title: Stratifying healthcare costs using the Diabetes Complication Severity Index.
abstract: OBJECTIVE
  We aim to determine whether healthcare costs for patients diagnosed with Type 2 Diabetes Mellitus (T2DM) are associated with the severity of diabetes complications as measured by the Diabetes Complication Severity Index (DCSI).
  
  
  METHODS
  Retrospective cohort analysis was performed on a 2007 primary care cohort of T2DM patients. The DCSI is a 13-point scale, which comprises 7 categories of complications and their severity levels. Healthcare cost data from 2008 and 2009 were used as primary outcome. Inpatient and outpatient costs incurred for services consumed by patients within the provider network were included. Generalized linear model with log-link and gamma distribution was used to predict healthcare costs.
  
  
  RESULTS
  Of the 59,767 T2DM patients, 2977 (5.0%) deaths occurred and 1336 (2.2%) were lost to follow up. Healthcare cost was strongly associated with increase in DCSI score. Compared to patients without complications, those with more complications (higher DCSI score) had an increased risk of higher healthcare costs. Risk ratio (RR) increased from 1.25 (95%CI: 1.19-1.32) for DCSI=1 to 1.61 (1.51-1.72) for DCSI=2; 2.10 (1.91-2.31) for DCSI=3; 2.52 (2.21-2.87) for DCSI=4 and 3.62 (3.09-4.25) for DCSI≥5. As a continuous score, a one-point increase in the DCSI was associated with a cost increase of 27% (95%CI: 1.25-1.29).
  
  
  CONCLUSIONS
  The DCSI score is a useful tool for predicting direct healthcare costs. The DCSI can be used to triage high-risk patients for more focused secondary prevention interventions at primary care level, in a bid to lower overall healthcare costs.
authors.affiliation: Health Services and Outcomes Research, National Healthcare Group, Singapore 149547. Christine_WU@juronghealth.com.sg
authors.forename: C X
authors.initials: CX
authors.lastname: Wu
authors.forename: W S
authors.initials: WS
authors.lastname: Tan
authors.forename: M P H S
authors.initials: MP
authors.lastname: Toh
authors.forename: B H
authors.initials: BH
authors.lastname: Heng
mesh_terms: D000368:Aged; D048909:Diabetes Complications / Q000191:economics* / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000191:economics / Q000401:mortality; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human