The data presented in this report are weighted estimates, unless otherwise noted. The CTADS/CTUMS survey weights assigned by Statistics Canada in the annual datasets were used for CTADS/CTUMS analyses, and CSTADS/YSS survey weights were used for CSTADS/YSS analyses; CTADS/CTUMS and CSTADS/YSS were not analysed together and there was no overlap of the survey weights between the two surveys. Estimates for categorical measures were generated using the SURVEYFREQ procedure in SAS statistical software (Version 9.4), while estimates for continuous variables (e.g., cigarettes per day) were generated using the SURVEYMEANS procedure in SAS.
Confidence intervals were generated using SAS and the statistical software Stata (Version 14.2) using the bootstrap weights where they were available (CTADS 2013 to 2017, CTUMS 2001 to 2012, CSTADS 2014-15 and 2016-17, and YSS 2004-05 to 2012-13). Confidence intervals for CTADS/CTUMS were calculated in SAS or Stata using the Mean Square Error (MSE) method of calculation with bootstrap weights. Confidence intervals for CSTADS/YSS in the current (2019) edition were calculated in SAS using the MSE. However, the confidence intervals for CSTADS/YSS reported in previous versions of this report did not use the MSE method and were calculated in Stata. This also applies to any CSTADS/YSS confidence intervals in this report that were drawn directly from previous reports.
Confidence intervals are available in data tables posted on the website (www.uwaterloo.ca/tobacco-use-canada/); caution should be used when making comparisons without first checking the confidence intervals. Estimates are not reported where specific categories included less than 30 individuals (unweighted), except where noted as not meeting Statistics Canada’s quality standards. In addition to this rule, Health Canada also recommends calculating the coefficient of variation to determine the quality level of the estimate (for further information, please refer to the documentation for specific surveys and waves/years). Estimates with coefficients of variation in excess of 33.3% are suppressed in the analysis of CTADS 2015 and 2017, CSTADS 2016-17, and most historical CSTADS/YSS (i.e., 1994 to 2014-15); otherwise, such estimates may not have been suppressed. Some estimates included in this report may be reported “with caution” or not reported by Health Canada in their releases. In some cases for CSTADS 2014-15 estimates, to facilitate interpretation of these suppressed estimates based on less than 30 individuals, an upper bound of the estimate was calculated. The upper bound is the percentage that would occur if 30 individuals were in the numerator rather than the number less than 30. Similarly, for estimates with coefficients of variation in excess of 33.3%, an upper bound of the estimate was calculated. The upper bound, in this case, is the percentage estimate that would be needed to achieve a coefficient of variation of 33.3%. When either of these upper bounds are <2%, they have been reported as such.
Estimates in figures and the associated data tables have been rounded to one decimal place. Provincial estimates for numbers of smokers reported in sections 2.1-2.10 have been rounded to the nearest thousand.