Parents of children with a rare condition recruited within the Australian Genomics (n = 492) and Melbourne Genomics Health Alliance (n = 190) were invited to participate in the DCE survey. In total, 94 parents completed the survey independently (response rate = 14%). As shown in Supplementary Table 1, the mean age of respondents was 42 years (SD = 7) and the majority of parents were female (90.4%; n = 85), married, or in a de facto relationship (83%; n = 78), had more than one child (83%; n = 78), had private health insurance (63.8%; n = 60), lived in metropolitan area (75.5%; n = 71) and had received a genomic diagnosis for the child (56.4%; n = 53). Parents were interested in an analysis for AF (92.6%; n = 87) and especially in AF that included childhood-onset AF for the child (87.3%; n = 82). Across all participant responses, AF alternatives were chosen in 70% of the overall choice tasks. Supplementary Fig. 1 shows that most parents were over 90% confident that they would make this choice about receiving AF in real life (65%; n = 61). The regression results from the choice analysis are presented in Table 1 and discussed in detail below:

Table 1 Marginal utilities and willingness-to-pay (WTP)Preferences for receiving results from analyses for AF

Parents demonstrated a preference for receiving results from analyses for AF, as evidenced by the statistically significant constant term. Preference heterogeneity existed with regards to the level of utility for receiving AF, as evidenced from the statistically significant parameter estimate for the derived standard error of the constant term.

Preferences for an opportunity to change the choices made about AF over time

Parents on average showed preference for the opportunity to change the choices they made about AF over time, such as the choice to delay the decision to receive AF, receive a different type of AF, or opt out of receiving AF at all. Significant preference variability was identified amongst parents. On average, parents would be willing to pay $375 (US$250) for the opportunity to change the choices made. This attribute was ranked 6th in terms of priority with an importance score of 6.3%.

Preferences for how the results of additional analysis are returned in the presence of an AF

We found a preference for receiving positive results directly in person compared to an electronic return of results through a secure online portal. No statistically significant difference in the preference for receiving positive results directly through telehealth or phone was identified compared to the electronic return of results. On average, parents would be willing to pay $980 (US$660) to receive the results in person instead of electronically. This attribute was ranked 2nd in terms of priority with an importance score of 16.4%.

Preferences for who returns the results of additional analysis in the presence of an AF

We found a preference for receiving positive results from a genetic counsellor instead of their general practitioner, and homogeneity in this preference existed. No statistically significant difference in the preference for receiving positive results from a relevant medical specialist or a clinical genetics specialist compared with a general practitioner was identified. On average, parents would be willing to pay $725 (US$485) to receive the results from a genetic counsellor instead of their GP. This attribute was ranked 3rd in terms of priority with an importance score of 12.3%.

Preferences for how the results of additional analysis are returned in the absence of an AF

No statistically significant preferences were identified with regards to how negative results are returned. This attribute was ranked 8th in terms of priority with an importance score of 3.8%.

Preferences for who returns the results of additional analysis in the absence of an AF

No statistically significant preferences were identified with regards to who returns negative results. This attribute was ranked 9th in terms of priority with an importance score of 0.1%.

Preferences for the waiting period until seeing a medical specialist in the presence of an AF

Parents showed negative preference for increased waiting time for seeing a medical specialist. Statistically significant variability existed in the disutility associated with the increased waiting time for seeing the medical specialist. On average, parents would be willing to accept $100 (US$67) for every additional month they need to wait for seeing a medical specialist following the return of a positive AF. This attribute was ranked 5th in terms of priority with an importance score of 9.1%.

Preferences for accessing relevant high-quality information if there is an additional finding

Positive preference for an immediate access to relevant high-quality online resources was identified, and preferences were homogenous. On average, parents would be willing to pay $390 (US$260) for immediate access to relevant high-quality online resources. This attribute was ranked 7th in terms of priority with an importance score of 6.4%.

Preferences for what happens if new information relevant to individual results becomes available

Parents demonstrated a preference for receiving automatic updates through a secure online portal compared to not receiving updates. No statistically significant difference existed in the preference between receiving updates upon request and not receiving updates. On average, parents would be willing to pay $570 (US$380) to have automatic updates through a secure online portal if new relevant information becomes available. This attribute was ranked 4th in terms of priority with an importance score of 9.6%.

Preferences for the cost of the analysis for additional findings to parents

Parents demonstrated negative preference for higher costs. The extent of the disutility associated with the cost attribute varied among parents. This attribute was ranked 1st in terms of priority with an importance score of 35.9%.

Parents with higher household income were found to have significantly higher utility for receiving AF. Living in a metropolitan area, health-related quality of life and having a confirmed genomic diagnosis had no statistically significant effect on the utility of receiving AF. The results in Supplementary Table 2 show that there are two distinct classes of participants with more homogenous preferences. In Class 1, which includes 75% of participants, there is a positive preference towards an analysis for AF (when there are no costs involved and no waiting time to see a medical specialist), with preferences towards the DCE attributes being similar to the ones described above. In Class 2, which includes 25% of participants, there is negative preference towards an analysis for AF, with participants being very price-sensitive and with a strong preference for receiving AF from a genetics specialist.

Based on the preferences of this sample, and with a process of receiving AF in which (a) parents have the option to change the choices made about AF, (b) positive results are returned in person from a genetic counsellor, and (c) there is 5 months of waiting time to see a medical specialist, the mean WTP compared to a context where there is no analysis for additional findings was estimated at $1675 (US$1120). However, not all families would choose to undergo diagnostic genomic sequencing, and amongst those who would, the uptake of analyses for AF may vary. Figure 1 presents the estimated WTP for AF analysis as a function of uptake. For uptake rates ranging between 50–95%, the mean WTP for receiving results from analyses for AF is estimated to range between $450–$1700 (US$300–$1140).

Fig. 1: Mean per person value of analysis for additional findings across different uptake thresholds.

The figure presents the average willingness-to-pay, in Australian dollars (AU$), for an analysis for additional findings (AF) as a function of the AF uptake percentage among parents.