All-cause and cardio-renal-metabolic mortality in people with or without type 2 diabetes: a comparative international trend study

Study type
Protocol
Date of Approval
Study reference ID
18_296
Lay Summary

Diabetes is a serious condition where a person cannot control their blood sugar levels. It is associated with a lot of health complications, including kidney damage, problems with the heart or blood vessels, and strokes. These combined diseases are called 'cardio-renal-metabolic conditions'. Diabetes can also increase someone's risk of dying.

Over the last 20 years, there have been significant improvements in the treatment of diabetes. This has meant that people with diabetes are now living longer than they did in the 1980s and 1990s. However, people who do not have diabetes are also living longer. We do not know whether the improvement is the same for people with and without diabetes and whether there are international differences.

To test this, we will do a study comparing people with and without diabetes. We will look at all deaths and deaths due to cardio-renal-metabolic conditions. We will ask our colleagues in Norway, Sweden, Spain and Canada to do the same with their own databases so that we can see how things have changed and whether there are any differences between countries.

Technical Summary

Using data collected from the Clinical Practice Research Datalink (CPRD) Gold database with linkage to Hospital Episode Statistics (HES) and Office for National Statistics (ONS), we will investigate changes in all-cause and cardio-renal-metabolic mortality rate of patients with type 2 diabetes in the period 1998 - 2017 and compare these to patients without diabetes. The cohort will include incident subjects with diabetes identified within CPRD (exposed individuals) along with 5:1 matched participants without diabetes (non-exposed individuals). The outcomes are all-cause and cardio-renal-metabolic deaths, identified via linkage to ONS. All-cause and cause-specific (cardio-renal-metabolic) mortality rates will be estimated by age, sex, and calendar time in subjects with and without diabetes; then, rate ratio and rate differences between people without and without diabetes will be quantified separately for each country.

Health Outcomes to be Measured

All-cause and cardio-renal-metabolic deaths defined by ONS death records (codes in the Appendix)

Collaborators

Kamlesh Khunti - Chief Investigator - University of Leicester
Francesco Zaccardi - Corresponding Applicant - University of Leicester
Freya Tyrer - Collaborator - University of Leicester
Melanie Davies - Collaborator - University of Leicester
Suping Ling - Collaborator - University of Leicester

Linkages

HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation