|10 Canadian Congenital Anomalies Surveillance System (CCASS)
Canadian Congenital Anomalies Surveillance System (CCASS)
|Original source: Canadian Institute for Health Information (CIHI)|
Distributed by: Public Health Agency of Canada (PHAC)
Suggested citation (see Data Citation Notes): CCASS [years], Public Health Agency of Canada, Extracted: [date]
- The Canadian Congenital Anomalies Surveillance System (CCASS) is an ongoing and passive population-based congenital anomalies surveillance system. The system was established in 1966 as a result of the thalidomide tragedy. CCASS is administered by the Maternal and Infant Health Section of the Public Health Agency of Canada (PHAC). Canada reports national CCASS data to the International Clearinghouse for Birth Defects Surveillance and Research.
- In 2004, the birth prevalence of identified congenital anomalies (CAs) in Canada was 4.8% (or 479.8 per 10,000 total births). The prevalence of CAs at birth is defined as the number of liveborn or stillborn babies identified as having at least one CA, expressed as a proportion of the total number of live births and stillbirths (in a given place and time). (1)
- Currently, the Canadian Institute of Health Information (CIHI) Discharge Abstract Database (DAD) is the primary source of data for most provinces, with exception of Alberta and Quebec. Registered stillbirths (≥20 weeks gestation or ≥500 grams) and live births from 20 weeks are captured.
- Historically, CA cases resulting in spontaneous and therapeutic abortions prior to 20 weeks have not been included in CCASS. With the integration of BORN Ontario data with CCASS beginning in 2012, these prenatally detected cases of CAs ending in pregnancy termination will begin to be captured.
- Until 2000, CCASS captured CA cases diagnosed in acute care hospitals in infants from birth through the first year of life. Since 2001, CIHI no longer released birth dates to PHAC and ascertainment has been limited to 30 days following birth. Because the majority of CAs, particularly the most severe anomalies, are generally diagnosed in the first month of life, this change in CIHI reporting is not expected to greatly impact the completeness of CCASS data for most anomalies.
- In 2008, PHAC introduced the Canadian Anomalies Surveillance Enhancement initiative to support enhanced provincial and territorial congenital anomalies surveillance systems.
- As part of this initiative, BORN Ontario will be submitting CA data for Ontario to CCASS in early 2012 and on an annual basis moving forward. This data will include a set of 16 CCASS national variables with ascertainment up to 1 year after birth. BORN Ontario will ascertain cases from live births, stillbirths and terminations in which a fetal or CA has been detected in hospital.
- Since infants with CAs are often hospitalized more than once in their first month, PHAC processes the CCASS data to identify duplicates. Duplicates are identified by matching records of the baby's admission date, age in days, sex, province issuing the health care number, postal code or geocode, medical conditions, and scrambled health insurance number. Because there are no unique identifiers to ensure accurate identification of duplicates, matching is imperfect. In addition, incomplete records make matching less accurate and may result in over-counting of the number of CA cases. The margin of error is thought to be small and equally distributed across Ontario.
- The CCASS system captures ICD-10-CA coded diagnoses and reports CAs by ICD-10-CA categories. These classifications are not confirmed once they are abstracted from the hospital records.
- Since CCASS is based on hospitalization inpatient data, CAs diagnosed on an ambulatory basis or from outpatient clinics are not captured.
- Evaluations of the quality of CCASS data indicate that major diagnoses are well captured, but more complex, obscure or less clear-cut diagnoses are less reliably coded.
- Hospital data can be influenced by factors that are unrelated to health status such as availability and accessibility of care, and administrative policies and procedures. This may influence comparisons between regions in Ontario and over time, particularly for non-major congenital anomalies.
- Data are based on geographic maternal/infant residence and not location of hospital of birth or treatment admission. Ontario residents treated outside the province are included in the national dataset when CA data are provided directly from the CCASS system by PHAC; the Ontario health card number is used to extract records by province of residence.
- Data are available at the census division and census sub-division levels but not by public health unit. Although Ministry of Health codes are available in CIHI data, these are converted to the Standard Geographical Classification (SGC) by the Public Health Agency of Canada and only the SGC is retained by CCASS. In many cases, the public health unit corresponds to a census division or grouping of census divisions with exceptions being in the north. See the Geography in Ontario resource for a listing.
- Aggregated CA data are available directly from the Maternal and Infant Health Section of the Public Health Agency of Canada. Email email@example.com to request data. Data are provided in Excel spreadsheets with rates and confidence intervals calculated. The CA categories provided are listed below in Appendix A. The number of cases refers to the number of infants with one or more anomalies. Infants may have multiple anomalies.
- In 2006, CIHI reprocessed and replaced data from 1993 to 2001. As a result there may be discrepancies between old and more recently acquired data. Use only the latest data.
- The denominator provided by CCASS to calculate rates of CAs is the total number of live births and stillbirths occurring in hospitals. Once jurisdictions participating in the Canadian Anomalies Surveillance Enhancement initiative begin submitting CA data to CCASS, terminations will also be collected, which will then also be reflected in the denominator.
- Rates and proportions of CAs from CIHI for counts less than 5 are suppressed; however, rates and proportions from BORN data for counts less than 6 are suppressed.
References and Resources
- Public Health Agency of Canada. Canadian Perinatal Health Report, 2008. Available from: http://www.phac-aspc.gc.ca/publicat/2008/cphr-rspc/pdf/cphr-rspc08-eng.pdf. Accessed: March 5, 2012.
- Paquette D, Lowry RB, Sauve, R. Two to three percent of infants are born with a congenital anomaly, but who's counting? A national survey of congenital anomalies surveillance in Canada. Chronic Diseases in Canada. 2006;27(1):36-38. Available from: http://www.phac-aspc.gc.ca/publicat/cdic-mcbc/pdf/cdic271e.pdf. Accessed: January 31, 2012.
- Rouleau J, Arbuckle TE, Johnson KC, Sherman GJ. Description and Limitations of the Canadian Congenital Anomalies Surveillance System (CCASS). Chronic Diseases in Canada. 1995;16(1):37-42.
- Health Canada. Congenital Anomalies in Canada: A Perinatal Health Report, 2002. Available from: http://www.phac-aspc.gc.ca/publicat/cac-acc02/pdf/cac2002_e.pdf. Accessed: January 31, 2012.
- Lowry, RB. Congenital anomalies surveillance in Canada. Canadian Journal of Public Health. 2008 Nov-Dec; 99(6):483-5.
| Appendix A: Categories of Congenital Anomalies Provided by CCASS|
Central nervous system anomalies
Neural tube defects
Anencephalus & similar anomalies
Microcephalus & brain reduction
Other specified & unspecified CNS anom.
Other eye anomalies
Ear face & neck anomalies
Anomalies of ear causing impairment
Other ear anomalies
Anomalies of face & neck
Congenital heart defects
Transposition of great vessels
Tetralogy of Fallot
Ventricular septal defect
Atrial septal defect
Endocardial cushion defects
Other septal closure defects
Heart valve anomalies
Hypoplastic left heart syndrome
Other heart anomalies
Circulatory system anomalies
Coarctation of aorta
Other anomalies of aorta
Pulmonary artery anomalies
Other circulatory system anomalies
Respiratory system anomalies
Lung agenesis & hypoplasia
Other respiratory system anomalies
Cleft lip and/or palate
Cleft palate with cleft lip
Digestive system anomalies
T-E fistula, esophageal atresia & stenosis
Other upper alimentary tract anomalies
Intestinal, anorectal atresia & stenosis
Other digestive system anomalies
Genital organ anomalies
Other genital organ anomalies
Urinary system anomalies
Renal agenesis & dysgenesis
Cystic kidney disease
Other urinary system anomalies
Certain musculoskeletal anomalies
Congenital dislocation of hip
Limb reduction anomalies
Other, unspecified limb anomalies
Anomalies of abdominal wall
Other musculoskeletal anomalies
Anomalies of integument
Other chromosomal anomalies
Sex chromosome conditions
Other & unspecified anomalies
| Date of last revision: January 3, 2013|