@article {746, title = {Trajectories of health for older adults over time: accounting fully for death.}, journal = {Ann Intern Med}, volume = {139}, year = {2003}, month = {2003 Sep 02}, pages = {416-20}, abstract = {

The process of healthy aging can best be described by plotting the trajectory of health-related variables over time. Unfortunately, graphs including data only from survivors may be misleading because they may confuse patterns of mortality with patterns of change in health. Two approaches for creating graphs that account for death in such situations are 1) to incorporate a category or value for death into the longitudinal health variable and 2) to measure time in years before death or some other event. The first approach has been applied to self-rated health (excellent to poor) and the 36-Item Short-Form Health Survey (SF-36). It allows for flexible and interpretable analyses and may be appropriate for other variables as well. The second approach also accounts fully for death, but the questions it can address are limited. Both approaches are useful and should be used at a minimum for supporting analyses in longitudinal studies in which persons die during observation.

}, keywords = {Aged, Aging, Death, Geriatric Assessment, Health Status Indicators, Health Surveys, Humans, Time Factors}, issn = {1539-3704}, doi = {10.7326/0003-4819-139-5_part_2-200309021-00007}, author = {Diehr, Paula and Patrick, Donald L} } @article {861, title = {Methods for incorporating death into health-related variables in longitudinal studies.}, journal = {J Clin Epidemiol}, volume = {58}, year = {2005}, month = {2005 Nov}, pages = {1115-24}, abstract = {

BACKGROUND AND OBJECTIVES: Longitudinal studies of health over time may be misleading if some people die. Self-rated health (excellent to poor) and the SF-36 profile scores have been transformed to incorporate death. We applied the same approaches to incorporate death into activities of daily living difficulties (ADLs), IADLs, mini-mental state examination, depressive symptoms, blocks walked per week, bed days, the timed walk, body mass index and blood pressure.

STUDY DESIGN AND SETTING: The Cardiovascular Health Study of 5,888 older adults, was followed up to 9 years. Mean age was 73 at baseline, and 658 had an incident stroke during follow-up.

METHODS: We recoded each variable as the probability of being healthy 1 year in the future (PHF), conditional on the current value of the variable. This was done for 11 health variables, using three definitions of healthy, and two estimation models. Deaths were set to zero, and mean PHF was plotted in the 3 years before and after an incident stroke.

RESULTS: Analyses without the deaths were too optimistic. The effect of stroke was greatest on hospitalization, self-rated health, and IADLs. Alternative transformation approaches had slightly different results.

CONCLUSION: These methods provide an additional approach for handling death in longitudinal studies.

}, keywords = {Activities of Daily Living, Death, Health Status Indicators, Humans, Longitudinal Studies, Proportional Hazards Models}, issn = {0895-4356}, doi = {10.1016/j.jclinepi.2005.05.002}, author = {Diehr, Paula and Johnson, Laura Lee and Patrick, Donald L and Psaty, Bruce} }