title: The debate about p-values.
abstract: The p-value is the most widely used statistical concept in biomedical research. Recently, there are controversies over its utility and over the possible relationship between p-value misuse and the relatively high proportion of published medical research that cannot be replicated. In this paper, we introduce the p-value in layman's terms and explain its randomness and limitations. However, we also point out that the available alternatives to p-value suffer similar limitations. We conclude that using p values is a valid way to test the null and alternative hypotheses in clinical trials. However, using the p-value from a single statistical test to judge the scientific merit of a research project is a misuse of the p-value; the results of inference tests using p-values need to be integrated with secondary results and other data to arrive at clinically valid conclusions. Understanding the variability and limitations of the p-value is important for the interpretation of statistical results in research studies.
authors.affiliation: VA (Veterans Affairs) Cooperative Studies Program Palo Alto Coordinating Center, VA Palo Alto Health Care System, Palo Alto, CA, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Biomedical Data Science, Stanford University, Stanford, CA, USA.
authors.forename: Ilana
authors.initials: I
authors.lastname: Belitskaya-Levy
keywords: hypothesis testing; inferential statistics; p-value; scientific repeatability; statistical significance