Several studies have revealed unaddressed construct validity threats in preclinical studies as well. A total of 2,029 citations were identified through our search strategy.
In addition, it has been suggested that these mice may be more susceptible to infections and other non-ALS related illnesses and that it is this illness rather than the ALS that is alleviated by the experimental treatment. Academic Editor: Parkinsonism Relat Disord 17: N Engl J Med 357: For example, biased outcome assessment due to experimenter expectation can lead to spurious inferences about treatment response. View Article Google Scholar 14.
Among the 25 recommendations that addressed threats to construct validity, the most commonly included recommendations called for characterization of the properties of the animal model before experimentation and matching of the animal model to the human manifestation of the disease. For instance, these may have had insufficient statistical power to detect a true benefit of the treatment under study. Depending on the disease under investigation, a range of physiological variables may affect outcome, and inadequate control of these factors may lead to erroneous conclusions.
View Article Google Scholar 15. Extraction and categorization disagreements were resolved by discussion until consensus was reached. Juutilainen J, Kumlin T, Naarala J 2006 Do extremely low frequency magnetic fields enhance the effects of environmental carcinogens?
Our analysis is subject to several important limitations.
The extent to which the design and conduct of the trial eliminate the possibility of bias. Vaccine 23: The probability that a study will detect a statistically significant effect of a specified size. Why Was This Study Done? View Article Google Scholar 32. Another study suggested that nonpublication of negative studies resulted in an overestimation of effect sizes by one-third .