Temporal Changes in the Size and Composition of Transgender and Gender Nonconforming Population in the Kaiser Permanente System, 2006 to 2014 Open Access

Rechler, Willi (Spring 2020)

Permanent URL: https://etd.library.emory.edu/concern/etds/sn009z747?locale=en


Background: Transgender and/or gender-nonconforming (TGNC) people are an understudied but sizable minority, and studies show that the size of the TGNC population is increasing. Current studies do not estimate the proportion of TGNC people in the general population. The present study utilizes existing transgender health research program at Kaiser Permanente. This study examines the temporal changes in the proportion TGNC people among individuals enrolled in three Kaiser Permanente sites, and to investigate whether the trends differ by age and geographic location, and by sex assigned birth status.

Methods: This study uses data from the Study of Transition Outcomes and Gender (STRONG), an electronic health record-based cohort of TGNC people enrolled in Kaiser Permanente in Georgia and California from January 2006 through December 2014. We calculated the proportion of TGNC individuals among all Kaiser Permanente enrollees by year and by site. The temporal changes in the assigned male at birth (AMAB)-to- assigned female at birth (AFAB) ratio according to participants’ age were then examined. Group specific changes were studied for trend. The average age at index was calculated for each calendar year by AMAB/AFAB status. The slope was estimated as a regression coefficient representing an average annual change in the age of presentation.

Results: The proportions of STRONG cohort members among all enrollees increased at all sites. The regression analyses yielded slope estimates of 7.07 (95% CI: 6.77-7.38) for KPNC, 4.58 (4.22-4.94) for KPSC and 4.14 (3.55-4.73) for KPGA. From 2006 to 2014 the AFAB:AMAB ratio among members of all ages changed from  1: 1.67 to 1:1. The AFAB:AMAB ratio in the under 18-year age group changed from 1.0 in 2006 to 1.8 in 2014 (P-trend < 0.001). The average age at initial presentation significantly decreased, with an annual change of ‑0.98 years (95% CI: -1.34, -0.62) for AMAB and ‑1.38 years (95% CI: -1.90, -0.85) for AFAB.

Conclusions: This analysis shows that the proportion of individuals who identify as TGNC increased significantly at all Kaiser Permanente sites, and the TGNC population appears to be getting younger. The AFAB:AMAB ratio, especially in persons under 18-years of age, is changing as well.

Table of Contents

Introduction - Page 1

Methods - Page 3

Results- Page 5

Discussion- Page 7

References- Page 11

Tables and Figures- Page 15

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