OBJECTIVES: Hypertension, hyperglycemia and hyperlipidemia (HHH) are important health problems due to their relationship with cardiovascular, cerebrovascular and peripheral vascular diseases. Previous studies have found that individuals with HHH were associated with more health care resource use, yet no study has been conducted in Taiwan to estimate the cost impact of HHH on society. This study aimed to determine the incremental costs among the individuals with HHH, compared with no symptom individuals in Taiwan with no symptons. METHODS: A retrospective case-control analysis was performed using a unique dataset that linked the 2002 Taiwanese Survey on Prevalence of Hypertension, Hyperglycemia and Hyperlipidemia (TwSHHH) with the 2003-2006 National Health Insurance (NHI) claims records. Study cases were 1277 individuals with hypertension, 409 individuals with hyperglycemia, and 1808 individuals in Taiwan with hyperlipidemia. For each symptom group, controls without symptoms were matched at a 1:3 ratio by demographics. The difference in medical costs between cases and controls was assumed to be attributable to HHH. Negative binomial regression based on generalized estimating equations were performed to compute regression-adjusted annual total medical costs. All costs were reported in NT dollars (US$1.00 = NT$34.42 in 2003). RESULTS: Adjusted mean annual number of outpatient visits for HHH were 5.81, 11.62 and 4.36, respectively. Mean annual number of hospital days for HHH were 1.67, 3.13 and 0.97, respectively. Mean annual drug costs for HHH were NT$8,612, NT$ 14,665, and NT$ 3,578, respectively. Mean annual total medical costs for HHH were NT$21,117, NT$ 34,853, and NT$ 9,678, respectively. CONCLUSIONS: This study demonstrated a substantial increase in resource usage in terms of the frequency of care use and medical costs associated with HHH. Indirect morbidity costs need to be estimated in the future to provide the information on the overall economic burden of HHH to policy-makers in Taiwan.