Surveillance and occupational health.

This report explains the basics of two important uses of surveillance data: determining the magnitude of a specific occupational health or injury problem and examining temporal trends to determine whether the problem is increasing or decreasing. Types of data available for the purpose and some of their strengths and weaknesses are described. The utility of surveillance data is illustrated with examples from surveillance of acute injuries, musculoskeletal disorders, lead overexposures, and hazard surveillance data sets. Increasingly, surveillance systems may be used to evaluate the effectiveness of interventions. Surveillance is most important in times of rapid change in the economy and when resources for prevention may be limited. Both conditions are common in the world today.