HRQOL using EQ5D utility scores
Diabetic patients reported an average EQ5D utility score of 0.74 (SD 0.27), which is only slightly lower than the scores seen in individuals of similar age in the general population (U.K. population: 60–69 years of age; women 0.81, men 0.78) (Table 1) (12). Women, older patients, and patients with a longer duration of diabetes reported a lower HRQOL than other patients. Both insulin therapy and presence of complications were associated with a lower quality of life. Patients without complications reported the highest HRQOL, whereas patients with both microvascular and macrovascular complications reported the lowest HRQOL (i.e., 0.191 units lower). Patients with only microvascular complications and patients with only macrovascular complications reported an HRQOL between these two extremes. obesity was associated with a lower utility score ( 0.07 units). Higher fasting blood glucose and HbA1c levels were associated with a lower utility score, although the association seen for HbA1c was more pronounced (a decrease of 0.02 Euroqol units per increase in HbA1c by 1%) (Table 2).
Multivariate analysis resulted in a model containing age, female sex, obesity, insulin therapy, microvascular complicationsonly, macrovascular complications only, and both microvascular and macrovascular complications (Table 2). Multilevel modeling showed that only 1.6% of the variance in EQ5D utility scores was seen at the general practitioner level and 98.4% was seen at the patient level. The differences between the model based on linear regression and the model based on multilevel modeling were insubstantial.