Survey on Living with Chronic Diseases in Canada (SLCDC)
Detailed information for 2014 (mood and anxiety disorders)
Every 2 years
The purpose of the Survey on Living with Chronic Diseases in Canada (SLCDC) is to provide information on the impact of chronic disease on individuals, as well as how people with chronic disease manage their health condition.
Data release - October 30, 2014
The SLCDC is a cross-sectional survey sponsored by the Public Health Agency of Canada that collects information related to the experiences of Canadians with chronic health conditions. The SLCDC takes place every two years, with two chronic diseases covered in each survey cycle.
The SLCDC asks respondents about a number of issues related to chronic health conditions, including diagnosis of a chronic health condition, care received from health professionals, medication use and self-management of their condition. The survey has the following objectives:
- To assess the impact of chronic health conditions on quality of life
- To provide more information on how people manage their chronic health conditions
- To identify health behaviours which influence disease outcomes
- To identify barriers to self-management of chronic health conditions
The SLCDC data can be used by governments to better plan and provide health services for persons with chronic health conditions and to develop public education campaigns primarily aimed at health promotion and disease prevention. Researchers will be able to use the data to monitor, analyse, measure and report on those factors affecting chronic health conditions.
Reference period: Varies according to the question (for example: "currently" or "during the past month", etc.)
- Diseases and health conditions
- Mental health and well-being
Data sources and methodology
The SLCDC covers the population living in the ten provinces who have been diagnosed by a health professional with one or more of the following conditions: mood and anxiety disorders (18 years of age and over). Excluded from the survey coverage are: persons living on reserves and other Aboriginal settlements; full-time members of the Canadian Forces; the institutionalized population and residents of certain remote regions (Quebec health regions of Région du Nunavik and Région des Terres-Cries-de-la-Baie-James). Altogether, these exclusions represent less than 3% of the target population.
The questionnaire was developed by Statistics Canada, in collaboration with the Public Health Agency of Canada and their expert group: the Mental Health and Illness Surveillance Advisory Committee. Qualitative testing by Statistics Canada's Questionnaire Design Resource Centre, using face-to-face interviews, was conducted in March 2013.
The questions are designed for computer-assisted interviewing (CAI), meaning that, as the questions were developed, the associated logical flow into and out of the questions was programmed. This includes specifying the type of answer required, the minimum and maximum values, on-line edits associated with the question and what to do in case of item non-response.
This is a sample survey with a cross-sectional design.
The sample for this survey was drawn from respondents of the 2013 Canadian Community Health Survey (CCHS) (see record number 3226). In order to produce reliable estimates by age and sex groups, it was decided to select every person who reported living with either or both conditions (mood or anxiety disorder). The raw sample size included 5,875 persons.
Data collection for this reference period: 2013-10-23 to 2014-03-31
Responding to this survey is voluntary.
Data are collected directly from survey respondents.
Proxy interviews are not permitted. Respondents are interviewed using a computer assisted telephone interview (CATI) system.
View the Questionnaire(s) and reporting guide(s) .
Most editing of the data was performed at the time of the interview by the computer-assisted interviewing (CAI) application. It was not possible for interviewers to enter out-of-range values and flow errors were controlled through programmed skip patterns. For example, the CAI application ensured that questions that did not apply to the respondent were not asked. Pre-coded answer categories were also supplied for all suitable variables. Interviewers were trained to assign the respondent's answers to the appropriate category.
In response to some types of inconsistent or unusual reporting, warning messages were invoked in the application but no corrective action was taken at the time of the interview. Where appropriate, edits were instead developed to be performed after data collection at Head Office. Inconsistencies were usually corrected by setting one or both of the variables in question to "not stated". A critical error edit was used to reject ineligible respondent entries (for instance, out-of scope populations). Flow errors were also adjusted during data processing and a data inconsistency detection and correction program was applied.
There is no imputation in the SLCDC.
The "weight" is defined as the number of individuals that a respondent represents in the target population, including him- or herself. The sum of the weights of all individuals in the sample should equal the size of the target population. The principle behind estimation consists of using weights to assess the prevalence of a characteristic by extrapolating from the sample to the target population. For example, the number of women in the population aged 18 to 34 years old with a mood disorder is estimated by summing the weights of all women in the sample with those characteristics. Similarly, an estimate of the proportion of persons with anxiety disorder in the target population who are male is computed by dividing the sum of the weights of men with anxiety disorder by the sum of weights of everyone (male and female) with anxiety disorder. Since the SLCDC is a follow-up survey to the CCHS, the initial weights for the SLCDC were obtained from the final weights of the CCHS.
Once selected, individuals may fail to respond to surveys for any number of reasons (refusal, inability, unavailability during attempts to contact them, etc.). When more up-to-date information from the SLCDC is considered, a selected individual may no longer belong to the target population. In order to ensure that SLCDC respondents truly represent the target population, initial weights were adjusted to shift weight from non-respondents onto respondents. Selected individuals who were no longer part of the target population were removed from the file.
To measure the precision of the generated estimates, the variance must be computed. Owing to the complexity of the sample design, it is very difficult to obtain an expression for the variance. Therefore, the variance was estimated using the method known as bootstrap replication. This method consist of drawing B sub-samples from the full sample (in the case of the SLCDC, B=500) with replacement. For each of the B sub-samples, an estimate of the characteristic of interest (for example, the proportion of men having anxiety disorder) was computed. The observed variance between the B estimates is the bootstrap variance estimator.
For purposes of the SLCDC, the bootstrap replications started with the B sub-samples used to estimate the variance of the CCHS. For each bootstrap replication of the CCHS, weights were adjusted in the same way as during the sample design. The resulting adjusted-weight replications were considered bootstrap replications of the SLCDC, from which estimates of the variance were produced.
Statistics Canada has developed a program called bootvar that can use bootstrap samples to generate variance and the corresponding measures of precision.
Throughout the collection and processing processes, control and monitoring measures were put in place and corrective action was taken to minimize non sampling errors. These measures included response rate evaluation, reported and non reported data evaluation and on site observation of interviews.
Once processing steps were completed, other data validation steps were undertaken. First, a validation program was run in order to compare estimates for some indicators taken from the common content of the 2014 SLCDC, the annual Canadian Community Health Survey, and previous SLCDC surveys. This validation was performed by age group and sex. Significant differences were examined further to find any anomalies in data. In addition, an external validation step was also part of the validation process. Files were sent before release to the Public Health Agency of Canada for a two-week examination period. They could then scrutinize the data and inform Statistics Canada of any concerns or anomalies related to data quality.
Statistics Canada is prohibited by law from releasing any information it collects which could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.
Revisions and seasonal adjustment
This methodology does not apply to this survey.
The response rate for the 2014 SLCDC was 69%.
For more details on data accuracy measures and response rates, please refer to the User Guide documents. To obtain a copy of this documentation contact Client Services (613-951-1746; fax: 613-951-0792; firstname.lastname@example.org).