Eligibility criteria

The adequate description of eligibility criteria allows the reproducibility of a study.

The questions that need to be answered by the reviewers are the following:

1) are the eligibility criteria for inclusion and exclusion broad and clearly stated

2) is the condition used in the selection clear, such as tests, scores, signs, and symptoms

3) is the group homogeneous

4) are the characteristics of the patients representative of those of the clinical question

5) are the baseline characteristics reported

6) were patients similar at baseline in terms of demographics and comorbidity?

The authors have to describe how the confounding factors were controlled (exclusion criteria).

For example, some of the variables controlled could be: demographic characteristics (age and sex), habits (smoker, drinker), use of medications (steroids), comorbidities (diabetes mellitus, morbid obesity, neoplasm), general conditions of quality of life (unemployed), pregnancy, previous surgeries, degree of severity of the disease, and early or late presentation. The adequate description of eligibility criteria allows the reproducibility of the study.

Once the eligibility criteria for patients or a sample of the population has been described, it is necessary to examine the sample size calculation.

In clinical trials, requirements that must be met for an individual to be included in a study. These requirements help make sure that patients in a trial are similar to each other in terms of specific factors such as age, type and stage of cancer, general health, and previous treatment. When all participants meet the same eligibility criteria, it gives researchers greater confidence that results of the study are caused by the intervention being tested and not by other factors.