Abstract and Introduction
Abstract
Introduction Older adults who have diabetes vary widely in terms of comorbid conditions; these conditions help determine the risks and benefits of intensive glycemic control. Not all people benefit from intensive glycemic control. The objective of this study was to classify by comorbid conditions older American adults who have diabetes to identify those who are less likely to benefit from intensive glycemic control.
Methods We used latent class analysis to identify subgroups of a nationally representative sample of community-dwelling older adults (aged 57–85 y) who have diabetes (n = 750). The subgroups were classified according to 14 comorbid conditions prevalent in the older population. Using the Akaike Information Criterion, the Bayesian Information Criterion (BIC), the sample-size adjusted BIC, and the χ goodness-of-fit statistic, we assessed model fit.
Results We found 3 distinct subgroups. Class 1 (63% of the sample) had the lowest probabilities for most conditions. Class 2 (29% of the sample) had the highest probabilities of cancer, incontinence, and kidney disease. Class 3 (9% of the sample) had the highest probabilities (>90%) of congestive heart failure and myocardial infarction. Class 1 had only 0, 1, or 2 comorbid conditions, and both class 2 and class 3 had 6 or more comorbid conditions. The 5-year death rates for class 2 (17%) and class 3 (33%) were higher than the rate for class 1 (9%).
Conclusion Older adults who have diabetes, cardiovascular disease, and 6 or more comorbid conditions may represent a subgroup of older adults who are less likely to benefit from intensive glycemic control.
Introduction
According to the American Diabetes Association (ADA), the glycemic target for most adults who have diabetes is a glycosylated hemoglobin (HbA1c) of less than 7.0%. Although the strategy of intensive glycemic control (defined as an HbA1c of <7%) may benefit many people who have diabetes, it may not benefit many older adults. Older adults who have diabetes are more heterogeneous than younger adults in terms of diabetes duration, functional ability, and comorbid conditions. The number and type of comorbid conditions may determine the risks and benefits of intensive glycemic control. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial heightened concerns about the harms of very intensive glycemic control (defined as an HbA1c <6.5%) among older adults. In light of these concerns, the current challenge is to identify older adults who are likely to benefit from intensive glycemic control.
Clinical markers may help identify these subgroups of older adults. For frail adults and adults who have a life expectancy less than 5 years, the American Geriatrics Society recommends less intensive glycemic control than that recommended by ADA. The 2010 ADA guidelines identify comorbid conditions, diabetes duration, hypoglycemia risk, and previous failures at intensive control as considerations for less intensive glycemic control. Despite these recommendations, no simple approach for identifying subgroups of older adults who would benefit from intensive glycemic control has been well accepted. For health systems, the identification of subgroups is especially difficult because many relevant markers (eg, hypoglycemia risk, mortality prediction, functional status) are not readily available from electronic medical records.
Classifying older adults who have diabetes according to comorbid conditions may be a practical strategy for identifying subgroups. Unlike methods requiring additional assessments (eg, functional status), data on comorbid conditions are readily available. Comorbid conditions are also associated with life expectancy and the degree to which intensive glycemic control provides benefits. The objective of this study was to classify by comorbid conditions the population of older adults in the United States who have diabetes in order to identify older adults who are less likely to benefit from intensive glycemic control.