The value of knowing: preferences for genetic testing to diagnose rare muscle diseases

Table 1 Attributes and levels for the choice questions

Attribute	Level
Number of rare muscle diseases tested for (chance of getting a final diagnosis from the test)	100 diseases (60% chance) 34 diseases (30% chance) 1 disease (5% chance)
Treatment availability for diseases covered by the test^a	Treatment is available for 100 diseases Treatment is available for 34 diseases Treatment is available for 1 disease Treatment is not available
Time until results from the test	1 month 2 months 6 months
Test results may contain information about unrelated health risks	Yes No
A muscle biopsy is needed to confirm results	Yes No
Average time until final diagnosis, if the first test is negative	2 years 4 years 7 years

^a The experimental design was created using three levels: treatment is available for all diseases tested for by the genetic test, treatment is available for one of the diseases tested for by the genetic test, and treatment is not available for any of the diseases tested for by the genetic test. The text in the survey instrument used the four levels listed in Table 1. For example, if the number of rare muscle diseases tested for was 34 and treatment availability for diseases covered by the test was “all,” respondents saw “Treatment is available for 34 diseases.”

ISSN: 1750-1172