How your data makes a difference

Contributing data to CPRD ensures your patient population is represented in research evidence informing clinical guidance and best practice.

Here are some examples of how your anonymised patient data has been used in research to inform clinical practice. 

The effectiveness of the influenza vaccine against hospital admissions and mortality in individuals with type 2 diabetes

Seasonal influenza accounts for a significant proportion of excess winter mortality. Current policy in the UK and in many countries worldwide recommends annual flu vaccinations for patients with chronic conditions such as diabetes, though evidence to support such policies is limited.

Vamos and colleagues at Imperial College London investigated the effectiveness of the influenza vaccine at reducing cardiovascular and respiratory hospital admissions and mortality in patients with type 2 diabetes. The study used linkages between CPRD GOLD primary care data, Hospital Episode Statistics (HES) and the Office for National Statistics (ONS) mortality data to look at admissions and death in 125,000 patients over a seven-year period.

Influenza vaccination was associated with a reduction in the rate of hospital admissions for acute cardiovascular and respiratory disease and a reduction in all-cause mortality across the seven flu seasons. The study has been widely reported within healthcare and mainstream media and supports current flu vaccination initiatives in the UK and beyond. 

MMR and risk of autism

The Wakefield study in 1998 suggested a link between mumps-measles-rubella (MMR) vaccination and autism, based on an uncontrolled series of case studies of 12 children. Despite widespread criticism from the scientific community, the study generated media interest and led to a fall in MMR coverage in the UK.

Researchers at the London School of Hygiene and Tropical Medicine used CPRD data to investigate the possibility of a link between the vaccine and incident autism. A case-control design was used to determine whether autistic children were more likely to have received the MMR vaccine. The study found no evidence of an association between being vaccinated against MMR and the risk of developing autism.

The study was published in the Lancet and was instrumental in restoring public opinion of the vaccine. The Wakefield study was fully retracted, and authors withdrew their association with the original publication.

Pertussis and pregnancy 

Whooping cough can cause serious and fatal complications in new-born babies and young children. Babies are routinely vaccinated early, from two months of age, but can still be at risk if a mother catches whooping cough whilst pregnant.

After an outbreak of whooping cough in 2012, a national programme was introduced to give pregnant mothers a vaccine to protect their baby. Using the CPRD database, the MHRA took a proactive approach to pharmacovigilance, collecting data on a monthly basis from the start of the programme to identify a large cohort of vaccinated women. The study compared the vaccinated cohort to historical records. There was no evidence of an increased risk of adverse events in women who received the vaccine in the third trimester.

CPRD data was vital for checking the safety of the vaccine after the programme was introduced, in as near to real-time as possible. As a result of the research, all GPs and maternity services now routinely vaccinate all pregnant mothers from 20 weeks.

Blood pressure treatment for diabetes

This study evaluated the dogma of ‘lower is better’ when managing hypertension among patients with diabetes. Results showed a greater than three-fold increase in mortality among hypertensive patients with newly-diagnosed diabetes when systolic blood pressure was reduced to levels below 110 mmHg. Risk was further increased in patients with diabetes and hypertension who had previously had a stroke or myocardial infarction.

Subsequent guidelines from the European Society of Hypertension and the European Society of Cardiology (2013) now recommend lowering blood pressure to a goal of <140/90 mmHg.

How CPRD data was used in a study about patients with diabetes and high blood pressure

Our bibliography has details of more than 3,000 peer-reviewed publications using CPRD data.

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