Table 1.

Summary of information for CKD-specific and generic measures (n=485)

Measure/Scoringk% MissingMean (SD)ReliabilityaInterpretation of Lowest ScoreInterpretation of Highest Score
Internal ConsistencyTest-Retest
KDQOL-36
 Burden (+)41.061.0 (29.5)0.880.79Kidney disease interferes with life, frustrating, feels like burden on familyKidney disease does not interfere with life, is not frustrating, does not feel like burden on family
 Effects (+)81.472.2 (22.4)0.860.86Extremely bothered by eight effects of kidney disease on daily lifeNot at all bothered by eight effects of kidney disease on daily life (see Figure 2)
 Symptoms/Problems (+)121.275.8 (17.0)0.860.85Extremely bothered by 12 symptomsNot at all bothered by 12 symptoms (see Figure 2)
CKD-QOL
 CKD-QOL-6 (−)60.247.6 (9.3)0.940.89No impact on role, social, emotional, cognitive functioning, fatigue, or quality of life because of kidney diseaseSevere and frequent impact on role, social, emotional, cognitive functioning, fatigue, quality of life because of kidney disease
 CKD-QOL-CAT −)60.047.1 (10.2)0.93b0.89(Same as above)(Same as above)
 3- or 6-item CAT (−)3–60.047.4 (10.0)0.90b0.88(Same as above)(Same as above)
SF-12v2
 PCS (+)123.740.4 (11.1)0.890.87Limited physical, work, or daily activities; severe pain; low energy; health poorNo limits in physical, work, or daily activities; no pain; high energy; health excellent
 MCS (+)123.750.1 (10.4)0.840.84Frequent emotional distress and low energy; limited in everyday activities because of emotional problemsFrequent positive affect, not at all limited in everyday activities because of emotional problems
  • Scoring: (+) higher score is better, (−) lower score is better. k, number of items.

  • a Reliability: internal-consistency reliability for scales estimated with Cronbach α. Test-retest reliability estimated with intraclass correlation; sample size is n=65 for KDQOL-36 and CKD-QOL measures, and n=61 for SF-12v2 PCS/MCS. Reliability for PCS/MCS estimated on the basis of reliability of eight SF-12v2 scales, scale covariances, and scale weights used to estimate each component.48

  • b Mean reliability for CKD-QOL-CAT and three or six-item CAT on the basis of SEM for each patient score. Percentage of patients (for three- or six-item CKD-QOL-CAT) with reliability ≥0.90 is 78%/66%, reliability ≥0.80 is 82%/73%, and reliability ≥0.70 is 100%/100%.49