Table 1.
Canadian studies presenting herpes zoster incidence rates of outpatient visits and hospitalizations.
| Author and year of publication | Periods; province; number of incident herpes zoster cases (N) | Cases identification | Incidence rates (per 100,000 person-years) (standardized unless stated otherwise) | ||
|---|---|---|---|---|---|
| Consultations (outpatient visits) | Hospitalizations | Outpatient visits + hospitalizations | |||
| Brisson et al. 2001 [11] | 1979–1997; Manitoba; N: not documented |
(i) Annual billing claims database; first claim with a herpes zoster ICD-9 code (ii) Hospital length of stay ≥ 1 day; hospitalisations with herpes zoster (HZ) ICD-9 code in one of the first three positions |
Crude rates
(i) All ages: increase from 258 to 348 during the study period (ii) ≥ 65 years: average rate of 812 |
Crude rates
(i) ≥ 65 years: average rate of 86 |
Not documented |
|
| |||||
| Russell et al. 2007 [15] | 1986–2002; Alberta; N: not documented |
(i) Provincial registration database (ii) Physician claims data system (iii) Hospital morbidity inpatient database (iv) First-time healthcare service utilisation for an HZ ICD-9/10 code in any position |
Not documented | (i) All ages: decrease of hospitalized cases from 5% in 1993 to 3% in 2002 |
Crude rates
(i) All ages: increasing rate from 1986 to 2002 (roughly from 280 to 440 according to the presented figure) |
|
| |||||
| Edgar et al. 2007 [4] | 1994–2003; British Columbia; (i) N of outpatient visits = 114,596 (ii) N of hospitalizations = 3,887 |
(i) Physician billing data; physician visit for an HZ ICD-9 code (ii) Hospitalisations for an HZ ICD-9/10 code regardless of its position (iii) Physician visits and hospitalizations ≥ 365 days apart were included |
(i) All ages: increase from 324 to 366 (ii) ≥ 65 years: average crude rate of 703 |
(i) All ages: decrease from 12 to 8 (ii) ≥ 65 years: average crude rate of 51 |
Not documented |
|
| |||||
| Brisson et al. 2008 [12] | 2000–2003; Manitoba; N: not documented |
(i) Hospitalisations for an HZ ICD code in the first position vs. any position | Not documented |
Crude rates among ≥ 65-year-olds
(i) HZ code in any position: average rate of 3 for 65–69 years and 30 for ≥80 years (ii) HZ code in the first position: average rate of 1 and 9 for 65–69 years and ≥ 80 years, respectively |
Not documented |
|
| |||||
| Tanuseputro et al. 2011 [17] | 1992–2010; Ontario; (i) N of outpatient visits = 686,763 (ii) N of hospitalizations = 14,240 |
(i) First outpatient visit for an HZ ICD-9 code (ii) First hospitalization for an HZ ICD-9/10 code in any position (in a sensitivity analysis: hospitalization with HZ as primary diagnosis only) |
(i) All ages: decrease from 525 to 479 (ii) ≥ 60 years: average crude rate of 740 during 2005–2009 |
(i) All ages: decrease from 9 to 4 (and from 5 to 2 in a sensitivity analysis with HZ as primary diagnosis) | (i) All ages: steady mean annual rate between 309 during 1992–1998 (prevaricella vaccine availability) and 303 during 2005–2009 (publicly available vaccine) Rate ratio (2005–2009 vs. 1992–1998) = 0.98 (0.82–1.14) |
| Russell et al. 2014 [14] | 1994–2010; Alberta; N of outpatients and inpatients = 174,711 |
(i) Supplemental enhanced service event system (physician claims records) (ii) Alberta communicable disease reporting system (iii) Morbidity and ambulatory care reporting databases (hospital inpatients and hospital emergency department visits) (iv) First health service utilisation for an HZ ICD-9/10 code in any position (v) HZ codes ≥ 180 days after the first diagnosis classified as recurrent episodes |
Not documented | (i) All ages: decrease of hospitalized cases from 5% during prelicensure of the varicella vaccine period (1994–1998) to 3% during the publicly available varicella vaccination period (2002–2010) |
Crude rates (recurrent episodes included)
(i) All ages: increase from 350 to 450 |
|
| |||||
| Antoniou et al. 2014 [18] | 1997–2009; Ontario; N = 19,143 |
(i) Prescription drugs database (ii) Physician claims records database (iii) Hospitalisation admissions database (iv) Emergency department visits database (v) New diagnosis of HZ: first HZ ICD-9/10 code or first antiviral treatment for HZ |
Not documented | Not documented |
Crude rates
(i) ≥ 66 years: average rate of 1,232 (1,171 for patients not receiving statin and 1,325 for statin users) |
|
| |||||
| Marra et al. 2016 [10] | 1997–2012; British Columbia; N = 238,295 |
(i) Medical services plan and hospital discharge database (ii) PharmaNet (outpatient prescription database) (iii) HZ ICD-9/10 code in any position without any evidence of HZ or postherpetic neuralgia in the previous 12 months (iv) Sensitivity analysis: HZ diagnosis with antiviral treatment received within 7 days |
Not documented | (i) All ages: decrease of hospitalized cases from 4% during prelicensure of the varicella vaccine period (1997–1999) to 2% during the publicly funded vaccination period (2005–2012) | (i) All ages: increase from 316 to 449 (and from 162 to 300 in a sensitivity analysis with case definition as an HZ diagnosis with an antiviral treatment) Rate ratio (publicly funded varicella vaccination vs. prelicensure period) = 1.22 (1.20–1.24) |
| Friesen et al. 2016 [13] | 1997–2013; Manitoba; N: not documented |
(i) Physician claims database (ii) Hospital discharge database (iii) First HZ ICD-9/10 code in any position (iv) Multiple episodes included if a minimum of 2 years had elapsed since the first-time HZ and ≥ 180 days had elapsed since the last HZ diagnosis |
Not documented | Not documented | (i) ≥ 20 years: steady rate at 470 from 1997-1998 to 2008-2009 and increase since 2009-2010 to reach 570 in 2013-2014 |
|
| |||||
| McDonald et al. 2017 [16] | 2009–2015; Alberta; N of outpatients and inpatients = 49,243 |
(i) Physician claims database (ii) Morbidity and ambulatory care reporting database (iii) First HZ ICD-9/10 code in any position |
Not documented | Not documented |
Crude rates
(i) ≥ 50 years: average rate of 903 (ii) Incidence rates increased from 581 in 50–54 years to 130 in ≥ 75 years |
|
| |||||
| Queenan et al. 2017 [19] | 2013–2015; Canadian Primary Care Sentinel Surveillance Network; N of outpatients = 3,281 |
(i) Surveillance system electronic database (ii) HZ ICD-9 code in any position |
Prevalence in ≥ 18 years
(i) One year: 0.32% (ii) By age: (1) 18–39 years: 0.12% (2) 40–64 years: 0.35% (3) ≥ 64 years: 0.67% (iii) By status: (1) No chronic disease: 0.21% (2) Diabetes: 0.69% (3) COPD: 0.69% (4) Any neoplasm: 1.07% (5) HIV/AIDS: 1.00% |
Not documented | Not documented |
|
| |||||
| Quebec analysis | 1996–2015; Quebec; N of outpatients and inpatients = 543,290 |
(i) Physician claims records; first HZ ICD-9/10 code during a calendar year or during the entire study period (ii) Hospital discharge database; first HZ ICD-9/10 code as the main diagnosis or the first secondary diagnosis |
Not documented | (i) All ages: decrease from 9 to 6 (ii) ≥ 65 years: decrease from 50 to 31 |
(i) All ages: decrease from 369 during 1996–2000 (prelicensure of varicella vaccine) to 350 during 2006–2015 (publicly funded varicella vaccination period) Rate ratio (2006–2015 vs. 1996–2000) = 0.95 (0.94–0.95) (ii) ≥ 65 years: average rate of 949 (steady over the study period) |