INTRODUCTIONGallstone disease (GSD) is one of the most common diseases in developed countries. Recent studies indicate varying prevalence of GSD with several predisposing factors in different study populations [1][2][3][4][5][6][7][8][9] . From a medical economic perspective, the direct and indirect costs of treating GSD patients were estimated at $16 billion and account for more than 800 000 hospitalizations yearly in the United States [9,10] . In Taiwan, the prevalence of GSD in the general population was 4.3% in 1989 [8] while another voluntary screening revealed that the prevalence of GSD was 10.7% among healthy subjects in 1995 [2] . For this reason, due to westernization of the diet and the environment, GSD is not rare in the Chinese population and has become one of the major health problems in Taiwan [7] . Without an appropriate and effective screening program for symptomatic GSD, the medical treatment of GSD and related complications contributes substantially to health care costs.From the viewpoint of preventive medicine, it is
RAPID COMMUNICATION
RESULTS:The overall prevalence of GSD among this study-population was 5.3%, including 1.7% (n = 40) having a single stone, 2.3% (n = 55) having multiple stones, and 1.3% (n = 31) having cholecystectomy. The prevalence revealed a statistically significant increase with increasing age (P < 0.0001). Females exhibited a greater prevalence of multiple stones than did males (3.0% vs 1.7%, P = 0.04). Using multiple logistic regression analysis, the following appeared to be significantly related to the prevalence of GSD: older