birdwatcher (![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
birdwatcher) wrote2007-11-20 05:36 am
birdwatcher) wrote2007-11-20 05:36 am
Гпобальное потепление
CHICAGO TRIBUNE -- The United Nations' AIDS-fighting agency plans to issue a report on Tuesday acknowledging that it overestimated the size of the epidemic and that new infections with the deadly virus have been dropping each year since they peaked in the late 1990s.
Until recently, most national estimates were made by giving anonymous blood tests to some young women who came into public health clinics because they were pregnant or feared they had a sexually transmitted disease; those results were expanded with statistical models.
But epidemiologists have realized that such a method — usually applied in big urban clinics because it was more efficient — oversampled prostitutes, drug abusers and city sophisticates with many lovers and ignored rural women. Then the statistical extrapolations exaggerated those errors.
Until recently, most national estimates were made by giving anonymous blood tests to some young women who came into public health clinics because they were pregnant or feared they had a sexually transmitted disease; those results were expanded with statistical models.
But epidemiologists have realized that such a method — usually applied in big urban clinics because it was more efficient — oversampled prostitutes, drug abusers and city sophisticates with many lovers and ignored rural women. Then the statistical extrapolations exaggerated those errors.