Table 3. Treatment Modification and Sustained Virological Response (SVR).
| Intravenous Drug Users, No. (%) | No History of Drug Abuse, No. (%) | P values b | |
| SVR a all genotypes | 75 (70.75) | 122 (51.04) | 0.0009 |
| Genotypes 1 and 4 | 41 (65.08) | 96 (48, 73) | 0.0294 |
| PEG-IFN-α2a +RBV a | 26 (66.66) | - | |
| PEG-IFN-α2b +RBV | 15 (62.50) | - | |
| PEG-IFN-α2a +RBV | - | 56 (49.57) | |
| PEG-IFN-α2b +RBV | - | 38 (44.18) | |
| Genotypes 2 and 3 | 34 (79.07) | 29 (69.05) | 0.3300 |
| PEG-IFN-α2a +RBV | 21 (75.00) | - | |
| PEG-IFN-α2b +RBV | 13 (86.66) | - | |
| PEG-IFN-α2a +RBV | - | 13 (61.69) | |
| PEG-IFN-α2b +RBV | - | 15 (75.00) | |
| Lost of follow-up | 14 (13.21) | 11 (4.60) | 0.0071 |
| Therapy modification | |||
| Reduction of drug doses | 12 (11.32) c | 38 (15.89) d | 0.3210 |
| PEG-IFN-α a dose reduction | 6 (5.66) | 14 (5,86) | 1.0000 |
| RBV dose reduction | 4 (3.77) | 19 (7.95) | 0.1694 |
| PEG-IFN-α and RBV dose reduction | 2 (1.89) | 5 (2.09) | 1.0000 |
| Therapy discontinuation | 3 (2.83) | 17 (7.11) | 0.1390 |
a Abbreviations: peG-IFn-α, pegylated-interferon alpha; RBV, ribavirin; SVR, sustained virological response
b Fisher's exact test
c Reasons for treatment modification in IVDUs: anemia 4, neutropenia 3, hypothyroidism 2, depression 2, pancytopenia 1
d Reasons for treatment modification: anemia 14, neutropenia 8, thrombocytopenia 7, depression 5, hypothyroidism 4