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Volume 1: No. 1, January 2004
SPECIAL TOPICS IN PUBLIC
HEALTH:
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Frequency From study to study, estimates of the prevalence of Alzheimer's disease vary by two- to ten-fold; when disease severity is specified, variation is reduced (5). Using data on white individuals pooled from 20 studies, Hy and Keller estimated that 1.7 million Americans were affected with mild to severe Alzheimer's disease in 1996 (5). Other researchers estimated the prevalence of Alzheimer's disease in the United States to be between 1.1 and 4.6 million in 1997 (6). Despite this range, public health practitioners agree that the number of individuals with Alzheimer's disease could triple or quadruple in the next 50 years as a result of the aging of the U.S. population (6,7). If new treatments that would both delay onset and progression of disease are developed, the number of affected individuals would double by 2050 rather than quadruple (7). Dementia can also occur as a result of vascular disease, HIV infection, Parkinson's disease, and other diseases. Individuals with dementia account for nearly 58,000 hospitalizations each year in New York State. In 43% of the hospitalizations among individuals with dementia, the individual is discharged or returned to a skilled nursing facility (P.P.L., unpublished data, 2003). Severity In a recent study of hospitalizations in New York State, the majority of hospitalizations for individuals with a diagnosis of dementia occurred on an emergency basis (86%). Many of the hospitalizations were due to serious illness such as pneumonia and pneumonitis (13%), septicemia (4%), and heart failure (4%) (P.P.L., unpublished data, 2003). Disparities In hospitalizations in New York State, the number of hospitalizations among women with Alzheimer's disease was twice the number among men. Nearly half of New York hospitalizations that included a diagnosis of dementia among women occurred for women over the age of 84; for men, a third of New York hospitalizations that included a diagnosis of dementia occurred among men over the age of 84. African American individuals accounted for 10% of all hospitalizations among New York State's hospitalized individuals over the age of 65, but were 14% of the New York hospitalizations that included a diagnosis of dementia (P.P.L., unpublished data, 2003). Costs Preventability Public Interest Challenges in Surveillance of DementiasLevel of UsefulnessThe legislative intent of the law establishing the Registry was to create a registry as a resource for describing the magnitude of dementia in New York State and supporting research on dementia. The Registry has contributed to its research mission in a number of ways:
Many of the challenges described in this paper have limited the usefulness of the Registry in the past and are currently being addressed. System AttributesThe ob体育 guidelines list 9 attributes for evaluating a surveillance system (1). These include simplicity, flexibility, data quality, acceptability, sensitivity, positive predictive value, representativeness, timeliness, and stability. A brief review of these attributes as they apply to the Registry follows. A focus on data quality will serve to clarify the challenges faced in conducting surveillance of dementia. Simplicity
Figure 1.
Figure 2. Flexibility Data quality Use of the hospital discharge database does not eliminate all concerns about completeness of hospital reporting. Completeness also depends on dementia diagnoses being recorded in medical records in the first place. Dementia diagnoses may be underreported for several reasons. The first reason is diagnostic uncertainty. Unlike a cancer diagnosis, which is based on laboratory pathology, Alzheimer's disease and most other dementias are diagnosed clinically. Although it is commonly believed that Alzheimer's disease can only be definitively diagnosed at autopsy, practice parameters developed by the American Academy of Neurology indicate that Alzheimer's disease can be diagnosed clinically with good reliability (21). National Center for Health Statistics guidelines call for coding discharge diagnoses that are suspected, possible, or probable as if the condition "existed or was established" (22). Because of uncertainties in assigning a diagnosis, physicians may hesitate to record a clinical diagnosis or possible diagnosis of dementia in the medical record. Second, general practitioners have been found to delay diagnoses of dementia because of embarrassment about communicating the diagnosis (23). The degree to which doctors hesitate is unknown. Third, financial disincentives for reporting dementia have also existed. Insurers have denied payment for services such as physical, occupational, or speech therapy to patients with Alzheimer's disease in the belief that patients could not benefit from therapy (23,24). Automatic denial based solely on a diagnosis of dementia has been prohibited since September 2001 (24). Fourth, most individuals with dementia are hospitalized for illnesses other than dementia, such as cardiovascular disease or respiratory disease (P.P.L., unpublished data, 2003). Failure to record diagnoses may occur because of clinical attention to the primary reason for hospitalization. The degree to which hospitals vary in recording secondary diagnoses is unknown. Nursing homes provide another source of information on patients with dementia. A diagnosis of dementia is likely to be well recorded in nursing home data because nursing homes are mandated to assess residents' abilities and limitations frequently to provide a responsive plan of care. Higher reimbursement rates for residents who require more care may also encourage complete reporting of dementia by nursing homes. Approximately 200,000 assessments are performed each year for nursing home residents described as having dementia; the evaluations are recorded in the Centers for Medicare and Medicaid Services' Minimum Data Set. A registered nurse coordinates the assessment and certifies that the assessment form is complete. Other licensed health professionals, such as the attending physician, social workers, dietitians, and physical therapists may be assigned to complete relevant sections of the assessment instrument. The Registry is now pilot-testing the ability of this computerized database to replace paper reporting from nursing homes. Preliminary data show that only one third of nursing homes that reported using the Minimum Data Set also completed paper Registry reporting forms. Use of the Minimum Data Set to retrieve information on nursing home residents with dementia would eliminate the need for nursing home staff to report data to 2 systems, and Registry staff would not need to enter data separately. Administrators of the nursing home data system monitor quality control, provide training on filling out forms, and maintain relationships with nursing homes. Accuracy in coding the dementia diagnosis is another important component of data quality. Diagnoses in medical records are currently coded and reported under the ICD-9-CM coding system. Conceptualization of Alzheimer's disease and other dementias has evolved over time (25), and coding reflects this evolution. Under the ICD-9-CM system, dementias are grouped with psychotic mental disorders, while Alzheimer's disease is classified as a nervous system disorder. Consequently, reporting 2 codes is necessary for some dementias: one to document dementia symptoms and another to document the disease responsible for the dementia, such as Alzheimer's or Parkinson's disease. ICD-9-CM terminology further complicates coding accuracy because it has not kept pace with terms used by physicians and neurologists in discussing dementias. Recent practice parameters from the American Academy of Neurology discuss criteria for diagnosing Alzheimer's disease, vascular dementia, dementia with Lewy Bodies, and frontotemporal dementia (21). Several ICD-9-CM codes document Alzheimer's disease. In contrast, no ICD-9-CM codes existed prior to October 2003 for frontotemporal dementia or dementia with Lewy Bodies (26). As a result, the consistency of coding dementias may vary from facility to facility, given differences between how physicians describe dementia and how the coding system offers options. A study of hospitalizations that included a diagnosis of dementia found various dementia diagnoses recorded for the same patient both over time and within the same hospital stay (P.P.L., unpublished data, 2003). The Medical Economics and Management Subcommittee of the American Academy of Neurology is working to develop an ICD-9-CM Dementia coding index to address some of these issues (written communication, Gina Gjorvad, American Academy of Neurology, 31 July 2003). Acceptability Sensitivity Historically, the majority of Registry reports have come from hospitals and nursing homes. The mandate to report Alzheimer's disease and other dementias is not contained in the same section of New York State public health law as communicable diseases. Direct reporting of communicable diseases is a traditional public health activity that is familiar to physicians and county health departments. Reporting of dementia is less familiar to physicians than reporting communicable diseases, particularly since county health departments are not used as a conduit of dementia data to the state. Resources have not permitted the degree of outreach and education necessary to inform physicians of their duty to report or to monitor completeness and accuracy of their reporting. As a result, the surveillance system is sensitive enough to monitor changes over time, but is most sensitive to individuals with dementia who are frail or have comorbid conditions and least sensitive to individuals in relatively good health or those diagnosed in the early stages of dementia. The idea of representativeness is discussed further below. Predictive Value Positive Representativeness Timeliness Stability Conclusions and RecommendationsThis article has highlighted data quality as the main challenge to surveillance of dementias in New York State. Data quality is likely to be the primary challenge to other surveillance systems focusing on dementias. A system that obtains reports from existing hospital and nursing home databases can improve completeness of reporting, but such a system may be biased toward documenting illness in frail individuals with other health conditions as well as those living in nursing homes. Terminology reflected in ICD-9-CM coding has not kept pace with terms used by physicians and neurologists in discussing dementias. The accuracy of coding dementias in medical records from facility to facility is unknown; differences exist between how dementias are described in medical charts and how they are translated into coding choices. A number of additional activities may improve completeness and accuracy of dementia reporting from nursing homes and hospitals. These recommended activities include:
As medical advances lead to earlier diagnoses of dementia in individuals without other health conditions, we will need to develop better mechanisms for capturing data from organizations other than hospitals and nursing homes. A number of approaches could be tested:
Despite the limitations of dementia surveillance, surveillance data are useful to individuals and agencies involved in monitoring trends, conducting research, or planning future services for an aging population. To that end, the Registry will publish its first report on hospitalizations that include a diagnosis of dementia in New York State. The report is scheduled for release at the end of 2003. Its intended audience includes public health practitioners and planners, clinicians, Alzheimer's Disease Assistance Centers, Alzheimer's Disease Community Service Programs, and reporting facilities. By studying hospitalizations, the Registry can begin to characterize the experience of New York's frailest residents coping with dementias and other illnesses. Author InformationCorresponding Author: Patricia P. Lillquist, MSW, Alzheimer's Disease and Other Dementias Registry, Bureau of Chronic Disease Epidemiology and Surveillance, New York State Department of Health, Room 565, Corning Tower, Empire State Plaza, Albany, New York 12237. Phone: 518-473-7817. E-mail: [email protected] References
*URLs for nonfederal organizations are provided solely as a service to our users. URLs do not constitute an endorsement of any organization by ob体育 or the federal government, and none should be inferred. ob体育 is not responsible for the content of Web pages found at these URLs. |
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The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors’ affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above. ![]()
| This page last reviewed March 30, 2012
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