Missed opportunities for limb salvage in patients undergoing major amputation - a retrospective cohort study of the clinical practice research datalink

Date of ISAC Approval: 
Lay Summary: 
About two in every thousand adults per year suffer from a very serious condition called 'critical limb ischaemia'. People with this condition do not get enough blood flow to their limbs, particularly their legs. They can experience pain, ulcers, and gangrene. About one in 10 people need to have part or all of their limb amputated. Understandably, this can be devastating. Having an amputated limb reduces a person's quality of life as well as their life expectancy. For this study, we are focusing on people who have had their 'lower limb' (part or all of their leg) amputated. We want to see if people who had their lower limb amputated were seen by their GP (primary care) or in hospital (secondary care) in the months before their operation. We want to see if their condition could have been picked up earlier and if their amputation might have been avoided. We also want to compare those people who were seen by their GP or in hospital beforehand, with those who were not seen, to see if they were less likely to die. Ultimately, we hope to reduce the need for amputations for people with critical limb ischaemia.
Technical Summary: 
The primary aim of this study is to assess primary and secondary care episodes prior to major lower limb amputation for limb ischaemia to investigate if opportunities are present to enable earlier diagnosis and treatment of limb ischaemia and facilitate limb salvage. Using data collected in the CPRD Gold database with linkage to Hospital Episode Statistics (HES) (admitted care, accident and emergency and outpatient) and ONS death registry, the study will identify a cohort of adult patients who underwent major lower limb amputation for limb ischaemia during 2000-2016. Once identified, primary and secondary care episodes preceding the amputation will be scrutinised to assess if patients underwent cardiovascular assessment. Patients will be stratified into 5 groups - those that underwent their most recent assessment within 1 month, 3 months, 6 months, or 12 months prior to their amputation and those that did not undergo an assessment within the preceding 12 months. Subsequent cardiovascular and all-cause mortality will also be compared for each assessment group.
Health Outcomes to be Measured: 
- Cardiovascular mortality (30-day and 1-year) - All-cause mortality (30-day and 1-year)

Professor Rob Sayers - Chief Investigator - University Of Leicester
Mr Andrew Nickinson - Corresponding Applicant - University Of Leicester
Ms Briana Coles - Collaborator - University Of Leicester
Dr Francesco Zaccardi - Collaborator - University Of Leicester
Professor Kamlesh Khunti - Collaborator - University Of Leicester
Professor Matt Bown - Collaborator - University Of Leicester
Mr Robert Davies - Collaborator - University Hospitals Of Leicester

HES A&E;HES Admitted;HES Outpatient;ONS;Patient IMD