Association between bullying victimization and physical fighting among Filipino adolescents: results from the Global School-Based Health Survey. 
Interpersonal violence is an important, but neglected public health issue in low and middle-income countries.  Adolescent physical fighting not only results in injury, disability and death, but is also associated with other potentially harmful behaviors such substance use and premarital sex.  The study aims at dose-response association to prevent adolescent problem behaviors.  We used data from the 2003-2004 Global School-Based Health Survey conducted among school adolescents in the Philippines.  We estimated the prevalence of bullying victimization and physical fighting.  We also conducted logistic regression analysis to assess the association between a selected list of explanatory variables and physical fighting.  We hypothesized that there would be a dose-response relationship between physical fighting and number of times the adolescent reported being bullied in the past 30 days.  Of the 7,338 respondents, 35.5% (34.7% males and 36.1% females) were bullied and 50.0% (51.6% males and 48.8% females) reported having been in a physical fight in the past 12 months.  There was a dose-response relationship between bullying victimization and physical fighting (p-trend <0.001).  Compared to subjects who were not bullied, those who reported being bullied were more likely to engage in physical fighting after controlling for age, gender, substance use (smoking, alcohol drinking or drug use), and parental supervision (OR=2.38; 95% CI [1.99, 2.86] for 1-2 days of bullying victimization per month, OR=3.55; 95% CI [2.61, 4.83]) for 3-5 days/month per month, OR=4.45; 95% CI [2.61, 7.60]) for 6-9 days/ month, OR=1.91; 95% CI [1.17, 3.13]) for 10-30 days/month.)  The dose-response relationship between physical fighting and the number of times an adolescent had been a victim of bullying deserves further study.  If causal relationship exists, preventing bullying, even if not totally eliminated, may have significant results in preventing physical fighting.