Monday, January 10, 2011

Compression of Morbidity?

I just came across this comprehensive study of mortality and morbidity trends in the latest issue of The Journals of Gerontology. It makes for sober reading and illustrates the enormity of the challenge of promoting health for aging populations.

The abstract:

Objective. This paper reviews trends in mortality and morbidity to evaluate whether there has been a compression of morbidity.

Methods. Review of recent research and analysis of recent data for the United States relating mortality change to the length of life without 1 of 4 major diseases or loss of mobility functioning.

Results. Mortality declines have slowed down in the United States in recent years, especially for women. The prevalence of disease has increased. Age-specific prevalence of a number of risk factors representing physiological status has stayed relatively constant; where risks decline, increased usage of effective drugs is responsible. Mobility functioning has deteriorated. Length of life with disease and mobility functioning loss has increased between 1998 and 2008.

Discussion. Empirical findings do not support recent compression of morbidity when morbidity is defined as major disease and mobility functioning loss.

A few samples from the article:

In the following sections, we summarize what we have learned about recent trends in morbidity and mortality, primarily in the older population, as well as the interaction between mortality change and morbidity change. We begin with a discussion of the compression of morbidity hypothesis and then we discuss trends in morbidity and mortality. We provide empirical evidence of recent changes in morbidity and mortality and link these together to provide estimates of life expectancy with and without diseases and with and without loss of mobility functioning. This provides a link between changes in parameters of population health and the expected life cycles of individuals.

....There is substantial evidence that we have done little to date to eliminate or delay disease or the physiological changes that are linked to age. For example, the incidence of a first heart attack has remained relatively stable between the 1960s and 1990s and the incidence of some of the most important cancers has been increasing until very recently. Similarly, there have been substantial increases in the incidence of diabetes in the last decades. Although we have examined the increased prevalence in a number of individual diseases, we should note that the proportion of the population with multiple diseases and the number of diseases comorbid in an older individual has also increased (Crimmins & Saito, 2000).

....Can the increase in life expectancy continue? The recent reduction in the rate of progress for U.S. women is sobering. We have always assumed that each generation will be healthier and longer lived than the prior one. The growing problem of lifelong obesity and increases in hypertension and high cholesterol among cohorts reaching old age are a sign that health may not be improving with each generation. The increasing prevalence of disease may to some extent reflect better diagnostics, but there is little indication of less disease.

The compression of morbidity is a compelling idea. People aspire to live out their lives in good health and to die a good death without suffering, disease, and loss of functioning. However, compression of morbidity may be as illusory as immortality. We do not appear to be moving to a world where we die without experiencing disease, functioning loss, and disability.