Enhancing comprehension of online informed consent: the impact of interactive elements and presentation formats

Figures & data

Table 1. Consent form variations.

Form	Description	Words	Participants (%)
Control	Standard consent form, language adapted from IRB boilerplate	466	111 (14.8)
Special Formatting	Standard consent form with the use of bullet points, bold text, and highlighted words	466	114 (15.2)
Short	Word count significantly reduced, with option to view full consent form	89	119 (15.9)
4th Grade Reading Level	Consent form language revised to a 4th grade reading level	375	120 (16.0)
Interactive Control	Standard consent form, split over 5 pages with questions about the study at the end of each page	466	130 (17.4)
Interactive 4th Grade Reading Level	4th grade reading level version, split over 5 pages with questions about the study at the end of each page	375	155 (20.7)

Table 2. Participant demographics.

Variable	Frequency (%)
Group	Special Formatting	Short	4^th Grade Reading Level	Interactive Control	Interactive 4^th Grade Reading Level	Control	Total
N	114	119	120	130	155	111	749
Age (years)
18–24	12 (10.5)	8 (6.7)	9 (7.5)	5 (3.8)	5 (3.2)	7 (6.3)	46 (6.1)
25–34	11 (9.6)	7 (5.9)	12 (10)	15 (11.5)	15 (9.7)	9 (8.1)	69 (9.2)
35–44	17 (14.9)	15 (12.6)	18 (15)	16 (12.3)	24 (15.5)	13 (11.7)	103 (13.8)
45–54	16 (14)	26 (21.8)	15 (12.5)	32 (24.6)	26 (16.8)	22 (19.8)	137 (18.3)
55–64	28 (24.6)	35 (29.4)	26 (21.7)	25 (19.2)	32 (20.6)	29 (26.1)	175 (23.4)
65–74	26 (22.8)	25 (21)	31 (25.8)	34 (26.2)	43 (27.7)	25 (22.5)	184 (24.6)
75+	4 (3.5)	3 (3.5)	9 (7.5)	3 (2.3)	10 (6.5)	6 (5.4)	35 (4.7)
Level of Education
No schooling completed	1 (.9)	0 (0)	2 (1.7)	0 (0)	0 (0)	0 (0)	3 (.4)
Kindergarten to 8th grade	0 (0)	0 (0)	0 (0)	1 (.8)	1 (.6)	1 (.9)	3 (.4)
Some high school, no diploma	0 (0)	2 (1.7)	3 (2.5)	1 (.8)	0 (0)	4 (3.6)	10 (1.3)
High school graduate with diploma or GED	8 (7)	17 (14.3)	12 (10)	11 (8.5)	16 (10.3)	13 (1.7)	77 (10.3)
Some college, no degree	21 (18.4)	16 (13.4)	13 (10.8)	14 (10.8)	23 (14.8)	12 (10.8)	99 (13.2)
Trade/technical/vocational certification	3 (2.6)	6 (5)	3 (2.5)	7 (5.4)	9 (5.8)	8 (7.2)	36 (4.8)
Associate degree	9 (7.9)	15 (12.6)	12 (10)	9 (6.9)	10 (6.5)	8 (7.2)	63 (8.4)
Bachelor’s degree	33 (28.9)	33 (27.7)	45 (37.5)	52 (40)	55 (35.5)	33 (29.7)	251 (33.5)
Master’s degree	21 (18.4)	18 (15.1)	23 (19.2)	24 (18.5)	32 (20.6)	20 (18)	138 (18.4)
Professional degree	7 (6.1)	6 (5)	5 (4.2)	7 (5.4)	6 (3.9)	3 (2.7)	34 (4.5)
Doctorate degree	9 (7.9)	6 (5)	2 (1.7)	4 (3.1)	3 (1.9)	9 (8.1)	33 (4.4)
Other	2 (1.8)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	2 (.3)
Gender Identity
Man	68 (59.6)	61 (51.3)	67 (55.8)	65 (50)	81 (52.3)	62 (55.9)	404 (53.9)
Woman	45 (39.5)	58 (48.7)	53 (44.2)	63 (48.5)	74 (47.7)	48 (43.2)	341 (45.5)
Trans woman	1 (.9)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	1 (.1)
Genderqueer	0 (0)	0 (0)	0 (0)	1 (.8)	0 (0)	0 (0)	1 (.1)
Other	0 (0)	0 (0)	0 (0)	1 (.8)	0 (0)	1 (.9)	2 (.3)
Ethnicity origin (or Race)
White	93 (81.6)	103 (86.6)	99 (82.5)	111 (85.4)	129 (83.2)	90 (81.1)	625 (74)
Black or African American	11 (9.6)	7 (5.9)	10 (8.3)	9 (6.9)	13 (8.4)	10 (9)	60 (7.1)
American Indian or Alaska Native	3 (2.6)	4 (3.4)	4 (3.3)	0 (0)	1 (.6)	1 (.9)	13 (1.5)
Asian	9 (7.9)	8 (6.7)	11 (9.2)	7 (5.4)	7 (4.5)	8 (7.2)	45 (5.3)
Native Hawaiian or Pacific Islander	0 (0)	1 (.8)	2 (1.7)	0 (0)	1 (.6)	0 (0)	4 (.5)
Spanish, Hispanic or Latino/a	15 (13.2)	16 (13.4)	9 (7.5)	12 (9.2)	13 (8.4)	6 (5.4)	71 (8.4)
Other	5 (4.4)	6 (5)	3 (2.5)	4 (3.1)	6 (3.9)	3 (2.7)	27 (3.2)

Note: Participants were asked to check all that apply for ethnicity origin or race.

Table 3. Means and standard deviations for variables by condition.

		Comprehension	Readability
	N	M (SD)	M (SD)
Control	111	2.17a (1.40)	6.04 (2.85)
Special Formatting	114	2.22a (1.53)	5.96 (3.00)
Short “Brevity”	119	2.50a (1.60)	5.97 (2.83)
4th Grade Reading Level	120	2.26a (1.70)	6.38 (2.74)
Interactive Control	130	4.57b (1.53)	5.21 (2.78)
Interactive 4th Grade Reading Level	155	4.90b (1.30)	5.07 (2.77)
Total	749	3.22 (1.93)	5.73 (2.86)

Comprehension was scored on a scale from 0 to 7, where 7 was the highest score a participant could receive. Readability was ranked from 1 to 10 where 1 was the most readable.

Note: Means with different subscripts in the Comprehension column differ at p < .01 using the post-hoc Tukey test.

Table 4. Perfect scores for comprehension.

Group	n
Control	0
Special Formatting	2
Short “Brevity”	1
4^th Grade Reading Level	1
Interactive Control	2
Interactive 4th Grade	6

Table 5. Significant post-hoc tukey test results for readability.

Group	Group	Mean Difference	Std. Error	p
4th Grade Reading Level	Special Formatting	.418	.369	.868
	Interactive 4th Grade	1.312*	.343	.002
	Interactive Control	1.176*	.357	.013
	Control	.347	.372	.938
	Short “Brevity”	.409	.365	.874

Table 6. Regression Model for effect of self-efficacy on comprehension and readability.

	b	SE	β	95% CI		p
				LL	UL
Comprehension	.377	.095	.143	.190	.564	<.001
Readability	−.543	.141	−.139	−.821	−.266	<.001

Table 7. Regression Model for effect of trust on comprehension and readability.

	b	SE	β	95% CI		p
				LL	UL
Comprehension	−.503	.114	−.160	−.726	−.280	<.001
Readability	.897	.167	.192	.569	1.226	<.001

Table 8. Frequencies of participants’ coded open-ended responses to why they did not read the consent form (Q15).

Response code	n (%)	Sample quote
To long/too many words /wanted to get started	105 (20.8)	“Because it resembles the length of war and peace”
All the same	89 (17.6)	“After so many surveys they all look the same”
Answer N/A/not enough info in answer	84 (16.6)	“Not sure”
Didn’t want to/lazy/careless	66 (13.0)	“Because I didn’t want to”
Not important/not necessary /not concerned about risk	50 (9.9)	“I feel the risk was not great enough to bother”
Skimmed it/read part (but not all) of it	45 (8.9)	“I did skim for what I consider to be the critical parts.”
Couldn’t find/didn’t see/ didn’t realize it was a consent form/ nothing to do with research /not part of study	29 (5.7)	“i thought it was the initial page to the study”
Didn’t want to read legalese/jargon	12 (2.4)	“Because I’m sick of unnecessary legal verbiage that doesn’t mean anything to me”
Trust the source (e.g. institution or website administering survey)	9 (1.8)	“I feel safe doing surveys on this web site”
I did	7 (1.4)	“I did read it.”
Trouble concentrating/focusing/multitasking	6 (1.2)	“I was interrupted several times”
Required to get paid	4 (.8)	“you say no you don’t get paid”
Total	506 (100)

Note: The total N is greater than the number of participants who responded to this question as participants’ responses could correspond to multiple codes.

Table 9. Frequencies of participants’ coded open-ended responses to how consent forms could be improved (Q17).

Response code	n (%)	Sample quote
Shorter/more concise	349 (38.3)	“It should be short and straight to the point”
Answer N/A/not enough info in answer	160 (17.5)	“don’t know”
Simplified language/less jargon	143 (15.7)	“That they are in simple English and easy to read and understand”
Bold/colorful/ highlighting/bigger font	83 (9.1)	“Try to highlight important key points”
Nothing will help/no changes needed	41 (4.5)	“no way. Some will read and others just do not care”
Use bullet points/break up text/ layout changes	35 (3.8)	“Bullet points not blocks of text”
Put important info at the beginning	32 (3.5)	“Listing all important information on top”
Interactive/engaging/ask questions	30 (3.3)	“not allow people to move forward without asking questions”
Consent not needed	10 (1.1)	“no need for consent forms in the first place”
Manipulation feedback (specific to form they saw, not forms in general)	9 (1.0)	“Tell people that there will be specific questions relating to the consent form.”
Offer incentives for reading	6 (.7)	“offer bonus money if read”
Pictures	4 (.4)	“graphics”
Force time the consent /make reading required	4 (.4)	“make them so you can’t go past them without doing so”
Top header (READ, IMPORTANT INFORMATION, etc.)	3 (.3)	“emphasis at the very top as to why a reader should pay attention”
Educate people on importance of consent forms	3 (.3)	“Start up front with telling people why they need to read the consent form.”
Total	912 (100)

Note: The total N is greater than the number of participants who responded to this question as participants’ responses could correspond to multiple codes.

DATA AVAILABILITY STATEMENT

Data available on request from the authors.