A model-based approach to estimate the AIDS-free time distribution in homosexual men using longitudinal data

Incidence of functional limitation in older adults: the impact of gender, race, and chronic conditions

OBJECTIVES

To evaluate the relation of chronic conditions, gender, and race to the incidence of activities of daily living (ADLs) limitation in older adults.

DESIGN

The 2-year cumulative incidence of functional limitation was estimated from survival analysis methods by using elders without baseline functional limitations.

SETTING

Longitudinal Study of Aging (LSOA). Initial interviews: 1984; reinterviews: 1986, 1988, and 1990.

PARTICIPANTS

A total of 4205 elderly subjects from the LSOA.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

DEPENDENT VARIABLES

self-reported moderate (1-2 ADLs) and severe (> or =3 ADLs) functional limitation.

INDEPENDENT VARIABLES

sociodemographics, self-reported chronic conditions, and prior levels of functional limitation.

RESULTS

Gender and race predicted moderate functional limitation onset, after controlling for age and education. Arthritis, diabetes, prior cerebrovascular disease (CVD), incontinence, and impaired vision were significant predictors of moderate functional limitation onset after controlling for demographics. Differences in the prevalence of chronic conditions appear to explain why moderate functional limitation incidence rates are higher in older women and blacks. Gender, but not race, predicted onset of severe functional limitation, after controlling for age and education. Prior moderate functional limitation, CVD, and vision impairment predicted onset of severe functional limitation after controlling for demographics.

CONCLUSION

Prevention of functional decline should target chronic conditions and moderate functional limitation in older adults.

Predictors of decline in manual performance in older adults

OBJECTIVE

To determine factors that predict decline in manual performance using a multivariate model of determinants of functional limitation.

DESIGN

Longitudinal observational study.

SETTINGS

Ambulatory general medicine clinics, residences of homebound individuals, and a continuing care retirement community.

PARTICIPANTS

Subjects were 485 persons more than 60 years of age and included continuing care retirement community (CCRC) residents (n = 215), chronically homebound older persons (n = 65), and ambulatory older adults (n = 205). Mean age at baseline was 78 years.

MEASUREMENT

Independent variables included demographics, physician measures of upper-extremity joint impairment, comorbidities derived from physical examination and chart abstract, self-assessed arthritis pain, depression, and anxiety. The major dependent variable was 2-year decline in timed manual performance below a threshold associated with need for long-term care services.

RESULTS

The proportion of subjects who exceed a Timed Manual Performance Test threshold of 350 seconds increased slowly from baseline through Year 4 for all age groups but rose rapidly from Year 4 to Year 6 for the oldest group (> 85 years at baseline). Using a discrete survival model, we found that age, education, grip strength, and psychological status predicted crossing the manual performance threshold within a 2-year period.

CONCLUSIONS

The findings, coupled with earlier findings that upper extremity joint impairment predicted both grip strength and manual performance, suggest that joint impairment may be an important risk factor for future functional limitation. Since diminished hand function has been shown to predict dependency, development and testing of interventions to maintain or restore upper extremity joint function and reduce pain would appear to be a high research priority.

Disability in activities of daily living: patterns of change and a hierarchy of disability

OBJECTIVES

This paper examines longitudinal data over 6 years to evaluate incidence rates of disability and the pattern of dependency in activities of daily living.

METHODS

The Longitudinal Study of Aging (n = 5151) was used to evaluate incidence of disability in activities of daily living; biennial interview data from 1984 through 1990 were used. The median age to disability onset for individual activities was estimated from survival analysis. A prevalent ordering of incident disability was identified from patterns of disability onset within individuals.

RESULTS

The progression of incident disability among the elderly supported by longitudinal data, based on both the ordering of median ages to disability onset and patterns of incident disability, was as follows: walking, bathing, transferring, dressing, toileting, feeding. Gender differences were found in disability incidence rates.

CONCLUSIONS

This study provides a mathematical picture of physical functioning as people age. These findings, based on longitudinal data, indicate a different hierarchical structure of disability than found in previous reports using cross-sectional data. Furthermore, the study documents gender differences in incident impairment, which indicate that although women outlive men, they spend more time in a disabled state.