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U.S. Department of Health and Human Services

Post-Approval Studies (PAS)

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The FDA has the authority to require sponsors to perform a post-approval study (or studies) at the time of approval of a premarket approval (PMA), humanitarian device exemption (HDE), or product development protocol (PDP) application. Post-approval studies can provide patients, health care professionals, the device industry, the FDA and other stakeholders information on the continued safety and effectiveness (or continued probable benefit, in the case of an HDE) approved medical devices. This database allows you to search Post-Approval Study information by applicant or device information.

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Long-Term Study

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Application Number P970021 S014/ PAS001
Current Plan Approved 01/29/2008
Study Name Long-Term Study
General Study Protocol Parameters
Study Design Prospective Cohort Study
Data Source New Data Collection
Comparison Group No Control
Analysis Type Analytical
Study Population Adult: >21
Detailed Study Protocol Parameters
Study Design Description Prospective, multi-center, historically controlled study to confirm that the post-procedure incidence of amenorrhea observed with GYNECARE THERMACHOICE III (TC-III) Uterine Balloon Therapy System is comparable to that in the original THERMACHOICE I (TC-I) UBT System at 24 and 36 month post-procedure.

Study Population Description 381 subjects with the length of follow-up up to 36-month post-ablation procedure. Among the 381 subjects, 131 subjects were from TC-I study, and 250 subjects from TC-III study who will continue to be followed up to 36 months post-procedure.

Sample Size The study statistical hypotheses, for the rate of amenorrhea, at 24 and 36-month post-procedure are:

A power analysis estimated the sample size to be 121 subjects in each group to achieve 80% power to detect differences at 0.13 (this number was selected based on findings in the TC-I study).

Data Collection In addition to clinical visit at week 2, month 6 and 12 post-procedure, patients were contacted by telephone and/or by mail at 24 and 36 months following their ablation procedures to document long term response. If a patient reported any problems during the telephone contact that warranted further evaluation, a visit was scheduled to evaluate and treat the problem. The following information was obtained: menstrual bleeding and

pain patterns, incidence of pregnancy, contraception status, and incidence of any

adverse events and/or complications. Information was also be obtained related to incidence of

intervening gynecologic surgery such as hysterectomy or repeat ablations for continued or recurrent menorrhagia, and incidence of neoplasia or malignancy of the uterus. A quality-of-life questionnaire was completed at each clinical visit (week 2, month 6 and 12) and at 24 and 36 month post-procedure follow-up.

Follow-up Visits and Length of Follow-up Clinical visits were scheduled at week 2, month 6 and 12 months post-procedure. Telephone and/or mail interviews were done at 24 and 36 months following ablation procedure.

Final Study Results
Number of Patients 250
Number of Sites 13
Follow-up Rate 72.4%

Safety Findings The incidence of subjects with at least one adverse event was comparable in NPPC and PPC groups. A number of 56 subjects (45.2%) in NPPC experienced a total of 98 adverse events and a number of 57 subjects (45.2%) in PPC group experienced a total of 104 adverse events.

The incidence of subjects with severe adverse events was 12.1% (15 subjects) in NPPC group and 10.3% (13 subjects) in PPC group. The incidence of subjects with adverse events related to study device was 3.2% (4 subjects) in NPPC group and 5.6% (7 subjects) in PPC group. The incidence of subjects with adverse events related to study procedure was 6.5% (8 subjects) in NPPC group and 8.7% (11 subjects) in PPC group. Furthermore, there was no unanticipated adverse event reported in this study. The incidence of subjects with adverse events that needed action was 44.4% (55 subjects) in NPPC group and 42.1% (53 subjects) in PPC group.

The rate of adverse events was comparable between curettage and no curettage groups. The loss to follow-up was 11.6% overall, however long term-data is only available for 72.4%., making assessment of safety difficult

Effect Findings Analysis #1 (Missing data imputed as failures) ┬ĘC Primary Effectiveness Analysis

The success rate at 36-months was greater in TCIII group (26.8%, 67 of 250 subjects) compared to TCI group (13.0%, 17 of 131 subjects). The difference in amenorrhea rates between TCIII group and TCI group was statistically significant, based on a one-sided Chi-Square test (p=0.001). The one-sided 95% confidence interval (CI) for the difference (TCIII minus TCI) in proportion of amenorrhea rates between two groups was (7.1%, 100%). Therefore, the sponsor concluded that the difference in true success rates between TCIII and TCI groups was at least 7.1% with 95% confidence.

The one-sided 95% confidence interval for the success rate in TCIII group was (22.2% - 100%), while the one-sided 95% confidence interval for the success rate in TCI group was (8.4% - 100%).

The observed amenorrhea rates in TCIII and TCI groups, the associated one-sided 95% confidence intervals for these success rates, as well as the p-value and confidence interval for the comparison of the amenorrhea rates recorded in TCIII and TCI groups, are presented in Text Table 7 below

Strengths & Weaknesses Strengths include hypothesis driven sample size that was achieved for the duration of the study allowing greater than 80% power to detect differences, however the follow-up rate was 72.4%, decreasing the ability to accurately measure the rate and type of adverse events. Since treatment failures did not include those who had additional procedures, the ability to fully assess safety was minimized.

Label Changes Ethicon is required to submit revised labeling to include these long-term results as per their approval order. For the primary effectiveness endpoint, they should report the results using an ITT analysis where all treatment failures (including repeat EA/ hysterectomy) and loss to follow-up are counted as failures. Secondary endpoints may be reported using an evaluable analysis. Data tables should be revised to reflect the 24 and 36 month results including the revisions that were made in response to this deficiency

Long-Term Study Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
6 month report 01/04/2008 12/26/2007 On Time
24 month report 07/05/2008 07/02/2008 On Time
Final Report 11/30/2008 11/28/2008 On Time

Contact Us

Julie Unger
Project Manager, Post-Approval Studies Program
Food and Drug Administration
10903 New Hampshire Ave
WO66-4206v Silver Spring, MD

Phone: (301) 796-6134
Fax: (301) 847-8140

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