Outcome measures
The primary outcome measure was proportion of patients with a reduction
of postmenstrual spotting of more than 2 days at each follow-up point
and without the need for additional therapy, using the ITT analyses, we
called it the effective rate. If an IUD was removed because of symptoms
or if additional therapies were applied, we considered this as a
failure. We defined postmenstrual spotting as brownish discharge for
more than two days at the end of the menstruation, with a total duration
(menstruation and spotting) of more than seven days, or intermenstrual
blood loss that starts after the end of the
menstruation.3 Menstrual characteristics were
self-recorded in a menstruation diary at 3, 6, 9 and 12 months after
inclusion and uploaded in an electronic data system (Figure S2).
Secondary outcome measures were:
menstrual characteristics (eg,
duration of menstruation, total days of blood loss per month, presence
of spotting, amenorrhea was defined as no menstruation/irregular
bleeding or spotting for at least 3 months19 and need
for treatment because of gynecological complaints); direct medical costs
(including the costs of preoperative examination, medical consumption
and the surgery); Complications and side effects were evaluated using
digital questionaires, these included questions on urinary tract injury,
fever, infection, breast pain, pelvic pain, emotional wings, depression,
weight changes and acne;
MRI measurements at baseline were: presence of a niche (depth of ≥ 2mm),
width, depth, length and thickness of residual myometrium (TRM), uterine
position. Measurements were performed in line with previous
studies,17, 20 and as recommended by a group of
international experts (see Figure S3).21