HEALTHCARE UTILIZATION IN QUEBEC
IMMIGRANTS AND NON-IMMIGRANTS
WITH CHRONIC HEPATITIS C INFECTION
Supervisor:
Dr. Christina Greenaway
Thesis committee:
Dr. Laurent Azoulay
Dr. Marina Klein
Dr. Russell Steele
Rhiannon Kamstra
M.Sc. Student
McGill EBOH 50th Anniversary
May 1st, 2015
Chronic Hepatitis C
Up to 85% of people infected by
Hepatitis C Virus become
chronically infected
Cirrhosis
30%
HCC
Liver
failure
WHO Guidelines (April 2014)
develop liver
disease in
20-30 years
Transplant
2
Transmission
MEDICAL
PROCEDURES
300k cases/year
from unsafe injections
BLOOD PRODUCTS
Pre-screening era
INJECTION DRUG USE
60%
of new cases in
3
Canada
Burden
350k
global deaths per year
185 million
250,000
infections worldwide
Canadians infected
At least 35% of cases are undetected
Mohd Hanafiah et al. Hepatology (2013)
Lavanchy D. Liver Int. (2009)
Hepatitis C In Canada: 2005-2010 Surveillance Report (PHAC)
4
Rising healthcare use
Projected 60% increase in annual costs due
to HCV in Canada over the next 20 years(Myers 2014)
Myers et al. Can J Gastroenterol Hepatol (2014)
Hepatitis C In Canada: 10 2005-2010 Surveillance Report (PHAC)
5
Immigrants
Often migrate
from regions with
high
prevalence
Different risk
factors and
health status
Very limited data – modelling estimates suggest
20% of cases in Canada occur in immigrants
Hepatitis C In Canada: 2005-2010 Surveillance Report (PHAC)
Evolving epidemiology of hepatitis C virus. Lavanchy (2011)
6
Rationale
WHY?
Inform policy and planning with data
about healthcare utilization in the
Quebec HCV-infected population
Immigrants are a unique subgroup –
understanding differences will help
prevention and treatment efforts
7
Objective
Estimate and compare all-cause and
liver-related healthcare utilization for
immigrants and non-immigrants with HCV,
identifying predictors of utilization
8
Study Design
Retrospective longitudinal cohort study
Cases ascertained from mandatory reportable disease
database (MADO) from 1998-2007
Loss of RAMQ
coverage
(>6 months)
Death
1 year prior
to diagnosis
End of study
Dec. 31, 2007
Date of diagnosis
Censoring
Assess prevalent
comorbidities
Measure incident
healthcare utilization
9
Deterministic linkage
RAMQ ID
• AGE
• SEX
• LOCATION
• COVERAGE
MED-ECHO
PHYSICIAN
BILLING
OUTPATIENT VISITS
BILLING CODES
HOSPITALIZATIONS
DIAGNOSTIC CODES
PROCEDURES
Deterministic linkage
VISA #
• ARRIVAL DATE
• COUNTRY OF ORIGIN
HEALTH SERVICES
DATA
10
Cohort
Selection
11
Definitions
Focused on hospitalizations as measure of healthcare utilization
• Liver-related complications are serious
Primary measures of healthcare utilization
Hospital stays (N)
Days in hospital (N)
Liver-related hospitalizations required at least one diagnostic
code (ICD 9, ICD 10, or procedure code) to match a specified list
(including cirrhosis, liver transplant, liver cancer)
Prevalent comorbidities were identified using hospitalizations and
physician billing using ICD 9 and 10 codes
12
Analysis
1
2
Summarize and compare characteristics
of hospitalizations in immigrants and nonimmigrants
(e.g., mean N per subject, rate per 100PY,
length of stay, reason for stay)
Examined influence of demographic
differences on rate of hospitalizations in
immigrants/non-immigrants using
negative binomial modelling
13
Demographics
N = 20,139 cases (1998-2007)
Median follow-up: 3.9 years (immigrants)
4.8 years (non-immigrants)
Immigrants
accounted for
9% of cases
26% originated from
East Asia/Pacific
(most common region of origin)
Time from arrival to diagnosis was 9.8 ± 6.9 years
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Immigrants
Demographics
Older at diagnosis (47.6 years vs. 43.2 years)
Only 53% male (vs. 68%)
78% located in Montreal (vs. 38%)
30
Prevalence (%)
25
Immigrants
Non-immigrants
Drug/alcohol related
4-10x more common in
non-immigrants
20
15
10
5
More frequent in
immigrants at
baseline
0
15
All-cause hospitalizations
Most subjects were never hospitalized during follow-up.
Non-immigrants had a higher burden of all-cause hospitalizations
49.3% of
non-immigrants
ever hospitalized
Stays per subject and per person-time
higher in non-immigrants
Characteristic
Immigrants
N = 1821
Non-immigrants
N = 18318
p
N (%) ever hospitalized
652 (35.80)
9032 (49.31)
<.0001
Total hospitalizations (N)
1525
29239
Mean stays per person (95% CI)
0.84 (0.76-0.92)
1.60 (1.56-1.64)
Crude rate of stays / 100 PY
22.1 (20.2-24.2)
37.1 (36.2-38.1)
Mean days per person (95% CI)
7.34 (6.31-8.37)
15.77 (15.01-16.53) <.0001
Crude rate of hospital days / 100 PY 167.3
325.7
Mean length of stay ± SD (days)
11.51 ± 25.25
11.37 ± 16.61
<.0001
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All-cause hospitalizations
Category of primary diagnosis
% of all hospitalizations
Immigrants
Non-immigrants
1
Liver/viral hepatitis
11.6%
Mental disorders
20.5%
2
Nervous system/
sense organs
10.2%
Injury & poisoning
10.3%
3
Pregnancy/childbirth
8.7%
Digestive system (excl. liver)
8.7%
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Liver-related hospitalizations
7.2% of subjects contributed all liver-related stays
Characteristic
Immigrants
N = 1821
Non-immigrants
N = 18318
p
N (%) ever hospitalized
142 (7.80)
1299 (7.09)
0.27
Total hospitalizations (N)
286
3164
Mean stays per person (95% CI)
0.16 (0.13-0.19)
0.17 (0.16-0.18)
Crude rate of stays / 100 PY
6.4 (4.7-8.6)
5.8 (5.3-6.4)
Mean days per person (95% CI)
2.32 (1.72-2.92)
2.37 (2.16-2.58)
Rate of hospital days / 100 PY
52.9
48.8
Mean length of stay ± SD (days)
15.17 ± 21.02
14.04 ± 21.11
0.63
0.89
Liver-related hospitalization was similar for immigrants and
non-immigrants despite comorbidities
Most in-hospital deaths in immigrants were liver-related (57.9% vs. 41.8%)
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Modelling
What is driving similar rates of liver-related
hospitalization vs. different all-cause
All-cause hospitalizations
Covariate
Univariate
Rate ratio, 95%CI
p
Multivariate
(Rate ratio, 95%CI
p
Immigrant status
Non-immigrant
REFERENCE
Immigrant
Age (cont.)
0.60 (0.54-0.65)
1.02 (1.02-1.02)
REFERENCE
<.0001
<.0001
0.52 (0.47-0.57)
1.02 (1.02-1.02)
<.0001
<.0001
Sex
M
REFERENCE
F
1.26 (1.16-1.29)
REFERENCE
<.0001
1.28 (1.21-1.34)
<.0001
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Modelling
What is driving similar rates of liver-related
hospitalization vs. different all-cause
Liver-related hospitalizations
Covariate
Univariate
Rate ratio, 95%CI
Multivariate
(Rate ratio, 95%CI
p
p
Immigrant status
Non-immigrant
REFERENCE
Immigrant
Age (cont.)
1.10 (0.80-1.49)
1.09 (1.08-1.09)
REFERENCE
<.5652
<.0001
0.69 (0.52-0.92)
1.09 (1.08-1.09)
0.0102
<.0001
Sex
M
REFERENCE
F
0.89 (0.74-1.06)
REFERENCE
0.1935
0.69 (0.59-0.82)
<.0001
Relative rate of liver-related
affected by different age and
sex distribution
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Discussion
• Immigrants are different – implications for
prevention and treatment
• Non-immigrants have more all-cause
hospitalization but similar liver-related
– Despite more prevalent risk factors for progression (alcohol,
HIV)
• Suggests other drivers of liver-related in immigrants
– Older age (late detection)
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Main limitations
• Passive detection and reporting
– Symptom-based screening
– Determined by care-seeking
• Non-linkage – 20% non-linkage to RAMQ
• Limited accuracy of diagnostic coding
– Defining liver-related stays, comorbidities
– Detection depends on care seeking
• Reference group
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Acknowledgements
Supervisor: Dr. Chris Greenaway
Thesis committee members:
Dr. Laurent Azoulay
Dr. Marina Klein
Dr. Russ Steele
Members of the Greenaway team:
Alain, Viet, Nour & Catherine
McGill and LDI staff
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References &
Resources
Lavanchy, D. "The global burden of hepatitis C." Liver International 29.s1 (2009): 74-81.
Lavanchy, D. "Evolving epidemiology of hepatitis C virus." Clinical Microbiology and
Infection 17.2 (2011): 107-115.
Lozano R, Naghavi M, Foreman K, Lim S, Shibuya K, Aboyans V, et al. Global and regional
mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis
for the Global Burden of Disease Study 2010. The Lancet. 2012; 380(9859): 2095-128.
Mohd Hanafiah K, Groeger J, Flaxman AD, Wiersma ST. Global epidemiology of hepatitis C
virus infection: New estimates of age-specific antibody to HCV seroprevalence. Hepatology.
2013; 57(4): 1333-42.
Myers, Robert P., et al. "Burden of disease and cost of chronic hepatitis C virus infection in
Canada." Canadian journal of gastroenterology & hepatology28.5 (2014): 243.
Public Health Agency of Canada. Hepatitis C in Canada: 2005-2010 Surveillance Report;
2012. (Online)
Remis RS. Modelling the incidence and prevalence of hepatitis C infection and its sequelae in
Canada, 2007. Health Canada, Ottawa: Final report. 2007.
World Health Organization (WHO). Guidelines for the screening, care and treatment of
persons with hepatitis C infection. April 2014. (Online)
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Questions
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