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The decision making process of practicing veterinarians as well as farm personnel and animal scientists should be based on objective information.
Therefore, the implementation of evidence based medicine becomes increasingly important. However, there is a dearth of methodologically performed, rigorous, large-scale clinical studies in veterinary medicine resulting in a lack of research results of high evidence. Also, there is a remarkable variation in the quality of studies in veterinary and animal science. Hence, in veterinary medicine the increase of knowledge is mainly based on reviewing field reports rather than randomized, controlled clinical studies. Nevertheless, randomized, controlled, double blinded studies are the gold standard with regard to the evaluation of a given treatment.
Postpartum uterine infections are a frequent disorder in dairy cattle with a prevalence up to 57.7%. In addition, they are reported to have an immense negative impact on reproductive performance resulting in high opportunity costs for the farmers.
The overall objective of the conducted studies was to elucidate the status quo concerning the evidence of available literature and the implementation of evidence-based veterinary medicine (EBVM). In the first study, the quality and comparability of published literature concerning the treatment of bovine endometritis with PGF2α was evaluated.
A comprehensive literature search was conducted utilizing online databases revealing a total of 2723 references. After applying specific exclusion criteria, a total of 68 trials were eligible for further analysis. These articles were evaluated utilising specific parameters listed in an evaluation form such as randomization and the involvement of control groups.
The analysis revealed that more than half of the trials (51.5%) were at least 20 years old. Furthermore, we found that about one third (36.8%) of all trials was controlled and randomized, while 3 of those (4.4%) were also blinded. In conclusion, the first study showed a wide discrepancy between research results investigating the efficacy of PGF2α. The second study aimed at a quantitative assessment of the efficacy of the treatment of bovine endometritis with PGF2α by means of meta-analysis.
After applying specific exclusion criteria and evaluating specific evidence parameters, a total of five publications, comprising six trials, were eligible for being analysed by means of meta-analysis. Data for each trial were extracted and analysed using meta-analysis software Review Manager 5.1. Estimated effect sizes of PGF2α were calculated on calving to first service and calving to conception interval.
PGF2α treatment of cows with chronic endometritis had a negative impact on both reproductive performance parameters. Heterogeneity was substantial for calving to first service and calving to conception interval [I2 (measure of variation beyond chance) = 100% and 87%, respectively]; therefore, random effects models were used. Sensitivity analysis as well as subgroup analysis showed that the performance of randomization was influential in modifying effect size of PGF2α treatment.
The funnel plot illustrated a publication bias towards smaller studies that reported a prolonged calving to conception interval after a PGF2α treatment. In conclusion, the investigation of this subject by means of meta-analysis did not reveal an improvement of reproductive performance of cows with endometritis after treatment with PGF2α.
The objective of the third study was to outline the current assessment and employment of evidence-based veterinary medicine with the help of a survey among practitioners concerning continuing education (EBVM) and their skills in obtaining and evaluating scientific information. For this purpose, a survey amongst veterinary practitioners was conducted throughout five conferences between Mai 2010 and November 2011.
The questionnaire contained 32 questions concerning demographic data and profession (n = 4), qualification (n = 3), continuing education (n = 5) and skills concerning EBVM (n = 20). Besides evaluating the statements of all participants, veterinarians were classified based on the type of practice and their statements compared.
In total, 293 questionnaires were returned. The majority of small animal practitioners (58.3%) and those working with food animals (54.9%) declared being capable of comprehending scientific talks or papers in English without difficulty.
10.4% of all practitioners negated reading veterinary journals on a regular basis, while 20.8% stated to regularly read English veterinary journals. The majority of the practitioners sought advice from their employer or a colleague. They attribute a high or very high quality to both information sources. Almost every participant (92.6%) stated to consult medical books, and 88.6% certify this information source a high or very high quality. 68.6% of the practitioners evaluated their skills in finding suitable literature as high or very high. However, only about half (52.1%) of all participants attributed themselves a high ability to evaluate the quality of the found literature.
Based on these findings, it can be concluded that most practitioners are hardly able to assess the evidence of scientific information. Therefore, courses that introduce EBVM should be taught in veterinary education and post graduate education to train critical appraisal of information and to support decision-making based on valid, clinically relevant data.