Modal lifespan and disparity at older ages by leading causes of death: a Canada-U.S. comparison

Abstract

The U.S. elderly experience shorter lifespans and greater variability in age at death than their Canadian peers. In order to gain insight on the underlying factors responsible for the Canada-U.S. old-age mortality disparities, we propose a cause-of-death analysis. Accordingly, the objective of this paper is to compare levels and trends in cause-specific modal age at death (M) and standard deviation above the mode (SD(M +)) between Canada and the U.S. since the 1970s. We focus on six broad leading causes of death, namely cerebrovascular diseases, heart diseases, and four types of cancers. Country-specific M and SD(M +) estimates for each leading cause of death are calculated from P-spline smooth age-at-death distributions obtained from detailed population and cause-specific mortality data. Our results reveal similar levels and trends in M and SD(M +) for most causes in the two countries, except for breast cancer (females) and lung cancer (males), where differences are the most noticeable. In both of these instances, modal lifespans are shorter in the U.S. than in Canada and U.S. old-age mortality inequalities are greater. These differences are explained in part by the higher stratification along socioeconomic lines in the U.S. than in Canada regarding the adoption of health risk behaviours and access to medical services.

A modal age at death approach to forecasting mortality

“…The latter, also referred to as shifting mortality, has been the dominant determinant of life expectancy increase since the middle of the 21st century (Bergeron-Boucher et al 2015;Bongaarts 2009;Canudas-Romo 2008). Increases in the modal age at death are primarily driven by a decrease in mortality at older ages (Diaconu et al 2020;Horiuchi et al 2013), especially at ages above the mode (Canudas-Romo 2010), making this indicator particularly relevant for studying longevity extension.…”