BACKGROUND: Although disability in activities of daily living (ADLs) is a highly dynamic process, analytic strategies for estimating active and disabled life expectancy have assumed stability in ADL function between periodic surveys spanning 12--24 months or have used interval estimation or instantaneous rates based on long assessment intervals. We performed a prospective cohort study to compare estimates of active and disabled life expectancy based on traditional assessment intervals of 1--2 years with those based on more frequent assessments at 1-month intervals. METHODS: Participants included 754 initially nondisabled community-dwelling persons, aged 70 years or older, who were interviewed monthly for 4 years to ascertain ADL disability. Estimates of active and disabled life expectancy were calculated using an increment-decrement life table for assessment intervals of 1 month, 1 year, and 2 years. RESULTS: For each of five age groups, the monthly assessment strategy yielded the highest values for active life expectancy and the lowest values for disabled life expectancy. The 95% confidence intervals for these values, however, overlapped the corresponding point estimates for the annual and biennial strategies. CONCLUSIONS: Accurate estimates of active and disabled life expectancy may be obtained from epidemiologic studies that assess ADL function no more frequently than every other year.
BACKGROUND: Although disability in activities of daily living (ADLs) is a highly dynamic process, analytic strategies for estimating active and disabled life expectancy have assumed stability in ADL function between periodic surveys spanning 12--24 months or have used interval estimation or instantaneous rates based on long assessment intervals. We performed a prospective cohort study to compare estimates of active and disabled life expectancy based on traditional assessment intervals of 1--2 years with those based on more frequent assessments at 1-month intervals. METHODS:Participants included 754 initially nondisabled community-dwelling persons, aged 70 years or older, who were interviewed monthly for 4 years to ascertain ADL disability. Estimates of active and disabled life expectancy were calculated using an increment-decrement life table for assessment intervals of 1 month, 1 year, and 2 years. RESULTS: For each of five age groups, the monthly assessment strategy yielded the highest values for active life expectancy and the lowest values for disabled life expectancy. The 95% confidence intervals for these values, however, overlapped the corresponding point estimates for the annual and biennial strategies. CONCLUSIONS: Accurate estimates of active and disabled life expectancy may be obtained from epidemiologic studies that assess ADL function no more frequently than every other year.
Authors: Melanie K Tran; Patrick M Krueger; Emily McCormick; Arthur Davidson; Deborah S Main Journal: Am J Epidemiol Date: 2016-03-16 Impact factor: 4.897
Authors: Thomas M Gill; Jack M Guralnik; Marco Pahor; Timothy Church; Roger A Fielding; Abby C King; Anthony P Marsh; Anne B Newman; Christine A Pellegrini; Shyh-Huei Chen; Heather G Allore; Michael E Miller Journal: Ann Intern Med Date: 2016-09-27 Impact factor: 25.391
Authors: Liming Cai; Nathaniel Schenker; James Lubitz; Paula Diehr; Alice Arnold; Linda P Fried Journal: Stat Med Date: 2008-11-20 Impact factor: 2.373