Nevertheless, questions concerning a number of techniques constituting an important segment of clinical allergy remain unresolved even though the means of testing their validity are well understood. Accordingly, these techniques deserve our most serious attention. The techniques are considered controversial because the concepts underlying them have been reported and applied clinically without any apparent attempt at validation by accepted standards of scientific evidence. The clinical setting that generates the claims for therapeutic success appears to allow bias free play in both patient and physician, a factor that the proponents of these procedures must acknowledge as a source of error in interpreting their observations. For this reason, the proponents must expect much of the medical community to continue to reject the procedures as unproved and invalid until convincing evidence to the contrary is forthcoming.
Convincing evidence is a large order because a large number of untested procedures have accumulated.
Furthermore, the design and execution of clinical trials in which bias, pro or con, cannot influence the outcome are well known to be difficult and cumbersome. Double-blind control has been essential, except perhaps in special instances in which striking effectiveness is plainly evident. The establishment and maintenance of experimental control will require careful planning and strict adherence to the protocol. However, the feasibility of controlled clinical trials is unquestioned, as a cursory perusal of medical journals will readily confirm. The medical community and, to some extent, the patient have properly come to expect that today s diagnostic and therapeutic measures have the backing of competently performed studies.