Lessons from Recruitment and Engagement of over 4,000 Independent Adults with Autism into SPARK, an Online Research Cohort

Background:

The heterogeneity within autism spectrum disorders (ASD) presents considerable challenges for autism research. ASD research has historically been more focused on children than adults, but as individuals with ASD transition into adulthood, new challenges may emerge. More effective strategies for recruiting and engaging adults with ASD will help researchers improve our understanding of ASD as a lifelong disorder.

Objectives:

We sought to understand how independent adult participants with ASD use and engage with SPARK’s digital platform to inform future recruitment strategies for ASD research.

Methods:

All participants were recruited to join SPARK online (https://sparkforautism.org). During registration, independent adults with ASD consent to participate, share basic demographic and diagnostic information, and have the option to invite their biological parents and one non-ASD sibling to the study. They are presented with online surveys and sent saliva collection kits if they choose to participate in genetic studies. Participants are sent gift cards for participation and are enrolled in a lottery for an iPad if saliva samples are returned in a timely manner. We analyzed each step in the registration process as well as survey and saliva sample return for all independent adults in SPARK, and separated participants by age and referral source to understand how these factors relate to participation.

Results:

A total of 4,057 independent adults (44% male) created profiles on the SPARK website, which means they began the process, but did not yet complete informed consent. Of those, 2,029 (50%) consented to share their data with SPARK, and 2,001 (49%) consented to participate in genetic analyses. For comparison, 61% of all SPARK account holders consent to both aspects of the study. Consenting to participate in research varied by age: 28% of ages 18-24, 66% of ages 25-32, 59% of ages 33-44, 41% of ages 45-64, and 44% of 65 and older. Age was similarly associated with survey completion, saliva sample return, and the average length of time for task completion. There is a significant main effect of age group on the time to saliva sample return [F(4,1316) = 2.48, p < 0.05]. While the majority of independent adults were referred to SPARK by clinical sites (54%), this is a lower percentage compared to independent adults without ASD who enrolled dependent children in SPARK (65%).

Conclusions:

As a large-scale, online, longitudinal autism research cohort, SPARK is well-situated to recruit and engage thousands of independent adults with ASD. Surprisingly, the majority of independent adults in SPARK are female, in contrast to only 20% in the child ASD cohort, but this may reflect gender differences in research participation. Young adults who join SPARK are less likely than older adults to complete the registration process. On average, the older adults are more likely to complete their research tasks, and do so more quickly than younger adults. These are important lessons for informing recruitment and engagement of this under-studied group, and SPARK will focus on developing strategies to ensure that more adults, specifically young adults, fully participate by completing registration and research tasks.