[An evaluation of sampling design for estimating an epidemiologic volume of diabetes and for assessing present status of its control in Korea].
OBJECTIVE
An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation.


METHODS
We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices.


RESULTS
Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04% (95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%.


CONCLUSIONS
The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.
Department of Public Health, Korea University Graduate School, Korea.
Ji-Sung
JS
Lee
Jaiyong
J
Kim
Sei-Hyun
SH
Baik
Ie-Byung
IeB
Park
Juneyoung
J
Lee
D015982:Bias; D016000:Cluster Analysis; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000517:prevention & control; D004812:Epidemiologic Methods; D006801:Humans; D007345:Insurance Claim Review; D007723:Korea; D008499:Medical Records; D012494:Sampling Studies