In the study, we focused on unintentional suffocation among infants using data from the survey about the children’s characteristics, primary caregivers, and the mechanism of unintentional suffocation deaths leads to the following findings. First, infants 0 to 3 months old (especially those 1 month old) who were living in rural areas had the highest mortality attributable to unintentional suffocations. Second, most primary caregivers (87.3%) had not received first aid training in suffocating and most suffocated infants had caregivers who were less educated. Third, among infants died due to ASSB, overlaying was the most frequently reported contributing factor, and most cases featured bed sharing, even sharing a quilt with the caregiver. Fourth, the most common substance of inhalation suffocation was breast milk and other liquid substances, and most infants who died due to inhalation suffocation did not receive protective measures such as being held upright and patted by their caregivers and not being put to sleep immediately after eating. Therefore, our analysis suggests that several external factors influence the risk of infants dying due to unintentional suffocation: residence, age, unintentional suffocation safety training, and risky behaviours.
We found that the majority of infant deaths occurred in rural areas, consistent with the previous studies[13]. The possible explanations include a lack of adequate care from caregivers due to farming duties or other tasks, low safety awareness and less knowledge among rural caretakers of children[14, 15]. Relatively weak prehospital aid and hospital treatment for the children suffering from unintentional suffocation also increased the risk that injuries will result in mortality[16]. Therefore, the government should pay more attention to rural areas by strongly publicizing the importance of knowledge and awareness of unintentional suffocation prevention and safety measures, and more budget resources should be allocated to improve the construction of medical facilities and improve the medical treatment level.
The results showed that the highest percentage of cases occurring among infants who were 0 to 3 months old (especially 1 month old); these findings were consistent with a previous study in USA[17]. Regarding ASSB, the most likely explanation is that many parents and adult caretakers prefer to sleep with their children in a single bed in China, especially when the children are infants[18]. Regarding inhalation suffocation, the factors that predispose infants to these risks are often the habit of bringing objects to their mouths, inadequate chewing of food before swallowing (due to immature neuromuscular mechanisms of deglutition and airway protection) and incomplete development of posterior dentition with an absence of molars [9, 19]. Local communities could promote safety awareness regarding unintentional suffocation according to health education programmes and could send related suffocation knowledge via SMS or voice messages to parents’ mobile phones, which has effectively raised awareness and reduced the risk of drowning in many countries[20, 21] .
Professional knowledge of suffocation first aid can greatly improve the prognosis, especially for inhalation suffocation which prevents oxygen from getting to the lungs and brain, leading to brain damage or even death within four minutes[22]. However, we found that the majority (87.3%) of primary caregivers of the infants did not have knowledge of first aid. Therefore, it is important to educate caregivers about suffocation first aid. Paediatric health care providers should encourage parents and other caregivers to learn cardiopulmonary resuscitation (CPR) and choking first aid, and they should offer anticipatory, age-appropriate guidance to prevent unintentional injuries[2].
In our study, there were 194 infant deaths due to accidental suffocation and strangulation in bed, accounting for 44.1% of all deaths, including some cases of sudden infant death syndrome. ASSB deaths share many of the same characteristics of sudden infant death syndrome (SIDS) and cause unknown deaths[23], and there are no criteria to distinguish an ASSB death from a SIDS death, not even pathophysiological findings[24, 25]. Among the infant deaths due to accidental suffocation and strangulation, most occurred during sleeping, and risky infant behaviours are affected by unsafe sleeping environments. In our study, 50.8% of injuries occurred in winter, because parents in China are fond of using thick quilts and bed sharing with infants in cold winters. We also found that 93.8% were reported to occur while the infants were sleeping with their parents in the same bed, with 72.8% of the infants being covered with the same quilt as their caregivers. Bed sharing and the use of adult beds is a modifiable risk factor for sudden infant death syndrome and unintentional sleep-related suffocation because adults may lie on or roll over on top of or against an infant while sleeping and may wedge and trap an infant between two objects[26, 27][28]. A study in the United State showed that the risk for suffocation among infants in adult beds was 40 times higher than the risk for suffocation among infants sleeping on surfaces designed for infants[29]. We also found that overlaying was the most frequently reported contributing factor, which is similar to findings from other countries[17]. Preventative efforts should target those at highest risk and focus on helping caregivers provide safer sleep environments.
In our study, inhalation suffocation was not a negligible phenomenon. It contributed to 40.3% of the deaths, and most of those deaths (88.3%) were due to liquid food, such as breast milk and formula milk. In addition to immature neuromuscular mechanisms of deglutition and airway protection, swallowing liquid food often contributes to choking during babyhood[19, 30]. There are many other risk factors. We found that 80.5% of inhalation suffocation cases occurred after eating, and half of the infants were put to sleep immediately after eating. A small proportion of caregivers held the infants upright and patted them. Therefore, proper feeding practices, including appropriate feeding time, correct feeding position, careful observation during the feeding process and the expulsion of gastric gas after feeding, are critical for preventing infant inhalation suffocation. Governments and medical institutions should strengthen training on proper feeding for new mothers.
In view of the results of our study, it is important to enhance the focus on infant unintentional suffocation as a health issue and to integrate injury prevention efforts with a combination of education and policy. First, the government should strengthen publicity and education by disseminating unintentional suffocation prevention messages through channels such as TV, posters, parent and caregiver learning experiences for increasing knowledge, attitudes, and behaviour change conducive to preventing injuries. Second, healthcare systems should play a critical role in educating parents and caregivers about safety issues of unintentional suffocation and encourage widespread CPR training among them. Last, the government should enforce policies to provide environments and activities that reduce the risk of suffocation such as promoting the Safe to Sleep Campaign. Moreover, more attention should be given to injury prevention in rural areas.