National Addiction & HIV Data Archive Program

What enhancements are available when using SDA?

SAMHDA recently upgraded the Survey Documentation and Analysis (SDA) system to version 3.4. All of the previous statistical procedures are still available. Users who prefer to use the original interface may still use it by selecting the link entitled Use Classic Interface in the upper-left corner of the screen. SDA 3.4 improves the calculation of statistics for complex samples in the TABLES and MEANS programs.

For the TABLES program, enhancements include:

  1. Corrections to the calculation of standard errors and confidence intervals.
  2. Addition of Rao-Scott F-tests.
  3. Ability to display weighted or unweighted N of cases.
  4. Option to set the number of decimals for all statistics.

For the MEANS program, enhancements include:

  1. Corrections to the calculation of the standard errors and confidence intervals.
  2. Option to display the p-value of each difference from the cells in a base row or column.
  3. Default reporting of the weighted N of cases in each cell for weighted analyses.
  4. Option to include charts in output.
  5. Optional diagnostic table for design variables.

Further information is provided in the SDA Manual (SDA 3.4).

SDA 3.3, released in June 2009, contained the following changes to the analysis programs and features:

  1. Disclosure Protection: SAMHDA now has the ability to suppress output that may compromise the confidentiality of survey respondents by applying disclosure protection rules to a data file. Analysis programs, including RECODE and COMPUTE, now check for the presence of disclosure rules and enforce them. Disclosure rules may be specified to: a) prevent an analysis from being run; b) suppress the output after running an analysis; and c) suppress the unweighted number of cases from being reported in the output. The SDA 3.3 Documentation for Disclosure provides greater detail on the disclosure rules that may be specified.

  2. List Created Variables - View Button: The output from the listing of recoded and computed variables now includes a "View" button that provides access to descriptions of the variables. This feature can be accessed under the SDA Create Variables menu.

  3. Title: A title or label can be entered for each analysis request and will appear at the top of the HTML output produced by SDA analysis programs.

  4. Customized Subset: This procedure has also been revised in that recoded and computed variables may now be included in a subset. If pre-set selection filters have been defined by SAMHDA, these filters now apply to the interactive version of the subset procedure as well as to the analysis programs. A Comma Separated Values (CSV) file is available for output.

Content adapted from the SDA Manual (version 3.3).

For further information on SDA, please select the Getting Started button located in the upper-right portion of the screen or visit the SDA Tutorial.