Table 2.

Checklist of Methodological and Reporting Aspects for Articles Submitted to Circulation Research That Report Studies of Experimental Interventions in Animals

Methodological and Reporting AspectsDescription of Procedures
Study design◻ The experimental group(s) have been clearly defined in the article, including number of animals in each experimental arm of the study.
◻ An overall study timeline is provided.
◻ The protocol was prospectively written.
◻ The primary and secondary end points are specified.
◻ For primary end points, a description is provided as to how the type I error multiplicity issue was addressed (eg, correction for multiple comparisons was or was not used and why). (Note: correction for multiple comparisons is not necessary if the study was exploratory or hypothesis generating in nature).
◻ A description of the control group is provided including whether it matched the treated groups.
Inclusion and exclusion criteria◻ Inclusion and exclusion criteria for enrollment into the study were defined and are reported in the article.
◻ These criteria were set a priori (before commencing the study).
Randomization◻ Animals were randomly assigned to the experimental groups. If random assignment was not used, adequate explanation has been provided.
◻ Type and methods of randomization have been described.
◻ Allocation concealment was used.
◻ Methods used for allocation concealment have been reported.
Blinding◻ Blinding procedures with regard to masking of group/treatment assignment from the experimenter were used and are described. The rationale for nonblinding of the experimenter has been provided, if such was not performed.
◻ Blinding procedures with regard to masking of group assignment during outcome assessment were used and are described.
◻ If blinding was not performed, the rationale for nonblinding of the people analyzing outcome has been provided.
Sample size and power calculations◻ Formal sample size and power calculations were conducted before commencing the study based on a priori determined outcome(s) and treatment effect(s), and the data are reported.
◻ If formal sample size and power calculation was not conducted, a rationale has been provided.
Data reporting◻ Baseline characteristics (species, sex, age, strain, chow, bedding, and source) of animals are reported.
◻ The number of animals in each group that were randomized, tested, and excluded and died is reported. If the experimentation involves repeated measurements, the number of animals assessed at each time point is provided for all experimental groups.
◻ Baseline data on assessed outcome(s) for all experimental groups are reported.
◻ Details on important adverse events and death of animals during the course of the experiment are reported for all experimental groups.
◻ Numeric data on outcomes are provided in the text or in a tabular format in the main article or as supplementary tables, in addition to the figures.
◻ To the extent possible, data are reported as dot plots as opposed to bar graphs, especially for small sample size groups.
◻ In the online supplemental material, methods are described in sufficient detail to enable full replication of the study.
Statistical methods◻ The statistical methods used for each data set are described.
◻ For each statistical test, the effect size with its standard error and P value is presented. Authors are encouraged to provide 95% confidence intervals for important comparisons.
◻ Central tendency and dispersion of the data are examined, particularly for small data sets.
◻ Nonparametric tests are used for data that are not normally distributed.
◻ 2-sided P values are used.
◻ In studies that are not exploratory or hypothesis generating in nature, corrections for multiple hypotheses testing and multiple comparisons are performed.
◻ In negative studies or null findings, the probability of a type II error is reported.
Experimental details, ethics, and funding statements◻ Details on experimentation, including formulation and dosage of therapeutic agent, site and route of administration, use of anesthesia and analgesia, temperature control during experimentation, and postprocedural monitoring, are described.
◻ Both male and female animals have been used. If not, the reason/justification is provided.
◻ Statements on approval by ethics boards and ethical conduct of studies are provided.
◻ Statements on funding and conflicts of interests are provided.
  • The above checklist is a modified version of a similar checklist promulgated by Stroke in 2011 and revised and expanded in 2016. The purpose of the checklist is to provide important metrics for the conduct and reporting of preclinical studies that involve assessment of experimental interventions in vivo. The criteria listed herewith are intended to (i) clearly communicate the desired standards of rigor to authors and investigators and (ii) facilitate the journal’s overall mission of promoting robust, rigorous, and reproducible scientific inquiry and experimentation. We recognize the complexity and diversity of many studies, and the fact that different studies have different levels of emphasis on in vivo data. The information requested herein is meant to be used by reviewers and editors as an aid in assessing the value of the work, not as a rigid criterion for accepting or rejecting articles; thus, decisions on acceptance or rejection will be made on a case-by-case basis depending on the individual content and characteristics of each submitted article. In addition, we recognize that certain standards outlined above may not apply to exploratory, hypothesis-generating, or mechanistic animal studies. We encourage and welcome such studies; however, in these cases we encourage the authors to address the areas outlined here and describe why adherence to particular standards was not practical or meaningful. We promote the use of online supplements for providing detailed experimental protocols and communicating any secondary results not reported in the main article.