Decreasing uptake of predictive testing for Huntington's disease in a German centre: 12 years' experience (1993-2004)

Abstract

In this retrospective study, we examined changes in decision-making for and against the predictive genetic test for Huntington's disease including 478 persons at risk who had undergone genetic counselling in one centre in Germany between 1993 and 2004. At the outset of the counselling procedure the majority of subjects (71%) wanted to make use of the test, yet the actual demand of the predictive test result declined from 67 to 38% over the years. In addition, the time interval between counselling session and blood withdrawal was reduced, as determined by the counselees: in 2000-2004 the majority of persons at risk made the appointment for blood withdrawal after the shortest possible time span. Demographic factors of the cohort remained comparatively stable in the investigated time period. An association was evident between the ratio of test usage and the counselling person. These and other possible factors influencing the time flow of predictive DNA testing are discussed. Further studies are necessary to investigate whether changes of test demand rates are a general phenomenon.

Figure 1

Number of persons at risk (black bar) and predictive test performed (grey bars) during the period 1993–2004. χ² test: P<0.001; χ²=23.9; d.f.=2.

Figure 2

(a) Interval between the counselling session during the time period 1993–1996 and the blood withdrawal. (b) Interval between the counselling session during the time period 1997–2000 and the blood withdrawal. (c) Interval between the counselling session during the time period 2001–2004 and the blood withdrawal.