falsely positive warnings about outbreaks and epidemics at the level of local areas more than falsely negative warnings, and to provide information that will help public health officials responsible for local, state, and national emergency responses to mobilize early against emerging threats. As such, the principles guiding construction of surveillance systems are not necessarily the same as the principles that guide the construction of survey instruments for policy evaluation.
Nonetheless, we also can see that these survey data systems often fall short in terms of the principles of surveillance. It is difficult to characterize reports from these systems as timely, although it is clear that available resources are not sufficient or are not deployed in a manner that allows more timely reporting. It also is difficult to characterize the systems as being useful for local responses to drug problems. It is feasible for MTF to provide reports on local areas, by aggregating information across schools, but the MTF staff has not produced reports of this type, reportedly because of concern about violation of the confidentiality and privacy of schools and students participating in the MTF assessments each year.
Partly in response to a recognition that the nation’s large data systems lack the timeliness and local area coverage of standard public health surveillance systems, the National Institute on Drug Abuse has fostered development of a Community Epidemiology Work Group (CEWG) initiative, and the Office of National Drug Control Policy has fostered development of Pulse Check. For the limited number of local areas that are included within their catchment boundaries, CEWG and Pulse Check provide a periodic check on local area conditions. For example, CEWG reports in the early 1980s represent one of the earliest sources of information about displacement of the use of powder cocaine by the freebase forms of cocaine, such as crack, which became more widely available during the later 1980s. CEWG reports also have provided one track of the epidemic spread of methamphetamine (“ice”) smoking from the West to the East, often along major interstate highways. NIDA has produced instructional manuals and guidelines for community groups and leaders who may wish to organize local area community epidemiology work groups, although CEWG participation continues to provide coverage of no more than a small fraction of local areas in the country.
It may be useful to consider the approaches that infectious disease epidemiologists have taken when they have faced the task of designing and maintaining surveillance for the U.S. population. Whereas a complete history and review of these approaches is beyond the scope of this report, a useful example is the National Notifiable Disease Surveillance System, which captures reports of cases of specific diseases of public health importance (mainly diseases of infectious origin). The reports themselves originate with practitioners and are published on a weekly basis in a