NEW YORK (Reuters Health) – Among children aged 5 to 12, the median time to awaken and median time to escape decreased with increasing age for all smoke alarm types, a new study finds.
An analysis of data from nearly 550 children with a median age of 9 revealed that the proportion of children awakened by a smoke alarm increased by 3.1% to 7.6% for each additional year of age. An alarm that included a human voice performed better, researchers report in Pediatrics.
“Young children are resistant to arousal during slow wave sleep – the deepest part of sleep – especially in response to the high-frequency tone alarm found in most homes,” said Dr. Gary A. Smith, sports medicine conference calender director of the Center for Injury Research and Policy at Nationwide Children’s Hospital in Columbus, Ohio. “Among 12-year-old children, which is the age group with the best alarm response rate in this study, only 56.3% escaped within one minute – and 67.6% escaped within 2 minutes – to the high-frequency tone alarm; younger children had even lower response rates.”
“However, the hybrid alarm, which combined a human voice with a low-frequency tone alarm, was more than 96% effective at awakening and prompting escape within one minute among children as young as 9 years old,” Dr. Smith told Reuters Health by email. “Because fire-safety professionals warn that individuals have as little as one to two minutes to escape after a smoke alarm sounds, these differences in response time could be life-saving. It is important to remember, a family fire escape plan that includes adult rescue of children is always strongly recommended.”
To take a closer look at how age impacts whether a child will wake up when a smoke alarm goes off, Dr. Smith and his team turned to 540 children who had been enrolled in three previous studies on smoke alarms. Children were eligible if they spoke English, did not have a clinical diagnosis, were not taking a medication that could affect sleep, arousal or their ability to perform the escape procedure, did not have an acute illness at the time of the study and did not have a hearing impairment.
The researchers evaluated smoke alarm responsiveness during the deepest part of the children’s sleep. The three studies included in the new study used identical methods with a randomized non-blinded, repeated-measures design, in which the children were each exposed to four smoke alarm signals, which included (1) human voice, (2) hybrid voice and low-frequency tone, (3) low-frequency tone and (4) high-frequency tone.
Among the children exposed to a human-voice alarm, 84% awoke and 83% escaped within five minutes. Among those exposed to the hybrid voice-tone, 89% awoke and 89% escaped. With the low-frequency tone, 88% awoke and 86% escaped, whereas with the high-frequency tone – the type currently found in most homes – only 53% awoke and 52% escaped.
Child age made a big difference. The proportion of children who awakened increased significantly at a rate of 5.3%, 5.1%, 3.1% and 7.6% for each one-year increase in age from 5 to 12 years in response to human voice, hybrid voice-tone, low-frequency tone and high-frequency tone alarms, respectively.
“To save lives, it is critical to have smoke detectors that are effective in ensuring a safe and timely escape for all ages of occupants,” said Dr. Leticia Ryan, director of pediatric emergency medicine at the Johns Hopkins Children’s Center and an associate professor of pediatrics at the Johns Hopkins University School of Medicine, in Baltimore, Maryland.
“As smoke-alarm technology evolves, knowledge of audible alarm responsiveness should inform design and be clearly communicated to the families purchasing and installing them,” Dr. Ryan, who was not involved in the new study, told Reuters Health by email. “Similarly, the importance of a fire escape plan that includes the adult rescue of children should continue to be stressed.”
SOURCE: https://bit.ly/37Vjtig Pediatrics, April 25, 2022.
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