This study is the first to examine the role of NH admission and dementia status on the provision of care for diabetes mellitus. Using Medicare billing records, whether rates of procedures related to diabetes mellitus in the year before admission differed from those experienced in the year after admission was evaluated. Using expert panel dementia determination, whether a patient's status as having or not having dementia was related to procedure rates was evaluated. Interaction effects for time and dementia for these procedures were also examined.
Demographic, health status, and healthcare utilization differences between people with diabetes mellitus newly admitted to NHs with and without dementia () reflect the short- and long-term care needs of these populations. Although no method of directly measuring severity of diabetes mellitus was available, greater severity of diabetic complications appears to be reflected in the younger age and higher preadmission healthcare costs of residents in the sample without dementia than of those with dementia. Research shows that having diabetes mellitus increases the risk of NH placement but only in persons who do not have dementia.23
At the same time, individuals with dementia had more ADL dependencies and longer stays, reflecting the debilitating and chronic nature of dementia, and were more likely to be on Medicaid and not an MQS. In contrast, the health problems experienced by people with diabetes mellitus admitted to NHs without dementia may not preclude an MQS with return to the community after stabilization or rehabilitation.
These results suggest that admission to an NH may improve the care that elderly persons with diabetes mellitus receive in relation to diagnostic and preventive procedures. With or without adjustment for demographics, health, and healthcare utilization, four of the five procedures examined occurred more frequently in the year after NH admission than in the year preceding admission (except eye examinations). Previous studies that have evaluated samples of community- and NH-dwelling elderly adults with diabetes mellitus separately present a mixed picture of procedure rates. For example, HbA1c testing occurred at higher rates in NH samples10,11
than in community samples,7–9
whereas dilated eye examinations and lipid profile testing occurred more often in community-dwelling7,9
than in NH samples.11,12
By examining the treatments provided to a single group of patients as they transition from community to institutional settings, differences in care after NH placement can be better evaluated.
A possible explanation for the findings of the current study is that the structure of NH care, and in particular the monitoring and regulating functions of the MDS Resident Assessment Instrument, helps to ensure that basic diabetes mellitus care takes place. To the extent that a diabetic complication acts as a “trigger” leading to NH placement, these data may also reflect heightened awareness of the diabetes mellitus care needs of new residents. The lack of improvement in dilated eye examinations after admission may reflect low rates overall for this procedure in NH residents,24
as well as the fact that such examinations take place offsite and so are more challenging to implement.
This study found that individuals with diabetes mellitus and dementia received lower rates of clinical tests for HbA1c, fasting plasma glucose, and serum creatinine and of dilated eye examinations in community and NH settings than those without dementia. Because of a dearth of outcome studies evaluating diabetic treatment for very frail older people, there is controversy over the level of intensity of care for diabetes mellitus that is appropriate for such persons.5,13,25
For some, the risks and discomfort associated with treatment may not outweigh the benefits, especially given research documenting that several years may be required before clinical improvements in areas such as microvascular complications and renal disease are seen5
and that tight glycemic control can increase the risks of cardiovascular disease and hypoglycemic episodes, potentially leading to greater falls risk.13
Others argue that, on a case-by-case basis, tighter glycemic control and higher insulin use in institutionalized elderly people should be considered because of their positive effects on hypertension, dyslipidemia, microalbuminuria, and cognitive function. Nevertheless, studies consistently find lower rates of treatment with antidiabetic medications for the oldest old and for NH residents who are more cognitively and functionally impaired.13,14
These controversies primarily address the provision of medications and not the monitoring procedures examined, but whether advisable or not, at the clinical level, looser adherence to recommended monitoring schedules is likely to accompany less-intensive pharmacological treatment. Acknowledgment of the need to consider the patient's overall prognosis in relation to monitoring schedules is stated clearly within the guidelines for institutionalized diabetes mellitus, which advises that tests can be excluded “if advanced dementia or poor prognosis” is present.6
Such decisions regarding monitoring and treatment may therefore underlie, at least in part, the lower rates of testing found for NH patients with diabetes mellitus who also have dementia.
After controlling for demographics, health status, and healthcare utilization, differences in the provision of procedures for the care of diabetes mellitus according to dementia status were no longer significant for eye examinations, but several of the interactions remained. This might indicate some attenuation of the effect with adjustment, but the overall effects showed lower rates of procedures and less increase after NH admission for people with dementia. It is likely that the variables for which it was possible to adjust the data do not sufficiently capture the extent of differences between elderly people with diabetes mellitus with and without dementia admitted to NHs. This research suggests that patients with dementia are receiving fewer tests and procedures, but further research is needed to more clearly delineate and confirm this finding.
Although NH admission is related to higher rates of procedures related to care of diabetes mellitus for people with and without dementia, for several procedures, the positive relationship between NH admission and procedure rates was stronger for those without dementia than those with. The dementia-by-time interactions found for three of the procedures (fasting plasma glucose, serum creatinine, and in the adjusted results, lipid profiling) reinforce the conclusion that NH admission, although beneficial for all in terms of care for diabetes mellitus, may be more beneficial for those who do not have dementia. Overall rates were lower for those with dementia, and these differences become most dramatic in the postadmission period. Here again it may be that the structure of the NH may lead to a review of the diabetic care needs of all people admitted with diabetes mellitus, with accompanying orders for diabetes-related testing, but that the greater medical care needs and higher potential benefits of treatment for new admissions without dementia result in greater increases in care for this group than for those who have dementia and diabetes mellitus.
This study has important limitations. First, the data are not timely, and community-based care and monitoring for diabetes mellitus has improved somewhat.26
Nevertheless, procedure rates for community- and NH-based care remain well below guidelines.4,26,27
Furthermore, no information or research was found suggesting that changes in management of diabetes mellitus in recent years have differentially affected those within and outside of NHs or those with and without dementia. Given this, it was felt that the advantages of this data set (including the ability to examine procedures for a significant time frame before and after NH admission within a single patient cohort and to compare those with and without dementia based on expert panel review) outweighed the negatives for examining this important and overlooked issue. Second, as with all studies that use the MDS to identify cases of diabetes mellitus, it was not possible to differentiate between type 1 and type 2 diabetes mellitus, examine care for those with undiagnosed diabetes (levels of which can be high in NHs), or measure diabetes mellitus objectively, for example with HbA1c levels or plasma glucose concentrations. Previous research guided the selection of CPT codes, but miscoding of conditions can occur.22
The current study suggests that the structured environment of care provided in an NH may affect evidence-based care (following practice guidelines that recommend preventive monitoring procedures) for older persons with diabetes mellitus, including those with dementia. This is critically important given the changing patient demographics in NH admissions, of whom 17% are discharges from acute hospital stays, and that 86% of all Medicare days in the NH are short-term rehabilitation days.28
Already one-tenth of all NH inpatient days are attributable to diabetes mellitus,2
and the responsibility for caring for Americans with diabetes mellitus grows steadily along with overall U.S. rates of diabetes mellitus and increasing life expectancies. Regardless of whether these residents return to the community or remain in an NH setting, the structure of NH care is critical for providing needed ongoing monitoring for symptoms and complications of diabetes mellitus. Research examining specific treatments and procedures provided to institutionalized elderly people is needed so that care providers have the information they need to maximize benefit while minimizing risk and cost.