The limitations of the studies reviewed here are substantial. Samples of patients, family members, and healthcare professionals who were interviewed or surveyed were generally small. Moreover, many studies relied on convenience samples, surveying patients from a single clinic or physicians from the authors’ departments or hospitals. Much of the recent empirical literature has been generated by just a handful of very productive authors, whose results have yet to be replicated in other locations. Perhaps even more problematic, patient and family samples were frequently drawn from persons already engaged in genetic research, whose attitudes and beliefs about genetics may not be typical of other patients, family members, or the general public. Hence, our ability to generalize from the current data is poor. Further complicating the situation is the absence of statistical comparisons in many studies and the failure, even when statistical tests are used, to control for possible sources of covariation (e.g., age, race, education).
