EVALUATION OF TREATMENTS
FOR ENDOMETRIOSIS
In women with endometriosis, the efficacy of treatment
has most often been measured by means of assessments
of pain and infertility. Three factors are
critical in evaluating pain in women with endometriosis
during treatment trials: a validated pain scale, a
time-dependent evaluation, and consideration of the
effects of placebo or sham surgery.
3
The measurement of fertility is also used to assess
the effect of treatment. Although the occurrence of
pregnancy may seem an objective criterion, it has several
characteristics that make its use as an outcomevariable problematic. First, multiple confounding factors often affect a woman’s fertility. In addition, pregnancy
(like pain) is a time-dependent phenomenon.
That is, the pregnancy rate will vary depending on
the duration of follow-up. Finally, endometriosis rarely
causes an absolute inability to conceive; thus, the
rate of pregnancy in untreated women must be used
as a basis for comparison.
4
In an attempt to predict prognosis, the severity of
endometriosis has been classified by numerous staging
systems. The revised classification system of the American
Society for Reproductive Medicine, currently
widely used, consists of four stages (I through IV),
with higher-numbered stages representing more extensive
disease of the reproductive structures.
5,6
However,
the classification scheme is limited in that it is
designed to predict only the likelihood of future fertility.
There is no correlation between the stage of
disease and the degree of pain or the prognosis with
treatment.