Design of field trials for the evaluation of antibacterial products for therapy of bovine clinical mastitis.
In this paper, the design and statistical analysis of field trials for the evaluation of the efficacy of clinical mastitis therapeutics is covered. First, general issues underlying the design of clinical trials are reviewed. These include bias and confounding; randomization and blocking; and study objectives and choice of the corresponding hypothesis. Specific issues in the design of clinical mastitis trials are also discussed. Selection of subjects is discussed with regard to choice of experimental units, identification of reference population and study population, inclusion and exclusion criteria, and sample size calculation. Next, a section on treatment administration and evaluation of cure reviews treatment, blinding, choice of response measure, as well as compliance, withdrawal, and early termination. The statistical analysis section addresses possible statistical models, treatment of confounding, and fixed vs. random effects. In conclusion, well-conducted clinical mastitis trials represent an invaluable, albeit difficult and expensive, effort to evaluate efficacy and tolerance under usual circumstances of use.
Schukken
Y H
YH
Department of Herd Health and Reproduction, College of Veterinary Medicine, Utrecht, The Netherlands.
Deluyker
H A
HA
D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D002986:Clinical Trials as Topic / Q000592:standards*; D017321:Clinical Trials, Phase I as Topic; D017322:Clinical Trials, Phase II as Topic; D017326:Clinical Trials, Phase III as Topic; D017327:Clinical Trials, Phase IV as Topic; D015986:Confounding Factors, Epidemiologic; D005260:Female; D008414:Mastitis, Bovine / Q000188:drug therapy*; D008433:Mathematics; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D012107:Research Design; D015983:Selection Bias
D000890:Anti-Infective Agents