title: 5-Year longitudinal study of determinants of glycemic control for multi-ethnic Asian patients with type 2 diabetes mellitus managed in primary care.
abstract: OBJECTIVE
  This study aims to determine the risk factors associated with glycaemic control of ambulatory patients with type 2 diabetes mellitus (T2DM) who are managed in primary care.
  
  
  METHODS
  The data was retrieved from a primary care site within the Singapore Consortium of Cohort Studies-Diabetes Cohort (SCCS-DC). Demographic and clinical variables were described, in association with the risk of having a deteriorating glycaemic control (defined as an absolute increase of at least 1% HbA1c from one year to a subsequent year). Next, multivariate model was performed to define the independent effect of each factor. The longitudinal analysis of the HbA1c was performed using Generalised Estimating Equation (GEE).
  
  
  RESULTS
  The 5 year longitudinal data of 1256 patients (54% Chinese, 25% Malays, 12% Indians, 9% others) were analysed. Their mean HbA1c decreased by <0.1% in the initial 3 years, but increased thereafter. 12% of them had absolute HbA1c increment of ≥1% in the first year, and 22% over 5 years. Based on GEE analysis, insulin, was associated with an increase of HbA1c (≥1%) from one year to another (all p<0.05). Compared with Chinese patients, Malays had higher HbA1c (+0.3%), Indians (+0.3%), and others (+0.2%), (all p<0.01). Patients with retinopathy had higher HbA1c (+0.2%) and those with cataract had lower mean HbA1c (-0.2%) (p<0.01).
  
  
  CONCLUSIONS
  Most cohort patients achieved glycaemic control within the initial 3 years. Patients of Malay and Indian ethnicity and those with retinopathy were associated with subsequent risk of glycaemic control deterioration. Those with cataract were associated with trend towards improved glycaemic control.
authors.affiliation: SingHealth Polyclinics, 167, Jalan Bukit Merah, Tower 5, #15-10, Connection One, Singapore 150167, Singapore; Duke NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore. Electronic address: tan.ngiap.chuan@singhealth.com.sg.
authors.forename: Ngiap Chuan
authors.initials: NC
authors.lastname: Tan
authors.affiliation: Center for Quantitative Medicine, Duke NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore. Electronic address: sylvaine.barbier@duke-nus.edu.sg.
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Barbier
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, 12 Science Drive 2, #10-01, Singapore 117549, Singapore. Electronic address: wei-yen_lim@nuhs.edu.sg.
authors.forename: Wei Yen
authors.initials: WY
authors.lastname: Lim
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, 12 Science Drive 2, #10-01, Singapore 117549, Singapore. Electronic address: ephdean@nus.edu.sg.
authors.forename: Kee Seng
authors.initials: KS
authors.lastname: Chia
mesh_terms: D001786:Blood Glucose / Q000032:analysis*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000208:ethnology*; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011320:Primary Health Care / Q000379:methods*; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: Diabetes mellitus; Glycaemic control; Primary care