Indiana University Health clinics will perform a randomized trial on Carevix™ vs tenaculum for IUD insertions.  All patients presenting for IUD insertion who fit inclusion criteria will be approached with this study.  Upon consent and review of the study information sheet (attached), they will be randomized to receive either the Carevix™ device or the tenaculum.  The patient will be consented for the IUD insertion as per normal clinic protocol and for the study as per study protocol.

Randomization will occur by blocked randomization to ensure that equal numbers are allocated to each group.  To accomplish this, a random number generator will be utilized to assign interventions, blocked in groups of 6, with stratified randomization for each individual clinic. All assignments then being put into sealed, opaque, sequentially numbered envelopes to be opened after the participant has consented to the study.  

Baseline characteristics and demographics will be collected on all participants enrolled, flow of participants through study using CONSORT diagram, number and reasons participants not randomized, and comparison between those randomized and those not randomized. All participants randomized reported according to Intention-to-Treat (ITT) principle. Number and reasons for switching from Carevix™ to the standard cervical traction device (tenaculum) will be reported. Device efficacy and usability outcomes, and patient pain assessments and outcomes to be compared by randomized arm, and within Carevix™ arm according to actual method used.

Power analysis: For our analysis, we used the Wilcoxon test instead of the t-test because the data is not normally distributed. Since the Wilcoxon test does not rely on the normality assumption, we used a simulation approach to estimate the power rather than the t-test power analysis. With the pilot trial dataset, we have 44% power to detect a 1.64-point difference in pain scores. If we increase the sample size to 100 patients (50 in each group), the power increases to 94% for detecting the same 1.64-point difference in pain scores.

In the pilot trial, we assessed pain scores at only 2 points: at cervix grasping and at completion of the procedure.  In the European trial, they analyzed pain at 7 different points during the procedure.  We will expand our pain assessment to include: at baseline (prior to any examination or procedure), at cervix grasping, at cervix traction, and at completion of the procedure.

Following completion of their procedure, the patient will also agree to fill out a survey (attached) asking their demographics and about their experience, which takes about 1-2 minute to complete.  The provider performing the procedure will finish the survey with provider-specific questions about bleeding, ease of use and satisfaction. The purpose of this study is to compare Carevix™ to the tenaculum and determine if the Carevix™ shows similar results in the United States population as it has in the European study and with IUD insertions.