@article{ref1,
title="The avalanche hypothesis and compression of morbidity: testing assumptions through cohort-sequential analysis",
journal="PLoS one",
year="2015",
author="Silberman, Jordan and Wang, Chun and Mason, Shawn T. and Schwartz, Steven M. and Hall, Matthew and Morrissette, Jason L. and Tu, Xin M. and Greenhut, Janet",
volume="10",
number="5",
pages="e0123910-e0123910",
abstract="BACKGROUND: The compression of morbidity model posits a breakpoint in the adult lifespan that separates an initial period of relative health from a subsequent period of ever increasing morbidity. Researchers often assume that such a breakpoint exists; however, this assumption is hitherto untested. <br><br>PURPOSE: To test the assumption that a breakpoint exists-which we term a morbidity tipping point-separating a period of relative health from a subsequent deterioration in health status. An analogous tipping point for healthcare costs was also investigated. <br><br>METHODS: Four years of adults' (N = 55,550) morbidity and costs data were retrospectively analyzed. Data were collected in Pittsburgh, PA between 2006 and 2009; analyses were performed in Rochester, NY and Ann Arbor, MI in 2012 and 2013. Cohort-sequential and hockey stick regression models were used to characterize long-term trajectories and tipping points, respectively, for both morbidity and costs. <br><br>RESULTS: Morbidity increased exponentially with age (P<.001). A morbidity tipping point was observed at age 45.5 (95% CI, 41.3-49.7). An exponential trajectory was also observed for costs (P<.001), with a costs tipping point occurring at age 39.5 (95% CI, 32.4-46.6). Following their respective tipping points, both morbidity and costs increased substantially (Ps<.001). <br><br>CONCLUSIONS: Findings support the existence of a morbidity tipping point, confirming an important but untested assumption. This tipping point, however, may occur earlier in the lifespan than is widely assumed. An &quot;avalanche of morbidity&quot; occurred after the morbidity tipping point-an ever increasing rate of morbidity progression. For costs, an analogous tipping point and &quot;avalanche&quot; were observed. The time point at which costs began to increase substantially occurred approximately 6 years before health status began to deteriorate.<p /> <p>Language: en</p>",
language="en",
issn="1932-6203",
doi="10.1371/journal.pone.0123910",
url="http://dx.doi.org/10.1371/journal.pone.0123910"
}