The WHO STEPwise approach to Surveillance (STEPS) is a sequential
process (Fig. 1) (9): it starts with the compilation of key information on risk
factors and self-reported health using a questionnaire, and then moves on to
simple physical measurements, followed by more complex measurements for
biochemical analysis. The instruments may include core, expanded and
optional data. STEPS emphasizes that fewer good-quality data are more valuable than large quantities of poor-quality data. By using the same standardized
questions and protocols, countries can use the information produced by