Health-related quality of life and metabolic control in children with type 1 diabetes: a prospective cohort study.

OBJECTIVE To assess change in health-related quality of life (HRQOL) in children with diabetes over 2 years and determine its relationship to change in metabolic control. RESEARCH DESIGN AND METHODS In 1998, parents of children aged 5-18 years attending a tertiary diabetes clinic reported their child's HRQOL using the Child Health Questionnaire PF-50. Those aged 12-18 years also self-reported their HRQOL using the analogous Child Health Questionnaire CF-80. HbA(1c) levels were recorded. In 2000, identical measures were collected for those who were aged < or =18 years and still attending the clinic. RESULTS Of 117 eligible subjects, 83 (71%) participated. Parents reported no significant difference in children's HRQOL at baseline and follow-up. However, adolescents reported significant improvements on the Family Activities (P < 0.001), Bodily Pain (P = 0.04), and General Health Perceptions (P = 0.001) scales and worsening on the Behavior (P = 0.04) scale. HbA(1c) at baseline and follow-up were strongly correlated (r = 0.57). HbA(1c) increased significantly (mean 7.8% in 1998 vs. 8.5% in 2000; P < 0.001), with lower baseline HbA(1c) strongly predicting an increase in HbA(1c) over the 2 years (r(2) = 0.25, P < 0.001). Lower parent-reported Physical Summary and adolescent-reported Physical Functioning scores at baseline also predicted increasing HbA(1c). Poorer parent-reported Psychosocial Summary scores were related to higher HbA(1c) at both times but did not predict change in HbA(1c). CONCLUSIONS Changes in parent and adolescent reports of HRQOL differ. Better physical functioning may protect against deteriorating HbA(1c), at least in the medium term. While the HRQOL of children with diabetes does not appear to deteriorate over time, we should not be complacent, as it is consistently poorer than that of their healthy peers.