Change in perceived health and functioning over time in patients with type I diabetes mellitus

Objective: The objective of this study was to investigate perceived health and functioning (PHF) of patients with type I diabetes mellitus (DMT1) over time and to compare change in perceived PHF with that of a sample of the general population. Methods: In a Dutch cohort of 234 patients with DMT1 we assessed PHF over time with two generic instruments: RAND-36 and EuroQol. We applied multilevel modelling to estimate change in PHF over the years 1995-2001. We compared change in PHF with change estimated from a comparably aged sample from the general population using a one-sample t-test. Results: Patients reported a significant decrease in PHF for most RAND-36 subscales. Mean changes in RAND-36 scores ranged from -0.09 (mental health) to -1.18 per year (bodily pain). EQ scores decreased significantly as well. Patients in the cohort had a faster decrease in three RAND-36 subscales and EQ-VAS over time than the estimated decrease in the general population. Conclusion: This study showed that patients with DMT1 have a faster decrease in PHF over time than comparably aged persons from the general population. The generic instruments used in our study were sensitive enough to measure changes in PHF over time in an adult diabetes population.