Table 3.

Survey questions summary statistics and pairwise comparisons

Question		Significant pairwise comparison*	N	M	SD	IQR
Q1: Which answer(s) best describe your reason for joining the Brain Health Registry
Q1a:	I want to learn about Brain diseases such as Alzheimer’s	Q1b, Q1f, Q1g	222	4.41	0.98	1
Q1b:	I want to learn about my own brain health	Q1f, Q1g	222	4.66	0.74	0
Q1c:	I want to help with current research/treatments for brain health	Q1f, Q1g	222	4.60	0.76	1
Q1d:	I want to help research to benefit the brain health of future generations	Q1f, Q1g	222	4.61	0.73	1
Q1e:	Someone I know has/had a brain disease such as Alzheimer’s	Q1f, Q1g	222	4.42	1.28	1
Q1f:	I was referred by someone I know	Q1g	83	1.25	1.39	0
Q1g:	Other		55	2.47	1.77	4
Q2: Which answer(s) best describe your reason for continuing participation in the Brain Health Registry?
Q2a:	I want to learn about Brain diseases such as Alzheimer’s	Q2b, Q2f, Q2g, Q2h	222	4.46	0.92	1
Q2b:	I want to learn about my own brain health	Q2e, Q2f, Q2g, Q2h	222	4.67	0.75	0
Q2c:	I want to help with current research/treatments for brain health	Q2e, Q2f, Q2g, Q2h	222	4.65	0.74	0
Q2d:	I want to help research to benefit the brain health of future generations	Q2f, Q2g, Q2h	222	4.59	0.77	1
Q2e:	Someone I know has/had a brain disease such as Alzheimer’s	Q2f, Q2g, Q2h	222	4.32	1.38	1
Q2f:	I was referred by someone I know	Q2g	82	1.87	1.48	1
Q2g:	I enjoy completing the study tasks	Q2h	222	3.73	1.47	2
Q2h:	Other		48	2.17	1.64	3
Q3: If the Brain Health Registry released additional features, which of the following would you be interested in?
Q3a:	Personalized report based on how you answered questionnaires	Q3b, Q3c, Q3d, Q3e, Q3g	212	4.59	0.85	1
Q3b:	Additional cognitive tests	Q3c, Q3e, Q3f, Q3g	212	4.24	0.96	1
Q3c:	More of the current study tasks available on smartphones and tablets	Q3d, Q3e, Q3f, Q3g	212	3.73	1.44	2
Q3d:	Specific information and resources regarding brain disease	Q3e, Q3f, Q3g	212	4.21	0.97	1
Q3e:	More frequent newsletters	Q3f, Q3g	212	2.85	1.32	2
Q3f:	Summary of your performance on brain tests	Q3g	212	4.67	0.68	0
Q3g:	Other		212	2.19	1.72	3
Q4: What would encourage you to return to the Brain Health Registry or complete all the study tasks?
Q4a:	Monetary compensation	Q4b, Q4c, Q4d, Q4f, Q4h, Q4i	212	3.86	1.27	2
Q4b:	Fewer questionnaires or brain tests	Q4e, Q4f, Q4g, Q4h, Q4i	212	3.16	1.25	2
Q4c:	A chance to win a prize	Q4e, Q4f, Q4g, Q4h, Q4i	212	3.02	1.48	2
Q4d:	Better technical support	Q4e, Q4f, Q4g, Q4h, Q4i	212	2.85	1.37	2
Q4e:	More educational resources	Q4f, Q4g, Q4h, Q4i	212	3.67	1.17	2
Q4f:	Scores or feedback on brain tests	Q4g, Q4h, Q4i	212	4.63	0.71	1
Q4g:	Additional opportunities to participate in clinical research	Q4h, Q4i	212	4.01	1.10	2
Q4h:	More details on how my participation helps research or impacts my community	Q4i	212	4.20	1.04	1
Q4i:	Other		212	2.04	1.60	2
Q5: Over the past 2 months, how often have you used the following websites?
Q5a:	Facebook	Q5b, Q5c, Q5d, Q5e, Q5g, Q5h, Q5i	212	2.59	1.25	3
Q5b:	Twitter	Q5c, Q5d, Q5e, Q5f, Q5i	212	1.67	1.03	1
Q5c:	Instagram	Q5d, Q5e, Q5f, Q5h, Q5i	212	1.89	1.14	1.25
Q5d:	TikTok	Q5e, Q5f, Q5g	212	1.34	0.78	0
Q5e:	Snapchat	Q5f, Q5g, Q5g	212	1.13	0.54	0
Q5f:	YouTube	Q5g, Q5h, Q5i	212	2.68	0.93	2
Q5g:	LinkedIn		212	1.61	0.87	1
Q5h:	Pinterest		212	1.54	0.76	1
Q5i:	Other		212	1.35	0.91	0

^*Note. Significant pairwise comparisons with Bonferroni correction. For example, for Q1a, this demonstrates that the mean of the response option Q1a (I want to learn about Brain diseases such as Alzheimer’s) is significantly different from the mean of the response options Q1b (I want to learn about my own brain health), Q1f (I was referred by someone I know), and Q1g (Other).

The scale for Questions 1 through 4 ranges from “1”-“5.” The scale for Question 5 ranges from “1”–“4.”