title: The prediction of subjective wellness among the old-old: implications for the "fourth-age" conception.
abstract: OBJECTIVE
  As the "fourth-age" conception suggests that the adaptability of psychosocial capabilities is disrupted at old-old age due to failures in maintaining balanced functions, this study examines the predictability of subjective wellness outcomes by factual dysfunction markers of health among old-old people across 12 years.
  
  
  METHODS
  Participants were self-respondents in a 3-wave survey that sampled the older (age 75-94) Jewish population in Israel. Wave 1 (N = 1,369, mean age = 83.5) preceded Wave 2 (N = 687, mean age = 85.4) by 4 years and Wave 3 (N = 164, mean age = 91.6) by 12 years.
  
  
  RESULTS
  The dysfunction markers (comorbidity, medication consumption, doctor's visits, and difficulties in activities of daily living [ADL]) predicted subjective wellness by relating to an increase in depressive symptoms, as well as to a decrease in life evaluation and self-rated health, beyond adjustment for sociodemographics. However, in most cases, an interaction finding indicated that dysfunction markers were weaker predictors of age-related change in subjective wellness among older participants.
  
  
  CONCLUSIONS
  At old-old age, the results point to reduced predictability of subjective wellness by factual dysfunction. This finding supports the fourth-age model. Still, researchers should consider an alternative interpretation, by which increasing independence between factual and subjective indicators is protective, rather than debilitating, among old-old people.
authors.affiliation: School of Psychological Sciences and Herczeg Institute on Aging, Tel Aviv University, Israel. shmotkin@post.tau.ac.il.
authors.forename: Dov
authors.initials: D
authors.lastname: Shmotkin
authors.affiliation: The Interdisciplinary Department of Social Sciences, Bar-Ilan University, Ramat Gan, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Shrira
authors.affiliation: Herczeg Institute on Aging, Tel Aviv University, Israel.
authors.forename: Nitza
authors.initials: N
authors.lastname: Eyal
authors.affiliation: Gertner Institute for Epidemiology and Health Policy Research, Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Tzvia
authors.initials: T
authors.lastname: Blumstein
authors.affiliation: Herczeg Institute on Aging, Tel Aviv University, Israel.
authors.forename: Aviva
authors.initials: A
authors.lastname: Shorek
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology; D016330:Frail Elderly / Q000523:psychology*; D006304:Health Status; D006801:Humans; D007557:Israel; D008137:Longitudinal Studies; D008297:Male; D010549:Personal Satisfaction; D011237:Predictive Value of Tests; D012649:Self Concept
keywords: Aging; Dysfunction markers; Fourth age; Old-old; Subjective wellness.