[The quality of life: should it be taken into account as a therapeutic objective?]

Traditionally, biomedical or clinical outcomes have been the main foci of attention in the care of the chronically ill, but efforts are now being made to measure other outcomes that derive from patient-reported experiences. In diabetes treatment and care, the situation has become particularly complex as rigid glycaemic control, now believed to be correlated with a reduced incidence of long-term complications, may not be compatible with a high level of quality of life. The acceptance of a linear relationship between levels of glycaemic control and relative risk of complications does not address the fact that quality of life has not been included as a variable in these analyses. If a reduction from 11 to 9.9% leads to a lower risk of retinopathy progression of 6.67 cases per 100 patient years, a reduction from 8 to 7.2% decreases risk by only 0.95 cases per 100 patient years. In the latter case, it may be asked whether this relatively small reduction is worth a lifetime deterioration in quality of life. We suggest that clinicians in their treatment of diabetic patients must give as much attention to quality of life as to biological outcomes and complications. An important question remaining is: How good are our tools for measuring quality of life?