***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: CONTEXT Despite the recent declines in rates of teenage pregnancy , relatively little is known about the few programs that have been successful in reducing adolescent pregnancy . METHODS Six agencies in New York City each r and omly assigned 100 disadvantaged 13 - 15-year-olds to their usual youth program or to the intervention being tested -- the Children 's Aid Society-Carrera program  , a year-round afterschool program with a comprehensive youth development orientation . Both program and control youth were followed for three years . Multivariate regression analyses assessed the effects of program participation on the odds of current sexual activity , use of a condom along with a hormonal contraceptive , pregnancy and access to good health care . RESULTS Seventy-nine percent of participants remained in the program for three full years . Female program participants had significantly lower odds than controls of being sexually active ( odds ratio , 0.5 ) and of having experienced a pregnancy ( 0.3 ) . They had significantly elevated odds of having used a condom and a hormonal method at last coitus ( 2.4 ) . However , participation in the program created no significant impact on males ' sexual and reproductive behavior outcomes . Nonetheless , program participants of both genders had elevated odds of having received good primary health care ( 2.0 - 2.1 ) . CONCLUSIONS This program is one of only four whose evaluation has successfully documented declines in teenage pregnancy using a r and om-assignment design . Better outcomes among males may be achieved if programs reach them even earlier than their teenage years 
    Output:
    
Synthesis of outcomes , published elsewhere , found no overall evidence of reducing substance use or violence but notable variability of fidelity .
Collaboration with other agencies could broaden the activities offered .
Calm but authoritative staff increased acceptability .
Staff continuity underpinned diverse activities and durable relationships .
Empowering participants were sometimes in tension with requiring them to engage in diverse activities .
Conclusion : Our systematic review identified factors that might help improve the fidelity and acceptability of PYD interventions .
Addressing these might enable PYD to fulfill its potential as a means of promoting health