Temporal trends in sudden unexpected death in a general population: the Hisayama study

Studies addressing the temporal trends in the prevalence of sudden unexpected death (SUD) and its underlying causes in the general population are limited.

Among a total of 1934 residents aged ≥20 years of the town of Hisayama, Japan, who died of endogenous causes of death and underwent autopsy examination (autopsy rate 78.5%) from 1962 to 2009, 204 were determined to be cases of SUD within 24 hours.

The trend in the age- and sex-adjusted prevalence of SUD among all autopsy subjects was stable over four 12-year periods (13.1% in 1962-1973, 13.4% in 1974-1985, 15.0% in 1986-1997, and 14.6% in 1998-2009; P for trend = .80). Regarding causes of death, the prevalence of SUD from stroke significantly declined with time (8.0%, 5.0%, 2.3%, and 2.1%, respectively; P for trend < .001), whereas significant increments were observed in the prevalence of SUD from heart disease (4.0%, 6.2%, 8.6%, and 9.7%; P for trend = .02) and from aortic aneurysm and dissection (0.2%, 1.2%, 2.9%, and 2.8%; P for trend = .01). In particular, the prevalence of ischemic heart disease increased 3-fold from 2.1% in 1962-1973 to 6.6% in 1998-2009 (P = .04). Reflecting the increment of ischemic heart disease, SUD within 1 hour increased significantly from 2.5% to 7.6% during this period (P = .01).

The trend in the prevalence of SUD was stable across a half century in a general Japanese population. Despite the decrement in the prevalence of SUD from stroke, that from heart disease, especially ischemic heart disease, increased significantly with time.