Safety-belt and helmet use among high school students - United States, 1990

Morbidity and Mortality Weekly Report, Feb 21, 1992

During 1988, injuries were the leading cause of death among persons aged 15-19 years in the United States. More than half (53%) of these deaths were motor-vehicle related, including crashes involving bicycles and motorcycles with motor vehicles (CDC, unpublished data, 1988). Among persons aged 15-19 years, motor-vehicle-related injuries are the leading contributor to hospital and emergency department medical costs associated with injuries [1]. This article presents 1990 self-reported data from U.S. students in grades 9-12 regarding the prevalence of three behaviors that reduce the risk for injuries from motor-vehicle crashes-safety-belt use, motorcycle-helmet use, and bicycle-helmet use.

The national school-based Youth Risk Behavior Survey (YRBS) is a component of CDC's Youth Risk Behavior Surveillance System, which periodically measures the prevalence of priority health-risk behaviors among youth through representative national, state, and local surveys [2]. The 1990 YRBS used a three-stage sample design to obtain a representative sample of 11,631 students in grades 9-12 in the 50 states, the District of Columbia, Puerto Rico, and the Virgin Islands. Students were asked how often they wore safety belts when riding in a car or truck driven by someone else and how often they wore a helmet when riding a motorcycle or a bicycle.

Less than one fourth (24.3%) of all students in grades 9-12 "always" used safety belts when riding in a car or truck driven by someone else (Table 1). An additional 23.0% of students used safety belts "most of the time," and 13.4% reported "never" using safety belts. Use of safety belts did not vary significantly by sex, race/ethnicity, or grade.

Male students (44.8%) were significantly more likely than female students (23.6%) to ride motorcycles, and white students (37.3%) were significantly more likely than Hispanic (24.8%) or black students (18.9%) to ride motorcycles. Among students who rode motorcycles, 57.9% wore motorcycle helmets "always" or "most of the time" (Figure 1). White students (59.8%) were significantly more likely than Hispanic students (39.3%) to wear motorcycle helmets. Helmet use by black students (55.9%) was not significantly different from helmet use by either white or Hispanic students. Use of motorcycle helmets did not vary significantly by sex or grade.

Male students (67.3%) were significantly more likely than female students (53.4%) to ride bicycles; 2.3% of students wore bicycle helmets "always" or "most of the time" (Figure 1). Use of bicycle helmets did not vary significantly by sex, race/ ethnicity, or grade.

Editorial Note: Not using a safety belt is one of the major risk factors for fatalities and injuries to motor-vehicle occupants (3). The National Highway Traffic Safety Administration (NHTSA) estimated that, among front-seat motor-vehicle occupants, safety-belt use reduces the risk for fatal injury by 40%-50% and the risk for moderate to critical injury by 45%-55% [4]. Accordingly, national health objectives for the year 2000 include increasing the use of occupant protection systems (e.g., safety belts, inflatable safety restraints, and child-safety seats) to at least 85% of motor-vehicle occupants (objective 9.12) [3]. However, to reach this objective among high school students, the percentage who report they "always" wear safety belts will have to increase to 3.5 times the level indicated in the 1990 YRBS. [TABULAR DATA OMITTED]

Comparisons between self-reports and observations of safety-belt use indicate that the "always use" category of self-reported rates is the response category that corresponds most closely to the observed rates [5]. Observational surveys of safety-belt use in 19 cities [6] indicate that adolescents have the lowest safety-belt use of any age group-28.9% in 1989; the observational surveys support the findings in this report and suggest that high school students should be targeted for efforts to increase safety-belt use.

From 1979 through 1986, 12% of the 46,500 average annual motor-vehicle fatalities were associated with riding motorcycles, and 53% of these deaths involved head injuries [7]. From 1984 through 1988, bicyclists involved in motor-vehicle crashes accounted annually for an average of 597 deaths associated with head injuries and an average of 180,000 head injuries treated at emergency departments in the United States [8]. Helmets reduce the risk for death from motorcycle crashes 28%-73% [9] and reduce the risk for head injuries from bicycle crashes 85% [10]. One national health objective for the year 2000 is to increase use of helmets to at least 80% of motorcyclists and at least 50% of bicyclists (objective 9.13) [3]. To reach this objective, the percentage of students who wear helmets when they ride motorcycles will have to increase 38% and the percentage of students who wear helmets when they ride bicycles will have to increase to 22 times the level indicated in the 1990 YRBS (Figure 1).

National health objectives call for enactment and enforcement of laws requiring safety-belt and motorcycle-helmet use for persons of all ages (objective 9.14) [3]. State laws mandating safety-belt use have increased use from 10%-20% to 40%-60% in those states [11], and state laws mandating universal motorcycle-helmet use have increased helmet use from 40%-60% to nearly 100% in those states [9]. However, laws mandating motorcycle-helmet use that apply only to persons in certain age groups appear to be ineffective [9]. A law that went into effect in mid-1990 requiring the use of bicycle helmets in Victoria, Australia, immediately increased helmet use among secondary school students from 25% to 87% (J. Ozanne-Smith, Victorian Injury Surveillance System, personal communication, 1990).