Abstract
This study examines mortality due to unintentional suffocation from 1999 to 2015 in the United States among infants younger than 1 year.
Unintentional suffocation is largely preventable, but it caused 87% of deaths due to unintentional injury among children younger than 12 months in the United States in 2015. During the past 2 decades, substantial public and private efforts have been devoted to preventing mortality from infant suffocation, especially through safer sleeping. Based on recently updated data, we examined mortality from unintentional suffocation from 1999 to 2015 in the United States among infants younger than 1 year.
Methods
Mortality data were extracted from the Centers for Disease Control and Prevention online WONDER (Wide-ranging Online Data for Epidemiologic Research) database. Unintentional suffocation includes International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes w75 to w84. Based on preliminary analysis, we divided suffocation into the following 4 groups: suffocation and strangulation in bed (ICD-10 code w75), inhalation-related suffocation (ICD-10 codes w78, w79, and w80), other specified suffocations (ICD-10 codes w76, w77, w81, and w83), and suffocations with unspecified cause (ICD-10 code w84).
The rate ratios in mortality between 1999 and 2015 and 95% CIs were calculated using negative binomial regression. Subgroup analysis was conducted by sex, race (black vs white, with other racial groups excluded owing to small numbers of deaths), ethnicity (Hispanic vs non-Hispanic), and urbanization (urban vs rural areas). Interactions of the 4 demographic factors with year were examined using negative binomial regression. Spearman rank correlation examined the compensatory effect between increasing mortality from unintentional suffocation and decreasing mortality from sudden infant death syndrome (ICD-10 codes R95) that was previously suggested by Shapiro-Mendoza et al using mortality rates from 1984 to 2004. All statistical analyses were conducted using Stata, version 12.1 (StataCorp), with P < .05 considered to be statistically significant.
Results
From 1999 to 2015, unintentional infant mortality from suffocation among infants younger than 1 year increased from 12.4 to 28.3 per 100 000 persons (rate ratio, 2.27; 95% CI, 2.04-2.53) (Table). Despite some variation in the increase in mortality between 1999 and 2015 across demographic subgroups (rate ratios ranging from 1.90 to 2.77), the increase in mortality occurred in all subgroups by sex (male and female), race (white and black), ethnicity (Hispanic and non-Hispanic), and urbanization (urban and rural areas). Interaction analyses indicated that the change in mortality did not differ significantly across the demographic subgroups. The Figure shows that the increase in suffocations and strangulations in bed was the primary driver of the substantial increase in overall mortality from unintentional suffocation among US infants younger than 12 months between 1999 and 2015.
Table. Mortality From Unintentional Suffocation by Sex, Race/Ethnicity, and Urbanization in Infants Younger Than 1 Year in the United States, 1999-2015.
| Year | Mortality, per 100 000 Persons | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Total | Sex | Racea | Ethnicity | Urbanizationb | |||||
| Male | Female | White | Black | Hispanic | Non-Hispanic | Urban | Rural | ||
| 1999 | 12.4 | 14.5 | 10.3 | 10.1 | 25.4 | 7.8 | 13.6 | 12 | 15.1 |
| 2000 | 13.8 | 15.5 | 12.1 | 11.1 | 28.6 | 6.9 | 15.6 | 13.6 | 15.2 |
| 2001 | 15.3 | 17.5 | 13 | 12.2 | 32.8 | 8.1 | 17.3 | 14.6 | 19.8 |
| 2002 | 16.1 | 18 | 14.1 | 12.3 | 38.3 | 7.3 | 18.6 | 15.9 | 17.1 |
| 2003 | 15.6 | 18 | 13 | 12.5 | 34.9 | 6.2 | 18.3 | 15.2 | 17.7 |
| 2004 | 18.1 | 20.3 | 15.7 | 14.9 | 36.6 | 8.7 | 21 | 17.4 | 22.2 |
| 2005 | 18.7 | 20.4 | 16.9 | 16.1 | 35.5 | 10 | 21.4 | 17.9 | 23.5 |
| 2006 | 20.9 | 24.4 | 17.1 | 16.4 | 44.1 | 11 | 24.1 | 19.9 | 26.4 |
| 2007 | 23.1 | 25.8 | 20.3 | 18.5 | 48.6 | 9.6 | 27.7 | 21.8 | 30.9 |
| 2008 | 25.6 | 27.7 | 23.4 | 21.4 | 50.2 | 12.4 | 30.1 | 24.4 | 32.8 |
| 2009 | 22.7 | 26.4 | 18.7 | 18.4 | 46.5 | 11.4 | 26.3 | 21.9 | 26.9 |
| 2010 | 22.9 | 26.2 | 19.5 | 18.6 | 45.9 | 11.2 | 26.9 | 21.7 | 30.3 |
| 2011 | 22.4 | 24.6 | 20.2 | 18.3 | 44 | 10 | 26.6 | 21.3 | 29.6 |
| 2012 | 24.5 | 28.2 | 20.6 | 19.3 | 51.9 | 12.4 | 28.6 | 23.3 | 32.2 |
| 2013 | 24.8 | 28 | 21.5 | 19.4 | 56.4 | 12 | 29.2 | 23.6 | 32.9 |
| 2014 | 25.1 | 28.3 | 21.7 | 20 | 54.5 | 12.4 | 29.3 | 23.3 | 36.6 |
| 2015 | 28.3 | 32.2 | 24.2 | 23.3 | 55.2 | 14.8 | 32.8 | 26.2 | 41.7 |
| Rate ratio (95% CI)c | 2.27 (2.04-2.53) |
2.23 (1.94-2.56) |
2.35 (1.98-2.78) |
2.31 (2.02-2.65) |
2.17 (1.80-2.62) |
1.90 (1.41-2.57) |
2.42 (2.15-2.71) |
2.18 (1.94-2.46) |
2.77 (2.15-3.56) |
Results for Asian and Native American race were excluded owing to extremely small numbers of deaths.
Urbanization was based on the 2013 urbanization classification; the first 4 categories were regarded as urban areas and the last 2 categories as rural areas.
Rate ratio was calculated between 1999 and 2015.
Figure. Mortality From Unintentional Suffocation by Mechanism Among Infants Younger Than 1 Year in the United States, 1999-2015.
Other suffocations with specified threat include other unintentional hanging and strangulation (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code w76); threat to breathing due to cave-in (ICD-10 code w77); falling earth and other substances, confined to or trapped in a low-oxygen environment (ICD-10 code w81); and other specified threats to breathing such as suffocation by plastic bag (ICD-10 code w83). Suffocations with unspecified mechanisms refer to unspecified threat to breathing (ICD-10 code w84). SIDS indicates sudden infant death syndrome.
Results of Spearman correlation analysis showed a negative correlation between increasing mortality from unintentional suffocation and decreasing mortality from sudden infant death syndrome from 1999 to 2015 (rs = –0.63).
Discussion
The continuous increase of unintentional suffocation from 1999 to 2015 among US infants younger than 12 months is concerning. Our results show that the increase was primarily a result of increases in deaths from suffocation and strangulation in bed.
Multiple stakeholders have recently addressed safe sleep for infants, promoting interventions such as safe sleeping without blankets, stuffed animals, and other risks; reduction of cosleeping; and removal of unsafe baby products, such as some infant sleep positioners that are not approved by the US Food and Drug Administration but were marketed to the general public. Despite these efforts, our results indicate that infant deaths from suffocation are continuing and efforts by government and nongovernment agencies must continue and be enhanced.
There is insufficient evidence to interpret the mechanism behind our results, especially the 1.27-fold increase in mortality. The observed increase is likely associated with multiple factors, including use of unsafe products and improved differentiation between suffocation and sudden infant death syndrome in death certificate reporting. Regardless of the cause, our data indicate more than 1100 preventable infant deaths occurred in 2015, a statistic that warrants attention and action.
References
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