Abstract
The public health burden of arthritis and related conditions is incompletely described by commonly used public health surveillance systems. We examined the potential of administrative data as a supplement. The administrative data sources we used underestimated the prevalence of arthritis and overestimated service utilization for persons with arthritis when data from only one year were used. The use of five year's data doubled the prevalence estimate and reduced the service utilization estimate by half. The demographics of the population covered by administrative data also infl uence the prevalence estimate. Administrative data may usefully supplement routine public health surveillance systems but must be used with caution.
After the 1999 publication of The National Arthritis Action Plan: A Public Health Strategy and subsequent funding from the Centers for Disease Control and Prevention (CDC) for state-based arthritis prevention and control programs, many state health departments have been working to improve their arthritis-related surveillance and program evaluation activities.1 In most state health departments, death certifi cates, hospital discharge databases, and the Behavioral Risk Factor Surveillance System (BRFSS) are the foundation for chronic disease surveillance. Mortality and hospital discharge rates do not adequately reflect the disability and chronic pain associated with arthritis. The BRFSS, a statewide telephone survey of adults, provides prevalence estimates based on self-reported symptoms and history of a doctor's diagnosis of arthritis. The BRFSS, however, provides insufficient information about specific types of arthritis and may not be the best source for information about outpatient needs and experiences.2-4 The National Arthritis Action Plan suggests that other data sources be explored as potential complements to existing sources of surveillance data.1
The purpose of our research was to explore the usefulness of health-related administrative data to estimate the prevalence of arthritis-related conditions and the use of outpatient services for arthritis. Administrative data are maintained by organizations for accounting and other nonclinical purposes. Administrative data came from the Kaiser Permanente Georgia Region and the Georgia Medicaid program. They are a rich source for health care research, but are not commonly used for public health surveillance. The definitions and codes established by the National Arthritis Data Workgroup5 were used. The data sets were explored to determine how prevalence and utilization of services are affected by membership definitions and by the span of years during which the diagnosis could have been noted. It was discovered that the span of years searched profoundly affects the magnitude of the estimates.