The diffusion of genetic testing for cystic fibrosis and breast cancer susceptibility among physicians

• Main Author: Doksum, Teresa
• Format: Dissertation
• Language: English
• Subjects: health sciences, public health
• ISBN: 9780599528666; 0599528664

The role of non-geneticist physicians in the provision of genetic testing services is expanding as advances in genetics lead to the development of new tests. The specific aims of this study were to (1) describe the extent of non-geneticist physicians' knowledge about and adoption of genetic testing for cystic fibrosis (CF) carrier status and for inherited susceptibility to breast cancer (BRCA); and (2) identify the physician, patient, and practice characteristics associated with adoption of these tests, and explore whether these characteristics differ by test or stage of adoption.
The Diffusion of Innovations conceptual framework was used to develop a questionnaire that was mailed to a random sample of 2,250 obstetrician-gynecologists (Ob-Gyns), oncologists, and internists in five New England and Mid-Atlantic states. The overall response rate was 40%. Only 29% of Ob-Gyns correctly answered all CF knowledge questions and 13% of internists, 21% of Ob-Gyns and 40% of oncologists correctly answered all BRCA test knowledge questions. Almost half (42%) of Ob-Gyns had ever discussed CF carrier testing with a Caucasian patient with no family history of CF, and only one-fourth (28%) had ever ordered a test. Over two-thirds of Ob-Gyns (69%) and oncologists (73%) but only one-fourth of internists (24%) had ever discussed BRCA testing with an unaffected patient with a family history of breast/ovarian cancer. Very few respondents had ever ordered a BRCA test for these patients (7% of internists, 15% of Ob-Gyns, and 20% of oncologists). In multivariate logistic regression analysis, adoption was significantly associated with practice style and patient characteristics (level of education or perceived interest in testing), although individual characteristics associated with adoption varied by specialty, test, and stage of adoption. Familiarity with professional society statements on these tests was associated with adoption, regardless of whether the statement recommended for or against offering testing. These findings indicate that non-geneticist physicians' knowledge about CF and BRCA testing is low, yet many have discussed or ordered these tests. Physicians appear to be influenced by the level of patient interest, and by professional society statements, although these may not have the desired effect of discouraging adoption.