Cardiovascular disease in type 2 diabetes: characterisation of treatment variation in the UK CPRD

Date of ISAC Approval: 
27/03/2020
Lay Summary: 
Type 2 diabetes is a long-term condition that causes blood sugar levels to become too high. Cardiovascular disease (problems with the heart and circulatory system) is a common problem experienced by people with type 2 diabetes. There are many different types of medications used in type 2 diabetes to help reduce blood sugar. Research suggests that some of these medications may reduce cardiovascular problems and death from cardiovascular causes. However, the extent to which these medications are being actively used to treat patients with type 2 diabetes in the UK, whether this is consistent throughout the UK, and which patients are more likely to receive these medications versus alternatives, is unclear. Our study aims to gain insight into current prescribing patterns for type 2 diabetes in the UK, with a focus on how this may differ by whether or not patients have a history of cardiovascular disease. We will use primary care data to summarise the types of type 2 diabetes medications being currently and newly prescribed, looking separately by history of cardiovascular disease and by UK geographical region. Further, to investigate whether other factors might be associated with the decision to prescribe a particular drug type, we will compare other patient characteristics (such as age, ethnicity, and lifestyle factors) between patients starting different types of diabetes medications at different treatment stages. The results of this study will provide important information that may aid decision making and improve care for people with type 2 diabetes.
Technical Summary: 
Recent studies suggest that selected diabetes treatments (namely sodium-glucose co-transporter 2 inhibitors (SGLT2 inhibitors) and glucagon-like peptide 1-receptor agonists (GLP1-RAs)) have significant cardio-protective benefits. A recent estimate of the UK prevalence of cardiovascular disease (CVD) within type 2 diabetes (T2DM) is 35%; but the treatment patterns of these patients remains unclear. In particular, the extent to and stage at which SLGT2 inhibitors and GLP1-RAs are used across the UK, and how usage differs from those without CVD is unknown. With a shift to looking beyond glycaemic control to manage diabetes and its complications, it is important to understand the current treatment patterns of these patients; what clinical and demographic characteristics may be associated with class choice at point of intensification; and how this compares to recent ADA/EASD recommendations. This study therefore aims to: - Describe prescribing variation by class in patients with T2DM by history of CVD; by UK geographical region; and by calendar year since 2017. - Describe and compare characteristics of those initiating different classes of medication within the past 3 years by CVD history and intensification stage. The study will use primary care data to establish a cohort of patients with T2DM, from which we will use cross sectional sub-populations to estimate prevalence of class use through time. From the same underlying cohort, a sub-cohort of initiators will be used for comparisons of patient characteristics. The main outcomes (prescription for/ initiation of a particular class of T2DM medication) will be ascertained using prescription data. The main exposure (CVD history) will be ascertained using clinical diagnoses in the primary care record. Prevalence by time, CVD history and treatment stage will be presented descriptively, with exact 95% confidence intervals for proportions to quantify uncertainty. The association between patient characteristics and choice of class initiated will be estimated using multinomial regression models.
Health Outcomes to be Measured: 
Current prescription for a: Biguanide Sulfonylureas (SU) Dipeptidyl peptidase-4 inhibitor (DPP-4 inhibitor) Thiazolidinedione (TZD) Sodium-glucose co-transporter-2 (SGLT2 inhibitor) Glucagon-like peptide 1-receptor agonists (GLP1-RA) Insulin Any other glucose lowering medication (Nateglinide, Repaglinide, Acarbose) New prescription of an: SGLT2 inhibitor GLP1-RA DPP-4 inhibitor Sulfonylurea s Insulin Other (TZD, Biguanide, Nateglinide, Repaglinide, Acarbose)
Collaborators: 

Dr Ruth Farmer - Chief Investigator - Boehringer-Ingelheim Pharmaceuticals, Inc
Dr Andrew McGoven - Collaborator - University of Exeter
Dr Andrew Ternouth - Collaborator - Boehringer-Ingelheim Pharmaceuticals, Inc
Mr Ivan Beard - Collaborator - Boehringer-Ingelheim - UK
Dr Naresh Kanumilli - Collaborator - NHS England
Dr Nick Gollop - Collaborator - Boehringer-Ingelheim - UK
Dr Niraj Patel - Collaborator - Boehringer-Ingelheim - UK
Dr Ruth Farmer - Corresponding Applicant - Boehringer-Ingelheim Pharmaceuticals, Inc
Mr Syed Raza - Collaborator - Boehringer-Ingelheim - UK