Preclinical research studies

Preliminary considerations

This category includes in vitro studies, ex vivo studies, in vivo studies in animal models and computer simulation/modelling.

The preclinical research studies submitted must include the items specified below, in accordance with complementary recommendations. Please access the CRIS guidelines ( for in vitro studies, and the ARRIVE guidelines ( for studies involving animal models, which have been used to prepare the present Guidelines.

Guidelines for abstract and paper preparation
• Title: it should rigorously describe the nature of the work, as well as explicitly mention, if applicable, whether it is an in vitro study, an ex vivo study, or an in vivo animal model.
• Introduction: this section should include a general summary of the topic, including the specific knowledge framework leading to the study rationale.
• Objective(s): the objectives and/or hypotheses of the study must be in line with the title of the work.
• Materials and methods: a full description of the materials (generic names of drugs and equipment must be used, unless brand identification is crucial for the study) must be provided, as well as the methods used (including type of study, study design, study groups and allocation criteria, sample size used, interventions performed, primary and secondary outcomes considered and the way in which they were measured).

1. When human cells were used, irreversible anonymisation of the donor must be ensured.

2. For in vivo studies, a description of the type of study, including the study groups and animal model, and a justification for the use of this study type shall be provided. Mention should be made of the way the animals were kept and the care provided to them, safeguarding their wellbeing. The methods of statistical analysis for comparison of primary and secondary outcomes between groups should be clearly indicated.
• Results: presentation of the primary and secondary outcomes of the study. The statistical significance of the results and their precision must be indicated.
• Discussion: interpretation must be consistent with the results, considering strong and weak points and integrating them with the existing relevant evidence. The limitations of the study should be indicated.
• Conclusions: they must briefly answer the questions initially posed. Only the conclusions that are directly based on the evidence generated by the study should be included.
• Final indication of funding sources (if any).
• Conflict of interest disclosure statement (if any).
• Research on animal models must have prior authorisation by the competent authority, which should be attached in the submission form in the field for that purpose. In the case of ex vivo studies and/or using in vitro human cells or tissues, these must have prior approval by the corresponding ethics committee, to be attached in a specific field in the submission form.