Table 4.

Representative pretest interview findings and survey updates organized by select FDA-recommended qualities of PPI studies (6)

Round 1 Interview Findings (N=7)	Survey Updates	Round 2 Interview Findings (N=9)	Survey Updates
Patient centeredness
Considered risks (serious bleeding and infection) important to their RRT decision making	N/A	Consistent with round 1	N/A
Found treatment descriptions easy to understand (see minimal cognitive bias)	N/A	Consistent with round 1	N/A
Effective communication of benefit, harm, risk, and uncertainty
Displayed good understanding of the potential risks and benefits of the treatments	N/A	Displayed good understanding of the potential risks and benefits of the treatments	N/A
All but one participant displayed good understanding of the pictorial representation of riska	N/A	Displayed good understanding of the pictorial representation of risk	N/A
		Misunderstood the risk comparator to be the average person (versus other dialysis patients)	Underlined the phrase “other dialysis patients” to emphasize comparator
Minimal cognitive bias
Indicated that the in-center HD description was accurate	N/A	Consistent with round 1	N/A
Indicated that the wearable description was straightforward and understandable	N/A	Raised specific questions about the wearable (e.g., battery life, fluid storage, cleaning)	Added that the descriptions are of wearables in general and that features may vary by device
Found the wearable graphic helpful in showing the different ways could carry the device	N/A	Noted that the wearable graphic made the device look inconvenient and questioned whether they would want to use it	No change as participants understood the graphic
Comprehension by study participants
Desired more information about patient monitoring and caring for the wearable in the comparison table of wearables and in-center HD	Added information about patient monitoring and device care to the comparison table	Indicated that the comparison table was understandable and sufficient	N/A
Expressed unfamiliarity with the term “peritoneum”	Added definition of term	Expressed understanding of all terminology	N/A
		Thought waiting time might be on current dialysis modality (versus in-center HD) in the time trade-off questionb	Clarified the instructions by adding text to emphasize the assumption of in-center HD use while waiting for device B
Exhibited difficulty understanding longer, complex sentences	Shortened and simplified sentence structure.	Exhibited sufficient understanding	N/A

Based on FDA PPI guidance document (6). Some interview findings apply to more than one FDA-recommended quality (e.g., input on treatment graphics and descriptions applicable to minimal cognitive bias and comprehension by study participants). FDA, Food and Drug Administration; PPI, patient preference information; HD, hemodialysis; N/A, not applicable.

^aNo changes were made in response to this finding given understanding by all other participants and use of best practices in risk communication (e.g., use of text and pictures, absolute scales). This is consistent with FDA guidance that PPI studies “should aim to measure preferences and perspectives on benefits and risks of well-informed patients” (6).

^bTime trade-off questions were not included in round 1 interviews because they were under development at the time.