New Test Method for the Determination of the Sample Size to Use in Testing Medical Devices
1. Scope
1.1 This specification covers the determination of the number of samples that must be tested in static testing of medical devices. It is intended to help the user compute an appropriate number of specimens for pilot, comparative or performance testing of a device. 1.2 This current version applies to medical devices, such as those in F04.22 Arthroplasty Subcommittee. 1.3 This specification does not apply to the determination of the sample size required during fatigue testing. 1.4 This test method does not provide advice to the user in how to interpret the results after the pilot, comparative or performance testing has been performed. This test method is only a statistical tool. 1.5 The user needs to make certain decisions, such as what is an appropriate predicate device (section 4.9) and what is an appropriate zone of indifference (section 6). The user may need to adjust those selections depending upon the type of testing or the type of implants, as these selections can greatly affect the results. The user must justify and report those selections. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Keywords
medical devices, sample size
Rationale
In the Spring of 2019, a version of this document was balloted as part of a revision to F1378 (Total Shoulder Specification). At the Spring, 2019 F04.22 meeting, we decided that it was best to have a separate document to help determine the sample size for the testing of arthroplasty devices. It was therefore extracted from the previously proposed revision of F1378. For the Spring, 2019 ballot, there were 2 negatives and 4 comments. The negative from John Goode was determined to be persuasive. The below includes many of the suggested changes from the negatives and comments and will be balloted at the subcommittee level. If accepted, individual arthroplasty specifications could then be modified to reference this test method. In the future this test method could be used by other subcommittees.
