What this Trial Is About

People with diabetes sometimes consider that they are subjected to unfair discrimination in the occupational or work environment. These include safety-critical activities, such as operating machinery and driving 1-3. Some occupations preclude the use of medications that lower blood glucose, particularly insulin. Safety regulators, occupational health physicians and national organisations frequently have to balance the competing priorities of individual rights against public safety. Modern treatment, with advances in insulin therapy and glucose monitoring, combined with rigorous clinical assessment and review, has allowed stereotypical attitudes to be challenged and advocated individual assessment with respect to safety criteria. Along with the UK Driving and Vehicle Licensing Agency (DVLA) and Civil Aviation Authority (CAA), the Maritime and Coastguard Agency (MCA) have accepted that insulin-treated diabetes should not be an absolute contra-indication to partaking in these occupational activities4. However, as the Disability Discrimination Act (1995) recognises that there may be specific employment-related hazards, fitness to work should be assessed on an individual basis. Therefore, each of these transport agencies has established regulatory standards for their respective domains, with the priority of minimising hypoglycaemic incapacitation risks. The CAA, for example, has worked alongside other European countries to use the ARA.MED.330 protocol and require medically certified pilots to check their blood glucose levels regularly before and during flights. In 2010, the UK CAA's expert committee reviewed the knowledge and policies concerning flying and it was decided that Continuous Glucose Monitoring (CGM) systems were not accurate enough and instead used finger prick-blood glucose monitoring (SMBG) as the gold standard. Since then, the protocol has been successfully implemented and there are current works in progress that demonstrate sufficient accuracy in modern CGMs as a viable alternative to SMBG. Similarly, the guidelines devised by the MCA, Approved Doctor's Manual (ADM), place a great emphasis on the type and treatment of diabetes, with the primary concern being risks of cognitive impairment or incapacitation5. Emphasis is placed on the need for able glycaemic control and "full awareness of impending hypos, with no reported or observed significant hypoglycaemic episodes in the last year". The guidance stipulates that certification may be restricted on individuals pending their medication side effects, compliance, and vascular risk factor control. Previous regulations prevented seafaring individuals such as insulin-treated seafarers from partaking in lone watchkeeping/lone-working roles and restricted them to near-coastal duties (150-200 nautical miles) (Appendix 1). Current regulations allows for exemptions for certain vessels, provided that the seafarer's diabetes control remains stable and is subject to blood glucose monitoring. Regardless, an approved medical assessor is needed to conduct these specific medical assessments in line with the statutory standards in MSN 1886 and guidance in the ADM. All seafarers who are insulin-dependent and licenced to undertake seafaring in the UK will be invited to participate in this study.

The Seafarers' Continuous Glucose Monitoring Systems Study