Table 1.

Characteristics of included studies

CharacteristicN (%)
Study related
 Year of publication
  2010 to present14 (41)
  2000–200910 (29)
  Pre-200010 (29)
 Country of publication
  United States20 (59)
  The Netherlands3 (9)
  Canada2 (6)
  Egypt2 (6)
  Finland2 (6)
  Other5 (15)
 No. of patients per study (n)
  0–9927 (79)
  100–1995 (15)
  200+2 (6)
 Study design
  Cross-sectional25 (74)
  Cohort9 (26)
Patient related
 Mean age, yra
  0–63 (9)
  7–1216 (47)
  13+13 (38)
 Stages of CKDb
  Mild to moderate stage CKD25 (74)
  Dialysis6 (18)
  Transplant15 (44)
 Use of controlsb
  Direct non-CKD controls19 (56)
  Normative population data28 (82)
Test related
 Outcome domains
  Intelligence25 (74)
  Academic achievement10 (29)
  Attention11 (32)
  Executive function9 (26)
  Memory12 (35)
 Intelligence
  Wechsler scales (IQ)22 (65)
  Stanford Binet Intelligence Test2 (6)
  Test of nonverbal intelligence1 (3)
  Other9 (26)
 Attention
  Conners Continuous Performance Task5 (15)
  Continuous performance taskc3 (9)
  Gordon Diagnostic System2 (6)
  Other8 (24)
 Executive function
 Behavior Rating Inventory of Executive Function5 (15)
  Delis–Kaplan Executive Function System2 (6)
 Halstead–Reitan Category Test2 (6)
  Other8 (24)
 Memory
  Wide range assessment of memory and learning5 (15)
 Nonverbal selective reminding test2 (6)
  Other9 (26)
 Academic achievement
 Wechsler Individual Achievement Test6 (18)
  Wide Range Achievement Test3 (9)
 Peabody Individual Achievement Test2 (6)
  Other2 (6)
 Subtestsc
  Full-scale IQ21 (62)
  Verbal IQ18 (53)
 Performance IQ16 (47)
  Reading8 (24)
Arithmetic8 (24)
 Spelling4 (12)
  • IQ, intelligence quotient.

  • a Two studies did not specify.

  • b There is overlap in the number of studies.

  • c Not all studies reporting outcomes contained data suitable for meta-analysis.