Using U.S. Medicare records to evaluate the indirect health effects on spouses: a case study in Alzheimer’s disease patients

Table 1 Annual profiles of corroborated AD patients, 2001-2005

Population annual characteristics	2001	2002	2003	2004	2005
Number	23,038	30,935	35,392	37,500	34,601
Observed AD prevalence¹	1.6%	2.1%	2.3%	2.4%	2.2%
Gender
Male	28.9%	28.9%	29.3%	29.5%	29.2%
Female	71.2%	71.1%	70.7%	70.5%	70.8%
Age in year (<1% in below 55 ages)
Age 55-64	1.1%	1.1%	1.2%	1.2%	1.2%
Age 65-74	12.4%	11.6%	11.0%	10.7%	10.0%
Age 75+	86.3%	87.0%	87.5%	87.8%	88.5%
Mean age	82.41	82.72	82.91	83.03	83.36
Race/ethnicity
White	87.5%	87.0%	86.7%	86.5%	86.3%
Black	9.0%	9.3%	9.4%	9.5%	9.5%
Other race/ethnicity	3.5%	3.7%	3.9%	4.1%	4.2%
Geographical region
Northeast	20.2%	20.2%	19.9%	19.8%	19.6%
Midwest	26.0%	25.2%	25.1%	24.8%	24.8%
South	40.0%	40.6%	40.7%	41.0%	41.0%
West	12.0%	12.2%	12.4%	12.7%	12.9%
Other	1.9%	1.8%	1.8%	1.8%	1.7%
Urban	72.5%	72.8%	73.1%	73.4%	73.5%
Rural	24.8%	24.5%	24.1%	23.7%	23.6%
Unknown	2.7%	2.7%	2.8%	2.9%	2.9%
Patient status
Nursing home at index²	39.5%	31.8%	26.6%	22.5%	20.3%
Nursing home entry during follow-up²	11.2%	13.4%	12.1%	11.3%	10.9%
Death during follow-up	68.3%	60.2%	48.4%	34.6%	20.3%
Mean follow-up months	34.6	35.6	35.7	33.9	32.4
Identified spouses
Number	2,581	3,234	3,606	3,717	3,184
Percent of total AD patients	11.2%	10.5%	10.2%	9.9%	9.2%
Incident AD diagnoses ³
Number	N/A⁴	9,447	8,728	7,758	3,518
Percent of total AD patients	N/A⁴	30.5%	24.7%	20.7%	10.2%
Identified incident AD spouses
Number	N/A⁴	1,077	975	836	342
Percent of total AD patients	N/A⁴	3.50%	2.80%	2.20%	1.00%

¹Percentage of listed year’s Medicare fee-for-service population.
²To be considered a nursing home resident, a patient’s Medicare Part B claims had to record a pattern of nursing home-specific evaluation and management codes and/or nursing home place of service. This pattern had to be indicative of long-term nursing home residency rather than typical post-acute care.
³Incident cases have ≥12 months of Medicare fee-for-service eligibility prior to their first AD diagnosis.
⁴Lack of data before 2001 meant that there could be no determination of incidence during that year.

ISSN: 1472-6963