One size does not fit all: the need for a continuous measure for glycemic control in diabetes.
BACKGROUND
The assessment of glycemic control, most commonly using glycosylated hemoglobin (A1C), has been a major measure for care of patients with diabetes. Historically, dichotomous thresholds have been set for intermediate outcomes such as A1C (in this case, > 9%) on the basis of levels associated with high risk, that is, thresholds for what would be considered poor control for all persons.
Dichotomous threshold measures may not accurately reflect the true impact of care on population health because absolute risk reduction for micro- and macrovascular complications of diabetes is not linear but rather log-linear, with greater impact of a given improvement on patients with worse rather than better glycemic control. Also, an "all or none" measure for all patients set at "optimal" control may unfairly evaluate physician/health care performance.
A continuous measure of A1C, as the cornerstone in quality assessment for diabetes, can incorporate each of the Institute of Medicine's (IOM)'s quality domains: effectiveness and equity, patient safety, patient-centered care, timeliness, and efficiency.


CONCLUSIONS
A continuous measure of A1C can better capture than a dichotomous measure the complexity of glycemic control at a population level.
Aron
David C
DC
Center for Quality Improvement Research, Louis Stoker Cleveland Veterans Affairs Medical Center, USA.
Pogach
Leonard M
LM
D000293:Adolescent; D000328:Adult; D000368:Aged; D048909:Diabetes Complications / Q000517:prevention & control; D003920:Diabetes Mellitus / Q000097:blood / Q000628:therapy*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D008875:Middle Aged; D008962:Models, Theoretical; D017063:Outcome Assessment, Health Care; D018802:Patient-Centered Care; D015397:Program Evaluation; D011785:Quality Assurance, Health Care / Q000379:methods*; D012449:Safety; D014481:United States
D006442:Glycated Hemoglobin