Blood glucose self-monitoring provides a snapshot of the blood glucose level. Depending on the measured value, patients can then take appropriate measures, for example, by eating something. However, blood glucose self-monitoring is not suitable for determining the quality of metabolic control. The HbA1c value is used for this. It is an indicator for long-term blood glucose control and serves as the "memory" for the blood glucose level. High HbA1c values in diabetes indicate poor metabolic control.

All trials included in the assessment additionally investigated the impact of blood glucose self-monitoring on the HbA1c value. The joint analysis revealed that blood glucose self-monitoring actually does assist in lowering blood glucose. However, the difference was marginal compared to the group that did not carry out self-monitoring. It was inside the range that is acceptable within the context of drug approval for describing a new drug as "not inferior" compared to existing drugs. No health advantage from this difference can therefore be anticipated.

Furthermore, the HbA1c value alone has no validity in assessing the benefit of glucose self-monitoring, since the more the blood glucose level drops, the greater the risk of hypoglycaemia. In this case, hypoglycaemia is not merely unpleasant, but can also represent a serious complication in individual cases. For this reason, it is always necessary to assess changes in the HbA1c value in relation to the occurrence of hypoglycaemia. The available trials on blood glucose self-monitoring were inappropriate for this, however. Thus, an advantage of hypoglycaemia is not proven. In addition, it remains unclear whether glucose self-monitoring has contributed towards patients being able to make changes to their lifestyle.

Overall, IQWiG and its external experts come to the conclusion, therefore, that a benefit of blood glucose self-monitoring cannot be proven from the available trials. Due to a lack of trials on urine glucose self-monitoring, no conclusions can be drawn from a comparison of urine and blood tests, either.

IQWiG published the preliminary results in the form of the preliminary report in June 2009 and interested parties were invited to submit comments. When the comments stage ended, the preliminary report was revised and sent as a final report to the contracting agency, the Federal Joint Committee, in October 2009. Documentation of the written comments and minutes of the oral debate are published in a separate document simultaneously with the final report. The report was produced in collaboration with external experts.

Source: Institute for Quality and Efficiency in Health Care