ARCHIVED: Congenital anomalies surveillance in Canada: results of a 2006–2007 survey on availability of selected data variables in Canadian provinces and territories – Methods

Methods

The survey was developed concurrently with the ‘Recommended Data Variables for Congenital Anomalies Surveillance in Canadian Provinces & Territories’ (Appendix A). This list of data variables was established by the DRIWG to promote the use of common standards and methods for congenital anomalies surveillance programs in Canadian jurisdictions and to provide a basis for development of program-specific data collection procedures. It was developed after examination of existing recommendations for data collection from surveillance systems in Canada, the United States and Europe, and through review of the scientific literature. The resulting list contains 36 minimum variables (which are deemed necessary to meet provincial/territorial program objectives) and 49 recommended variables (which can enhance the capacity of the system).

In an effort to maximize response from the programs asked to participate, the survey (Appendix B) was restricted to questions corresponding to 14 of the minimum data variables and 11 of the recommended data variables (Table 1). The variables chosen for inclusion in the survey were those that were felt to be the most essential for surveillance and also took into consideration the variables that are currently part of the national CCASS database. The survey asked about availability of information on parental age, ethnicity and socio-economic information, residence, place of delivery, prenatal screening and diagnostic testing, pregnancy length and outcome, length of ascertainment period for identification of congenital anomalies, diagnostic codes for congenital anomalies and infant variables (infant sex, gestational age, plurality and birth weight). In addition, the survey asked for information on the types of data sources that were available for these variables.

Programs that either collected data or were custodians of data sources containing information on congenital anomalies were identified, which included provincial/territorial government departments, perinatal programs, congenital anomaly surveillance programs, and clinical groups involved with prenatal diagnosis of congenital anomalies (e.g., maternal serum screening). Effort was made to identify at least one program from each province and territory.

Only programs that had jurisdiction-wide coverage of the population and that collected data on all types of congenital anomalies were invited to complete the survey. The exception was Ontario, for which five programs were sent a copy of the survey due to the size of the province and due to the close collaboration between the five programs under the auspices of the Ontario Perinatal Surveillance System.

Nevertheless, several jurisdictions have other programs that were not included in the distribution of this survey, but which collect data on congenital anomalies. For example, the provincial Medical Genetics Program in Newfoundland and Labrador conducts province-wide screening for neural tube defects and the Manitoba Maternal Serum Screening Program provides prenatal screening of pregnancies representing about 70% of the live births in Manitoba. Additional information on these and other programs can be found at: www.phac-aspc.gc.ca/ccasn-rcsac/dss/index-eng.php.

Table 2 lists the 19 programs that were sent a copy of the survey in late 2006/early 2007. The majority of programs responded to the original survey, and those that did not were subsequently contacted and reminded to complete the survey. Between October 2007 and April 2008, a summary for each program was sent back to the individual who completed the survey to ensure the accuracy of the summarized information. The results contained in this report are based on the completed surveys of the 16 responding programs.