Circadian variation in sudden unexpected infant death in the United States

Understanding three approaches to reporting sudden unexpected infant death in the USA

INTRODUCTION

In the USA each year, there are approximately 3400 sudden unexpected infant (<1 year of age) deaths (SUID) which occur without an obvious cause before an investigation. SUID includes the causes of death (COD) undetermined/unknown, sleep-related suffocation/asphyxia and sudden infant death syndrome (SIDS); these are often called SUID subtypes. Three common ways SUID subtypes are grouped (SUID subtype groups) include International Classification of Diseases (ICD) Codes, SUID Case Registry Categories or Child Death Review (CDR)-Assigned Causes. These groups are often used to monitor SUID trends and characteristics at the local, state and national levels. We describe and compare the characteristics of these three SUID subtype groups.

DISCUSSION

SUID subtype groups are distinct and not directly interchangeable. They vary in purpose, strengths, limitations, uses, history, data years available, population coverage, assigning entity, guidance documentation and information available to assign subtypes.

CONCLUSION

Making informed decisions about which SUID subtype group to use is important for reporting statistics, increasing knowledge of SUID epidemiology and informing prevention strategies.

Common Ground between Biological Rhythms and Forensics

Simple Summary

Biological clocks regulate the timing of numerous body functions in adaption to daily repeating cycles in the environment, such as the sleep–wake phases that are trained by the cycling changes of night and day light. The identification of a deceased victim is a critical component in a forensic investigation, but it can be significantly hampered by the condition of the dead body and the lack of personal records and documents. This review links current knowledge on the molecular mechanisms of biological rhythms to forensically relevant aspects, including the time period since death, cause of death, the use of insects for forensics, sex and age of a person, ethnic background and development. Putting these findings in context demonstrates how the analysis of molecular clock analysis could be used as tool for future personal identification in forensic investigations.

Abstract

Biological clocks set the timing for a large number of essential processes in the living human organism. After death, scientific evidence is required in forensic investigations in order to collect as much information as possible on the death circumstances and personal identifiers of the deceased victim. We summarize the associations between the molecular mechanisms of biological rhythms and forensically relevant aspects, including post-mortem interval and cause of death, entomological findings, sex, age, ethnicity and development. Given their importance during lifetime, biological rhythms could be potential tools to draw conclusions on the death circumstances and the identity of a deceased person by mechanistic investigations of the different biological clocks in a forensic context. This review puts the known effects of biological rhythms on the functions of the human organism in context with potential applications in forensic fields of interest, such as personal identification, entomology as well as the determination of the post-mortem interval and cause of death.

Sudden Unexpected Death in Infancy [SUDI]: What the clinician, pathologist, coroner and researchers want to know

The loss of an apparently healthy infant is confronting for any family, puzzling for a clinician and challenging for the pathologist charged with the task of demonstrating a cause for death. The term "cot death" evolved to "sudden infant death syndrome" [SIDS] and now "sudden unexpected death in infancy [SUDI]" as the epidemiology and pathology of infant death changed. Community interventions were successful in changing sleep practices for young babies. The current research focus is on understanding genetic predispositions to unexpected death in early childhood. Whilst much has been achieved in reducing the infant mortality rate from SUDI by between 50%, and 80% in some countries, over the last 30 years, there remain challenges for improving rates of accurate diagnosis and reaching out to more vulnerable families with clearly modifiable risk factors for SUDI. These challenges directly involve the clinician through taking a systematic and detailed history and better standardised death scene evaluations with specifically accredited assessors. Better knowledge regarding circumstances of SUDI cases will help Coroners and researchers provide answers for grieving families now, and in the future contribute to further reductions in the rate of SUDI in communities across the world.

Circadian variation in sudden unexpected infant death in the United States

Aim

To determine which factors are associated with sudden unexpected infant death (SUID) by time of day.

Methods

Data were analysed from the National Fatality Review Case Reporting System (2006‐2015). Out of 20 005 SUID deaths in 37 states, 12 191 (60.9%) deaths had a recorded nearest hour of discovery of the infant. We compared distribution patterns between time of death and 118 variables to determine which were significantly correlated with SUID time of death using advanced statistical modelling techniques.

Results

The 12‐hour time periods that were most different were 10:00 to 21:00 (daytime) and 22:00 to 09:00 (nighttime). The main features that were associated with nighttime SUID were bed sharing, younger infants, non‐white infants, placed supine to sleep and found supine, and caregiver was the parent. Daytime SUID was associated with older infants, day care, white infants, sleeping in an adult bed and prone sleep position. Factors not associated with time of death were sex of the infant, smoking and breastfeeding.

Conclusion

Sudden unexpected infant death deaths that occur at night are associated with a separate set of risk factors compared to deaths that occur during the day. However, to minimise risk, it is important to practice safe sleep guidelines during both nighttime and daytime sleep.