Friday, March 4, 2011

CCHS Data on Smoking

Question

“I am a medical resident interested in conducting some research on smoking in the Quebec region as part of my fellowship training. I am interested in data about smoking behaviour, specifically, in the Abitibi-Temiscamingue region of Quebec and its peer groups.

I tried to obtain this data from the Canadian Community Health Survey using the Stats Can website but was only able to access data collected up until 2005. I now understand that the format and method of data collection has changed from 2007 and that it is now continuous.

I have been in touch with Stats Can who passed along your coordinates and suggested that I contact you regarding the data I am interested in.

My question is if and how I can get access to the CCHS data from 2007 including additional information like variance rates.

Many thanks in advance for your help.”

I have difficulty interpreting the comment “I now understand that the format and method of data collection has changed from 2007 and that it is now continuous.” I have found a reference to a “rapid response component of the CCHS -- would that component be collecting data on smoking in some continuous fashion?

In CANSIM I found only table 105-0502, with info about smoking from health-regions, but it only refers to the January 2007 version of the CCHS.

Should there be some ‘continuous’ data somewhere?

Answer

The Canadian Community Health Survey (CCHS) underwent a redesign in 2007 and the way CCHS data is collected changed with this redesign.

"Prior to 2007, data collection occurred every two years on an annual period. Data are available for the 2001, 2003 and 2005 periods. In 2007, major changes were made to the survey design with the goal of improving its effectiveness and flexibility through data collection on an ongoing basis. Data collection now occurs every year, rather than every two years as was the case prior to 2007.

The CCHS produces an annual microdata file and a file combining two years of data. The CCHS collection years can also be combined by users to examine populations or rare characteristics." (http://www.statcan.gc.ca/cgi-bin/imdb/p2SV.pl?Function=getSurvey&SDDS=3226&lang=en&db=imdb&adm=8&dis=2#a1)

The most recent CCHS PUMF currently available through the DLI covers 2007/2008.

This change to continuous data collection is further described in: "Interpreting Estimates from the Redesigned Canadian Community Health Survey (CCHS)" (http://www.statcan.gc.ca/imdb-bmdi/document/3226_D44_T9_V3-eng.pdf)

The reference to rapid response component you found refers to one of the three components of the CCHS, the others being common content and optional content.

"The CCHS has three content components: the common content, the optional content and the rapid response content. The common content is collected from all survey respondents. Some modules are collected every year and remain relatively unchanged over several years. Other common modules are collected for one or two years and rotate every two or four years. The optional content fulfills the need for data at the health region level. This content, while often harmonized across the province, is unique to each region or province and may vary from year to year. The rapid response component is offered to organizations interested in national estimates on an emerging or specific issue related to the population's health. The rapid response content may be included in the survey in each collection period, that is, in every two month period. The data will be released shortly after the collection period via data availability announcement in the Daily." (http://www.statcan.gc.ca/cgi-bin/imdb/p2SV.pl?Function=getSurvey&SDDS=3226&lang=en&db=imdb&adm=8&dis=2#b2)

As mentioned above, rapid response data are announced in the Daily when they becomes available, for example http://www.statcan.gc.ca/daily-quotidien/101213/dq101213e-eng.htm. These rapid response data are usually disseminated as custom tabulations.

CANSIM table 105-0502 Health indicator profile, two year period estimates, by age group and sex, Canada, provinces, territories, health regions (2007 boundaries) and peer groups, occasional provides data for the 2007/2008 reference period and CANSIM 105-0501 Health indicator profile, annual estimates, by age group and sex, Canada, provinces, territories, health regions (2007 boundaries) and peer groups, occasional includes data up to 2009.

Footnote 57 at the bottom of CANSIM table 105-0502 discusses the differences between these two tables:

"57. Since 2007, data for the Canadian Community Health Survey (CCHS) are collected yearly instead of every two years. While a sample of approximately 130,000 respondents has been interviewed during the reference periods of 2003 and 2005, it has been changed to 65,000 respondents each year starting in 2007. Two indicator profiles based on CCHS core content are available, featuring the same variables, geography and age breakdowns, but different reference periods. The CANSIM table 105-0501 includes data from 2008, 2007, 2005 and 2003. These estimates present the most up-to-date population health characteristics and will be updated yearly. The CANSIM table 105-0502 includes estimates from 2007/2008 combined as well as the statistical comparison to 2005. The two-year combined data are less current than annual estimates, but have higher precision (less variability). Users should refer to the CANSIM annual data table 105-0501 as the primary source for most current estimates from the survey as well as to obtain the 2005 and 2003 data. However, where data quality flags indicate suppression (F) or higher variability (E), the CANSIM two-year data table 105-0502 should be used." (CANSIM 105-0502. http://www5.statcan.gc.ca/cansim/pick-choisir?lang=eng&searchTypeByValue=1&id=1050502&pattern==105050)

I hope that the information above is helpful. Please don't hesitate to contact us if you have any other questions.

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