Differences in Cause-Specific Lifespan Distributions: The Confounding Effect of Age

Viorela Diaconu, Université de Montréal
Robert R. Bourbeau, Université de Montréal
Nadine Ouellette, Institut National d'Études Démographiques (INED)
Carlo G. Camarda, Institut National d'Études Démographiques (INED)

Differences in cause-specific lifespan distributions are usually monitored on an absolute time scale. We argue that such results are confounded by the tempo of cause-specific mortality. Using the Canadian Vital Statistics Death Database, we investigate the presence of such “tempo bias” by comparing the age-at-death distributions of leading causes of death in Canada using absolute and modal-age-at-death standardized time scales. We estimate cause-specific smooth density functions describing the lifespan distributions using a P-spline nonparametric smoothing approach that we have specifically adapted to the context of cause-of-death analysis. Preliminary results show, for instance, that when the tempo at which individuals survive operates, mortality from cardiovascular diseases is dispersed over an older age range relative to colorectal cancer. Removing this effect reveals, however, that deaths from cardiovascular diseases are in fact concentrated into a narrower age range, which is within the bounds of the age range for colorectal cancer.