Diabetes - Mobile Telephone Telemedicine System
Type 1 diabetes mellitus is caused by the failure of insulin-producing beta cells in the pancreas. Patients inject insulin to control their blood glucose levels, adjusting the insulin dose to account for diet, exercise and their current blood glucose level, which they can measure using an electronic meter. An intensive therapy (typically four insulin injections per day) is widely used, since it has been shown to delay long-term complications caused by high blood glucose levels. In conventional care, patients discuss their blood glucose control at three-monthly clinics without access to computer-based data or visualisations. Overall blood glucose control during recent months is also assessed at clinics by measuring the proportion of haemoglobin A1c (HbA1c) in the blood.
Telemedicine for the Self-Management of Type 1 Diabetes
A mobile phone-based telemedicine system to assist patients in the
self-management of Type 1 diabetes has been developed by the University of
Oxford and e-San Ltd. The patient uses a standard mobile phone which has
been interfaced to a blood glucose meter (see figure to the left). Custom software on the
phone collects data from the meter and asks the patient a short series of
questions about their diet, exercise levels and the insulin dose they have
chosen to inject. This information is immediately transmitted to a server,
and the phone provides simple graphical feedback to the patient on their
blood glucose control. The patient, and healthcare professionals, can view
the data via a secure web site [1].
Clinical Trial
The telemedicine system was tested in a 9-month clinical randomized controlled trial: 93 patients (age 18-30 years) from the Oxford Young Adult Clinic were recruited and randomized into intervention and control groups. Both the intervention and control groups used the phone system as described above, but the intervention group additionally had more intensive feedback: proactive nurse support via telephone, and an extra histogram display of recent BG readings shown on the phone screen [2].
Trial Results
There was a statistically significant reduction in HbA1c in each group in the trial: in the intervention group from 9.2% to 8.6% (p=0.001) and in the control group from 9.3% to 8.9% (p=0.04), although the difference in HbA1c change between the two groups was not statistically significant (p=0.3). The figure above shows the normalised distributions of blood glucose readings taken by each group during the trial: the difference in median blood glucose between the groups was statistically significant (p<0.0001). The trial demonstrated that the mobile-phone based telemedicine system was technically feasible (over 55,000 blood glucose readings were transmitted) and helped patients to achieve improvements in blood glucose control. Differences in the frequency of blood glucose measurements showed the importance of feedback and proactive nurse support in maintaining compliance [3].
Automatic Measures of Blood Glucose Control
The data set gathered during the trial allowed automatic measures of blood glucose control to be investigated, to provide extra feedback to the patient and better targeting of nurse support. A blood glucose forecasting model was developed, from which the prediction error could be used to assess patient self-management. These and related measures can be implemented within the mobile phone telemedicine system to make the best use of nurses' time and provide targeted support to patients via the mobile phone. Research into other similar algorithms is ongoing.
[1] A.J. Farmer, O.J. Gibson, C. Dudley, K. Bryden, P.M. Hayton, L. Tarassenko, A. Neil (2005), A randomized controlled trial of the effect of real-time telemedicine support on glycemic control in young adults with Type 1 diabetes. Diabetes Care, 28(11): pp. 2697-2702.
[2] A.J. Farmer, O.J. Gibson, P.M. Hayton, K. Bryden, C. Dudley, A. Neil, L. Tarassenko (2005), A real-time, mobile phone-based telemedicine system to support young adults with Type 1 diabetes. Informatics in Primary Care, 13(3): pp. 171-178.
[3] O.J. Gibson, P.E. McSharry, P.M. Hayton, A.J. Farmer, H.A.W. Neil, L. Tarassenko (2005), A mobile phone telemedicine system for the self-management of Type 1 diabetes: results of randomized controlled trial and measures of glycemic control in Diabetes Technology Meeting: San Francisco, USA.