Table 1.

Sample of patients with missing data (n=366) derived from the total sample (n=767)

Missing Data in Cognitive Indicators	n
Patient-reported cognitive functioning score only (KDQoL-SF cognition)	0
Cognitive switching speed only (TMT-B)	2
Selective attention score only (d2-R)	172
Cognitive switching speed and selective attention score	192
Cognitive switching speed or selective attention score and documented reason	366

One of two patients who only performed the d2-R test and not the TMT-B was analphabetic and hence, unable to connect the TMT-B letters, and the other one misunderstood the instructions of the TMT-B. KDQoL-SF, Kidney Disease Quality of Life Short Form; TMT-B, Trail Making Test-B; d2-R, d2-Revision.