Systematic Random Sampling
A sampling technique in which the first sample is selected randomly and then subsequent samples are selected according to a simple, systematic rule -- often at a fixed interval or time period. For example, sampling every tenth individual in population.
To investigate the utilization of ambulatory care in the U.S., CDC conducts the National Ambulatory Medical Care Survey (NAMCS) and samples ambulatory developments annually. Over the study period, physicians were instructed to keep a daily listing of all patient visits using an arrival log or optional worksheet. Visits were selected from the list using a random start and a predetermined sampling interval (eg. every 10th patient walking in the clinic).
Last, J. 1983. A Dictionary of Epidemiology, New York, NY: Oxford Medical Publications.
Gliner, J.A. and G.A. Morgan. 2000. Research Methods in Applied Settings, Mahwah, NJ: Lawrence Erlbaum Associates.
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