Cost-effectiveness analysis of the multidisciplinary risk assessment and management program for Chinese patients with diabetes mellitus (RAMP-DM) in primary care of the Hospital Authority

Abstract

Given the increasing prevalence and burden of diabetes mellitus (DM), it is imperative to implement effective and affordable interventions that can control DM, prevent diabetic complications, reduce mortality and enhance quality of life. The Hospital Authority (HA) has launched the Multidisciplinary Risk Assessment and Management Program for Chinese Patients with Diabetes Mellitus (RAMP-DM) to enhance the quality of DM care in its public primary care clinics since August 2009. This study aimed at evaluating the cost-effectiveness of RAMP-DM in reducing complications in comparison to usual care from the health service provider’s perspective. This research comprised of five parts. First, 7 existing risk prediction models for DM complications were tested in a cohort of 26,872 Chinese DM patients without previous complications under usual primary care over 5-year to determine which one model, if any, was valid and accurate for our population. Second, a longitudinal 5-year cohort study was carried out on 128,309 patients to estimate the clinical outcomes including annual incidences of various DM complications and mortality and public health care costs of DM. Third, a cross-sectional study was conducted in 1,275 DM subjects to assess the health-related quality of life (HRQoL), health preference and annual private direct medical costs in patients with different DM complication status. Fourth and fifth were the evaluation of the effectiveness and cost-effectiveness of RAMP-DM within a 3-year observational period and over a lifetime using a Discrete Event Simulation (DES) model, respectively. It was found that none of the 7 existing risk prediction models of DM complications was valid or accurate for our primary care Chinese DM patients. The health preference for DM patients without complications was 0.88, and the presence of heart diseases, stroke, STDR and ESRD was associated with adjusted health preference decrements of -0.017, -0.042, -0.055 and -0.043, respectively. The longitudinal 5-year cohort study showed 8,374(6.53%) died and 22,805(17.77%) developed complications with stroke and NPDR/pre-PDR having the highest annual incidences of 0.0102 and 0.0113, respectively. AMI and ESRD increased the risk of mortality most in the event year. In subsequent years, a history of stroke and ESRD increased the risk of mortality most. Lower limb ulcer, ESRD and stroke were the complications that increased public direct medical costs most in the event year, with multipliers of 10.84, 9.24 and 7.04, respectively. Private direct medical cost was about one tenth of public direct medical cost in DM patients under HA care. The RAMP-DM was associated with lower incidences of DM complications and mortality and a saving of HK$ 20,186 in public medical cost per subject within the 3-year observation period. The lifetime cost-effectiveness analysis showed RAMP-DM gained 0.359 quality adjusted life year (QALY) and saved HK$ 7,351 per subject. The add-on of RAMP-DM to usual care was associated with lower incidences of complications and mortality and had lower public healthcare costs compared to usual care only. The evidence supports the provision of RAMP-DM to all DM patients.