Demographic and Health Surveys Methodology - Measure DHS

Before using an exported DHS data file, it is important to check for duplicate variable names. Softwarelike SPSS allows only a maximum of eight characters for variable names. If variable Q1005A is definedin a record with a maximum number of occurrences of 20, it will be exported as Q1005A$01,Q1005A$02, Q1005A$20. When this syntax is read by SPSS it will chop the last character with the resultof nine ($01 thru $09) variables with the same Q1005A$0 name.Recode Files and Recode Variable Naming ConventionsThere are three core questionnaires in DHS surveys: A Household Questionnaire, a Women’sQuestionnaire, and a Male questionnaire. There are also several standardized modules for countries withinterest in those topics. Except for the Service Provision Assessment (SPA), which is a separatequestionnaire in itself, all the other modules are applied as part of the household, women, or malequestionnaires.Since the very beginning of DHS a recode file was designed. There were two outstanding reasons todevelop a recode file, to define a standardized file that would make cross-country analysis easier and tocompare data with the World Fertility Surveys (WFS) to study trends. In DHS-I the recode was definedonly for the Women’s Questionnaire. The reason was that in WFS there was not a recode file defined forthe Household Questionnaire and on the other hand there were very few countries that used a malequestionnaire. The recode file proved to be very useful and as a result since DHS-II, a recode file, wasintroduced for the household and male questionnaires.DHS questionnaires have changed extensively since the first phase. For this reason there is a differentrecode definition for each DHS phase. However, if a variable is present in one or more phases, thatvariable has the same meaning in wherever phase it is present. If a question is dropped from one phase toanother, the name of the variable used for that question is not reusable. The variable will not be present inthe recode definition of the phase were it was dropped. If a new question is added to the corequestionnaire a new variable will be added to the recode definition.Recode files are initially created using a hierarchical model and later exported to flat or rectangular files.There are two physical recode hierarchical data files. The first one includes the household and Women’sQuestionnaire and the second one is for the male questionnaire. The hierarchical data file is broken downinto a number of records. The records were originally designed to map different sections of the modelquestionnaires, but because of changes among phases that may not be the case anymore. Some of theserecords are repeating or multiple-occurrence records while others are single-occurrence records. Singlerecords contain simple, single-answer variables. Multiple records are used to represent sets of questionsthat are repeated for a number of events. The birth history is an example of a multiple section, where eachchild has an entry in the birth history. Multiple records are used for sets of questions where the number ofoccurrences may vary. 3There are special records to keep variables that are not part of the model questionnaires but were includedin a particular country. These records are known as country-specific records and they can also be multipleor single depending on whether the question was added to a single or multiple section in thequestionnaire.3 A full description of recode files can be found in the document Description of the Demographic and Health Surveys Individual Recode DataFile by Trevor Croft.Guide to DHS Statistics 8 September 2003