ANIMAL MODELS FOR OSTEOARTHRITIS--ENSURING EXPERIMENTAL VALIDITY

Confounding factors, bias factors and hidden variables affectthe design of experiments involving animal models. In a frequentlyused dog model for osteoarthritis these can arise, for example,because of the influence of age, sex and breed of dog. Controlsare required to investigate the progression of osteoarthritiseven in experiments forming time series. However, there areno true controls in animal models for joint degeneration. Analysisof data collected from experiments involving animal models dependson the number of factors being varied. The number of animalsinfluences the level of confidence associated with a result.Ignoring statistics can invalidate conclusions drawn from theexperiments. Statistical considerations are also important inthe presentation of results KEY WORDS: Joint degeneration, Dogs, Controls, Study design