The life expectancy of gay men : does HIV make much difference?
   
  The background
   
 

In 1997 a team from Vancouver, Canada, published a methodology for estimating the impact of the HIV epidemic on the average life expectancies of gay and bisexual men.  The team used infection and mortality data from Vancouver and for the period 1987 to 1992.

It had long been difficult for HIV/AIDS researchers to estimate, with gratifying certainty, the impact of the disease on the general population.  The difficulties were compounded when estimating the impact on the sub-group of gay and bisexual men because there was little consensus on just how large this sub-group was.

For example, should figures be based on:
  • the 2-3% of men who will be open open about their current homosexual behaviour in a survey, or
  • the larger group (4-6%) of men who will be open about having had a same-sex relationship during the past 5 to 10 years, or
  • the still larger again group of men that will -- at some time in their life -- do so at least once?

Whatever figure is used, and whatever is not, has a considerable impact on epidemiological models for the spread and containment of the disease.  This is because of an inherent multiplier effect whenever a small minority is examined and when the base assumptions thereby vary by a factor of -- in this case -- up to 4 or 5.

Attempting to simply side-step any debate about the size of the sub-group of men that are gay/bisexual and yet still be able to provide meaningful data; Hogg et al published a methodology that made the estimations across a range.  Readers were able to select their own preferred size for the sub-group.  For their purposes, the researchers took figures of 3%, 6% and 9% as the proportion of men that could be classified as gay or bisexual and used these to generate the reported outcomes.

The outcomes reported in this paper have been seized upon by many anti-gay political groups, and in turn quoted ad nauseum on many occasions.  The paper has been quoted for as varying reasons as marriage legislation around same-sex couples, influencing sex education in schools and providing reasoning behind ex-gay programs.  In general, a quote of "homosexuality cuts 20 years off your life" or "homosexuality is more dangerous than smoking" is usually attributed to this paper; particularly as the use of a parallel claim by the virulently anti-gay (and disreputable) psychologist Paul Cameron has been exposed as a fiction and fallen into disuse.

(As a general rule: when the term "20 years off your life" or similar is used, the claimant is referring to this work by Hogg and his colleagues.  Use of words such as "the average age is only 42 years" points to Paul Cameron.  Hogg's paper was valid, although now clearly out of date and sorely misused -- it requires a considered response.  Cameron's scurrilous work is without any merit, and needs only be rejected out of hand.)

In the time since the data for Hogg's paper was collected a great deal has changed around the demographics of the epidemic.  For example, Hogg assumed that 95% of HIV-related deaths were within the homosexual sub-group; and this has both dramatically fallen over the past 15 years and/or was never applicable in the first instance for areas outside Vancouver.  Likewise, improved health management since the mid-1990's has considerably extended the average lifespan of HIV-positive individuals.

This page updates the work of Hogg and his colleagues using HIV/AIDS infection data and mortality tables for the 2002/03 period.  The base data is for the entire United States, rather than just the the city of Vancouver.  We have also examined the impact on three racial sub-groups of gay and bisexual men.

Feel free -- really -- to go through this with a fine tooth comb.
The spreadsheet is provided for a reason, and that is to be
completely open with the data and workings.
                                                                      grantdale
   
  Results
   
 

The following table presents both the figures given by Hogg et al in their 1997 paper (using data from 1987-92) and the comparison figures calculated using data from 2002-03.  As can be seen, the latter figures present a dramatic improvement in the average life expectancy of gay and bisexual men when compared to the earlier estimation.
   
    Loss in expectation of life due to HIV/AIDS    
    Hogg et al (1994)
Vancouver, 1987-92		 Revised figures
United States, 2002-03		  
  Gay / bisexual males as a proportion
of the adult male population		      
       3% 20.3 years 2.2 years  
       6% 11.7 years 1.0 years  
       9% 8.0 years 0.7 years  
   
 

 

Using 5.2% as the proportion of adult men that are behaviourally homosexual, as reported by Laumann et al (1994), the revised calculations indicate a difference of 1.2 years -- some 14 months -- as the average loss of life expectation for gay and bisexual men when compared to their heterosexual peers.  This is the impact of sexually acquired HIV.

  Loss in expectation of life due to HIV/AIDS.
Gay/Bisexual men at 5.2% of the population.
       All races 1.2 years  
       White 0.9 years  
       Black 7.7 years  
       Hispanic 1.9 years Figures calculated
from 2002/03 data.
 

 

However, as is obvious, the spread of HIV is uneven among gay and bisexual men; just as it is in the overall male population.  In particular, black Americans have substantially worse outcomes both in terms of infection rates to begin with and in access to health care after infection.

At only 12% of the adult male population, black Americans now comprise half of all new infections.  Half of these are heterosexually transmitted, or as a result of sharing needles during injecting drug use; but infection rates by male-to-male sexual contact are some 4 to 5 times higher among black gay men when compared to white gay men.  Overall, the infection rate is 7 times higher for black males than for their white peers. (The difference in rates are even higher between white and black women).

Having taken the higher risk of infection into account, black Americans -- both gay and straight -- are further disadvantaged in life expectancy through having lower average access to medical care that can prolong life.

The results are rather stark, as the following graph indicates:
   
 

   
 

Looking at a range of 3% to 6% of black men as gay or bisexual -- a range that can be considered to cover those who are more than incidentally homosexual -- the figures suggest that there is a loss of somewhere between 7 to 15 years in average life expectancy.  This compares very unfavourably with white gay men, who present figures of 1 to 2 years.

Yet, this type of difference is (appallingly) in keeping with average life expectancies for black straight men and white straight men.  For these two groups the difference is also 7 years (68 years versus 75 years).

(One wonders why there are not more calls for black straight men to "give up their lifestyle" -- apart, I presume, from it being an utterly absurd and offensive suggestion.)
 
   
  The Spreadsheet
   
 

You may download the Excel97 spreadsheet used to calculate data on this page.

The usual disclaimer applies: do so at your own risk.

I have been running this spreadsheet on my PC and the spreadsheet has been checked for viruses but I make no claim to it being virus free.  If it isn't, your problems will be the least of my concerns.  Perhaps it contains errors, although I believe it does not.  I also make no claim about the spreadsheet being suited to any purposes.  In any case, the spreadsheet remains my property although I am making it available for your personal use.  Should you have some other use in mind you will need to contact me at grantdalexgw@hotmail.com and ask for my permission.  That permission will not be forthcoming unless I am assured your purposes are ones that I could support.

If all the above is acceptable, feel free to download and enjoy fiddling around with a few scenarios.

Gay Life Expectancies revisited: an update of the work of Hogg et al

The spreadsheet is approx. 316 KB in size. It is designed to be viewed with a screen resolution of 1024 x 768.

   
  Differences, Changes, Notations etc
   
 

The methodology used to prepare this page mirrors that used by Hogg et al in preparing their paper.  However a great deal more information is now available and this is reflected in what we are able to show.  Please note our heavy use of the words 'may' and 'could'.

  1. We have examined data for the entire United States; rather than the population of Vancouver, Canada.

  2. Our data used the most recent publicly available data at June 2005.  Due to reporting lags; our data is based on figures for the 2002-03 period.  Hogg et al used data from 1987-92.

  3. Hogg assumed that 95% of Vancouver's HIV-related deaths were within the deemed population of gay and bisexual men.  This was a valid assumption in the late 1980's, but even at that time researchers anticipated that this proportion would fall as this new disease moved outwards from the groups first affected.  An assumption of 95% is certainly not applicable today.

    For the United States as a whole; male-to-male sexual contact now figures in 45% of HIV-related deaths for adult men and injecting drug use (IDU) by heterosexual males provides a further 31%. Male-to-Female sexual contact has moved from almost nil in the late 1980's to some 12% today.  This single change -- from an assumed 95%, to the figures now tracked by the CDC -- does have a significant impact on the overall results.

  4. As with Hogg, we have applied the overall life expectancy tables to all non-HIV related deaths.  While this provides a valid method for examining the impact of HIV/AIDS alone, it does not -- and cannot -- attempt to measure the true average life expectancy of any particular population group used with those overall life tables.

    For that to be done, risk factors other than that of HIV/AIDS would need to be considered.  Unusual circumstances can become critical when examining small populations of minorities; particularly for minorities within minorities (such as black gay men).

  5. As with Hogg, we can only use data that is currently available.  Deaths from HIV/AIDS reflect infection rates from prior years, rather than what may be applicable today.  For older population cohorts these figures will be reasonably accurate, but a different regime around the epidemiology of HIV may be revealed for younger cohorts at some time in the future.  This could have either a positive or negative influence.

  6. Similarly, today's life expectancy data reflects the medical care that is currently available.  It would be valid to assume that future medical care will prolong the average life expectancy of HIV-positive people however we have not assumed that in our calculations.  As such, our estimations can be viewed as conservative -- eventual outcomes may not as severe, particularly for younger age groups.

  7. We cannot predict how HIV may evolve as a disease.  The virus may become more or less benign and in turn alter any impact on average life expectancy.
   
  Citations: Hogg et al (1997)
   
 

The authors of the original paper may be contacted at:

British Columbia Centre for Excellence in HIV/AIDS, St Paul's Hospital,
University of British Columbia, Vancouver Canada,
e:mail bobhogg@hivnet.ubc.ca

The full title of the original paper is:
Hogg RS, Strathdee SA, Craib KJ, O'Shaughnessy MV, Montaner JS, Schechter MT.
Modelling the impact of HIV disease on mortality in gay men.
International Journal of Epidemiology 1997;26(3):657-71. Jun;26(3):657-61.

The paper may be downloaded from:

Modelling the impact of HIV disease on mortality in gay and bisexual men

After their attention was bought to the misuse of their 1997 work by anti-gay groups in several countries, a follow-up letter by Hogg and his colleagues was published in 2001:
Letter to the Editor: Gay life expectancy revisited

A year earlier, Hogg et al had also provided an update that noted the life expectancy of HIV-positive gay and bisexual males had already seen a considerable increase with the introduction of several new drugs. In turn, this improved the average life expectancy for the entire gay and bisexual population.  Comparing data of 1990/92 and 1995/97, average life expectancy increased from 57 years to 61 years.  These improved outcomes have been further extended in the decade since.

Modern antiretroviral therapy improves life expectancy of gay and bisexual males
in Vancouver's West End.
   
  Citations: references used for this update
   
 

Centers for Disease Control and Prevention,
HIV/AIDS Surveillance Report
2003 (Vol. 15). 2004: Table 7

National Vital Statistics Reports,
Life table for males: United States, 2002
Vol. 53, No. 6, November 10, 2004: Table 2

U.S. Census Bureau,
Population by year of age (5 races and hispanic origin)
SC-EST2004-AGESEX_RES.csv
http://www.census.gov/popest/datasets.html

National Center for Health Statistics,
Deaths from 113 selected causes: Human immunodeficiency virus (HIV) disease (B20-B24)
Worktable Orig291.F

Centers for Disease Control and Prevention,
MMWR 2004; 53:1108
Table 2
   
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