; and (2) issue any requests for proposals the Secretary determines appropriate for such implementation. (e) Termination of clinical trials (1) Clinical guideline requirements or excessive risk The Secretary may terminate the clinical trials required by subsection (a) if the Secretary determines that the Department of Veterans Affairs is unable to meet clinical guideline requirements necessary to conduct such trials or the clinical trials would create excessive risk to participants. (2) Completion upon submittal of final report The Secretary may terminate the clinical trials required by subsection (a) upon submittal of the final report required under subsection (f)(2). (f) Reports (1) Periodic reports During the five-year period beginning on the date of the commencement of clinical trials required by subsection (a), the Secretary shall submit periodically, but not less frequently than annually, to the Committee on Veterans’ Affairs of the Senate and the Committee on Veterans’ Affairs of the House of Representatives reports on the implementation of this section. (2) Final report Not later than one year after the completion of the five-year period specified in paragraph (1), the Secretary shall submit to the Committee on Veterans’ Affairs of the Senate and the Committee on Veterans’ Affairs of the House of Representatives a final report on the implementation of this section. 5. Administration of study and clinical trials (a) Demographic representation In carrying out the study required by section 3 and the clinical trials required by section 4, the Secretary shall ensure representation in such study and trials of demographics that represent the population of veterans in the United States, as determined by the most recently available data from the American Community Survey of the Bureau of the Census. (b) Data preservation The Secretary shall ensure that the study required by section 3 and the clinical trials required by section 4 include a mechanism to ensure— (1) the preservation of all data, including all data