 years	3.8 years	3.8 years	3.9 years	3.7 years
Average time since first transition	5.4 years	5.7 years	5.4 years	5.4 years	5.5 years	5.3 years
Current Identity
Binary Transgender	n=298; 94.0%	n=276; 94.8%	n=112; n=90.3%	n=186; 96.4%	n = 194; 93.3%	n = 104; 95.4%
Cisgender	n=8; 2.5%	n=6; 2.1%	n=7; 5.6%	n=1; 0.5%	n = 7; 3.40%	n = 1; 0.9%
Nonbinary	n=11; 3.5%	n=9; 3.1%	n=5; 4.0%	n=6; 3.1%	n = 7; 3.40%	n = 4; 3.7%