This study presents findings from a systematic review of the evidence regarding the effectiveness of youth centers in increasing use of sexual and reproductive health (SRH) services in lower- and middle-income countries. Evidence from peer-reviewed and gray literature between 1990 and 2010 was reviewed. After the screening of 3,769 citations, 21 studies reporting on 17 youth center programs were included, and were ranked by strength of evidence. Considerable consistency in findings across studies was observed. Youth centers generally served a relatively small proportion of young people living nearby. The main users were young men attending school or college, with a significant proportion older than the target age. Users of the on-site SRH services were predominantly young women, with a significant proportion older than the target age group. Uptake of services was generally low. Despite widespread emphasis on youth centers as a strategy for encouraging young people to access SRH services, results from these studies have not been encouraging, and cost-effectiveness for these purposes is likely to be low

Geary, Rebecca S

Ross, David A

Zuurmond, Maria A

Maria A. Zuurmond

Rebecca S. Geary

David A. Ross

Crossref

Studies in Family Planning

The Effectiveness of Youth Centers in Increasing Use of Sexual and Reproductive Health Services: A Systematic Review

LSHTM Research Online

Ross, DA (2004) The toxicology of mercury. The New England jour-nal of medicine, 350 (9). p. 946. ISSN 0028-4793Downloaded from: http://researchonline.lshtm.ac.uk/14859/Usage GuidelinesPlease refer to usage guidelines at http://researchonline.lshtm.ac.uk/policies.html or alterna-tively contact researchonline@lshtm.ac.uk.Available under license: Copyright the publishers n engl j med  350;9 www.nejm.org february  26, 2004 correspondence 945 sartan group than in the captopril group (1.4 per-cent vs. 0.8 percent; excess, 6 per 1000; P<0.05).However, discontinuation because of any adverseevent was more frequent in the captopril group(7.7 percent, vs. 5.8 percent in the valsartan group;excess, 19 per 1000; P<0.05). We are conducting amore detailed analysis to attempt to identify pa-tient characteristics associated with a heightenedrisk of specific drug-related adverse events. Thedifferent side-effect profiles of these two effectivealternative approaches should assist clinicians inindividualizing therapy to extend the appropriateuse of these livesaving interventions to more survi-vors of myocardial infarction. Marc A. Pfeffer, M.D., Ph.D. Brigham and Women’s HospitalBoston, MA 02115mpfeffer@rics.bwh.harvard.edu John J.V. McMurray, M.D. Western InfirmaryGlasgow G11 6NT, Scotland Robert M. Califf, M.D. Duke University Medical CenterDurham, NC 27710 The Toxicology of Mercury to the editor:  As a public health official who hasbeen raising the consciousness of my communitywith regard to the potential hazards of eating mer-cury-containing fish, I am disturbed by the reviewarticle on mercury by Clarkson and colleagues (Oct.30 issue). 1  The Environmental Protection Agency,the Food and Drug Administration, and the healthdepartments of most states have not published ad-visories or reference doses on mercury in fish, fornebulous reasons. Over the past 30 years, the levelof mercury that we know is associated with a harm-ful effect has declined significantly, as has the reg-ulatory standard for what is considered a “safe” lev-el of exposure. Certainly there are safe and healthyalternatives to the use of mercury-containing dentalamalgams, as there are to the consumption of fishcontaining high mercury levels. The authors’ con-clusions that the health effects of a low level of mer-cury exposure are “open to wide interpretation” andthat “attempts to reduce such exposure may posegreater health risks than those hypothesized tooccur from mercury” sound like conclusions thatmight be drawn by the electric power or tuna in-dustry. Lawrence S. Block, M.D. Swampscott Board of HealthSwampscott, MA 01907lblock@partners.org 1. Clarkson TW, Magos L, Myers GJ. The toxicology of mercury —current exposures and clinical manifestations. N Engl J Med 2003;349:1731-7. to the editor:  Clarkson et al. find no hazard toadults or children in the United States from routinedietary, dental, or pharmaceutical  sources of mer-cury. The authors discount the findings of neuro-behavioral and cardiovascular abnormalities in theoffspring of women with blood mercury levels atthe upper limit for American women of childbear-ing age. 1,2  However, each year, an estimated 84,300pregnant women eat more than 100 g of fish perday. 3  Pregnant and lactating women should not haveto limit their intake of economical, healthy protein.Environmental policymakers must strive to reduceenvironmental mercury levels so that existing fish-consumption advisories will not be needed. TheMassachusetts Medical Society has advocated for re-ductions in mercury emissions from power plants,a major source of environmental mercury in fish. 4 We support strict efforts to control mercury andother hazardous emissions from coal- and oil-firedpower plants. The adoption of less strict emissionstandards could result in higher mercury levels inthe food supply of Americans. Bill Patterson, M.D., M.P.H. Occupational Health and RehabilitationHingham, MA 02043 James Ryan, M.D., M.P.H. Boston Medical CenterBoston, MA 02118 Jefferson H. Dickey, M.D. 51 Sanderson St.Greenfield, MA 01301 1. Murata K, Budtz-Jorgensen E, Grandjean P. Benchmark dosecalculations for methylmercury-associated delays on evoked poten-tial latencies in two cohorts of children. Risk Anal 2002;22:465-74. 2. Sorenson N, Murata K, Budtz-Jorgensen E, Weihe P, GrandjeanP. Prenatal methylmercury exposure as a cardiovascular risk factor atseven years of age. Epidemiology 1999;10:370-5. 3. Mercury study report to Congress. Vol. 6. An ecological assess-ment for anthropogenic mercury emissions in the United States.The New England Journal of Medicine Downloaded from nejm.org at LONDON SCH HYGIENE & TROPICAL MED on February 19, 2014. For personal use only. No other uses without permission.  Copyright © 2004 Massachusetts Medical Society. All rights reserved.  The  new england journal  of  medicine 946 n engl j med  350;9 www.nejm.org february  26, 2004 Washington, D.C.: Environmental Protection Agency, December1997. (EPA-452/R-97-008.) 4. Mercury. In: Massachusetts Medical Society policy compendi-um, 2003 edition. Waltham, Mass.: Massachusetts Medical Society,2003. (Accessed February 6, 2004, at http://www.massmed.org/about/policies/environment.asp.) to the editor:  Magical-religious and ethnomedi-cal use of elemental mercury is a major source of ex-posure in some Caribbean and Hispanic communi-ties. Clarkson et al. refer to these exposures only inpassing, although they are widespread and clini-cally significant. Between 25,000 and 155,000 mer-cury capsules (mean weight per capsule, 9 g) weresold for ritualistic use in the Bronx, New York, in1995, with some 30 percent of informants recom-mending that mercury be sprinkled on floors. 1  An-other study found that 5 of 100 Bronx children hadelevated urinary mercury levels. 2  Mercury vaporlevels in Hispanic housing were elevated in com-parison with those in control housing. 3  Ritualisticuse of mercury was the median source of mercuryinflux to the New York–New Jersey harbor. 4  Clark-son et al. state that “ingested liquid mercury [is] es-sentially unabsorbed,” whereas 0.01 percent isabsorbed 5  (or 1 mg retained) of a 10-g dose ethno-medically administered to an infant for stomach up-set. The National Center for Environmental Healthof the Centers for Disease Control and Preventionwill shortly measure urinary mercury levels in 250Hispanic children in the Bronx. Clinicians servingHispanic and Caribbean communities should bealert to signs and symptoms of these exposures. Arnold P. Wendroff, Ph.D. Mercury Poisoning ProjectBrooklyn, NY 11215mercurywendroff@mindspring.com 1. Zayas LH, Ozuah PO. Mercury use in espiritismo: a survey of bo-tanicas. Am J Public Health 1996;86:111-2. 2. Ozuah PO, Lesser MS, Woods JS, Choi H, Markowitz M. Mercu-ry exposure in an urban pediatric population. Ambul Pediatr 2003;3:24-6. 3. Stern AH, Gochfeld M, Riley D, Newby A, Leal T, Garetano G.Cultural uses of mercury in New Jersey. Research project summary.Environmental assessment and risk analysis element. Trenton: Divi-sion of Science Research and Technology, New Jersey Department ofEnvironmental Protection, May 2003. 4. de Cerreno ALC, Panero M, Boehme S. Pollution prevention andmanagement strategies for mercury in the New York/New Jerseyharbor. New York: New York Academy of Sciences, May 2002. 5. Clarkson T, ed. Mercury toxicity. Case studies in environmentalmedicine. No. 17. Atlanta: Agency for Toxic Substances and DiseaseRegistry, March 1992. to the editor:  Having recently worked in publichealth research in Mwanza, Tanzania, which iswithin the goldfields of the Lake Victoria basin, Iexpected that the review by Clarkson et al. wouldcontain information on the health risks associatedwith the widespread use of mercury to extract goldfrom ore.  This method is used by most small-scalegold miners throughout the world and usually in-volves both direct handling of mercury and inhala-tion of mercury vapor as the mercury–ore mixture isheated over an open flame during the extraction pro-cess. A recent review concluded that “miners whoused elemental mercury to amalgamate and extractgold were heavily contaminated with mercury.” 1 Hundreds of thousands of people are engagedin small-scale gold mining, mainly in relatively re-mote areas of developing countries, with little ifany knowledge of the health risks they face frommercury. The connection between the use of mer-cury and its insidious toxic effects is difficult to per-ceive and is usually missed by health workers andsufferers alike. David A. Ross, B.M., B.Ch., Ph.D. London School of Hygiene and Tropical MedicineLondon WC1E 7HT, United Kingdomdavid.ross@lshtm.ac.uk 1. Eisler R. Health risks of gold miners: a synoptic review. EnvironGeochem Health 2003;25:325-45. to the editor:  Clarkson et al. imply that theremight be consequences for the health of dental pa-tients if the use of mercury-containing dental amal-gam were to be curtailed. Advances in dental mate-rials over the past 20 years have rendered amalgampotentially obsolete, although some dentists con-tinue to use it. Composite dental filling materialsof micron-sized glass particles bound in resin havebeen proved durable, economical, easy to use, andpopular with patients because of their natural ap-pearance. They present far less potential for toxicitythan amalgam, which, as the authors acknowl-edge, releases mercury vapor on a continuousbasis. The majority of dental fillings in the UnitedStates in the past few years are reported to havebeen performed with the use of composites. Thedental profession is now in a position to leave theage of mercurial remedies behind. Stephan M. Koral, D.M.D. 2006 BroadwayBoulder, CO 80302 the authors reply:  Our article focused on thethree species of mercury to which billions of peo-ple are exposed: methyl mercury in fish; mercuryvapor from dental amalgam; and ethyl mercury (inThe New England Journal of Medicine Downloaded from nejm.org at LONDON SCH HYGIENE & TROPICAL MED on February 19, 2014. For personal use only. No other uses without permission.  Copyright © 2004 Massachusetts Medical Society. All rights reserved.  n engl j med  350;9 www.nejm.org february  26, 2004 correspondence 947 the form of thimerosal), present as a preservative inmany commonly used vaccines and some immuneglobulins. Although mercury in all these forms istoxic, the question is whether sufficient amountscan be absorbed from these sources to producetoxic effects. Moreover, each source of mercury isassociated with beneficial use. Fish consumptionlowers the risk of coronary heart disease 1  and per-haps even the risk of Alzheimer’s disease. 2  Dentalamalgam remains a safe and effective tooth filling.Thimerosal in vaccines makes possible the use ofmultiple-dose vials, which remain essential in de-veloping countries. Our point was that further at-tempts to reduce exposure to these forms of mer-cury present a dilemma, because they require thatthe health risks from mercury itself be balancedagainst the loss of the beneficial outcomes.Two letter writers decry what they see as our un-derplaying of health risks from methyl mercury infish. Our article questioned some of the evidencefor health risks from the three sources of exposureto mercury. This uncertainty in risk estimates fur-ther emphasizes the dilemma.Another writer claims that dental amalgam isassociated with higher health risks than alternativefillings. The issue we addressed was that of replac-ing amalgam fillings already placed in teeth. Theprocess of removal elevates mercury levels to peakheights that are about double the preremoval lev-els. In any case, alternatives to dental-amalgam fill-ings are not a panacea, as is shown by reports ofleakage and wear. 3,4 Two letters alert us to other routes of exposureto mercury vapor — namely, the use of liquid mer-cury to extract gold from river sediments and theethnoreligious uses of quicksilver in homes. Weagree that these two uses can lead to high expo-sures and overt poisoning, but they do not presenta dilemma to the health profession. Such uses ofmercury clearly should be discontinued. Tom Clarkson, Ph.D. University of RochesterRochester, NY 14642twc30@aol.com Laszlo Magos, M.D. Medical Research CouncilWallington SM6 0TE, United Kingdom Gary Myers, M.D. University of RochesterRochester, NY 14642 1. Hu FB, Bronner L, Willett WC, et al. Fish and omega-3 fatty acidintake and risk of coronary heart disease in women. JAMA 2002;287:1815-21. 2. Morris MC, Evans DA, Bienias JL, et al. Consumption of fish andn-3 fatty acids and risk of incident Alzheimer disease. Arch Neurol2003;60:940-6. 3. Jain P, Pershing A. Depth of cure and microleakage with high-intensity and ramped resin-based composite curing lights. J AmDent Assoc 2003;134:1215-23. 4. Kubo S, Yokota H, Yokota H, Hayashi Y. Effect of low-viscosityresin-based composite on microleakage of cervical restorations. AmJ Dent 2003;16:244-8.Gene Silencing to the editor:  Herman and Baylin (Nov. 20 issue) 1 provide an excellent review of gene silencing incancer in association with promoter hypermethyla-tion. However, some readers who are new to thefield will be confused by the introductory section oftheir article — in particular, the authors’ explana-tion of the term “epigenetic,” which suggests thatthis term describes “a heritable change in the pat-tern of gene expression.” In fact, in this context,promoter hypermethylation is a somatic event, andalthough it may be passed on to daughter somaticcells, it is not heritable in the germ line. Although itis later stated that “epigenetic change is not amechanism of the first hit” in familial cancer, theintroductory summary may be misleading. Judy Kirk, M.B., B.S. Westmead Hospital2145 Sydney, Australiajudy_kirk@wmi.usyd.edu.au 1. Herman JG, Baylin SB. Gene silencing in cancer in associationwith promoter hypermethylation. N Engl J Med 2003;349:2042-54. the authors reply:  We thank Dr. Kirk for herthoughtful comments regarding the definition ofthe term “epigenetic” in our review. She is certainlycorrect in stating that the heritable patterns de-fined by this term generally refer to gene-expres-sion changes not based on changes in the DNAbase sequence and that they are passed on todaughter cells in a somatic-cell, rather than a germ-cell, context. Thus, DNA-methylation patterns areheritable through cell division but are usually nothereditary in the sense of being passed on throughmeiosis. It should be noted, however, that there areDNA-methylation patterns, and attendant gene si-lencing, that are perpetuated in somatic cells fromThe New England Journal of Medicine Downloaded from nejm.org at LONDON SCH HYGIENE & TROPICAL MED on February 19, 2014. For personal use only. No other uses without permission.  Copyright © 2004 Massachusetts Medical Society. All rights reserved. 

The effectiveness of youth centers in increasing use of sexual and reproductive health services: a systematic review.

The effectiveness of youth centers in increasing use of sexual and reproductive health services: a systematic review.

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