i n f o p o e m s
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gmail.com) and Associate InfoPOEMS Editor Amy H. Wahlquist, MS, from www.infopoems.com. InfoPOEMs®
are created by experts who continuously survey medical journals worldwide. They identify and summa-
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InfoPOEMs®, please visit www.infopoems.com.
STUDY LEVELS OF EVIDENCE (LOE) tivitamin component (this study is
From the Centre for Evidence-Based Vitamins E and C and still ongoing). Complete follow-up
Medicine, Oxford. For the most up-to- Selenium Do Not Reduce occurred for 98% of men at 8 years.
date levels of evidence, see www.cebm.
net/levels_of_evidence.asp) Risk of Prostate or Total Individuals assessing outcomes
Cancer in Men remained masked to treatment
Therapy/Prevention/Etiology/Harm: group assignment. Using intention-
1a: Systematic reviews of randomized Clinical Question to-treat analysis, neither vitamin
controlled trials Do vitamins E and C or sele- E nor C had any significant effect
1b: Individual randomized controlled nium, alone or in combination, on the incidence of prostate can-
1c: All or none randomized controlled
reduce the risk of prostate cancer or cer, total cancer, or all-cause mor-
trials total cancer in men? tality. Neither vitamin significantly
2a: Systematic reviews of cohort studies reduced the individual incidence of
2b: Individual cohort study or low- Bottom Line colorectal, lung, bladder, or pancre-
quality randomized controlled
In this large, well-designed, ran- atic cancer. In secondary outcome
2c: “Outcomes” research, ecological
studies domized trial, vitamins E and C and analyses, vitamin E was associated
selenium, alone or in combination, with a significantly increased risk
Diagnosis: did not reduce the risk of prostate of hemorrhagic stroke. The study
1a: Systematic review of level-1 cancer, total cancer, or all-cause was designed to have a greater than
diagnostic studies mortality. (LOE = 1b) 80% power to detect a 13% reduc-
1b: Independent blind comparison
of an appropriate spectrum
tion in the risk of total cancer. A
of consecutive patients, all of Study Design related article in the same jour-
whom have undergone both the Randomized controlled trial nal (Lippman SM, et al. JAMA.
diagnostic test and the reference
standard, or a clinical decision rule
(double-blinded) 2009;301:39-51) also reported that
not validated on a second set of neither selenium nor vitamin E,
patients Funding alone or together, reduced the risk
1c: Absolute SpPins and SnNouts Industry + govt of prostate cancer.
2a: Systematic review of level >2
2b: Independent blind or objective
comparison, study confined
Concealed Gaziano JM, Glynn RJ, Christen WG, et al. Vita-
to a narrow spectrum of study
mins E and C in the prevention of prostate and
individuals, or a diagnostic clinical
total cancer in men. The Physicians’ Health
rule not validated in a test set
Setting Study II randomized controlled trial. JAMA.
Outpatient (any) 2009;301:52-62.
1a: Systematic review of inception
cohort studies Synopsis
1b: Individual inception cohort study