Disability Life Expectancy Research Articles

Estimating national disability risk

In this article, I provide a method to rebuild the active and disabled life expectancy (ALE and DLE) on the basis of ‘current’ death and disability risks, and to measure disability risk. This method uses national-level data, and is based on two main assumptions. The first is the Gompertz assumption that death rate rises with age exponentially, and the second is the Cox assumption that death rates of active status are proportional to those of disabled status across age. Applying this method to the US data, I find that the disability risk has increased between 1970 and 1990 for both men and women aged 40 and older. Situations in which above assumptions could be removed are also discussed.

Functional status and active life expectancy among senior citizens in a small town in Japan

The objectives of this study were to understand transition patterns and mechanisms of functional status, and to estimate active life expectancy (ALE) among senior citizens in a small town in Japan. With data drawn from surveys conducted annually from 1998 to 2002 ( n=638 at baseline), prevalence and incidence of functional disability in activities of daily living (ADL) and instrumental activities of daily living (IADL) were described and compared between the sexes. Then relationships between potential predictors and functional decline through a 4-year follow-up were examined using logistic regression. Finally, active and disabled life expectancy was estimated by Katz’s method. At baseline, 9 and 12% of subjects were dependent in performing ADL and IADL, respectively. Prevalence and incidence rates increased with age. The risk of mortality increased by 2.2–5.0-fold when the subject was functionally dependent at the previous year. Advanced age, difficulty in walking and poor interest were shown to be significant predictors of loss of independence in ADL. Mean durations with disability in ADL and IADL among women were longer than among men by around 1 year. Population-specific preventive care programs considering physical, cognitive and social aspects are needed not only to maximize ALE but also to improve quality of life during survival period with disability especially in old women.

Socioeconomic status and the expectation of disability in old age: estimates for England

OBJECTIVESThe longer life expectancy in old age of more privileged socioeconomic groups is well established, but less clear is whether the net effect of additional years of life is a...

Educational status and active life expectancy among older blacks and whites.

Persons of low socioeconomic status are known to have reduced life expectancy. In a study of the relation of socioeconomic status to disability-free or active life expectancy among older persons, we analyzed prospectively gathered data on 2219 blacks and 1838 whites who were 65 years of age or older in the Piedmont region of North Carolina. We defined disability as the inability to perform independently one or more basic functional activities such as walking, bathing, dressing, eating, and using the toilet. For subgroups defined by sex, race, and education, statistical models were used to estimate, for persons at each year of age, the probability of transition from not being disabled or being disabled at base line to not being disabled, being disabled, or having died one year later. These transition probabilities were then entered into increment-decrement life tables to generate estimates of total, active, and disabled life expectancy (with total life expectancy equal to active life expectancy plus disabled life expectancy). Sixty-five-year-old black men had a lower total life expectancy (11.4 years) and active life expectancy (10 years) than white men (total life expectancy, 12.6 years; active life expectancy, 11.2 years), although the differences were reduced after we controlled for education. The estimates for 65-year-old black women (total life expectancy, 18.7 years; active life expectancy, 15.9 years) were similar to those for white women. Black men and women 75 years old and older had higher values for total life expectancy and active life expectancy than whites, and the differences were larger after stratification for education. Education had a substantially stronger relation to total life expectancy and active life expectancy than did race. At the age of 65, those with 12 or more years of education had an active life expectancy that was 2.4 to 3.9 years longer than the values for those with less education in all the four subgroups defined by sex and race. Overall, the subgroups with longer total life expectancy and active life expectancy also lived more years with a disability. Among older blacks and whites, the level of education, a measure of socioeconomic status, has a greater effect than race on total life expectancy and active life expectancy.

Sex Differences in Morbidity and Mortality

HE differences between men and women in relation to the processes that lead to death are of more than passing interest for the student of human constitution. This branch of human biology, it has been emphasized (Pearl and Ciocco, I936; Ciocco, I936a, b), has for one of its major objectives to discover and eventually measure the stable organic correlationintegrated biological relations-between the morphological, physiological, psychological, and pathological traits of the individual. Therefore, the differences in morbidity and mortality observed for the two sexes assume special importance not only because the individuals of the two sexes are on the whole also morphologically and functionally differentiated but primarily because the sex dimorphism reflects a dissimilar biological make-up. This, it is of course realized, does not mean that sex differentiation is due simply to the chromosomal constitution of the individuals. In the first place, as Danforth (I93z) ably points out, the results of investigations on sex linkage have shown clearly that the so-called sex chromosomes are, one might say, only incidentally concerned with sex differentiation. Besides, as a result of the work of Bridges and of all those who have confirmed and extended his observations (Bridges, I932), it is accepted that the characteristics of each of the sexes are deternmined not only by the absence or presence of one of the sex chromosomes but also by the quantitative balance between the number of sex and autosomal chromosomes. The original simple scheme is further relegated into the background when an explanation is sought for Goldschmidt's observations on the alteration of the sex ratio and on the production of intersexes as the result of crosses between certain varieties of tussock moths. The conclusion which Goldschmidt (I9I7) reached and which he has maintained since (cf. Goldschmidt, I938), is that "every individual is -able to develop into one sex or the other or any stage between; further that every individual contains all the elements necessary for the development of either sex and its attributes; further that these elements or substances must have a certain quantitative relation to each other in order to secure to one of them the control of development; and that the introduction of quantities in a cross which do not fit the given quantity of the other partner set up the sex differentiation in favor of the higher quantity." That the final differentiation of sex is dependent also on extra-chromosomal factors is universally admitted today, thanks to the many observations and experimentations reported on gynandromorphism and sex reversal. Thus, the observation by Crew (I973) of the broody hen transformed through disease into a potent rooster is well known. Equally familiar are the studies of Hertwig (I906) continued and elaborated further by