Table 1. Definitions used to assess characteristics of publications from 5 leading veterinary and 5 leading medical journals in 2013.

Reporting of methodological domains was assessed in all the randomized controlled trials (RCTs) extracted. Full definition of each item is given in the main text and supplementary files.

	Terms	Descriptions
Characteristics of articles	Original articles	Primary research, including subgroup analyses, follow-ups of previous article and case series
	Effectiveness of intervention (EoI) articles	Primary research evaluating the benefits of an intervention
	Randomized controlled trials (RCT)	EoI studies with allocation to interventions reported as randomized
	Real patients RCTs	RCTs that included individuals or animals that suffered from a spontaneous disease and were exposed to real-life conditions
	Surgical (RCT/EoI) articles	Same as previous definitions, but evaluating the benefits of a surgical intervention
	Explicit RCT	Trials registered in a trial repository or self-defining “randomized controlled trial”
	Explicit parallel RCT	Same as pervious, but employing only two arms
	Standalone RCT	Lack of additional non-randomized work (i.e., in vitro or prospective data) reported in the same article of the RCT
	Crossover RCT	RCT in which participants receive a sequence of different treatments
	Cluster RCT	RCT in which groups of participants are randomized to different treatments
Key methodological domains evaluated in RCTs	Primary outcome	A primary outcome is explicitly reported in the published article
	Power calculation	A power calculation performed a priori to estimate the sample size is explicitly reported
	Random sequence generation	Methods employed to generate the random list and type of randomization are explicitly reported
	Allocation concealment	Methods used to prevent the individuals enrolling trial participants from knowing or predicting the allocation sequence in advance are explicitly described in the article
	Blinding of participants	Explicit description that participants/pet owners were unaware of participants’ group allocation
	Blinding of personnel	Explicit description that operators involved in the care of participants were unaware of participants’ group of allocation
	Blinding of outcome assessors	Explicit description that outcome assessors were unaware of participants’ group of allocation
	Intention-to-treat	Explicit mention that the analysis was made on an “intention-to-treat” basis.
	Effect size estimation methods	Results are reported with methods that estimate the effect size with confidence interval.

Note:

EoI, Effectiveness of intervention.