Patient self-management is important to successful diabetes care. Self-monitoring of blood glucose is promoted as a way that patients can better understand and manage their condition.
For patients on insulin, self-monitoring is important to help titrate doses. But for patients with type-2 diabetes, self-monitoring is more contentious.
The financial cost of glucose self-monitoring is considerable. The NHS spent around £32.9 million between October and December 2006 on blood glucose testing strips. Patients with non-insulin-treated type-2 diabetes make up the largest group of patients with diabetes. Policy on the use of self-monitoring in this group is therefore likely to have a very significant impact on these costs.
Research evidence on the impact of self-monitoring on glycaemic control is inconclusive. A recent review of six randomised controlled trials found that HbA1c was lower in the self-monitoring groups than in the group receiving usual care.
However, a study comparing blood and urine monitoring groups found no difference.
A recent randomised controlled trial found no significant difference in HbA1c after 12 months between patients receiving usual care and those self-monitoring, even though one of the self-monitoring groups received additional education about how to interpret and respond to results.
The authors concluded that 'routine self-monitoring of blood glucose for patients with reasonably well-controlled non-insulin treated type-2 diabetes seems to offer small advantages'. Other research has shown that patients often do not take any action based on their meter readings.
Despite these findings, practice guidelines often advocate self-monitoring in non-insulin treated patients. For example, the American Diabetes Association guidelines state that self-monitoring can be used to prevent hypoglycaemia, adjust medication and inform decisions about diet and physical activity.
We carried out some qualitative research to find out what non-insulin treated patients with type-2 diabetes think about self-monitoring.
We interviewed 40 patients three times in the first year following diagnosis. We then re-interviewed 20 of them three years later to see if their perspectives had changed.
In both studies, patients expressed both mixed views of self-monitoring. We found that most patients were unclear about why they had been encouraged to self-monitor.
Early on, self-monitoring gave asymptomatic patients visible evidence that they had diabetes. But high meter readings created a sense of failure and could lead patients to abandon self-monitoring.
Self-monitoring increased awareness of the impact diet had on blood glucose, but counter-intuitive readings, for instance when patients thought they had eaten appropriately but then recorded high readings, could cause patients to abandon their diet.
Some patients found readings difficult to interpret, even after three years of self-monitoring, and few patients actively used readings to affect and maintain ongoing changes to their behaviour or lifestyle.
Many patients expressed disappointment that health professionals seemed uninterested in their readings and did not use them to inform treatment decisions. Some had stopped monitoring as a result. Others continued to monitor out of habit even though the readings were not used.
Better communication with patients is essential. A discussion could usefully start with the patient's understanding of self-monitoring, the purpose of self-monitoring and how to interpret and act on readings. Otherwise many patients will continue to collect readings that serve no useful purpose.
Dr Peel is a lecturer at Aston University, Dr Douglas is a consultant in public health medicine on the Lothian NHS Board, Edinburgh, and Dr Lawton is a senior research fellow at the University of Edinburgh.
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