Donna Patricia Kelly's estimate
of the
prevalence of transsexualism in the United Kingdom
In October 2001, Donna Patricia Kelly e-mailed Lynn Conway some calculations she had just done regarding the prevalence of transsexualism in the UK. Donna's work provides additional evidence that past estimates are seriously in error by a huge factor. Lynn's and Donna's data and calculations suggest that the prevalence of transsexualism is at least 30 to 100 times as large as the "1 in 30,000" value most commonly proffered by the psychiatric establishment.
Donna's e-mail and her calculations follow below, along with Lynn's reply.

 Dear Professor Conway,

I'd very much appreciate it if you would take a little time to review this
data and, if you would be so kind, to comment on my conclusions. FYI, I'm
writing this on the urging of Christine Burns, who you may have heard of as
(until very recently) Vice-President of Press For Change (PfC) here in Great
Britain. She said: "I think it would be marvellous for you to compare notes
with Lynn .. who is similarly passionate about the topic."

FYI, I come from an science/engineering background, not a
medical/social/legal one. I'm a consulting systems architect, by trade.

Best Regards,
Donna Patricia Kelly


 Dear Donna Patricia,

Thanks so much for sending me your calculations of the prevalence of transsexualism in
the UK. Your results are remarkably close to mine for the US.
I've received lots of feedback since posting my original calculations in January of this year.
People here have been totally astonished that the prevalence of transsexualism is so very
much larger than the numbers promulgated by the psychiatric establishment via the media.
However, no one has been able to refute the estimates, since the data is so basic and the
calculations are so obvious and simple - once pointed out.
I'm very pleased to post your calculations here in my website. Together our calculations
show that the old "survey-based" prevalence data of the psychiatrists is totally erroneous
for both the US and the UK, being off by between one and two orders of magnitude.
I hope that many people in the UK will learn about your results and will think carefully
about the implications of the numbers there. Hopefully our calculations will encourage
more serious consideration of legal and social policies regarding a condition that is not
so very, very rare as once believed.
All the best,


by Donna Patricia Kelly
October 13, 2001
Copyright @ 2001, Donna Patricia Kelly.
All Rights Reserved.
This note presents my calculation of an estimated lower bound on the prevalence of transsexualism in the UK. In so doing I use the methodology of calculation used by Lynn Conway of the US, contained in her webpage at:

I. Estimating the prevalence of postop TS women in the UK:

The Interdepartmental Working Group to Parliament on Transsexual People, "Press for Change, however, estimate the figures at around 5,000 post-operative transsexual people." [in the UK].

I first assume that the vast majority of this 5,000 are T>F women, on the grounds that these figures are relatively easy to obtain as compared to for T>M men (where I know that a lot of surgery is documented as something other than Genital Reconstruction Surgery (GRS)). I also assume that there are quite a number of women who have had GRS and who simply don't show up in PfC surveys. 'coz it was done abroad and since then these women have simply blended in to the rest of society and no longer appear in *any* numbers.

Guesstimating that the incidence of transsexualism is about 3-4 times higher in born-males than born-females, then it seemed reasonable to take PfC's number as a baseline. That is, that there are about 5,000 T>F women in the UK who have had GRS and completed triadic therapy.

Of course, if that's the *total* number of all trans women in the UK, then given a possible GRS age group 18 to 60 years old, the prevalence of transexualism in the UK for T>F is about 1:3800, thus killing the very old 1:30,000 and the newer 1:11,700 (Goorens, 1993) prevalence figues stone dead right there.

The numbers crunch like this:

1. Number of people in UK (input): 56,000,000

2. Number of males in UK: 28,000,000
(using a ratio of 0.5 - input as given)

3. Number of males between 18 and 60: 18,760,000
(using a ration of 0.67 - input as given)

4. Number of born-males with GRS (input): 5,000

5. Prevalence of post_GRS women: 1:3752
(line 4 DIV line 3)

My calculated prevalence of 1:3750 is thus closely in agreement with Lynn Conway's 1:2500 ratio for the US.

II. Estimating a lower bound on the prevalence of transsexualism in the UK:

The prevalence of surgery is *not* the prevalence of transsexualism in the general population. The prevalence of transsexualism must be very substantially higher than the prevalence of those who have completed triadic therapy and are no longer suffering from Gender Identity Disorder (GID).

I use a 1:4 ratio of those who have completed triadic therapy versus those who have not. I would contend that this ratio is a very conservative one, and that Lynn Conway's 1:5 or 1:10 may indeed yet prove more representative. However, I chose a low number quite deliberately, while recognising that people may not have gone the whole route yet for many, many reasons (including, but not limited to):

* Many people simply get _no_ help from the National Health Service (NHS) in the UK;

* Their local Health Authority is contructively obstructive (mine certainly was - and is!);

* The NHS Gender Identity Clinics (GICs) are snail-like in responding to requests for help A year's wait just to get on to an eighteen month waiting list for a first appointment with an NHS psychiatrist is considered normal, as it multi-year waits after several years of RL to get to a first appointment with a surgeon;

* Many, many people cannot afford to do things privately - and thus *have* to got through the NHS;

* There's a heck of a lot of people struggling with gender problems to the point of a classic GID diagnosis and who are in tradic therapy, but who just haven't come to the point of surgery yet (yes, I know that it is self-diagnosed - but we still need the psychiatrist's imprimatur - after all, there are a few people who /are/ deluded);

* There's a heck of a lot of people struggling with gender problems but are not yet to the point of a diagnosis - but *will* be (I'm quite a good example of this. It took me 40+ years to figure it out!);

* There's a heck of a lot of older persons who are locked into their gender role by reasons of marriage, parenthood, employment, family relationships, long-term residency and known in their current gender role, and a myriad of other reasons. These people are real, do suffer from GID, and just don't feel that can do any thing about it;

* There is one *HECK* of a lot of people who are just plain lacking data - no internet access, no peers, nothing. They know 'something' is wrong, but not what.

Certainly, the main GIC (Charing Cross in London), saw 470 new cases in 1999, and has roughly 1000 people on its books at any one time. These tertiary referrals are from secondary (local) psychiatrists who in turn can only be seen via referral from the primary physician - the general practitioner. This excludes the other GICs, and also the many people who go private and pay for treatment themselves. That's a *lot*, compared to a total of 5000 post-op women over all time across the country.

To have the data, to be aware of what it means, to understand it, to act on it, and to complete triadic therapy with GRS? I believe that people who have gone the whole route are to be commended for moral integrity and toughness of spirit. I further submit that transsexual persons who have not yet gone the whole route should be supported, educated, and helped. I contend that there are at least 4 times as many people who are transsexual and have not yet completed triadic therapy as those who have. I can't substantiate this ratio, but no-one on the Press for Change email Forum challenged it.

I would make one further point. If the 5,000 is all that there is, then GRS would stop right now. But the rate is actually *increasing*! This can easily be seen by looking at the NHS GIC and GRS waiting lists and appointment delays.

Or to put it another way, I believe that the prevalence of transsexualism in the general population is (at least!) 4 times higher as the prevalence of those who are known to have had GRS.

Those are the only two numbers I can find that matter. 5,000. And 4:1. (and of course, the total population of the country).

Plugging these numbers in, we get:

6. Factor for born-males for whom GID not surfaced yet/stealth: 4.0000

7. Number of born-males for whom GID not surfaced yet/stealth: 20,000

8. Total number of born-males with GRS or will have GRS: 25,000

9. Prevalence of men with transsexualism: 1:750
(line 8 DIV line 3)

10. Factor for number of born-females with GRS or will have GRS 0.3300

11. Number of women with transsexualism: 8,250
(line 8 TIMES line 10)

12. Total population with transsexualism: 33,250

13. Prevalence of transsexualism within the total population: 1:1128

There needs to be a large error factor included here. Firstly, the 5000 post-op number is almost certainly too low. For many years, many British TS women went abroad for GRS, and simply blended, post-op. Secondly, I used a very conservative 1:4 'known post-op' to 'pre-op/has/will have GID/post-op&stealth' ratio. This could very well be too low. The social and monetary pressures (especially to use the NHS) here in the UK are really quite high, and the degree of personal resources (both fortitude and financial) required to complete triadic therapy are correspondingly high. Finally, I feel that the 1:3 ration for T>F versus T>M may also be too low. Certainly, several trans men of my acquaintance would put the ratio some where between unity and 1:2.

Given all, that, I still feel that the order of magnitude is /about/ right, even though there are real uncertainties in the data.

III. Conclusions:

My calculations therefore indicate that the number of transsexual people in the UK (including post-ops) is at least 1:1000 + or - a third or thereabouts. Or, to put it another way, I would be *very* surprised if it the prevalence were smaller than 1:1400, thus indicating a /minimum/ of about 35,000 trans people in the UK. This
number is likely to be substantially higher, perhaps 50,000 or even more. This engineering approach from basic demographics of course completely demolishes previous estimates which were a full order of magnitude smaller. Within the limits of data and the range of assumptions, this is *very* consistent with Lynn Conway's estimate for the US, where she calculates that "The prevalence of MtF transsexualism is thus greater than 1:500 and may be as high as 1:250".

"Donna Patricia Kelly" <>


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