Sudden Infant Death Syndrome: Changing Epidemiologic Patterns in California 1989-2004

Objective

To evaluate the changes of sudden infant death syndrome (SIDS) epidemiology in California.

Study design

We used 1989 to 2004 California statewide death registry data. SIDS cases were selected by “age of decedent” <1 year and “cause of death” listed as SIDS.

Results

We identified 6303 cases (61% males) of SIDS. SIDS incidence rate decreased by 77%, from 1.38 per 1000 births in 1989 to 0.31 per 1000 births in 2004. No further decrease in SIDS incidence was noted from 2002 to 2004. The incidence rate was highest among blacks (2.02 per 1000 births) and lowest in Asian/Pacific Islanders (0.46 per 1000 births). The overall median age at death was 82 days, with no significant change over time. However, the peak age at death shifted from 2 months of age in 1989 to 2001 to 3 months of age in 2002 to 2004. Seasonal variation in the incidence of SIDS was attenuated. The difference in incidence rates between weekdays and weekends increased over the study period.

Conclusions

The incidence rate of SIDS declined in California from 1989 to 2001, with no further decline after 2002. Several epidemiologic changes were noted: The peak age of SIDS death shifted from 2 months to 3 months of age; seasonal variation diminished; and weekday to weekend difference became more pronounced.

Abbreviations: ICD, International Classification of Disease, SIDS, Sudden infant death syndrome