Quality of Reporting of Clinical Trials of Dogs and Cats and Associations with Treatment Effects

Abstract

Background: To address concerns about the quality of reporting of randomized controlled trials, and the potential for biased treatment effects in poorly reported trials, medical journals have adopted a common set of reporting guidelines, the Consolidated Standards of Reporting Trials (CONSORT) statement, to improve the reporting of randomized controlled trials.Hypothesis: The reporting of clinical trials involving dogs and cats might not be ideal, and this might be associated with biased treatment effects.Animals: Dogs and cats used in 100 randomly selected reports of clinical trials. Methods: Data related to methodological quality and completeness of reporting were extracted from each trial. Associations between reporting of trial features and the proportion of positive treatment effects within trials were evaluated by generalized linear models.Results: There were substantive deficiencies in reporting of key trial features. An increased proportion of positive treatment effects within a trial was associated with not reporting: the method used to generate the random allocation sequence (P o .001), the use of double blinding (P o .001), the inclusion criteria for study subjects (P 5 .003), baseline differences between treatment groups (P 5 .006), the measurement used for all outcomes (P 5 .002), and possible study limitations (P 5 .03).Conclusions and Clinical Importance: Many clinical trials involving dogs and cats in the literature do not report details related to methodological quality and aspects necessary to evaluate external validity. There is some evidence that these deficiencies are associated with treatment effects. There is a need to improve reporting of clinical trials, and guidelines, such as the CONSORT statement, can provide a valuable tool for meeting this need.

Deficiencies of effectiveness of intervention studies in veterinary medicine: a cross-sectional survey of ten leading veterinary and medical journals

“…Finally, key methodological domains were underreported in veterinary RCTs compared with those in medical RCTs (research question 3). This latter finding is critical as under-reporting of methodological domains in veterinary RCTs has been associated with increased treatment effects (Sargeant et al, 2010). Observational non-randomized articles are fundamental in certain stages of the development of interventional procedures (Schünemann et al, 2013).…”

“…In a subset of 63 RCTs on dogs and cats, Brown (2007) reported that most RCTs with losses to follow-up did not account for these losses in the data analysis and did not acknowledge the potential impact on the outcomes of these RCTs. Another study found substantive deficiencies in the reporting of key methodological domains in RCTs with dogs and cats published between 2006and 2008(Sargeant et al, 2010. RCTs performed in laboratory animal research showed similar methodological problems: an overview of 31 systematic reviews found that only 29% of studies reported randomization, 15% of studies reported allocation concealment, and 35% of studies reported blinded outcome assessment (Hirst et al, 2014).…”

“…In fact, RCTs should also adhere to a wide variety of other quality parameters (Schulz et al, 1995;Moher et al, 2010). When the RCTs published in the veterinary literature were evaluated, several methodological issues were identified (Elbers & Schukken, 1995;Lund, James & Neaton, 1998;Brown, 2006;Brown, 2007;Sargeant et al, 2009;Sargeant et al, 2010;Giuffrida, Agnello & Brown, 2012;Giuffrida, 2014). Lund, James & Neaton (1998) identified a lack of reporting of at least 2 of 6 evaluated domains (random sequence generation, informed consent, eligibility criteria, blinding, power calculation and statistical analyses) in all RCTs on dogs and cats published between 1986and 1990.…”

Defining the primary research question in veterinary clinical studies

“…22 The potential for false-positive results is often obscured because published manuscripts generally only report tests that achieved statistical significance, rather than indicate every test that was performed or explored. 3,12 A clearly defined primary research question can help mitigate the risk of excessively high rates of falsepositive results. An efficient study design formulated on the basis of specific, relevant hypotheses is one of the central protections against multiplicity 21 because it tends to limit the number of subgroups and other sources of multiple comparisons.…”

“…As veterinarians become increasingly familiar with the principles of evidence-based medicine, they are looking to the results of clinical trials to guide their practice. However, the methodological quality of published veterinary clinical trials is often poor, [1][2][3][4] which means that readers could draw incorrect conclusions from trial results and in turn make unfounded changes in patient care. Results of a recent review of study power in reports of small animal trials indicated that not only did most trials contain methodological flaws, but only a handful of studies even stated the primary research question.…”