Regional differences in hepatitis C treatment with peginterferon and ribavirin in Japan: a retrospective cohort study

Figures & data

Table 1 Clinical characteristics

Clinical characteristic
N	11,672
Age, mean ± SD, years	57.9±10.5
Sex, n (%)
Male	5,896 (50.5)
Female	5,776 (49.5)
Genotype, n (%)
1	7,950 (68.1)
2	3,703 (31.7)
3	19 (0.2)
Platelet count, n (%)
≤15×10^4/μL	4,705 (40.3)
>15×10^4/μL	6,967 (59.7)
ALT level, n (%)
>30 IU/L	9,118 (78.1)
≤30 IU/L	2,554 (21.9)
HCV viral load, n (%)
High	10,903 (93.4)
Low	769 (6.6)
Treatment experience, n (%)
Initial treatment	8,628 (73.9)
Retreatment	3,044 (26.1)

Abbreviations: ALT, alanine aminotransferase; HCV, hepatitis C virus.

Table 2 SVR rate in each prefecture

Prefecture no	n	SVR rate	%
1	256	169	66.02
2	250	143	57.20
3	100	56	56.00
4	535	307	57.38
5	112	59	52.68
6	249	135	54.22
7	177	104	58.76
8	62	38	61.29
9	381	253	66.40
10	419	245	58.47
11	298	185	62.08
12	220	122	55.45
13	195	113	57.95
14	130	79	60.77
15	12	7	58.33
16	141	70	49.65
17	333	217	65.17
18	326	193	59.20
19	360	225	62.50
20	126	81	64.29
21	894	507	56.71
22	847	491	57.97
23	174	113	64.94
24	19	9	47.37
25	133	74	55.64
26	35	22	62.86
27	427	247	57.85
28	1,391	849	61.04
29	349	210	60.17
30	73	34	46.58
31	57	25	43.86
32	536	324	60.45
33	561	344	61.32
34	895	583	65.14
35	532	308	57.89
36	67	48	71.64
Total	11,672	6,989	59.88

Abbreviation: SVR, sustained virologic response.

Figure 1 Distribution of sustained virologic response (SVR) rate in Japan.

Table 3 Logistic regression analysis

Variable	Odds ratio (95% CI)	P-value
Age, years	0.964 (0.959–0.968)	<0.0001
Sex (male vs female)	1.376 (1.267–1.494)	<0.0001
Platelet count (>15×10^4/μL vs ≤15×10^4/μL)	1.505 (1.385–1.636)	<0.0001
ALT level (>30 IU/L vs ≤30 IU/L)	1.194 (1.079–1.320)	0.0006
HCV viral load (high vs low)	0.321 (0.263–0.392)	<0.0001
Genotype (genotype 2/3 vs 1)	3.847 (3.491–4.239)	<0.0001
Treatment experience (retreatment vs initial treatment)	0.691 (0.631–0.756)	<0.0001

Note: Odds ratios for sustained virologic response, comparing the former category with the latter category, are shown.

Abbreviations: ALT, alanine aminotransferase; CI, confidence interval; HCV, hepatitis C virus.

Figure 2 Parameters of sustained virologic response (SVR) dispersion and quality of model fit.

Notes: (A) Model including prefecture as a fixed effect. (B) Model including prefecture and other confounding variables as fixed effects. (C) Model including prefecture as a random effect. (D) Model including prefecture as a random effect and other confounding variables as fixed effects. β is the fixed-effect parameter, and u is the random-effect parameter.
Abbreviations: AIC, akaike information criterion; BIC, bayesian information critreion.