The objectives of this two-year (2013-2015) cross-sectional study are to determine whether there are associations between ethnicity and medication adherence to oral hypoglycaemic agents (OHAs), and ethnicity and HbA1c levels, in UK patients with type 2 diabetes mellitus (T2DM). We will also test whether adjustment for medication adherence alters the predictive value of ethnicity for HbA1c levels.
The population will include all patients >18-years with T2DM using OHAs. Patients will be grouped by ethnic category using the standard Office for National Statistics (ONS) 5-category classification. Medication adherence will be defined and analysed as ‘proportion of days covered’ (PDC), both as a continuous variable, and PDC ≥0.8 (binary variable). Similarly continuous HbA1c (= mean over 2-year period) and binary HbA1c (= continuous measure collapsed into < or > 7.5% categories) outcome variables will be analysed.
Linear and logistic regression analyses will be used to determine whether there are associations between ethnicity and these outcome variables. We will calculate unadjusted and adjusted coefficients and odds ratios, with Huber-White standard errors, with the adjusted measures of effect accounting for various previously identified potential confounders. These confounders have been identified from extensive literature review and include demographic and socioeconomic factors, other prescriptions and comorbidities.
Michael Soljak - Chief Investigator - Imperial College London
Robert Watson - Corresponding Applicant - Imperial College London
Ailsa McKay - Collaborator - Imperial College London
Azeem Majeed - Collaborator - Imperial College London
Jonathan Valabhji - Collaborator - Imperial College London
Roger Newson - Collaborator - Imperial College London