The aim of this study is to establish if the self-administered electronic Oral Glucose Tolerance Test kit can increase the annual uptake of screening for CFRD in children who are between 10 and 17 years of age with CF.

Cystic fibrosis related diabetes (CFRD) is the most common secondary complication of Cystic fibrosis. It affects nearly 20% of adolescents and 40-50% of adults. Undiagnosed CFRD is associated with significant decline in lung function and nutritional status with an increase in mortality. This emphasises the importance of screening for CFRD in children with CF to minimise the nutritional and pulmonary consequences of diabetes.

The UK CF trust guidelines, the European consensus statement and US Cystic Fibrosis Foundation clinical care guidelines recommend the 2hr (1.75g/kg) oral glucose tolerance test as a screening tool on an annual basis in all CF patients without CFRD.

The American Diabetes Association (A.D.A) recommends that annual screening for CFRD should begin by age 10 years in all CF patients who do not have CFRD. The European Consensus Statement on this is in agreement for screening to start at age 10 years. This standard is often applied within the United Kingdom.

The current gold standard screening tool, the Oral Glucose Tolerance Test, is resource intensive. This requires an individual/child and a parent to attend a clinical facility while fasted and requires trained health care professionals to take venous samples, analyse and interpret the results.

There are also problems encountered in standardising the test. The patient should be fasted and must travel to clinic for the test in the morning. The OGTT, if done at hospital, can therefore affect an individual's time off work, time off school, can cause inconvenience and expensive for an individual, parent and child to travel to clinic. The unpredictability of workload for hospital staff means that test times are often not strictly adhered to or accurately recorded. In patients with cystic fibrosis there is also an additional risk of cross infection when they attend the hospital for OGTT. These factors limit the uptake of OGTTs for screening in children with cystic fibrosis.

To overcome these issues a simple, disposable, self-administered electronic OGTT Kit containing everything required to perform the OGTT at home with simple written and pictorial instructions has been used in this study.

The aim of this study is to establish if the self-administered electronic Oral Glucose Tolerance Test kit can increase the annual uptake of screening for CFRD in children who are between 10 and 17 years of age with CF.

Inclusion Criteria:

• Children diagnosed with cystic fibrosis who are between 10 years and 17years old and managed at Great Ormond Street Hospital.

Exclusion Criteria:

• Children who are diagnosed with cystic fibrosis related diabetes.