The main results are as follows. (1) The mortality rate of children under 5 years old showed a downward trend, but the death rate of unintentional suffocation showed an upward trend, and the proportion of unintentional suffocation death in children under 5 years old also increased. (2) The unintentional suffocation mortality rate of children under 1-year-old (51.7/100000) was much higher than that of 4-year-old children (10.4/100000). Children under 1-year-old were more likely to die at home from unintentional suffocation than children aged 5 years old, and more of the younger children did not receive treatment. (3) The unintentional suffocation mortality rate of boys and children in rural areas was higher than that of girls and children in urban areas.
The death rate of unintentional suffocation has changed from a decline to an upward trend, which is consistent with the direction of the United States . The proportion of unintentional suffocation deaths to the number of children under 5 years old is also on the rise, which is consistent with a national study . Most unintentional suffocation deaths (83.3%) were children under 1-year-old, which is consistent with reports from China , the United States , Canada  and Japan . Children younger than 1-year-old cannot yet walk, and their injuries are mainly due to the negligence or abuse of their parents, while children aged 1–4 years old demonstrate hyperactivity, curiosity and exploration, resulting in many injuries to themselves .
The unintentional suffocation mortality rate of boys and rural children is higher than that of girls and urban children, which is consistent with previous studies [12, 19, 20]. Especially among children over 1-year-old, boys tend to be more impulsive and active and engage in riskier behaviors than girls . The frequency of child injuries in underdeveloped communities in Pakistan is three times higher than that in developed cities . The difference in injuries between rural and urban areas of China increases significantly with time , which may be related to the living environment, health awareness, medical facilities and inconvenient transportation in underdeveloped rural areas. In 2019, a total of 17.787 million migrant workers in Hunan left (https://www.anhui365.net/PostCenter/ThreadDetail/id/8761234) and approximately 700,000 children stayed at home with their grandparents , which may lead to inadequate care of these left-behind children. The study  have shown that the childhood injury rate of left-behind children in rural areas (33.5%) is significantly higher than that of non-left-behind children (28.6%).
The situation for children who die of unintentional suffocation is not optimistic. In the first and fourth quarters, the number of unintentional suffocation deaths was higher than that in the second and third quarters, which may be related to lower temperatures in the first and fourth quarters, thicker quilts for sleeping at night and being pinned down when sleeping with parents. Low weight and non-term infants were concentrated in children under 1-year-old, which may be related to immature organs, imperfect sucking and swallowing function, small stomach capacity, lack of digestive enzymes, poor absorption and digestion ability, and so on. Nearly 50% of children under the age of one died at home, 24.8% of children aged 1 to 4 died on their way to the hospital, and more than 80% of the children did not see a doctor because they did not have time to go to the hospital. This situation may be related to the rapid occurrence of unintentional suffocation and the short time of death. There are many rural and mountainous areas in Hunan Province, and the accessibility of medical services needs to be improved. The prevention of unintentional suffocation is the fundamental measure. Many parents do not know how to provide first aid on the spot, and they often panic when their children have accidents and do not give first aid treatment . In China, the lack of standardized procedures for emergency rescue often results in the inappropriate or incorrect medical treatment of trauma and failure to stabilize patients before hospital admission .
The United Nations has incorporated injury prevention into the Sustainable Development goals action plan . In 2008, a study in the Lancet reported on “injury-related deaths in China, a public health problem that has not been fully recognized” . In 2011, China issued the Program for the Development of Chinese Children (2011–2020) , which called for a nearly 17% reduction in injury-related mortality among children under the age of 18. The outline of the Healthy China 2030 Plan  aims to establish a comprehensive injury monitoring system and formulate guidelines and standards for strengthening injury prevention and intervention, reducing traffic injuries and drowning, and preventing poisoning. These policies can play a specific role in reducing the occurrence of injuries. Nevertheless, the data from our province in the past 10 years show that the death rate of unintentional suffocation has an upward trend. Compared with developed countries such as the United States  and the United Kingdom , China lacks precise and specific action plans for child injury prevention.
The primary factor chain of an accidental injury is “no foresight consciousness—no preventive measures—no skill learning—no effective first aid”. According to the incidence, individual characteristics, urban and rural distribution, cause analysis and treatment of accidental injury death, the following prevention and control measures are proposed.
First, safe feeding care should be provided. The critical issue is to improve the feeding and nursing of infants and young children to prevent the occurrence of unintentional suffocation. Guardians need to master correct nutritional knowledge (e.g., feeding posture, feeding volume), especially premature infants, low birth weight infants and other at-risk children. It is necessary to pay attention to sleep care (sleep posture, bedding thickness, and weight). Children aged 1 to 4 years old have a high risk of inhalation suffocation . Attention should be paid to the inhalation of foreign bodies in the respiratory tract and the management of nuts, beans and buttons as dangerous substances to avoid exposure to young children.
The second proposal is to build a safe environment and strengthen the management of the children’s living environment. Ribas Rde et al.  shows that the majority (61.7%) of accidental injuries occur in or near the home, and appropriate preventive measures can reduce the risk by 26%. Most unexplained infant deaths are potentially preventable and occur in highly dangerous sleep environments . The safest way for infants to sleep is on their backs, on an unshared sleep surface, in a crib or bassinet in the caregivers’ room, and without soft bedding (e.g., blankets, pillows, and other soft objects) in their sleep area .
The third suggestion is to popularize the knowledge of first aid. Because of the sudden and unpredictable nature of accidental death, the on-the-spot rescue of accidental death is very important. A useful primary aid measure is the last line of defense to reduce death or disability. The experience of first aid is widely publicized in a variety of ways, such as providing common first aid knowledge, such as emergency handling of foreign body inhalation and cardiopulmonary resuscitation, into brochures, children’s songs, collective rap songs, dance, and demonstration videos. to improve caregivers’ awareness of injuries and their ability to deal with emergencies. In particular, it is necessary to involve maternal and child health care institutions with Chinese characteristics and make use of the three-level network of child health care for publicity and education.
A few factors limited to this study. First, our questionnaire was a retrospective survey with retrospective bias. However, our inquiry was conducted as early as possible to minimize information bias, and data quality control was conducted at all levels of provinces, cities, and counties every year. Second, our questionnaire did not collect information about children’s unintentional suffocation exposure, such as appropriate time, activity, and risk factors. We did not conduct a detailed analysis to credibly explain recent changes in mortality. Third, the contents of the unintentional suffocation death case card may be filled incorrectly or omitted. By setting logical detection and required options, and all levels of on-site quality control, our data quality has been guaranteed to a certain extent.