PEG-IFN-α Plus Ribavirin in Elderly Chronic Hepatitis C Figure 1. Treatment Response to PEG-IFN-α plus Ribavirin Therapy in El- derly versus Non-Elderly CHC Patients (A) Overall (B) Patients with HCV genotype 1 (C) Patient with HCV genotype 2 or 3 EVR, early virologic response; ETR, end of treatment response; SVR, sus- tained virologic response; BR, biochemical response. of the elderly patients were comparable to those of the non-elderly group (81.6% vs. 92.3%, 81.6% vs. 90.9%, 65.8% vs. 76.2%, 73.7% vs. 79.0%, 16.1% vs. 12.3%; P = 0.07, 0.14, 0.15, 0.50, 0.56, respectively) (Figure 1A). In the subgroup analysis of patients with HCV genotype 1, the elderly group had a significantly lower SVR and higher relapse rate than the non-elderly group (30.8% vs. 66.0%, 44.4% vs. 10.5%; P = 0.03 and 0.03, respectively) (Figure 1B). However, SVR and Hepat Mon. 2012 Kim HI et al. relapse rate in patients with HCV genotype 2 or 3 were not significantly different between the elderly and non- elderly groups (84.0% vs. 81.3%, 4.5% vs. 13.0%; P = 0.90, 0.45, respectively) (Figure 1C). 4.3. Factors Associated with Sustained Virologic Re- sponse in Elderly Patients To determine which baseline factors were predictive of SVR in the elderly patients, univariate and multivariate analyses were performed. HCV genotype (type 1 vs. type 2 or 3) was found to be significantly associated with in- creased SVR (P = 0.004) (Table 2). Other factors that were considered, but were not found to be significantly associ- ated with SVR included; sex, body mass index, presence of cirrhosis, platelet count, baseline serum aminotransfer- ase level, GGT, total bilirubin, albumin, total cholesterol, APRI score, and baseline serum HCV RNA level (≥ 800 000 IU/mL vs. < 800 000 IU/mL). Furthermore, multivariate analysis showed that only the HCV genotype was signifi- cantly associated with SVR (genotype 1 vs. 2 or 3, odds ra- tio: 0.18, 95 % confidence interval: 0.000-0.869, P = 0.03) (Table 3). 4.4. Tolerability and Adverse Events Of the 181 study subjects, 21 (11.6 %) showed premature discontinuation of treatment, which was more frequent in the elderly (21.1 %) than the non-elderly group (9.1 %) (P = 0.05) (Table 4). Furthermore, the rate of dose modifica- tion was significantly higher in the elderly than in the non-elderly group (52.6 % vs. 31.5 %; P = 0.016), especially the frequency of dose modification of ribavirin (34.2 % vs. 13.3 %; P = 0.003). The incidence of adverse events was not statistically different between the groups, but the incidence of alopecia was significantly higher in the non-elderly group (0 % vs. 13.3 % ; P = 0.02) (Figure 2). The incidence of neutropenia (≤ 750 cells/mm3) and throm- bocytopenia (≤ 5 × 105 cells/mm3) were also not statisti- cally different between the groups. However, the elderly group had a significantly higher incidence of anemia (< 10 g/dL) (31.6 % vs. 12.6 % ; P = 0.01) (Figure 2). 5. Discussion It is generally expected that elderly patients will expe- rience adverse events more frequently and have poorer treatment adherence, leading to inferior treatment effi- cacy. In this study, the elderly patients (≥ 65 years) with HCV genotype 1 showed significantly lower SVR and higher relapse rate than the non-elderly patients. How- ever, the SVR rates of the elderly patients with genotype 2 or 3 were comparable to those of younger patients. HCV genotype was significantly associated with SVR. In addi- tion, the incidence of premature treatment discontinu- ation and dose modification were higher in the elderly group than in the non-elderly group. Previous studies from Japan have shown that the SVR rates of PEG-IFN-α 433