Saved analyses
Median change after about 12 months of hormone treatment, adult transgender women
Question: After about a year of testosterone suppression and estrogen, how much do testosterone, hemoglobin, muscle size, lean mass and strength change in transgender women?
Result: Median change after about 12 months: testosterone -95.6% (12 groups), hemoglobin -7%, muscle size -6.4%, lean body mass -4%, strength +0.5% (range -7.1% to +2%).
Operation: For each measure, the median of the percentage changes across included study groups; range = lowest and highest group. Testosterone change computed from each group's before and after values; other changes as printed by Harper et al., or computed from before and after means where not printed.
Scope: Study groups of adult, mostly untrained transgender women in Europe and the U.S., 1999-2020.
Estimates with uncertainty
| Estimate | Value | Uncertainty | Method | n |
|---|
| Testosterone |
-95.6 % change after about 12 months (range -97.8 to -48.8) |
range |
Median of the percentage changes in the included study groups; the range is the lowest and highest study group. |
12 |
| Hemoglobin (red blood cells) |
-7 % change after about 12 months (range -14 to -4.6) |
range |
Median of the percentage changes in the included study groups; the range is the lowest and highest study group. |
5 |
| Muscle size |
-6.4 % change after about 12 months (range -9.5 to -1.5) |
range |
Median of the percentage changes in the included study groups; the range is the lowest and highest study group. |
4 |
| Lean body mass |
-4 % change after about 12 months (range -5.4 to -0.8) |
range |
Median of the percentage changes in the included study groups; the range is the lowest and highest study group. |
8 |
| Strength |
0.5 % change after about 12 months (range -7.1 to 2) |
range |
Median of the percentage changes in the included study groups; the range is the lowest and highest study group. |
5 |
View this analysis
- Participants were adults and mostly untrained; no study measured athletes or adolescents through this design.
- Small groups (11 to 249 women) and few groups per measure (4 to 12).
- About 12 months only; Harper et al. found strength, lean mass and muscle area still above women's after 36 months, but with too few studies to chart.
How much faster transgender women in the Air Force ran 1.5 miles than the average woman, by time on hormones
Question: How much faster than the average Air Force woman under 30 did transgender women run 1.5 miles before and during hormone treatment?
Result: Transgender women ran 1.5 miles 147 seconds faster than the average Air Force woman before hormones (20.8% faster), 97 s after under a year, 64 s at 1-2 years and 90 s at 2-2.5 years (95% CI 10 to 169; 11.8% faster).
Operation: Table 4 differences from the average woman, sign reversed so faster is positive; speed advantage = average woman's time / transgender women's time - 1.
Scope: 46 transgender women in the U.S. Air Force, 2016-2018 records.
Estimates with uncertainty
| Estimate | Value | Uncertainty | Method | n |
|---|
| averageWomanSeconds: 855, speedAdvantagePct: 20.8, timeOnHormones: Year 0 (before), transWomenSeconds: 708 |
147 seconds faster than the average Air Force woman over 1.5 miles (95% CI 121 to 173) |
95% confidence interval |
Roberts et al. (2021) Table 4 mean difference from the average Air Force woman under 30, sign reversed so faster is positive; 95% CI from the paper. |
— |
| averageWomanSeconds: 855, speedAdvantagePct: 12.8, timeOnHormones: Year 0-1, transWomenSeconds: 758 |
97 seconds faster than the average Air Force woman over 1.5 miles (95% CI 70 to 124) |
95% confidence interval |
Roberts et al. (2021) Table 4 mean difference from the average Air Force woman under 30, sign reversed so faster is positive; 95% CI from the paper. |
— |
| averageWomanSeconds: 855, speedAdvantagePct: 8.1, timeOnHormones: Year 1-2, transWomenSeconds: 791 |
64 seconds faster than the average Air Force woman over 1.5 miles (95% CI 26 to 101) |
95% confidence interval |
Roberts et al. (2021) Table 4 mean difference from the average Air Force woman under 30, sign reversed so faster is positive; 95% CI from the paper. |
— |
| averageWomanSeconds: 855, speedAdvantagePct: 11.8, timeOnHormones: Year 2-2.5, transWomenSeconds: 765 |
90 seconds faster than the average Air Force woman over 1.5 miles (95% CI 10 to 169) |
95% confidence interval |
Roberts et al. (2021) Table 4 mean difference from the average Air Force woman under 30, sign reversed so faster is positive; 95% CI from the paper. |
— |
View this analysis
- Air Force members, not competitive athletes; fitness tests measure endurance, not maximal speed.
- The comparison is an Air Force-wide average for women under 30, not matched controls; training was not recorded.
- Few women reached the 2-2.5 year band, so its confidence interval is wide (10 to 169 seconds).
- Results may differ for people who began treatment early in puberty, as the authors note.
Push-ups, sit-ups and run: transgender women vs the average Air Force woman, by time on hormones
Question: How did transgender women's push-up, sit-up and run advantages over the average Air Force woman change with time on hormones?
Result: Push-ups: 14.8 more than the average woman before hormones, 2.1 more (not significant) at 2-2.5 years. Sit-ups: 7.9 more before, 0.9 fewer (not significant) at 2-2.5 years. Run: 147 seconds faster before, 90 seconds faster (significant) at 2-2.5 years.
Operation: For each measure and time band: transgender women's mean, the implied average woman's value, the printed difference and its 95% CI, the advantage in percent (run: % higher speed; push-ups and sit-ups: % more repetitions than the average woman), the paper's own percentage convention (difference / transgender women's mean), and whether the 95% CI excludes zero.
Scope: 46 transgender women in the U.S. Air Force, 2016-2018 records.
View this analysis
- Push-up and sit-up advantages were no longer statistically significant at 2-2.5 years; the run advantage was.
- Weight gain on hormones can lower push-up scores, which the authors say may understate the remaining advantage.
Every study group behind the 12-month medians
Question: Which study groups and values make up each 12-month median, and which were left out and why?
Result: 34 included rows and 8 excluded rows across five measures.
Operation: Lists every row of the Harper et al. table with its percentage change and inclusion flag.
Scope: All rows of harper-groups.
View this analysis
- Values are as printed in the review; we did not re-extract every one from the original studies. Scharff et al. (2019) and Wiik et al. (2020) were cross-checked against the original papers.
harper-12-month-study-groups.csv
text/csv · 4.5 KB (4,574 bytes)
