Category 1
Baseline: Assessment
Description
This category contains information collected from the baseline assessment questionnaire (available to view in
English or
Spanish), and is divided into sub-categories based on subject.
Notes
The baseline assessment questionnaire was administered by recruitment teams (comprising two or three specially trained nurses) who visited individual households (pre-identified via census style door-to-door interviews) in two contiguous urban districts of central and north-east Mexico City during the period 1998-2004. The baseline assessment of each participant took place in the participant's home.
Data at baseline (recruitment period April 1998 - December 2004) was entered directly into handheld devices:
- Microwand 32ES barcode optical reading devices (Hand Held Products) (April 1998 - November 2001)
- SPT 500 personal digital assistants with Palm Operating system (Symbol) (November 2001 - December 2004)
The devices were programmed to take the field workers through the questionnaire in the same prescribed manner, automatically skipping questions that were not relevant (for example, questions about obstetric history for male participants). The data recorders queried moderately extreme physical measurements and prevented the input of highly implausible values.
At the end of each working day, the data collected was automatically uploaded to the study's electronic database. The electronic procedures minimised the costs of data collection, processing and checking, while improving data accuracy and completeness. A database-checking programme was used to identify possible data errors in the study database, which were regularly reviewed by a data monitoring team and, when necessary, checked by field workers (e.g. by revisiting participants).