The impact of learning disabilities on control of type 2 diabetes risk factors and outcomes in UK primary care

Date of Approval
Application Number
21_000432
Technical Summary

People with learning disabilities (LDs) experience higher rates of mortality, chronic disease, and Type 2 Diabetes (T2DM). There is little evidence exploring the impacts of LDs on control of diabetes-related risk factors and outcomes such as cardiovascular and microvascular disease. It is hypothesised that later diagnosis and poor glycaemic control contribute to worse outcomes, but the extent of these contributions is unknown. The aim of this study is to assess the impact of LDs on the control of cardiometabolic risk factors and clinical outcomes amongst people with T2DM.

Linear and logistic regression will be used to assess differences in control of cardiometabolic risk factors. Cox proportional hazards regression will be used to examine differences in the risk of vascular complications, initiation of insulin and mortality between those with and without LDs. Sensitivity analyses will be conducted to explore outcomes by subtypes of LD. This can allow us to better understand differences in the progression of T2DM in those with and without LDs. This research will identify the need for updating T2DM care guidelines to meet the needs of those with LDs, a population that carries a proportionally larger burden of chronic diseases.

Index of multiple deprivation (IMD) is a key confounder in this study and must be controlled for in analyses. We will use patient level IMD where available and practice level IMD elsewhere to reduce missing data points. Premature mortality is an important outcome of type 2 diabetes- determining whether this differs between people with and without learning disabilities is important for understanding if inequalities exist and generating hypotheses for how these can be mitigated. Linked ONS data will be essential for identifying diabetes-related and all-cause mortality as it contains information on the underlying cause of death and accurate date of death not available in the primary care data.

Health Outcomes to be Measured

Haemoglobin A1c (HbA1c)
Blood Pressure
Macrovascular and microvascular complications
Prescription of antidiabetic medication
All-cause and diabetes-related Mortality

Collaborators

Rohini Mathur - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Rohini Mathur - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Archie Wing - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )

Linkages

ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation