CHANGES IN SIZE AND DEMOGRAPHIC COMPOSITION OF TRANSGENDER AND GENDER NON-BINARY POPULATION RECEIVING CARE AT INTEGRATED HEALTH SYSTEMS

ABSTRACT Background Transgender/ gender non-binary (TGNB) people are an understudied population that appears to have undergone changes in both its size and demographic composition; however, population-level data on the magnitude of these changes are sparse. Methods Electronic health records from Kaiser Permanente health plans in Georgia and Northern and Southern California were used to identify TGNB individuals who sought care from January 2006 through December 2014, and the data were analyzed by year, site and age, and by sex assigned at birth. Results In 2006 the number of TGNB people (and corresponding 95% confidence intervals) per 100,000 population were 3.5 (1.9, 6.3) in Georgia, 5.5 (4.8, 6.4) in Southern California and 17 ( 16 , 19 ) in Northern California. In 2014, these frequencies increased to 38 (32, 45), 44 (42, 46) and 75 (72, 78) per 100,000 population, respectively. When analyzed by age, the most rapid increase was observed among persons 18 to 25 years old, and this increase accelerated after 2010. The ratio of transmasculine to transfeminine persons also changed from 1:1.7 in 2006 to 1:1 in 2014 overall, and from 1:1 in 2006 to 1.8:1 in 2014 among persons under the age of 18 years. Conclusions This analysis confirms previous observations that the proportion of TGNB people is growing especially among young adults. The composition of TGNB population is also changing from predominantly transfeminine to roughly 1:1 overall, and predominantly transmasculine in children and adolescents.