Evaluation of the Evidence

Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
Veterinary Clinics of North America Small Animal Practice (Impact Factor: 0.82). 06/2007; 37(3):447-62. DOI: 10.1016/j.cvsm.2007.01.004
Source: PubMed


Evaluating the evidence describes the scientific basis of evidence as presented in papers describing the results of clinical research. The types of errors that may lead to misinterpretation of evidence are discussed. This article includes descriptions of the main types of research performed in veterinary clinical research and notes on their advantages and disadvantages.

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    • "This study was designed to provide a high rank of evidence when considering anaesthetic death risk factors. A cohort observational study was thought to be adequate (Holmes 2007). Major difficulties encountered when building this type of cohort observational study were thought to be: 1) including a representative group of the exposed population ; and 2) limiting the loss related to poor followup . "
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    ABSTRACT: To evaluate the anaesthetic death risk for dogs and cats in a French private practice. Observational cohort study. All small animals anesthetized at the Centre Hospitalier Vétérinaire des Cordeliers between April 15th, 2008 and April 15th, 2010. General anaesthesia was defined as a drug-induced unconsciousness characterised by a controlled and reversible depression of the central nervous system and analgesia, sufficient to allow endotracheal intubation. Patient outcome (alive or dead) was assessed at the end of anaesthesia defined as the meeting point of the return of consciousness, rectal temperature >36 °C and ability to maintain sternal recumbency. Death occurring during anaesthesia was recorded. Relationship between anaesthetic death and ASA status, species, age, nature of the procedure, anaesthetic protocol and occurrence of epidural administration of a combination of morphine and bupivacaine were analysed. During the study period 3546 animals underwent general anaesthesia. The overall death rate in the present study was 1.35% (48 in 3546, 95% CI 0.96-1.75). The death rate of healthy animals (ASA 1 and 2) was 0.12% (3 in 2602 95% CI 0.02-0.34). For sick animals (ASA status 3 and over), the overall death rate was 4.77% (45 in 944 95% CI 3.36-6.18). The death rates in the ASA 3, 4 and 5 categories were 2.90%, 7.58% and 17.33%, respectively. The main factor associated with increased odds of anaesthetic death in ASA categories 3 and over was poor health status (ASA physical status classification). The nature of the procedure the patient underwent and epidural administration of a combination of morphine and bupivacaine were not correlated with the occurrence of death during anaesthesia. Neither species nor age effects were detected. Specific factors were associated with increased odds of anaesthetic death, especially poor health status. Efforts must be directed towards thorough preoperative patient evaluation and improvement of clinical conditions if possible. Identification of risk factors before anaesthesia should lead to increased surveillance by trained staff. This could result in better outcomes.
    Full-text · Article · Jan 2012 · Veterinary Anaesthesia and Analgesia
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    • "However, because of the structure of dog ownership, it is challenging to develop study protocols that allow high quality research in the field of small animal reproduction . Main problems are costs, small number of dogs available fitting the inclusion criteria, missing compliance of the owners and individual differences in feeding and housing (Lund et al. 1998; Holmes 2007). It can also be elaborate and expensive to meet the legislation of animal experimentation for scientific purpose (Bayne 2003). "
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    ABSTRACT: The objective of this study was to evaluate the quality of published literature on reproduction in dogs. A systematic search in online databases revealed 287 papers that met the inclusion criteria. For evaluation a questionnaire comprising 40 criteria regarding materials and methodology, study design, statistics, presentation and information content, applicability and conclusions was developed. In a pre-test including seven independent scientists the applicability and explanatory power of the questionnaire and its results were validated. Out of 287 publications evaluated, 90 (31.4%) were classified as clinical trials. The remaining 197 publications were case reports or contained information based on personal experience. Not a single meta-analysis was found. Sixty (66.7%) of the 90 clinical trials included a control group. Randomization was conducted in 23 and blinding in eight articles respectively. In total five articles were determined as randomized, controlled and blinded clinical trials. Information content of the publications was variable concerning details on included animals, type or dosage of used remedies or conducted interventions. For example, in 99.7% of the articles, the exact number of animals was given, but in 79.8%, housing and feeding of the animals were not described. Statistical procedures of clinical trials were determined adequate in 55.6%. However, the data of 67.9% of the articles were evaluated to be not sufficient to draw valid conclusions. This study revealed evidence of deficits in the field of canine reproduction. The demand for more high quality clinical research is obvious. Requisite for the further implementation of the evidence-based veterinary medicine is an improvement of the quantity and the quality of well-designed, conducted and reported clinical trials. The practitioner should always assess the quality of information before implementing results into practice to provide best available care for the animals.
    Full-text · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: Data implicating mucosal cytokines in the pathogenesis of canine inflammatory bowel disease (IBD) are limited. The aims of the present study were to report new findings of intestinal cytokine expression in dogs with IBD and to compare these data with previous studies through meta-analysis. Cytokine mRNA abundance in intestinal biopsies collected prospectively was evaluated by using a semiquantitative RT-PCR technique. For meta-analysis, an electronic database search revealed 3 clinical trials, all of which were nonrandomized (type III) case series. Prospective analysis showed that the intestines of healthy dogs and those with IBD express numerous cytokines and that a proinflammatory expression profile is not a feature of small or large-intestinal IBD. The meta-analysis data included 158 dogs characterized as healthy (n = 45), diarrheic nonIBD dogs (n = 6), nonresponders (n = 2), small-intestinal IBD (n = 41), colonic IBD (n = 25), and chronic enteropathy (n = 39). German shepherd dogs were overrepresented in 3 of the 4 studies. Healthy dogs showed mRNA expression for most cytokines including IL2, IL4, IL5, IL10, IL12, IFNgamma, TNFalpha, and TGFbeta. Only IL12 mRNA expression was increased consistently in small-intestinal IBD, whereas IBD colitis lacked consistent patterns of expression. In summary, dogs with IBD fail to express a predominant Th1- or Th2 cytokine bias in inflamed mucosa. Heterogeneity of results among these studies might be explained by numerous factors including the method of mRNA quantification, stage of disease, and demographic differences in study populations.
    Preview · Article · May 2009 · Comparative medicine
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