Does beta-carotene prevent (cervical) cancer?
The perceived informativeness of a publication can be assessed by measuring the change in belief it induces among the scientific public, regarding a certain hypothesis. In a randomized trial, we studied the effect of empirical evidence from a clinical experiment and a case-control study on the hypothesis that beta-carotene protects against (cervical) cancer. The study population consisted of first authors of recently published patient-oriented research papers. They received an abstract of the clinical experiment, of the case-control study, or a “placebo” abstract. The latter was used to assess the specific effect of the empirical evidence in the two real studies. The change in belief in the hypotheses was expressed as a likelihood ratio (LR). All three abstracts led to a decrease in belief in the hypothesis. The median LRs of the abstracts of the experiment, case-control study and “placebo” were 0.33, 0.45, 0.75 respectively. This paper shows that the belief in a certain hypothesis is
