Research of Note for December 2002-January 2003

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As winter sets in, there is less emphasis on outdoor activities, so it is important to know about new research showing that adolescents may need more encouragement to be physically active. A new analysis of school-based violence prevention programs suggests these programs may be more effective for girls than boys. And a new policy from the American Academy of Pediatrics provides useful research-based guidance to youth workers who must set policies regarding head lice.

Fighting the Decline in Teen Physical Activity

Longitudinal Study of the Number and Choice of Leisure Time Physical Activities From Mid to Late Adolescence
Deborah Aaron, Ph.D., Kristi Storti, M.S., Robert Robertson, Ph.D., et al.
Archives of Pediatrics and Adolescent Medicine, Vol. 156, Nov. 2002, pp. 1075-1080. Available free from Aaron, Department of Health and Physical Education, University of Pittsburgh, 155 Trees Hall, Pittsburgh, PA 15261, or

Young children like to run around when they play, but the older they get, the more sedentary they become. Team sports keep some adolescents active, but this new study confirms what most youth workers already know: Physical activity declines during the teenage years. Fortunately, the study provides enough information to help youth workers think of ways to reverse that trend.

The study followed 782 seventh-, eighth- and ninth-graders who were 12 to 15 at the start of the study and 16 to 19 at the end. All attended suburban public schools in Pittsburgh. Eighty percent were white and most of the others were black.

Physical activity decreased substantially over the four years of the study. On average, boys were more active than girls at each age, but the decline over the four years was 43 percent for boys and 26 percent for girls.

Much of the decline was due to the decrease in the actual number of physical activities that the youths participated in, which dropped by 56 percent, from an average of seven to three. Only 5 percent reported an increase in activities, whereas 85 percent reported a decrease. There was an 80 percent to 90 percent chance that an adolescent would discontinue any given physical activity over the four years of the study.

Even so, the more physically active the youths were at the start of the study, the more active they were likely to be at the end. Participating in fewer activities at the end of the study was related to lower socio-economic status for boys. For girls, being older or African-American correlated with less participation.

In contrast, the amount of time spent on specific sports activities did not necessarily change. Boys and girls who reported the same activity at the start of the study as they did four years later tended to spend the same amount of time on that activity. The exception was that boys who continued to play basketball tended to report playing more as they got older.

The top activities reported were: aerobics, baseball, basketball, bicycling, bowling, football, roller-skating, running, skateboarding, soccer, softball, street hockey, tennis, volleyball and weight lifting. Boys were more likely to report participating in baseball, basketball, football, street hockey and weight lifting, while girls were more likely to report participating in aerobics and softball.

Overall, the likelihood of participating in each sport decreased over the four years, but there was increased participation in aerobics among girls and in roller-skating and softball among boys. Weight-lifting also became more popular for both boys and girls. The activity that was most likely to be stopped was bicycling.

Part of the decline in physical activity may be related to school requirements. Only 49 percent of the youth in grades nine through 12 were enrolled in physical education classes and only 27 percent attended PE every day. The lack of PE may decrease the incentive to continue in a sport and decrease the chances of being exposed to a new sport that is enjoyable.

The authors suggested that because most kids reduce the number of activities over time, it is important to encourage young adolescents to try lots of different physical activities, in the hope that they will continue with at least some of them. This theory is consistent with the decreased number of activities over time, but it’s not clear that it would work.

The opposite strategy might work at least as well: Young adolescents who are not very athletic should perhaps be helped to find just one or two sports where they can succeed. After all, kids’ participation in sports is not random; it reflects their athletic abilities and interests. Young athletes tend to try a lot of sports because they enjoy sports, doing well at sports is reinforcing, and their friends want them to join their teams.

As they get older, different sports interfere with each other (soccer, for example, is now played year-round in many communities) and athletes are likely to be encouraged by parents or coaches to focus on fewer sports in order to excel.

Less athletic youths may try various sports but drop out because they are discouraged by their lack of skill. If these youth become involved in many sports when they are younger, they may just get more discouraged more quickly. If they were instead guided to focus on a few sports where they are most likely to excel, they might enjoy themselves more and be more likely to stay with those activities.

So the implications may be more complicated than the authors suggest. Youth workers should certainly encourage children of all ages to be involved in physical activities, but to help youth stay physically active, we need to find ways to make sports more enjoyable for adolescents of all ages, and to help less athletic adolescents find sports and other physical activities that they will want to stick with.

Can Schools Prevent Violence?

School-Based Violence Prevention Programs
Julie Mytton, M.S., Carolyn DiGuiseppi, M.D., David Gough, Ph.D., et al.
Archives of Pediatrics and Adolescent Medicine, Vol. 156, August 2002, pp. 752-762. Available free from Mytton at, or from the Archives of Pediatric and Adolescent Medicine,

School-based gun-violence prevention programs don’t appear to work very well (see “Gun Safety Programs Take a Shot,” Youth Today, September), but this study says other kinds of school-based violence prevention programs are effective.

The meta-analysis of 28 studies of programs for children at high risk of violent behavior was cautiously optimistic about their effectiveness. This analysis differs from other studies because it focuses on “randomized controlled trials of secondary violence prevention programs.” That means that all the studies randomly assigned kids to participate in a violence prevention program or a “no treatment” comparison group, and that all the children in the study had already been identified as aggressive or at risk for aggressive behavior. Many of the studies measured the impact immediately after the program was completed, and also 12 months later.

The programs involved a range of approaches dating from the 1970s through the 1990s, such as individual or group anger management (or conflict management) training, the Think Aloud (self-control) program, therapeutic mentoring, PATHS Curriculum (Promoting Alternative Thinking Strategies), empathy training, peer mediation and social skills training.

By including data from many studies, some of them quite small, in one large statistical analysis, it is possible to determine whether these types of programs in general are at least moderately successful. In contrast, most program evaluations analyze the impact of one program in one school or school jurisdiction, and those results may not be replicable in facilities without the same teachers or curriculum.

Effectiveness for each study in the meta-analysis was measured by children behaving less aggressively (as measured by standardized tests or actual counts of fights or bullying) and by school or agency actions such as suspensions, detentions and sending the youths to court.

Improvements were not dramatic, not all the programs worked, and those that worked didn’t work for all children. Training in self-control and anger management and programs that improved relationship skills were both effective. The decrease in aggressiveness among children was similar for elementary schools and high schools, but high schoolers saw the largest decrease in school or agency actions.

The programs were more effective in girls-only or “co-ed” groups than in boys-only groups. The meta-analysis did not determine whether the co-ed programs were more effective for girls than boys.

The implication is that school-based programs focused on the most aggressive kids may be worthwhile, especially those that involve girls or girls and boys in the same program. It may be that school-based programs aimed at all students are not effective, and that programs may be more effective for girls than boys.

The researchers were British, but almost all the studies were conducted in the United States or Canada. More research is needed to determine which programs work best for which students, and it would be more helpful to have studies based on currently used programs, rather than programs that were evaluated more than 20 years ago.

Lice are Lousy but not Unhealthy

Head Lice
American Academy of Pediatrics Clinical Report, Pediatrics, Vol. 10, No. 3, September 2002. Available online at, or youth workers can receive a free copy by calling (202) 347-8600.

Head lice are not a popular topic of conversation or research, but maybe they should be – 6 million to 12 million children (mostly ages 3-12) have them every year. This report sets the record straight and makes clear recommendations that may surprise many teachers, school administrators and youth workers at residential centers and other facilities where lice pose a potential problem.

The report starts with the statement, “Head lice are not a health hazard or a sign of uncleanliness and are not responsible for the spread of any disease.” It explains that lice affect all socioeconomic groups, but are less common among blacks, probably because their oval-shaped hair shafts are harder for a louse (that’s the singular of lice) to grasp.

It is “probably impossible” to totally prevent head lice infestations, but it helps to teach children not to share combs, brushes and hats, the report says.

It emphasizes that head lice screening programs are not cost-effective and often are not effective at all. Healthy children with lice should not be excluded from school nor even allowed to miss school because of lice: A child with live lice has probably had the lice for a month or more by the time they are discovered and poses little risk to others.

However, infected children should be discouraged from having “close head contact” with others.

The report recommends that the information about a child’s lice be confidential rather than public, with a call to the parent or guardian stating that prompt treatment is in the child’s best interest. Exceptions might be necessary if a child has hundreds of live lice.

The American Academy of Pediatrics and the National Association of School Nurses discourage the “no nits” policy that many schools have established. Nits are the tiny lice eggs, which can be easier to spot than live lice, since lice crawl up to 30 centimeters per minute. No-nits policies are especially problematic because nits are easily confused with the empty lice egg cases, dandruff and even dirt.

Treatments include a variety of toxic and not-so-toxic shampoos and creams. The report describes Nix as a cream rinse that is the “recommended treatment of choice” because it is less toxic to humans than other products and does not cause allergic reactions in children with plant allergies.

It describes Lindane as a prescription product that must be used carefully, because it can cause severe seizures in children and is not very effective. Malathion is also a prescription lotion. Although it is also a neurotoxin, it is highly flammable and very dangerous if ingested.

Several lice shampoos are made from extracts from chrysanthemums – RID, A-200, R & C, Pronto, and Clear Lice System. These are toxic to lice but not very dangerous to humans. However, some children and adults have allergic reactions, especially if they are sensitive to ragweed.

The report also lists several products that are sometimes used but not proven safe or effective for lice: creams such as Elimite and Eurax; pills such as Septra, Bactrim and Stromectal; natural products such as HairClean 1-2-3; and petrolatum shampoo.

Traditional treatments such as gasoline, kerosene and other flammable substances should never be used, according to the report.