On 2014 Jun 29, David Keller commented:

2014 United States Preventative Services Task Force report omitted mandatory analysis by sex

The following is quoted from the NIH Guideline on The Inclusion of Women and Minorities as Subjects in Clinical Research (1):

"In the case of any clinical trial in which women or members of minority groups will be included as subjects, the Director of NIH shall ensure that the trial is designed and carried out in a manner sufficient to provide for valid analysis of whether the variables being studied in the trial affect women or members of minority groups, as the case may be, differently than other subjects in the trial."

While this regulation may appear to apply to women subjects in clinical trials but not to men, implicit protection for men can be derived from the fact that all trial subjects are either men or women, so variables which affect men differently than women must necessarily also affect women differently than men. Thus, any tested variable which affects either sex differently actually affects both sexes differently, and must therefore be examined in a sex-specific analysis.

In their recently-updated report on multivitamin supplements, the United States Preventative Services Task Force (USPSTF) again found "insufficient evidence" to recommend their general use. The report dismissed the significant reduction in cancers seen in men taking multivitamins in both the SU.VI.MAX and the Physicians' Health Study, citing "the lack of effect in women" (2). This failure to analyze and apply the data separately for women and for men violates the NIH mandate to quantify gender differences in clinical trials.

The USPSTF should re-analyze the data separately for women and for men, which would almost certainly yield a "C" recommendation for men to discuss their diet and nutritional status with their doctors and consider taking a multivitamin supplement daily to reduce their risk of cancer, based on the significant findings of benefit in two large well-designed studies.

References

1) NIH website, accessed on 6/29/2014 http://grants.nih.gov/grants/funding/women_min/guidelines_update.htm

2) Moyer VA. Vitamin, Mineral, and Multivitamin Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: U.S. Preventive Services Task Force Recommendation Statement. Ann Intern Med. 2014 Feb 25. doi: 10.7326/M14-0198. [Epub ahead of print] PubMed PMID: 24566474.

On 2014 Jun 29, David Keller commented:

2014 United States Preventative Services Task Force report omitted mandatory analysis by sex

The following is quoted from the NIH Guideline on The Inclusion of Women and Minorities as Subjects in Clinical Research (1):

"In the case of any clinical trial in which women or members of minority groups will be included as subjects, the Director of NIH shall ensure that the trial is designed and carried out in a manner sufficient to provide for valid analysis of whether the variables being studied in the trial affect women or members of minority groups, as the case may be, differently than other subjects in the trial."

While this regulation may appear to apply to women subjects in clinical trials but not to men, implicit protection for men can be derived from the fact that all trial subjects are either men or women, so variables which affect men differently than women must necessarily also affect women differently than men. Thus, any tested variable which affects either sex differently actually affects both sexes differently, and must therefore be examined in a sex-specific analysis.

In their recently-updated report on multivitamin supplements, the United States Preventative Services Task Force (USPSTF) again found "insufficient evidence" to recommend their general use. The report dismissed the significant reduction in cancers seen in men taking multivitamins in both the SU.VI.MAX and the Physicians' Health Study, citing "the lack of effect in women" (2). This failure to analyze and apply the data separately for women and for men violates the NIH mandate to quantify gender differences in clinical trials.

The USPSTF should re-analyze the data separately for women and for men, which would almost certainly yield a "C" recommendation for men to discuss their diet and nutritional status with their doctors and consider taking a multivitamin supplement daily to reduce their risk of cancer, based on the significant findings of benefit in two large well-designed studies.

References

1) NIH website, accessed on 6/29/2014 http://grants.nih.gov/grants/funding/women_min/guidelines_update.htm

2) Moyer VA. Vitamin, Mineral, and Multivitamin Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: U.S. Preventive Services Task Force Recommendation Statement. Ann Intern Med. 2014 Feb 25. doi: 10.7326/M14-0198. [Epub ahead of print] PubMed PMID: 24566474.