Clinical relevance of cognitive scores in hepatitis C patients with advanced fibrosis

Mild neuropsychological impairment has previously been reported in chronic hepatitis C(CHC) patients. The aim of this study was to assess the presence and severity of cognitive impairment among a cohort of CHC patients with advanced fibrosis using clinician ratings compared to classification based upon statistical methods. In addition, we set out to determine the relationship between cognitive scores and functional status. Two experienced neuropsychologists provided "clinician ratings" on a battery of 10 neuropsychological tests performed in 100 randomly selected patients participating in the HALT-C clinical trial. The overall kappa between the 2 graders on level of impairment was 0.59. Clinician ratings (the gold standard) were similarly sensitive to identifying cognitive impairment as was classification based on standard scores (44% vs. 40%). Global Deficit Scores (GDS), derived from pooling standard scores, also identified 44% of patients as having mild impairment and were highly correlated with clinician ratings (r =.81 p = < 0.0001). Neither clinician ratings nor deficit scores correlated with SF-36 subscale or summary scores but did correlate with depression scores (p <.0007). In summary, clinician ratings and deficit scores identified a similar prevalence of cognitive impairment amongst CHC patients with advanced fibrosis. There was a significant correlation between cognitive impairment and self-reported depression.