Table 4.

Response patterns per perspective

Response patterns	Proxy 1 perspective n (%)	Proxy 2 (substitute) perspective n (%)
The same utility for each state	3 (1.5%)	3 (1.5%)
Fewer than 5 unique utilities	39 (19.7%)	32 (15.7%)
No negative utilities	68 (34.5%)***	105 (51.4%)
No use of 0.5-year increments	48 (24.3%)	48 (23.5%)
States valued equal to or lower than 33333	220 (12.4%)**	171 (9.3%)
All strict dominance violations	590 (14.2%)	559 (13.3%)
Total non-trading responses (utilities of 1)	364 (16.7%)	396 (17.7%)
Total all-in trading responses (utilities of − 1)	239 (10.9%)***	161 (7.2%)
Round responders (only utilities of − 1, − 0.5, 0, 0.5 or 1)	7 (3.6%)	7 (3.4%)
States flagged in the feedback method	165 (8.4%)	158 (7.7%)

33333 worst state defined by the EQ-5D-Y-3L instrument, n number of observations

**, ***Indicate ${\chi }^2$ test significance at p < 0.01 and p < 0.001, respectively