Abstract
Background
Immigrants to Canada are disproportionately affected by hepatitis C virus (HCV) infection. Little is known about treatment outcomes among immigrants at the national level or how outcomes vary across Canadian provinces.
Methods
We used data from the Canadian Network Undertaking against Hepatitis C (CANUHC), a prospective cohort enrolling HCV RNA–positive patients from 17 sites across 6 Canadian provinces between 2015 and 2025. Sociodemographic data, clinical characteristics, immigration details, time to first consult, and treatment outcomes were evaluated. Treatment outcomes included direct-acting antiviral (DAA) initiation, sustained virological response (SVR) bloodwork completion, and SVR achievement.
Results
Of 2521 patients, 427 (16.9%) were immigrants to Canada. Immigrants had higher educational attainment (60.8% vs 28.2% college/university, P < .001), higher employment (47.1% vs 28.0%, P < .001), and lower proportions with a history of injection drug use (25.8% vs 75.3%, P < .001), incarceration (12.9% vs 49.1%, P < .001), or recreational drug use (43.5% vs 91.8%, P < .001). Immigrants demonstrated excellent DAA treatment outcomes with higher crude rates of DAA initiation (95.6% vs 92.2%, P = .02), posttreatment SVR bloodwork completion (81.6% vs 70.5%, P < .001), and SVR (100% vs 98.6%, P = .03). However, after adjustment for age, sex, race, and key socioeconomic measures, immigration status was not independently associated with these outcomes. The mean time from immigration to specialist assessment was 24.9 years (standard deviation, 18.6 years). The delay in accessing care trended downward with each 5-year interval from 1990 to the present (median years, 26, 22, 16, 12, 7, and 2; P < .001).
Conclusions
Immigrants in the CANUHC cohort achieved excellent DAA treatment outcomes comparable to or exceeding those of Canadian-born patients. When engaged in care, immigrants can successfully complete the HCV treatment cascade.
Keywords: Canada, CANUHC, direct-acting antiviral, hepatitis C, immigrants, sustained virologic response
Hepatitis C virus (HCV) infection remains a significant global public health challenge, with approximately 50 million people worldwide living with chronic infection [1–3]. In Canada, an estimated 214 000 individuals were living with chronic HCV in 2021, with 41.5% unaware of their infection [4]. The World Health Organization (WHO) has called for global elimination of viral hepatitis as a public health threat by 2030, a goal that Canada has committed to achieving [2, 3].
Immigration patterns have substantially shaped the epidemiology of HCV in Canada. Since the 1950s, there has been a steady increase in immigration from HCV-endemic regions including Asia, sub-Saharan Africa, the Middle East, and Eastern Europe [4, 5]. Immigrants from these regions have an estimated HCV prevalence of 2.2%, compared to 0.56% in the general Canadian population [6]. Additionally, immigrants account for approximately 30%–35% of all HCV infections in Canada despite representing a smaller proportion of the total population [5, 7].
Immigrants face disproportionate HCV-related health burdens compared to Canadian-born individuals. Studies have demonstrated that immigrants are more likely to develop hepatocellular carcinoma and require hospitalization for HCV-related complications [5–10]. These disparities may be attributed to multiple factors, including older age at the time of engagement in care, hepatitis B virus (HBV) coinfection, prolonged delays from immigration arrival to linkage to specialty services (averaging 10–17 years), limited healthcare literacy, language and cultural barriers, and socioeconomic challenges [11–14].
Direct-acting antivirals (DAAs), widely available in Canada since 2014 and universally accessible since 2018, have revolutionized HCV treatment with sustained virological response (SVR) rates exceeding 95% [15, 16]. More than 74 000 HCV-infected individuals were successfully treated in Canada within the first 5 years following DAA introduction [17]. Despite this treatment success, questions remain about whether immigrant populations are achieving comparable outcomes to Canadian-born individuals and whether disparities exist across different regions of Canada [6, 18].
Most existing Canadian studies evaluating HCV treatment outcomes among immigrants have been limited in duration, or to single-center or single-province analyses [11–14, 19]. Given Canada's decentralized healthcare system, with each province and territory responsible for delivering health services, understanding national-level outcomes and interprovincial variation is critical for developing effective, targeted interventions [9, 10]. To address this knowledge gap, we conducted a national multisite cohort analysis using data from the Canadian Network Undertaking against Hepatitis C (CANUHC). Our objectives were to (1) compare baseline characteristics and DAA treatment outcomes between immigrants and Canadian-born individuals; (2) examine provincial variation in treatment outcomes; (3) assess time from immigration to specialist care engagement; and (4) identify site-specific differences that may inform targeted public health strategies to support HCV elimination goals.
METHODS
Study Design and Setting
CANUHC is a national prospective cohort study that enrolled HCV patients from 17 Canadian-based, publicly funded HCV clinic sites across 7 Canadian provinces. The cohort consists of patients eligible for DAA therapy from January 2015 to May 2023 who gave informed consent. CANUHC was designed with the primary objective to assess short- and medium-term outcomes of antiviral treatment in key priority populations including people who inject drugs, Indigenous peoples, and newcomers/immigrants to Canada, in addition to broader HCV-positive patient populations. The 17 participating sites were specifically selected based on their capacity to recruit and treat diverse populations, including marginalized and at-risk groups. Data were collected using REDCap (Research Electronic Data Capture), a secure online database maintained by the University of Calgary.
At assessment, patients were instructed to complete an intake form to capture demographic and lifestyle information including age, sex, race/ethnicity, country of origin, year of immigration (for foreign-born patients), education level, employment status, and housing stability. Clinicians were required to complete a separate intake form for each patient to identify comorbidities, baseline biochemical data, human immunodeficiency virus (HIV) serology, HBV coinfection, HCV viral load, genotype, fibrosis stage, past treatment history, and current HCV treatment plan. Patients were followed from their index assessment until their SVR assessment date, death, or loss to follow-up if they initiated DAA treatment, defined as having received a DAA prescription. SVR was determined as being HCV RNA negative at least 12 weeks following completion of DAA treatment.
The final study cohort included treatment-naive patients with available information on immigration status. We only included patients who were treatment naive to ensure that the CANUHC assessment visit would correspond to their initial consultation with the viral hepatitis clinic. Baseline was defined as the date of this initial visit. Baseline demographic variables included age at consult, sex, race, site of assessment, time period of consult (prepandemic: 2015–March 2020; pandemic: April 2020–March 2022; postpandemic: April 2022–May 2023), education, employment status, housing stability, and drug use. Sites were identified by province (British Columbia [BC], Alberta [AB], Saskatchewan [SK], Ontario [ON], New Brunswick [NB], Quebec [QC], Nova Scotia [NS]) and then numbered.
We compared baseline characteristics, treatment initiation, and SVR results of immigrant and Canadian-born patients. Provincial variation in treatment outcomes was assessed by calculating outcome proportions separately for each province, stratified by immigration status. Among immigrants with documented year of arrival, time from immigration to specialist assessment was calculated and analyzed by 5-year arrival cohorts (1990–1994, 1995–1999, 2000–2004, 2005–2009, 2010–2014, 2015–2020) to assess temporal trends. Regional variation in time to care was also examined. A t-test or one-way analysis of variance was employed to determine differences in means, and the Kruskal–Wallis test was used for median values. A χ2 test was used to compare differences among categorical variables. Missing data were not used to compare differences among variables. We conducted multivariate logistic regression to assess potential association between immigrant status and outcomes of interest: DAA initiation, SVR bloodwork completion, and SVR status. Our models adjusted for the following potential confounders: race, sex, site, time period, incarceration history, injection drug use (IDU), and employment status. All analyses were conducted by using SAS Enterprise Guide version 7.15 (SAS Institute, Inc). The study was performed in accordance with the Helsinki Declaration of 1964 and its later amendments.
RESULTS
Study Population and Baseline Characteristics
A total of 3270 chronically HCV-infected patients were enrolled into CANUHC, of which 2958 (90.5%) contained information about immigration status. A total of 2521 (85.2%) HCV patients who were treatment naive were included in the analysis. Of these, 2094 (83.1%) were Canadian born and 427 (16.9%) were immigrants to Canada (Table 1). Of the 427 immigrants, most came from Europe (29.9%), followed by South Asia (19.3%), Southeast Asia (15.7%), the Americas (12.9%), East and Central Asia (8.4%), sub-Saharan Africa (8.1%), the Middle East and North Africa (5.1%), and Oceania (0.5%).
Table 1.
Baseline Characteristics of Canadian-Born and Immigrant Patients
| Baseline Characteristic | Overall (N = 2521) |
Canadian-Born (n = 2094) |
Immigrant to Canada (n = 427) | P Value |
|---|---|---|---|---|
| Age at consult, y, mean (SD) | 49.52 (13.3) | 48.8 (12.9) | 52.9 (14.7) | <.001 |
| Age group, y | ||||
| 0–20 | 13 (0.5%) | 12 (0.6%) | 1 (0.2%) | <.001 |
| 21–39 | 651 (26.2%) | 559 (27.1%) | 92 (21.7%) | |
| 40–59 | 1178 (47.3%) | 1004 (48.6%) | 174 (41.1%) | |
| 60–69 | 546 (21.9%) | 434 (21.0%) | 112 (26.5%) | |
| ≥70 | 100 (4.0%) | 56 (2.7%) | 44 (10.4%) | |
| Sex | ||||
| Female | 923 (36.6%) | 717 (34.3%) | 206 (48.2%) | <.001 |
| Male | 1597 (63.4%) | 1376 (65.7%) | 221 (51.8%) | |
| Race | ||||
| White | 1662 (67.2%) | 1493 (72.7%) | 169 (40.1%) | <.001 |
| Black | 60 (2.4%) | 14 (0.7%) | 46 (10.9%) | |
| Asian | 180 (7.3%) | 14 (0.7%) | 166 (39.4%) | |
| Indigenous | 469 (18.9%) | 466 (22.7%) | 3 (0.7%) | |
| Other | 104 (4.2%) | 67 (3.3%) | 37 (8.8%) | |
| Province | ||||
| Alberta | 521 (20.7%) | 401 (19.1%) | 120 (28.1%) | <.001 |
| Atlantic Provinces | 445 (17.7%) | 431 (20.6%) | 14 (3.3%) | |
| British Columbia | 698 (27.7%) | 632 (30.2%) | 66 (15.5%) | |
| Ontario | 542 (21.5%) | 335 (16.0%) | 207 (48.5%) | |
| Quebec | 53 (2.1%) | 49 (2.3%) | 4 (0.9%) | |
| Saskatchewan | 262 (10.4%) | 246 (11.7%) | 16 (3.7%) | |
| Years from immigration to consult, mean (SD) | 24.93 (18.6) | … | 24.93 (18.6) | |
| Period of consult | ||||
| Prepandemic (2015–Mar 2020) | 2054 (81.5%) | 1690 (80.7%) | 364 (85.2%) | .002 |
| Pandemic (Apr 2020–Mar 2022) | 393 (15.6%) | 348 (16.6%) | 45 (10.5%) | |
| Postpandemic (Apr 2022–May 2023) | 74 (2.9%) | 56 (2.7%) | 18 (4.2%) | |
| Education | ||||
| College or university | 688 (33.7%) | 477 (28.2%) | 211 (60.8%) | <.001 |
| High school or less | 1352 (66.3%) | 1216 (71.8%) | 136 (39.2%) | |
| Employment | ||||
| Yes | 746 (31.3%) | 554 (28.0%) | 192 (47.1%) | <.001 |
| No | 1638 (68.7%) | 1422 (72.0%) | 216 (52.9%) | |
| Housing | ||||
| Stable | 1786 (87.5%) | 1465 (86.1%) | 321 (94.4%) | <.001 |
| Unstable | 256 (12.5%) | 237 (13.9%) | 19 (5.6%) | |
| Current frequency of alcohol use | ||||
| None | 1479 (64.2%) | 1223 (63.5%) | 256 (67.9%) | <.001 |
| ≤3 drinks per day | 667 (28.9%) | 553 (28.7%) | 114 (30.2%) | |
| >3 drinks per day | 158 (6.9%) | 151 (7.8%) | 7 (1.9%) | |
| History of incarceration | ||||
| Yes | 1044 (43.6%) | 997 (49.1%) | 47 (12.9%) | <.001 |
| No | 1350 (56.4%) | 1033 (50.9%) | 317 (87.1%) | |
| History of injection drug use | ||||
| Yes | 1502 (68.0%) | 1418 (75.3%) | 84 (25.8%) | <.001 |
| No | 707 (32.0%) | 466 (24.7%) | 241 (74.2%) | |
| History of recreational drug use | ||||
| Yes | 1935 (84.7%) | 1789 (91.8%) | 146 (43.5%) | <.001 |
| No | 349 (15.3%) | 159 (8.2%) | 190 (56.5%) | |
| History of psychiatric diagnosis | ||||
| Yes | 775 (32.2%) | 707 (34.5%) | 68 (19.1%) | <.001 |
| No | 1631 (67.8%) | 1343 (65.5%) | 288 (80.9%) | |
| Opiate substitution therapy | ||||
| Yes | 594 (24.8%) | 568 (27.9%) | 26 (7.3%) | <.001 |
| No | 1797 (75.2%) | 1469 (72.1%) | 328 (92.7%) | |
| Platelets (count ×109 per L), median (Q1-Q3) | 225 (177–273) | 228 (180–274) | 209 (163–259) | <.001 |
| ALT, U/L, median (Q1–Q3) | 50 (30–89) | 51 (31–91) | 46 (30–77) | .02 |
| AST, U/L, median (Q1–Q3) | 42 (29–70) | 43 (29–71) | 39 (29–63) | .06 |
| HCV RNA viral load, IU/mL, median (Q1–Q3) | 762 720 (110 082–2 580 000) | 733 596 (100 629–2 556 030) | 891 000 (167 000–2 893 182) | .17 |
| Genotype | ||||
| 1 | 42 (1.8%) | 27 (1.4%) | 15 (3.9%) | <.001 |
| 1a | 1180 (51.1%) | 1097 (57.0%) | 83 (21.7%) | |
| 1b | 206 (8.9%) | 106 (5.5%) | 100 (26.1%) | |
| 2 | 221 (9.6%) | 180 (9.3%) | 41 (10.7%) | |
| 3 | 579 (25.1%) | 489 (25.4%) | 90 (23.5%) | |
| 4 | 40 (1.7%) | 9 (0.5%) | 31 (8.1%) | |
| 5 | 1 (0.0%) | 1 (0.1%) | 0 (0.0%) | |
| 6 | 19 (0.8%) | 1 (0.1%) | 18 (4.7%) | |
| Mixed | 21 (0.9%) | 16 (0.8%) | 5 (1.3%) | |
| Transient elastography score, kPa, mean (SD) | 9.58 (9.62) | 9.61 (9.58) | 9.46 (9.76) | .79 |
| Fibrosis stagea | ||||
| F0–F1 | 1395 (61.3%) | 1146 (61.3%) | 249 (60.9%) | .33 |
| F2 | 188 (8.3%) | 160 (8.6%) | 28 (6.8%) | |
| F3 | 243 (10.7%) | 203 (10.9%) | 40 (9.8%) | |
| F4 | 451 (19.8%) | 359 (19.2%) | 92 (22.5%) | |
| Resistance testing | ||||
| Yes | 139 (5.9%) | 129 (6.5%) | 10 (3.0%) | .01 |
| No | 2198 (94.1%) | 1870 (93.5%) | 328 (97.0%) | |
| Resistance present if tested | ||||
| Yes | 111 (87.4%) | 103 (88.0%) | 8 (80.0%) | .46 |
| No | 16 (12.6%) | 14 (12.0%) | 2 (20.0%) | |
| HIV coinfection | ||||
| Yes | 113 (5.5%) | 108 (6.1%) | 5 (1.6%) | .001 |
| No | 1960 (94.5%) | 1657 (93.9%) | 303 (98.4%) | |
| HBV coinfection | ||||
| Yes | 36 (1.9%) | 24 (1.5%) | 12 (4.3%) | .002 |
| No | 1812 (98.1%) | 1548 (98.5%) | 264 (95.7%) | |
| Diabetes | ||||
| Yes | 166 (6.9%) | 126 (6.1%) | 40 (11.2%) | <.001 |
| No | 2239 (93.1%) | 1923 (93.9%) | 316 (88.8%) | |
| Cirrhosis | ||||
| Yes | 451 (18.1%) | 359 (17.4%) | 92 (22.0%) | .03 |
| No | 2035 (81.9%) | 1708 (82.6%) | 327 (78.0%) |
Data are presented as No. (%) unless otherwise indicated.
Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; HBV, hepatitis B virus; HCV, hepatitis C virus; HIV, human immunodeficiency virus; Q1, first quartile; Q3, third quartile; SD, standard deviation.
aFibrosis stage determined by converted transient elastography scores and/or physician report.
Sociodemographic Characteristics
Multiple sociodemographic differences were observed between immigrant and Canadian-born groups (Table 1). Immigrants were older at the time of specialist consult (mean age, 52.9 ± 14.7 years vs 48.8 ± 12.9 years; P < .001) and more likely to be female (48.2% vs 34.3%, P < .001). The age distribution differed substantially with a higher proportion of immigrants aged ≥60 years (36.9% vs 23.7%, P < .001) and a higher proportion of Canadian-born patients aged 40–59 years (48.6% vs 41.1%).
Racial composition differed markedly between groups. Among immigrants, 40.1% were White, 39.4% Asian, and 10.9% Black compared to Canadian-born patients who were predominantly White (72.7%, P < .001). Indigenous persons comprised 22.7% of Canadian-born patients and 0.7% of immigrants.
Immigrant population distribution varied between sites (Figure 1). Ontario site ON02 assessed the highest proportion of immigrant patients (55.8%) followed by ON01 (47.2%). Alberta site AB01 (37.1%) also enrolled a large proportion of immigrant patients (Figure 1). British Columbia sites reported variable proportions ranging from 4.4% to 18.2%. Atlantic sites (NB01, NB02, NS01) had low immigrant proportions (0.9%–5.2%).
Figure 1.
Proportion of immigrant patients with hepatitis C virus recruited in each site. Abbreviations: AB, Alberta; BC, British Columbia; NB, New Brunswick; NS, Nova Scotia; ON, Ontario; QC, Quebec; SK, Saskatchewan.
Immigrants demonstrated higher educational attainment with 60.8% having completed college or university education compared to 28.2% of Canadian-born patients (P < .001). Employment rates were higher among immigrants (47.1% vs 28.0%, P < .001), and immigrants were more likely to be stably housed (94.4% vs 86.1%, P < .001).
Behavioral and Social History
Substantial differences in behavioral and social history variables were observed (Table 1). Canadian-born patients had markedly higher rates of IDU history (75.3% vs 25.8%, P < .001), recreational drug use history (91.8% vs 43.5%, P < .001), incarceration history (49.1% vs 12.9%, P < .001), psychiatric diagnoses (34.5% vs 19.1%, P < .001), and current opiate substitution therapy (27.9% vs 7.3%, P < .001). Canadian-born patients were more likely to report consuming more than 3 drinks per day (7.8% vs 1.9%, P < .001), though overall rates of alcohol use (including moderate consumption) were similar between groups.
Clinical Characteristics
Most clinical laboratory parameters were comparable between immigrant and Canadian-born groups (Table 1). HCV genotype distribution differed between groups. Genotype 1a was predominant among Canadian-born patients (57.0%) but less common among immigrants (21.7%). Genotype 1b was more common among immigrants (26.1% vs 5.5%) as were genotypes 4 (8.1% vs 0.5%) and 6 (4.7% vs 0.1%). Genotypes 2 and 3 were similarly distributed between groups. Resistance-associated substitution testing was performed less frequently among immigrants (3.0% vs 6.5%, P = .01). In those tested, the prevalence of detected resistance was similar (80.0% vs 88.0%, P = .46).
Fibrosis stage distribution was comparable between groups with approximately 61% of both groups having F0–F1 fibrosis and 19%–23% having cirrhosis (F4). When comparing differences in only cirrhosis distribution, we observed a higher proportion among immigrants (22.0% vs 17.4%, P = .03). Mean transient elastography scores were similar (9.5 [SD, 9.8] kPa in immigrants vs 9.6 [SD, 9.6] kPa in Canadian-born; P = .79).
HIV coinfection prevalence was lower in immigrants (1.6% vs 6.1%, P < .01) and HBV coinfection was higher (4.3% vs 1.5%, P < .01). Diabetes was more common among immigrants (11.2% vs 6.1%, P < .001).
Treatment Outcomes
DAA treatment outcomes were excellent for both groups, with immigrants demonstrating comparable or superior results to Canadian-born patients (Table 2). A higher proportion of immigrants initiated DAA therapy compared to Canadian-born patients (95.6% vs 92.2%, P = .02) with a crude odds ratio (OR) of 1.81 (95% confidence interval [CI], 1.11–2.95). However, after adjustment for age, race, sex, site, time period, incarceration history, IDU, and employment status, immigration status was not independently associated with DAA initiation (adjusted OR, 1.09 [95% CI, .45–2.67]).
Table 2.
Direct-Acting Antiviral (DAA) Treatment Outcomes by Immigration Status and Association Between Immigration and DAA Treatment Initiation, Completion, Sustained Virological Response (SVR) Bloodwork, and SVR
| Outcome | Canadian-Born (n = 2094) | Immigrant to Canada (n = 427) | Crude OR (95% CI) |
Adjusted ORa (95% CI) |
|---|---|---|---|---|
| No. of Events/Population (%) | No. of Events/Population (%) | |||
| DAA initiation | 1931/2094 (92.2) | 408/427 (95.6) | 1.81 (1.11–2.95) | 1.09 (.45–2.67) |
| SVR determination bloodwork completed | 1362/1931 (70.5) | 333/408 (81.6) | 1.86 (1.42–2.43) | 1.35 (.79–2.29) |
| SVR achieved | 1297/1316 (98.6) | 328/328 (100) | 9.87 (1.35 to >999.99) | 2.25 (.20–832.6) |
Abbreviations: CI, confidence interval; DAA, direct-acting antiviral; OR, odds ratio; SVR, sustained virological response.
aAdjusted for age, race, sex, site, time period, incarceration history, injection drug use, and employment status.
Immigrants were more likely to complete SVR bloodwork following DAA completion (81.6% vs 70.5%, P < .001) with a crude OR of 1.86 (95% CI, 1.42–2.43). After multivariable adjustment, this association was no longer observed (adjusted OR, 1.35 [95% CI, .79–2.29]).
Among patients who completed SVR bloodwork, 100% of immigrants achieved SVR compared to 98.6% of Canadian-born patients (P = .03) with a crude OR of 9.87 (95% CI, 1.35 to >999.99). After multivariable adjustment, this association was no longer observed (adjusted OR, 2.25 [95% CI, .20–832.6]).
Site-Level Variation in Outcomes
Variation in treatment outcomes were observed across the 17 CANUHC sites (Supplementary Figure 1). DAA initiation proportions ranged from 33.3% to 100% across sites, with most sites achieving >90% initiation in both immigrant and Canadian-born populations. Differences in DAA initiation between immigrants and Canadian-born patients were only seen at AB01 (100% vs 91.6%, respectively; P < .01).
Posttreatment SVR bloodwork completion varied by site (Supplementary Figure 2). Some Ontario, British Columbia, and Nova Scotia sites reported lower completion rates. Differences in SVR bloodwork completion between immigrants and Canadian-born patients was only observed at 1 site, BC02 (94.7% vs 72.1%, respectively; P < .05).
SVR achievement was high across most sites (>95%) (data not shown). Immigrants with available SVR information achieved cure at every site. There were no differences observed in SVR between Canadian-born and immigrant patients at any of the 17 sites.
Time From Immigration to Specialist Assessment
Of the 228 immigrants with who arrived in Canada on or after 1990, the mean time from immigration to specialist HCV assessment was 13.1 years (SD, 8.7 years). Analysis by 5-year arrival cohorts revealed a decreasing trend in time to assessment (Supplementary Figure 3): 1990–1994: 27 years; 1995–1999: 22 years; 2000–2004: 16 years; 2005–2009: 12 years; 2010–2014: 7 years; 2015–2020: 2 years) (P < .001).
DAA treatment outcomes among immigrants did not differ by year of arrival groupings (Table 3). DAA initiation proportions ranged from 90.6% to 100% across groupings (P = .47). Posttreatment SVR bloodwork completion proportions ranged from 72.9% to 89.5% (P = .26) and among those completing bloodwork, all arrival groupings achieved 100% SVR.
Table 3.
Treatment Outcomes for Immigrants With Information on Year of Arrival to Canadaa
| Outcome | Total | 1990–1994 (n = 35) | 1995–1999 (n = 28) | 2000–2004 (n = 38) | 2005–2009 (n = 38) | 2010–2014 (n = 36) | 2015–2019 (n = 53) | P Value |
|---|---|---|---|---|---|---|---|---|
| DAA initiation, No. (%) | ||||||||
| Yes | 216 (94.7) | 34 (97.1) | 26 (92.9) | 38 (100.0) | 36 (94.7) | 34 (94.4) | 48 (90.6) | .47 |
| No | 12 (5.3) | 1 (2.9) | 2 (7.1) | 0 (0.0) | 2 (5.3) | 2 (5.6) | 5 (9.4) | |
| SVR determination bloodwork completed, No. (%) | ||||||||
| Yes | 179 (82.9) | 30 (88.2) | 21 (80.8) | 34 (89.5) | 32 (88.9) | 27 (79.4) | 35 (72.9) | .26 |
| No | 37 (17.1) | 4 (11.8) | 5 (19.2) | 4 (10.5) | 4 (11.1) | 7 (20.6) | 13 (27.1) | |
| SVR achieved, No. (%) | ||||||||
| Yes | 176 (100.0) | 29 (100.0) | 21 (100.0) | 33 (100.0) | 32 (100.0) | 27 (100.0) | 34 (100.0) | |
| No | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Abbreviations: DAA, direct-acting antiviral; SVR, sustained virological response
aOnly immigrants who landed from 1990 onward. There was only 1 immigrant who landed on or after 2020.
Time from immigration to specialist assessment varied by region of origin (Supplementary Figure 4). Immigrants from South Asia had the shortest median time to care at 8 years followed by Oceania (14 years), East and Central Asia (15 years), sub-Saharan Africa (17 years), and Middle East and North Africa (20 years). Those from Europe and the Americas experienced the longest delays at 31 and 32 years, respectively.
DISCUSSION
This national multisite cohort study demonstrates that immigrants in Canada achieve excellent DAA treatment outcomes comparable to Canadian-born patients. Immigrants across all 17 sites with available posttreatment information achieved high SVRs that were comparable to Canadian-born patients. Similarly, after adjustment for relevant confounders, no differences were observed between immigrants and Canadian-born patients for either DAA initiation or SVR bloodwork completion. These findings from the CANUHC cohort spanning 6 provinces and 17 sites provide national-level, multisite evidence indicating that when immigrants are engaged in HCV specialty care, they successfully navigate the treatment cascade and achieve high proportions of virological cure.
A novel contribution of this analysis is the documentation of intersite variation in HCV care delivery. The sites demonstrated differing patient populations and recruitment patterns: Ontario sites (ON01, ON02) enrolled the highest proportions of immigrant patients (47.2% and 55.8%), while Atlantic sites (NB01, NB02, NS01) enrolled much lower proportions of immigrant patients. These variations reflect both local immigration settlement patterns and CANUHC site distribution. However, within-site differences between immigrant and Canadian-born patients were only observed in 2 clinics (AB01 and BC02). At these sites, immigrants achieved a higher proportion of preferable outcomes compared to their Canadian-born counterparts (AB01 DAA initiation: 100% vs 91.6%, P < .01; BC02 SVR bloodwork completion: 94.7% vs 72.1%, P < .05). Site-level differences in treatment outcomes suggest variation in healthcare access, provincial reimbursement policies for DAA therapy, and clinic resources. Provincial public drug plans vary substantially in DAA coverage criteria, including testing requirements, prior authorization timelines (ranging from same-day to 4 weeks), prescriber restrictions, and reinfection coverage policies [20]. These policy variations can create differential access to treatment across jurisdictions. Such delays and restrictions disproportionately affect marginalized populations including uninsured immigrants, delaying or preventing treatment initiation. Several publications suggest that clinic structure, resources, and care delivery models influence immigrant engagement and outcomes [21–23]. This is likely because of finding issues; reimbursement models research on HCV care delivery models demonstrates that certain structural and resource factors are associated with improved treatment outcomes [24–26]. Multidisciplinary models incorporating patient navigators, nurses, social workers, and specialty pharmacies improve patient engagement and SVR [24, 27]. A large academic health system example demonstrated that embedding specialty pharmacists within HCV clinics to serve as medication experts and care coordinators resulted in patient approval rates of 93% compared to 81%–91% in standard care [24]. Co-localization of HCV screening, evaluation, and treatment alongside primary care services and integration of HCV treatment with substance use disorder services have also been shown to improve care cascade completion [25, 28, 29]. Ontario site ON01, which enrolled the largest number of patients (n = 326 [47.2% immigrant]), achieved 94.8% DAA initiation among immigrants. The second highest patient enrollment site, AB01 (n = 264 [37.1% immigrant]), achieved 100% immigrant DAA initiation. The structure and resource allocation of these high-performing sites may offer important examples.
HCV care delivered by nonspecialist physicians, nurses, and/or peers rather than exclusively by specialists can similarly improved access and treatment outcomes, particularly in underserved communities [25, 30]. Primary care clinics functioning as treatment delivery systems have demonstrated increased HCV treatment uptake (67.4% vs 34.5%) with comparable SVR rates (94.9% vs 96.8%) when compared to specialty-only care [30]. The site-level variation observed in our cohort may reflect differences in whether sites employ these evidence-based care models and different levels of resources for patient care. We acknowledge that our data-gathering efforts may have influenced our findings. Even though the intake forms for data collection were standardized, each site may have employed different approaches to capturing the data. This may have resulted in some degree of over- or underrepresentation of outcomes when making intersite comparisons. We do recognize this to be a limitation of the study.
A mean 24.9-year (mean, 13.1 years for those that landed on or after 1990) delay from immigration to specialist assessment represents a substantial gap in the care cascade. However, temporal analysis reveals encouraging progress. Among immigrants arriving on or after 1990, median time to specialist assessment decreased with each 5-year interval. This trend mirrors findings already reported in one of our Ontario-based sites [19]. This positive trend likely reflects the combined impact of Canada's commitment to WHO elimination goals [31, 32], universal DAA funding [31], expanded screening programs, and increased health literacy among recent immigrants [33].
Regional variation by immigrant origin provides important insights for targeted interventions. South Asian immigrants experienced the shortest median time to care at 8 years compared to 31–32 years for European and American immigrants. These patterns are a consequence of multiple factors: differential screening priorities targeting immigrants from regions perceived as higher risk [5]; historical immigration patterns, with many European immigrants arriving in earlier eras when HCV awareness and treatment were limited; and community-level factors including health literacy, disease awareness, and healthcare utilization patterns [5, 10]. The particularly long delays among European and American immigrants suggest that provider education should emphasize that HCV affects immigrants from all regions, especially those who received medical care before improved infection control practices were implemented [5, 10, 19].
Immigrants achieved excellent treatment outcomes. The high SVR proportion reflects the influence of multiple factors: low active substance use and housing stability that facilitate healthcare engagement and medication adherence; high educational attainment associated with better health literacy and employment; and specialized CANUHC sites that provide culturally competent care, interpretation services, and multidisciplinary support [5, 10, 24, 25].
After adjustment for age, race, sex, province, time period, incarceration, IDU, and employment, immigration status was not independently associated with treatment outcomes. This suggests that observed differences are largely explained by sociodemographic characteristics and social determinants rather than immigration status. When immigrants access well-resourced HCV specialty care addressing language barriers and providing culturally appropriate services, they achieve outcomes equivalent to Canadian-born patients with similar profiles [5].
Our findings suggest that Canada's commitment to WHO HCV elimination targets by 2030 is in need of several priority actions. First, systematic HCV screening for newly arrived immigrants from endemic regions during or shortly after immigration medical examination could identify infections years earlier. Second, site-level best practices from high-performing CANUHC centers should be investigated and disseminated nationally. Third, the lower engagement observed at some sites requires investigation to understand whether the observed differences are due to differences in reporting or whether a targeted investment is warranted to understand barriers and implement evidence-based care models [25, 29]. Fourth, screening and outreach should be tailored by region of origin, with particular attention to European and American immigrants who may be missed by current risk assessment approaches. Fifth, partnerships between HCV programs and settlement agencies could facilitate earlier diagnosis and linkage [5, 9, 33].
This study has important strengths including national multisite scope, diverse populations from 6 provinces, and comprehensive data enabling robust multivariable analysis. However, limitations warrant consideration. The CANUHC cohort represents patients successfully engaged with specialty services and may underrepresent the most marginalized populations, though our deliberate recruitment of priority populations mitigates this to some degree. For example, 22.7% of our Canadian-born patients identified as Indigenous. Immigration data completeness was limited (53.4% with year of arrival documented), restricting temporal and regional analyses. Quebec and Atlantic provinces were underrepresented, and most sites are urban academic centers, potentially overrepresenting immigrants with better access to specialty care. The study captures only the DAA era (2015–2025), limiting assessment of longer-term historical trends. We lacked detailed information on language barriers, immigration category, health insurance coverage, and linkage pathways that may influence care engagement. Since this study utilized data from 17 different sites across Canada, we recognize that there is a possibility of differences in data capture and recording for each site.
CONCLUSIONS
This national multisite analysis demonstrates that immigrants achieve excellent HCV treatment outcomes when engaged in specialty care. Historical concerns with prolonged delay from immigration to care engagement have been addressed in recent years. Provincial and regional variation highlights opportunities to learn from high-success jurisdictions. To optimize immigrant HCV care, Canada should consider implementing systematic screening for newly arrived immigrants, enhance linkage mechanisms between settlement and healthcare services, provide culturally competent care, disseminate provincial best practices, and maintain ongoing surveillance. By combining accessible DAA therapy with proactive case-finding and patient-centered strategies, Canada can ensure that all populations, including immigrants who bear disproportionate HCV burden, benefit equitably from treatment advances and contribute to national elimination efforts.
Supplementary Material
Notes
Author contributions. H. I. analyzed the data. H. I., S. F., and C. L. C. were responsible for study design and drafting of the manuscript. G. M., D. W., D. S., S. B., J. J. F., and S. L. were responsible for critical editing and revision of the manuscript.
Data availability. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
Financial support. The Canadian Network Undertaking against Hepatitis C (CANUHC) acknowledges funding from Gilead and AbbVie. The Canadian Network on Hepatitis C (CanHepC) acknowledges funding from the Public Health Agency of Canada.
Contributor Information
Haris Imsirovic, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
Sabrina Fan, University of Toronto, Toronto, Ontario, Canada.
Gisela Macphail, University of Calgary, Calgary, Alberta, Canada.
Duncan Webster, Dalhousie University, Halifax, Nova Scotia, Canada.
Daniel Smyth, Dalhousie University, Halifax, Nova Scotia, Canada.
Sergio Borgia, Division of Infectious Diseases, William Osler Health System, Brampton, Ontario, Canada; Division of Infectious Diseases, McMaster University, Hamilton, Ontario, Canada.
Jordan J Feld, Toronto Centre for Liver Disease, University Health Network, University of Toronto, Toronto, Ontario, Canada.
Sam Lee, University of Calgary, Calgary, Alberta, Canada.
Curtis L Cooper, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; University of Ottawa, Ottawa, Ontario, Canada.
Supplementary Data
Supplementary materials are available at Open Forum Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author.
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