Table 2 Spearman’s rho coefficients (r) for correlations between CBI subsections and NPI, UPDRS and PDQ-39 subscales in PD (n = 112), demonstrating concurrent validity of the CBI
CBI subscaleNPI subscalerUPDRS (I and II) subscalerPDQ-39 subscalerUPDRS (III) subscaler
MemoryIntellectual impairment0.56Cognitions0.38
Orientation and attentionIntellectual impairment0.54Cognitions0.58Motor score0.28
Everyday skillsActivities of daily living0.45Activities of daily living0.42Motor score0.30
Self-careActivities of daily living0.58Activities of daily living0.66Motor score0.44
MoodDepression0.44Depression0.36Emotional well-being0.50
BeliefsHallucinations0.58Thought disorder0.40
Challenging behaviour
DisinhibitionDisinhibition0.38
Eating habits
SleepNight-time behaviour0.31Motor score0.28
Stereotypic and motor behaviour
MotivationApathy0.52Motivation/initiation0.48Motor score0.26
Insight/awareness
  • Highest correlations significant at the 0.01 level are shown.

  • CBI, Cambridge Behavioural Inventory; NPI, Neuropsychiatric Inventory; PDQ-39, Parkinson's Disease Questionnaire; UPDRS, Unified Parkinson’s Disease Rating Scale.