Article Text
Abstract
Participation in backcountry wilderness recreation has increased in recent years with children and adolescents making up an increasing number of participants visiting wilderness destinations. Engaging in wilderness activity involves the risk of injury, illness and even death. Unfortunately, there is very little research investigating the health challenges facing children and adolescents in the wilderness. With the intent of increasing awareness among the sports medicine community, this review examines reported paediatric and adolescent wilderness injuries reported in the state of Washington and in US National Parks, injuries reported during outdoor wilderness programmes and global youth expeditions, and health challenges in wilderness settings where the threat of acute mountain sickness is elevated. Future studies addressing the challenges of establishing numerator data linked to suitable denominator data and monitoring injured and non-injured children and adolescents in the wilderness are recommended.
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The exploration of backcountry wilderness destinations is a powerful attraction to many outdoor sport enthusiasts. In the USA and other countries, wilderness and outdoor recreation is a growing segment of the recreation industry that continues to expand as access to outdoor and wilderness environments improves.1 2 3 4 5 The National Sporting Goods Association estimates that from 1994 to 2004, the number of Americans pursuing backpacking and wilderness camping activities increased from 10.2 million to 13.3 million, and the number of hikers increased from 25 million to 29.8 million.1 6 Participation in other activities such as kayaking, rafting and mountaineering also increased over the same time period.1 6
Children and adolescents make up an increasing number of visitors to wilderness destinations. As recently as 2002, children and adolescents under the age of 17 were thought to make up 25% of all backpackers and wilderness campers in the USA.6 Although the benefits of physical activity are well known, engaging in such wilderness activity also involves the risk of injury, illness and death.7 8 9 In addition, despite recent findings that adolescents and children account for 14.2% and 7% of search and rescue operations in US National Park Service units, respectively, there are few studies examining the negative health incidents incurred by these special populations during their time in the wilderness.10 If recreation in wilderness areas is as popular as it appears, understanding the occurrence, nature and severity of injuries to children and adolescents is basic to developing preventive actions. The purpose of this article is to review the existing epidemiological literature on wilderness incidents involving children and adolescents.
Research constraints
Research investigating wilderness injuries tends to focus on topics related to the occurrence of injuries,1 11 13 the gender, age and participant activity of those involved in each incident,4 14 15 16 17 18 19 20 the environmental and seasonal factors contributing to wilderness incidents,21 22 23 the nature and severity of injuries,1 11 24 the emergency response25 26 and the economic impact related to each incident.10 27 It is important to note that many investigations of wilderness injuries are descriptive in nature and often fail to produce injury rates. This is primarily due to the difficulty of establishing baseline numbers for participation or exposure in activities not requiring a licence or a permit.27 It is also due to the fact that accessibility to wilderness areas is not easily controlled and that a large number of wilderness studies are retrospective in nature and rely on wilderness incident reports.28 These reports tend to be skewed and suffer from an under-reporting of minor injuries. However, as has been pointed out in the sport medicine literature, there still remain large gaps in the availability of descriptive epidemiological literature of many sports including those taking place in wilderness settings.9
Children and adolescents in the wilderness
Although there are few studies of wilderness injuries with a specific focus on children and adolescents, two studies from the state of Washington serve as baseline studies for paediatric and adolescent wilderness injuries. Table 1 specifically identifies paediatric and adolescent fatalities in five contiguous counties in western Washington that are some of the most popular outdoor recreation destinations in the state.2 Over a 5-year period, this study identified 40 wilderness recreational deaths among children and adolescents aged 12 months to 19 years. All but six of the fatalities involved those between 13 and 19 years of age. Moreover, the study reported age-related mortalities of 0.097 per 100 000 for those aged 0–4 years, 0.149 per 100 000 for those aged 5–9 years, 0.339 per 100 000 for those 10–14 years and 1.634 for those aged 15–19 years. Most of the fatalities occurred during the summer and were not associated with high-risk activities such as mountaineering, rock climbing or scuba diving. Instead, hiking and swimming were the most common preinjury activities. Four of the five paediatric fatalities involved children drowning after falling out of boats or after falling into water while playing at their campsite.
A general lack of wilderness preparedness played a role in the fatalities displayed in table 1, as 27 of the 40 individuals were wearing only a single layer of clothing, and none of the 21 non-scuba drowning cases were wearing a life vest. This trend was further reflected in a second study reporting wilderness injuries from Mount Rainer National Park and Olympic National Park in Washington.29 However, when compared with the first study, the second study found that even though there were no fatalities involving children or adolescents, almost 25% of the 535 total injuries reported over a 5-year period involved individuals 18 years or younger.29 Table 2 displays and compares the type of injuries sustained by adults and individuals younger than 18 years in the two national parks. Lumped into a single category, children and adolescents sustained lacerations, insect stings and burns, and experienced allergic reactions more frequently than adults. They were also more likely than adults to sustain injury while participating in winter sports (23% vs 12%), while camping (15% vs 3%) and during swimming or beach play (7% vs 1%).29 Hiking was the most common preinjury activity for children and adolescents, but an even higher percentage of adults were injured while hiking (60% vs 38%) and mountaineering (7% vs 1%).29 Finally, 32% of the injured children and adolescents required transport to a medical facility with 7% of that total requiring air transportation.
Expeditions and outdoor programmes
An increasing number of adolescents are visiting remote wilderness destinations around the world via youth expeditions and outdoor programmes.15 24 30 31 Such programmes often include young people with minimal wilderness experience, last in duration from 10 days to 3 months, generally involve long-distance hiking at high altitudes and entail basic low-level lodging such as camping tents and huts.30 31 32 33 Moreover, while some claims have stated that youth expeditions are safe, and the health risks of well-organised expeditions are minimal, the fact remains that they cannot avoid the possibility of injury or illness.30 31 33
Research exploring expedition health and safety has reported overall incidents rates at 6.4 per 1000 participant-days and that each day on the expedition added a 3.1–3.7% chance of becoming ill.30 32 In addition, during mixed-group expeditions, 77% of children aged 0–9 years and 57% of adolescents aged 10–19 years reported health problems which resulted in many seeking care from physicians, local clinics or local hospitals.32 Gastrointestinal challenges such as diarrhoea and respiratory irritation were the two most common illnesses incurred by expedition participants.30 32 33 Other illnesses and injuries that are commonly reported during expeditions include headaches and nausea associated with high altitude and dehydration, insect bites and stings, abdominal pain and injuries such as lacerations, concussions, and ankle and knee sprains resulting from falls on rough terrain.30 31 32
A recent study from the UK found that 64% of 2402 British youth aged 15–18 years experienced some type of illness or injury while on expedition.33 Table 3 summarises the injury and illness data collected in the study and identifies gastrointestinal complaints and injuries as the two leading health challenges. The study further found that gastrointestinal illness significantly increased with altitude, females reported 19% more medical problems than males, and illness and injury were most prevalent on expeditions to South America and least prevalent on expeditions to Australasia.33 Fortunately, only 6% of the illnesses and injuries were serious enough to require hospitalisation or outside medical advice.
A 5-year study reporting wildness injury and illness profiles of students participating in National Outdoor Leadership School (NOLS) programmes in Wyoming, Alaska, Arizona, Washington, Idaho, Mexico, Chile and the Yukon Territory also identified gastrointestinal illness and respiratory irritation as leading health challenges facing their students.24 For example, 26% of the total 549 illnesses reported from 1999 to 2002 were gastrointestinal-related, and 16.6% were respiratory-related. However, there were 678 injuries reported during the same time frame. Sprains and strains of knees, ankles and the back were responsible for 50% of all the reported injuries, and soft-tissue injuries such as burns, blisters, wound infections and stings were responsible for 31% of all injuries. Hiking with a pack (46.1%) and in camp activities (17.1%) were the most common preinjury activities, whereas falls, slips and overuse factors were contributing factors in 54.9% of the injuries.
It is important to note that the age of NOLS students was not identified in the study. NOLS is open to students of all ages and typically enrolls 3000 students annually in 150 000 field days of multiweek expeditions.24 However, the most common NOLS students are adolescent and college-age students. It is also important to note that NOLS has been keeping track of all wilderness injuries and illnesses since 1984 and has found that most injuries occur during the first 10 days of their wilderness expeditions.24
National parks
National parks are some of the most popular and heavily used wilderness areas in the USA.29 Recent research investigating recreational travel fatalities in US National Parks identified motor vehicle crashes, suicides, swimming and hiking as the four most common predeath activities.12 The majority of fatalities occurred on weekends during the summer months and were dominated by male visitors (75%) and visitors 20–29 years (27%) of age.12 Combined together, children and adolescents accounted for 13% of 356 fatalities over a 2-year period.
It should be pointed out that all National Park Service (NPS) units are not classified as wilderness. Hence, the previously mentioned study does not distinguish between deaths in wilderness backcountry destinations or frontcountry destinations such as roadways. However, other studies addressing a range of wilderness health and safety issues have identified that adolescents account for 23% of all search and rescue operations in Alaska’s NPS units that end with a death and children and adolescents account for 21.2% of all NPS visitors nationwide requiring search and rescue assistance.10 27 Hiking, mountaineering and boating were the three leading participant activities at the time search and rescue assistance was requested.10 27 Furthermore, a study of wilderness morbidity and mortality in eight California-based NPS units found that adolescents and children as young as 10 years were part of a group that suffer high numbers of hypothermia, diarrhoea, non-insect anaphylaxis and intoxication.11 Children and adolescents also suffered a range of injuries such as lacerations, dislocations, ankle and knee sprains and strains, scrapes, abrasions, avulsions and near-drownings.11
An additional study of visitor safety conducted by the National Park Service Social Science Program identified visitor incidents and other safety concerns in 30 NPS units between 1993 and 1998.34 Table 4 displays the number of paediatric and adolescent injuries reported in the 10 NPS units that specifically have a wilderness designation.34 Paediatric injuries were more common than adolescent injuries in all 10 NPS units. Moreover, combined together, paediatric and adolescent injuries accounted for over one-third of all injuries in Badlands National Park and over 20% of the total injuries in Big Bend National Park and Canyonlands National Park. The same study found that paediatric (9) and adolescent (52) fatalities accounted for 15% of the 411 total fatalities in the 30 NPS units. It is likely that these figures would be higher had the study included units such as the Grand Canyon, Great Smokies and Yellowstone National Parks.
Acute mountain sickness
A current issue gaining attention in paediatric circles is acute mountain sickness (AMS) in children and preverbal children.35 36 37 38 The exposure of children to high altitudes has increased with outdoor recreation participation and improvements in infant- and child-transporting systems.39 AMS is the most common altitude illness presenting in children and results from the rapid ascent to high altitudes generally above 2500 m.39 40 However, the chance of developing AMS is also determined by the speed of ascent, individual susceptibility, altitude attained, previous acclimation and age.41 42 In young children, AMS is characterised by fussiness shortly after arrival at high altitude, a lack of playfulness, change in stool pattern, vomiting, and appetite and sleep disturbances.35 41 42 Previous research at moderate altitudes (1890–2010 m) has estimated that 25% of children and adolescents aged 9–14 years develop AMS within 1–2 days after exposure.39 43 Additional high-altitude research conducted on tourists travelling with children in mountain regions of Chile identified a significantly lower haemoglobin saturation among children than adolescents and adults.41 All the children in the Chilean study developed AMS, whereas only 50% of the adolescents and 27% of the adults developed AMS.41
It is important to recognise that AMS often precedes more serious conditions such as high-altitude pulmonary oedema (HAPO) and high-altitude cerebral oedema (HACE). HAPO is characterised by hypoxia along with signs of dyspnoea, tachypnoea, cyanosis, reduced activity, haemoptysis, cough and fever.40 Children living at moderate to high altitudes can experience re-entry HAPO after spending as little as 1–2 days at lower altitudes.44 HACE symptoms range from a headache to ataxia, altered mentation and focal neurological signs.40 45 Accurate data for HAPO and HACE incidence among children are not available, even though HAPO is considered significantly less common than AMS, and HACE is considered even more rare. Nonetheless, it is recommended that the approach to wilderness activities at high altitudes should focus on planning the ascent, managing altitude-associated illness and following up with diagnostic tests after the venture.40 45 A slow ascent instead of a rapid ascent is the best way to prevent AMS. Watching for early signs of AMS in children and being prepared to descend if rest and time do not improve the condition is effective at dealing with all forms off altitude sickness.40 45
Prevention
Participation in wilderness sport activity is not without risk and may end with severe injury or death as well as enormously expensive medical costs.46 A recent trend in sports injury epidemiology has been a move from descriptive studies that quantify the incidence and severity of injuries to an aetiological approach that seeks to explain why and how injuries occur and attempts to develop and introduce injury prevention strategies.47 Although few studies have utilised this approach to investigate paediatric and adolescent injuries in wilderness settings, there is documentation of some promising initiatives. For example, NOLS has a very aggressive risk-management strategy that involves providing fitness information to students in their enrolment packets, working to reduce pack weights, carefully planning wilderness course routes, highlighting the importance of warming-up and stretching prior to hiking and participating in strenuous activities, and instructing students on how to best hike on rugged and uneven terrain. They also stress the importance of hand washing and camp hygiene, educating students on foodborne illnesses, and expect all wilderness drinking-water to be disinfected. As a result of these efforts, NOLS has decreased their injury rate from 2.3 incidents per 1000 programme days during 1984–1989 to 1.07 incidents per 1000 programme days during 1999–2002.24 Also, their illness rate per 1000 programme days has dropped from 1.50 during 1984–1989 to 0.87 incidents per 1000 programme days during 1999–2002.24
Future research
The study of wilderness sport injury is less developed than mainstream sport medicine, but the increasing levels of participation justify new research initiatives. Future research would do well to address the challenges of establishing numerator data linked to suitable denominator data, and developing cohort studies that monitor both the injured and non-injured children and adolescents. In addition, it is important that future research efforts focus on developing wilderness injury data that place an emphasis on understanding the modifiable risk factors that contribute to injury incidents. This in turn will form an important basis for testing these factors and lead to the development of effective preventive measures designed to enhance the wilderness experience.
What is already known on this topic
Children and adolescents make up an increasing number of outdoor sport participants in wilderness destinations.
In the USA, they account for 25% of backpackers and wilderness campers.
They also account for 21.2% of all search and rescue incidents and 13% of all fatalities in US National Parks.
REFERENCES
Footnotes
Competing interests None.
Provenance and Peer review Commissioned; externally peer reviewed.