Clinical Trial Summary
Purpose & Background Endometriosis is a chronic inflammatory condition believed to affect
8-10% of reproductive-age women and an unmeasured number of gender-diverse people. It is a
common cause of pelvic pain and infertility, is now known to be associated with other
conditions such as heart disease and ovarian cancer and can have a devastating impact on a
woman's ability to function and achieve their full potential. It has been shown that
endometriosis and chronic pelvic pain are associated with considerable costs to the
health-care system in Canada. The in-patient hospital costs for chronic pelvic pain were
estimated to be $25 million/year and the total societal costs for endometriosis were
estimated to be 1.8 billion/year.
Standard therapies for endometriosis and pelvic pain include pain medications, hormonal
suppressive therapies, and surgery. There is a tertiary referral centre of excellence for
endometriosis at BC Women's Hospital (Centre for Pelvic Pain and Endometriosis), which
provides advanced surgical treatment of endometriosis and interdisciplinary care for patients
with endometriosis who have developed other pain comorbidities (e.g. due to central nervous
system sensitization). Central sensitization responds best to treatments targeted to the
nervous system, such as Interdisciplinary care includes pain education, physiotherapy, and
mindfulness-based cognitive therapies. One randomized trial has shown the benefit of an
interdisciplinary approach compared to standard treatment for the management of chronic
pelvic pain. At our centre, the investigators reported improvements in pain, mental health,
quality-of-life, and self-reported reduction in health care utilization, after
interdisciplinary care, utilizing our ongoing prospective registry. However, a formal
economic analysis of health care system utilization is required to quantify savings to the
health care system with an interdisciplinary approach to endometriosis.
Despite surgery being a common treatment of endometriosis, there is variability in outcome
and a gap is the lack of ability to predict outcomes after endometriosis surgery. For
example, utilizing self-reported outcomes from our registry, the investigators found that
poorer outcome after endometriosis surgery was found in patients with evidence of pain
comorbidities and central sensitization (as surgery is not a direct treatment of these
factors) (in preparation). Moreover, the investigators have a biobank and have been studying
biomarkers in surgically excised endometriosis tissue that may predict outcomes after
surgery. These biomarkers include somatic cancer driver mutations and neuroinflammation. The
investigators have preliminary data that suggests that these biomarkers may predict rates of
re-operation at the centre. Beyond self-reported outcomes and re-operation at the centre,
there is a need to assess health care utilization and re-operation occurring throughout the
province as additional outcomes that may be associated with our clinical and biomarker
predictors.
Finally, the SARS-CoV-2 (COVID-19) pandemic has had profound physical and mental health
effects on populations worldwide. However, there exists limited empirical evidence focusing
on the wellbeing of patients with endometriosis and/or pelvic pain during the public health
crisis. Herein, the investigators propose to compare a pre-pandemic cohort to a pandemic
cohort of subjects with endometriosis and/or chronic pelvic pain, again in terms of health
care system utilization.
Therefore, the overall purpose of this project is to assess health care utilization patterns
of patients with endometriosis in British Columbia, and to perform an economic analysis of
interdisciplinary care, evaluate clinical-biomarker predictors of surgical outcome, and
assess the impact of the covid pandemic. This will be achieved by linking Population Data BC
datasets to our ongoing prospective registry (H16-00264) and prospective and retrospective
biobanks (H14-03040, H17-00329).
HYPOTHESIS Aim 1: The investigators hypothesize that health care costs for patients being
cared for in our clinic will be higher in the three years preceding their time with us than
the years following their discharge. The investigators hypothesize that the overall cost of
the interdisciplinary clinic, including physiotherapist, counsellor and nurse salaries and
administrative support, will be less than overall cost savings to the system from reduced
utilization of health care resources after discharge.
Aim 2: The investigators hypothesize that comorbidities associated with central nervous
system sensitization and biomarkers including somatic mutations and local
neurogenesis/neuroinflammation are linked to persistent pain and disease recurrence after
endometriosis surgery, which results in increased risk of re-operation and health care
utilization after surgery.
Aim 3: The pandemic cohort will have increased health care system utilization, and also
poorer health system outcomes after care the centre.
Aim 4: People with endometriosis, utilizing different case definitions, will experience
higher health care use and worse pregnancy outcomes, compared to people without
endometriosis.
