BACKGROUND:

The P value is the most widely used method of estimating the statistical significance of any finding, however, in recent years the debate over the P value has been increasingly intensified due to the low credibility and reproducibility of many studies.

OBJECTIVE:

To describe the current state of the concept of the value of P and the statistical significance (Null Hypothesis Significance Testing (NHST), specify the most important problems and point out the solutions proposed in the literature for their best use.

METHODOLOGY:

Search in MEDLINE and Google Scholar, with the terms: “NHST”, “Statistical significance; P value ”in English and Spanish, carried out from 2018-2019, limited to articles published from 2005 to 2019, and a narrative-type review with manual search. Articles on methodology were preferably selected.

RESULTS:

The global search yielded 1411 articles, 875 from PubMed and 536 from Google Scholar. 817 were excluded by duplication, 155 without full access, 414 from clinical trials, without statistical methodology. The 25 selected articles were the reason for the analysis.

CONCLUSIONS:

The concept of the value of P is not simple, and it has several fallacies and misinterpretations that must be taken into account to avoid them as much as possible. Recommendations: Do not use "statistically significant" or "significant", replace the threshold of 0.05 with 0.005, report accurate P values with 95% CI, relative risk, odds ratio, effect size or power, and Bayesian methods.