Table 1.
Extraction results
| Recommendation | Absolute frequency |
Relative frequency (%) |
| Adequate choice of sample size | 41 | 68 |
| Blinding of outcome assessment | 41 | 68 |
| Choice of statistical methods for inferential analysis | 38 | 63 |
| Randomised allocation of animals to treatment | 38 | 63 |
| Concealed allocation of treatment | 31 | 52 |
| Recording of the flow of animals through the experiment | 31 | 52 |
| A priori statements of hypothesis | 30 | 50 |
| Selection of appropriate control groups | 29 | 48 |
| Characterisation of animal properties at baseline | 28 | 47 |
| Addressing confounds associated with setting | 23 | 38 |
| Definition of outcome measurement criteria | 23 | 38 |
| Reporting on genetic background | 23 | 38 |
| Matching or balancing sex of animals across groups | 20 | 33 |
| Degree of characterisation and validity of outcome | 19 | 32 |
| Consistency of outcome measurement | 18 | 30 |
| Monitoring emergence of confounding characteristics in animals | 18 | 30 |
| Precision of effect size | 18 | 30 |
| Study of dose–response relationships | 18 | 30 |
| Addressing confounds associated with experimental setting | 17 | 28 |
| Establishment of primary and secondary end points | 17 | 28 |
| Reporting on breeding scheme | 16 | 27 |
| Assessment of outcome at late/relevant time points | 15 | 25 |
| Independent replication | 15 | 25 |
| Matching or balancing treatment allocation of animals | 15 | 25 |
| Specification of unit of analysis | 15 | 25 |
| Randomisation for analysis | 14 | 23 |
| Replication in different species or strains | 14 | 23 |
| Standardised handling of animals | 14 | 23 |
| Addressing confounds associated with anaesthesia or analgesia | 13 | 22 |
| Replication in different models of the same disease | 13 | 22 |
| Addressing confounds associated with treatment | 12 | 20 |
| Management of conflicts of interest | 11 | 18 |
| Treatment response along mechanistic pathway | 11 | 18 |
| Interstudy standardisation of experimental design | 10 | 17 |
| Assessment of multiple manifestations of disease phenotype | 9 | 15 |
| Use of multiple time points measuring outcomes | 9 | 15 |
| Definition of treatment | 8 | 13 |
| Interstudy standardisation of end point choice | 8 | 13 |
| Pharmacokinetics to support treatment decisions | 8 | 13 |
| Randomised distribution of animals in the animal facilities | 8 | 13 |
| Use of validated assay for molecular pathways assessment | 8 | 13 |
| Faithful delivery of intended treatment | 7 | 12 |
| Addressing treatment interactions with clinically relevant comorbidities | 6 | 10 |
| Any additional elements that do not fit in the list above | 6 | 10 |
| Comparability of control group characteristics to those of previous studies | 6 | 10 |
| Critical appraisal of literature or systematic review during design phrase | 6 | 10 |
| Define programmatic purpose of research | 6 | 10 |
| Replication at different ages | 6 | 10 |
| Replication using variations in treatment | 5 | 8 |
| Optimisation of complex treatment parameters | 4 | 7 |
| Replication at different levels of disease severity | 4 | 7 |
| Research within multicentre consortia | 4 | 7 |
| Preregistration of study protocol and analysis procedures | 3 | 5 |