• <samp id="ossg8"></samp>
    <tbody id="ossg8"><nobr id="ossg8"></nobr></tbody>
    <menuitem id="ossg8"><strong id="ossg8"></strong></menuitem>
  • <samp id="ossg8"></samp>
    <menuitem id="ossg8"><strong id="ossg8"></strong></menuitem>
  • <menuitem id="ossg8"><ins id="ossg8"></ins></menuitem>

  • <tbody id="ossg8"><nobr id="ossg8"></nobr></tbody>
    <menuitem id="ossg8"></menuitem>
        Skip Navigation Links
        Centers for Disease Control and Prevention
         CDC Home Search Health Topics A-Z

        Preventing Chronic Disease: Public Health Research, Practice and Policy

        View Current Issue
        Issue Archive
        Archivo de n鷐eros en espa駉l








        Emerging Infectious Diseases Journal
        MMWR


         Home 

        Volume 1: No. 3, July 2004

        ORIGINAL RESEARCH
        Using Focus Groups to Develop a Bone Health Curriculum for After-school Programs


        TABLE OF CONTENTS


        Print this article Print this article
        E-mail this article E-mail this article:



        Send feedback to editors Send feedback to editors
        Download this article as a PDF Download this article as a PDF (237K)

        You will need Adobe Acrobat Reader to view PDF files.


        Navigate This Article
        Abstract
        Introduction
        Methods
        Results
        Discussion
        Acknowledgments
        Author Information
        References


        Sara C. Folta, MS, Jeanne P. Goldberg, PhD, RD, Lori P. Marcotte, MPH, MS, RD, Christina D. Economos, PhD

        Suggested citation for this article: Folta SC, Goldberg JP, Marcotte LP, Economos CD. Using focus groups to develop a bone health curriculum for after-school programs. Prev Chronic Dis [serial online] 2004 Jul [date cited]. Available from: URL: http://www.cy118119.com/pcd/issues/2004/
        jul/04_0001.htm
        .

        PEER REVIEWED

        Abstract

        Introduction
        Childhood behaviors influence peak bone mass and osteoporosis risk in later life. The after-school environment provides an opportunity to enrich a child抯 learning and experience. Our objective was to gain a better understanding of the knowledge of, attitudes and beliefs about, and barriers to achieving bone health among children, parents, and after-school program leaders from low-income, ethnically diverse communities. Findings led to the development, implementation, and evaluation of a bone health curriculum in the after-school setting.

        Methods
        Eight focus groups were conducted in three representative communities. Focus group participants included children aged six to eight years, parents of children aged six to eight, and after-school program staff. Transcripts and written notes from each session were reviewed and common themes were identified within each group.

        Results
        Most adults had some understanding of osteoporosis, but did not recognize that childhood behaviors had a role in developing the disease. Program leaders raised concerns about their ability to implement a health program and recommended a flexible format. Parents and program leaders recognized the importance of maintaining a fun atmosphere.

        Conclusion
        It is feasible to create a curriculum for a bone health program that meets the unique needs and interests of children and program leaders in the after-school setting. Addressing the needs, interests, and common barriers of the target population is an essential first step in curriculum development.

        Back to top

        Introduction

        Osteoporosis is a childhood disease with adult consequences. Childhood behaviors, including diet and physical activity (1-4), have a major influence on the attainment of peak bone mass and the primary prevention of osteoporosis (5-11). The higher the peak bone mass in childhood, the more an individual can afford to lose in adulthood (12-14). The long-term benefits of increasing bone mineral density during childhood are compelling (15,16). A change in one negative standard deviation in bone mass may double fracture risk (17,18).

        In the United States, there is a large gap between childhood behaviors known to help maximize bone health and what children actually do. National survey data estimate that more than half of girls aged six to 11 years are not meeting 100% of the 1989 Recommended Dietary Allowance for calcium, and nearly half of boys are not meeting this requirement (19). The gap between recommendations and intakes is difficult to reverse as children age (20,21). Of equal importance is that children of all ages do not obtain adequate levels of physical activity (22-25). Studies show that sedentary behavior increases and moderate physical activity decreases as children advance through elementary school (26,27) and that this decline continues into adolescence (27,28). Furthermore, girls are less likely to engage in physical activity than boys (27-29), and black children are less active than white children (28,29). The gap between the long-term effect of modifiable influences on bone health and the behaviors of millions of children suggests that cost-effective interventions to promote bone health in children are urgently needed.

        After-school programs are ideal for complementing the school day with health education and physical activity. Several million children participate in after-school programs, and demand outstrips supply by a rate of approximately two to one (30). Furthermore, many programs lack adequate funding, and quality is highly variable (30). Curriculum-based interventions may enhance existing enrichment activities and provide structure to programs that are not highly developed. Reviews of nutrition and physical activity education curricula indicate that they can contribute to significant improvements in students?knowledge, skills, and behavior, but that they must have certain characteristics to be effective (31-33). A health curriculum should be theory driven and should address children抯 needs, interests, and concerns, in addition to their knowledge, attitudes, and beliefs (31-33). Addressing barriers to change is also important. This paper describes the design of a curriculum to promote bone health based on data obtained from focus group research to identify motivating factors, preferences, and barriers to change among children, parents, and after-school program leaders.

        Back to top

        Methods

        Eight focus groups were conducted in three low- to moderate-income, multiethnic Massachusetts communities in the three months from November 1999 through January 2000. In total, 66 individuals participated. Participants included three groups of children aged six to eight years (N = 26; 70% white, 30% African American; 61% male); three groups composed of parents with children aged six to eight (N = 24; 80% white, 20% African American; 8% male); and two after-school program staff groups (N = 16; race and ethnicity not specified; 19% male). Of the 16 program staff who participated, two oversaw staff and program development and 14 taught. Focus groups took place at the after-school program sites and were led by two professional focus-group facilitators with expertise in conducting groups with children. Sessions typically lasted two hours and included six to 11 participants. Each adult participant received $30 and each child received a $20 gift certificate to a local toy store. Each session was recorded on audiotape for subsequent transcription; focus-group facilitators took additional notes.  

        Focus-group facilitators provided a brief introduction and invited parents and leaders to offer general opinions and comments about health education and strategies for engaging children in desired behaviors in after-school programs. Facilitators told children that the purpose of the meeting was to learn about what children like to eat and play. All groups were told there were no right or wrong answers. Facilitators explored knowledge, attitudes, beliefs, preferences, and barriers related to bone health and to the potential implementation of a curriculum that focused on bone health in the after-school environment.

        The two facilitators systematically analyzed transcripts. Each one read the original transcripts to identify themes of each topic of discussion before collaborating on the summary report and submitting the report to an independent investigator. The investigator reviewed the transcripts and final report and recoded key phrases into a matrix constructed to conform to the project抯 conceptual framework. Recoding key phrases into the matrix allowed for a more detailed understanding of the key themes identified by the facilitators and provided the ability to incorporate these themes into the project development.

        The Institutional Review Board at Tufts University gave human subjects research approval for this project.

        Back to top

        Results

        Knowledge and awareness

        As expected, the children had limited knowledge about bone health and the factors that affect it. Some understood the connection between bone health and drinking milk. Not surprisingly, they were generally aware of something called 揷alcium?but did not understand that it is a mineral or know where it is found in the diet: 揑t抯 a kind of vitamin and cereal has it?was a typical response. After calcium was defined for them, many children commented, 揅alcium makes you stronger, smarter, and helps you learn.?nbsp;

        As expected, none of the children understood 搊steoporosis.?Among parents, knowledge of osteoporosis was mixed, whereas most after-school program leaders had a basic knowledge of what osteoporosis is and how to prevent it. In general, both parents and after-school program staff were aware of the effect of calcium and exercise on bone health and development.

        Attitudes, perceptions, and beliefs

        Children showed little interest in understanding osteoporosis, but some interest in knowing how to make bones healthy and strong. Children appropriately associated bones with certain foods: 揃ones make you think about dairy products.?Parents felt that nutrition played a critically important role in their child抯 development. Among their chief concerns were getting their children to eat enough fruits and vegetables and limiting their intake of sweets and other 搄unk foods? 揑 worry about the long-range effect of nutrition on them in their twenties, what will have been done by then.?揑 like to make sure my kids get their vitamins every day卋ecause I know they don抰 eat right. They don抰 eat enough vegetables.?揙ther than genetics, nutrition is the number-one thing for your child抯 health.?nbsp;

        Parents were less concerned that their children抯 diets had enough calcium and did not consider osteoporosis a major health threat: 揂s long as they抮e eating from the basic four food groups, I抦 not worried.? 揑 always think of osteoporosis as an adult issue.?揑 think I need the bone help more than them.?nbsp;

        Parents and after-school program leaders were both concerned about the amount of physical activity the children were getting. One parent commented, 揌e doesn抰 get enough exercise — never. He抯 healthy, but he has an interest in video games and anything electronic. I抦 worried about down the road.?An after-school program leader observed, 揑f you talk to a gym teacher or watch a class, these kids aren抰 in any shape at all. In my class, there are four or five kids who can抰 run around the bases without stopping and huffing and puffing.?

        Preferences

        Most children said they liked or drank milk. The perspectives of children and parents differed on the subject of physical activity. Children said that if given a choice, they would prefer physical activity, games, or sports during their free time: 揑 like to play tag and play games like when you pretend to be monsters and things匢抎 rather play outside.? In contrast, parents consistently said that if left on their own, children would choose television and video games rather than physical activity. Parents demonstrated an awareness of the importance of physical activity and of their role in promoting it: 揑 do make them go outside, but it抯 like kicking and screaming ?they don抰 like to go.?nbsp; 

        Barriers

        After-school program leaders were concerned about the amount of planning required to implement a curriculum. Said one participant, 揑抦 a second-grade teacher. I have enough planning to do all day long. I don抰 have the time.?Some after-school program leaders also expressed a desire for flexibility: 揑 think ideas would be better, because if you disagree with the format, then you抮e going to come to some conflict with 慜h, I have to do this??Make it more optional. 慪ou may want to do this, or you could do A, B, and C.挃 揫It] just depends on the mood of the children what I抦 going to do that day. If they抮e fidgety, we go out and run around the park.?/p>

        While after-school program leaders recognized the need to provide guidance for children about healthy eating and exercise, they did not perceive health education as a priority: 揑 think health education is important but as [another participant] said, they get a lot of it during the day at school, and we抮e more geared toward their social and emotional growth, socializing with other children and interacting with adults.?/p>

        Both parents and after-school program leaders expressed some concerns about the nutrition education component of the curriculum. They worried that the activity would replace the children抯 already limited time for play and fun. One after-school program leader stated, 揑 don抰 want it to be a bore for them. Especially since they抳e been in school all day long. I do think it抯 important, but when they come to us, it抯 time to let loose some steam.?A parent said, 揑抦 hoping they抣l come home and say 慖 had fun doing this and that today.?If he says, 慖 have to go here,?then he抯 in the wrong place.?/p>

        Parents also expressed a concern that the nutrition education activity might be too academic: 揑t needs to be addressed for children as not so medical. It needs to be presented as fun.?揑 think the calcium-focused activity would get old fast. You know: 慍alcium again, I抦 so sick of calcium.挃

        Despite wanting their children to enjoy a break from academics, getting homework done during the after-school time was a high priority for parents. After-school program leaders felt pressure to make sure homework was complete by the time parents arrived to pick children up. One parent commented, 揌omework has to be the first priority. I get home too late to get it done with him.?An after-school leader said, 揑 know my parents: they want [their children] to get their homework done.?/p>

        After-school program leaders consistently and poignantly expressed their concern that they might not know enough to effectively teach the bone-health curriculum. They were afraid they would be embarrassed if they could not answer a child抯 question. 揑抦 not saying I抦 ignorant about osteoporosis, but I抦 not as knowledgeable as I抎 like to be.?揫I would want] more knowledge about osteoporosis, questions the kids would ask us, so we could have answers for them.?Parents also expressed concern about the ability of the after-school program leaders to implement the curriculum: 揟he after-school teachers would need training. They抮e capable, but need training.?While an extensive training program was proposed, most after-school program leaders suggested that only minimal training would be possible because of limited available time. Because of high staff turnover rates in the after-school setting, they also voiced an interest in ongoing oversight and support so the curriculum could continue even if trained leaders left the after-school program.

        Shaping the curriculum

        Curriculum development relied heavily on information obtained in the focus groups. To respond to the needs of program leaders in the after-school setting, short and simple lessons were designed with alternate activity options, tips for implementation, and ideas for modifying games. Curriculum components could complement regular program activities without interfering with priorities such as homework. Ongoing support was offered via newsletters, and research staff were available to assist new leaders during the year.

        From the outset of the project, the objective was to package both a physical-activity component and a nutrition education component so that the children would have fun while learning. The children know the project as 揟he Bones Club.?To address the desire expressed in focus groups to allow children to use after-school time for fun activities that would enable them to socialize and 搇et off some steam?and to fulfill the objective of offering simple, non-academic language, the physical activity component was named 揕et抯 Play.?Activities identified as favorites with the children were adapted to weight-bearing activities (similarly titled 揕et抯 Run?and 揕et抯 Jump?. Because after-school program leaders indicated that they operate in a wide variety of physical environments, all games included simple modifications to accommodate play in different environments.

        Likewise, the nutrition education component was named 揕et抯 Explore?to reflect some of the preferred activities of children and to emphasize both teamwork and fun. During the focus groups, children indicated an interest in reading, and after-school program leaders reported 揷ircle time?as a common component of the after-school day. Age-appropriate books were provided to support the learning themes of the 揕et抯 Explore?lessons. Many after-school program leaders expressed concern that they may not know enough about bone health to teach the curriculum effectively. To begin to address this, an appendix was included with each section of the written curriculum that answered commonly asked questions and provided a quick reference guide for additional resources.

        Evidence shows that nutrition education programs and curricula targeted at elementary-aged children are more effective when they include a family component (33). Some parents received newsletters that corresponded to curriculum units to reinforce after-school program lessons at home. Newsletters included quick and easy recipes and physical activity tips that took into account the time constraint that was mentioned as a barrier in the focus groups. Parents also were given a directory that allowed them to leverage their own limited resources by using nutrition, physical activity, and health resources available in their communities.

        Back to top

        Discussion

        This study demonstrates how focus groups can be used to shape a curriculum to meet the needs of after-school program leaders, parents, and children so that maximum buy-in and learning can occur. Of particular importance, focus groups can identify key barriers to implementing the curriculum that might otherwise go unnoticed. Perhaps the most important barrier was that health education was not considered a priority by either parents or after-school program leaders. To succeed, the curriculum would need to focus on fun for the children and ease of implementation for the program leaders. The curriculum was designed to be short and flexible so it would not replace activities that were considered a priority.  

        Parents and program leaders indicated limited confidence in promoting health, particularly nutrition, to children. Still, program leaders believed they could incorporate such a program into their existing after-school program structure and implement it as long as they are given adequate support.

        Not surprisingly, children were not interested in osteoporosis the disease, but they did want to learn about how bones move and what they could do to grow big and strong. This perception confirmed that it is possible to engage even very young children in a health topic if the topic is presented at their level of comprehension and if it appeals to their interests.

        The children who participated in the focus groups were young. Sometimes they were wonderfully direct and open, and at other times their responses were colored by the need for peer acceptance. In this series of focus groups, their responses about likes and dislikes differed from those of their parents. For instance, children overwhelmingly expressed a preference for active games or sports over video games, but parents reported difficulty in engaging children in outdoor play. This observation confirms the need to conduct focus groups that include both children and parents to obtain a more balanced picture of preferences and behaviors.

        The inconsistency between children抯 reported desire for physical activity and parents?reports that children engage in sedentary behaviors if given a choice is difficult to reconcile. Possibly, while children may like the idea of physical activity, they are reluctant to engage in it once they have started other activities. Several factors may draw children to activities that are more sedentary. In the focus groups, parents noted the ubiquity of televisions and computer games in their homes. In addition, cold weather and early darkness were also mentioned as serious barriers to outdoor play. Regardless of these perceived barriers, children participated willingly when provided with the types of physical activities in the after-school programs that both the children and the program leaders agreed were fun.

        Focus groups do not provide data that are generalizable to other populations, but they can be a time-efficient and cost-effective method for identifying attitudes, beliefs, and barriers toward health behaviors among defined target populations. Through an interactive discussion led by trained professionals, it is possible to identify information that is critical to program success and that might not be uncovered in survey research. For example, the permissive environment allowed after-school leaders to openly describe their perceptions of their limited knowledge about osteoporosis and bone health, which, if not addressed, could limit their ability to implement the curriculum and could consequently hinder the success of the program.

        Response to the bone-health curriculum has been enthusiastic. More than 50 after-school programs in Massachusetts and Rhode Island have implemented it successfully, and it has been well-accepted by after-school program leaders, parents, and children. After-school program leaders report that the curriculum has enhanced their programs and has had the unexpected benefit of improving their relationships with the children. They indicate that children enjoy being in the 揃ones Club?and having something to call their own. Participation is optional, but remains at a high level, and dropout rates related to dissatisfaction are extremely low (less than 1%). Dropout is linked almost exclusively to children leaving the after-school program or the school district itself.

        An environment that fosters the development of behaviors to promote bone health can contribute to positive habits that children will adopt before entering their preteen years, when peer influences gain power. After-school programs have been an underused setting for health interventions. As they grow in number, they provide an opportunity to use time that traditionally has been difficult to fill consistently with appropriate physical and cognitive activities for all children who attend them. Health interventions that include an academic and a physical-activity component are difficult to implement given the varied experience of leaders and the lack of funds for training and technical support. Limited staff, high turnover rates, and competing demands on program time are major barriers. Curricula based on formative research can overcome these barriers, help to improve the health of children, and prevent chronic disease later in life.

        Back to top

        Acknowledgments

        This research was supported by a grant (NIH/1RO1 HD 37752-01) and is based on work supported by Grant P01-DK42618 from the National Institutes of Health, and the U.S. Department of Agriculture (USDA), under agreement number 58-1950-9-001. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the USDA.

        Back to top

        Author Information

        Corresponding author: Christina D. Economos, PhD, Associate Director, John Hancock Center on Physical Activity and Nutrition, Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, 150 Harrison Ave, Boston, MA 02111. Telephone: 617-636-3784. E-mail: christina.economos@tufts.edu.

        Author affiliations: Sara C. Folta, MS, Jeanne P. Goldberg, PhD, RD, Lori P. Marcotte, MPH, MS, RD, Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, Boston, Mass.

        Back to top

        References

        1. Bonjour J, Theintz G, Law F, Slosman D, Rizzoli R. Peak bone mass. Osteoporosis Int 1994;4 Suppl 1:7-13.
        2. Deal C. Osteoporosis: Prevention, diagnosis, and management. Am J Med 1997;102 (1A):S35-9.
        3. Lysen V, Walker R. Osteoporosis risk factors in eighth grade students. J Sch Health 1997;67 (8):317-21.
        4. Anderson J, Rondano P, Holmes A. Roles of diet and physical activity on the prevention of osteoporosis. Scand J Rheumatol Suppl, 1996;103:65-74.
        5. Teegarden D, Proulx WR, Martin BR, Zhao J, McCabe GP, Lyle RM, et al. Peak bone mass in young women. J Bone Miner Res 1995;10 (5):711-5.
        6. Recker RR, Davies KM, Hinders SM, Heaney RP, Stegman MR, Kimmel DB. Bone gain in young adult women. JAMA 1992;268 (17):2403-8.
        7. Slemenda C, Reister TK, Hui SL, Miller JZ, Christian JC, Johnston CC Jr. Influences on skeletal mineralization in children and adolescents: evidence for varying effects of sexual maturation and physical activity. J Pediatr 1994;125:201-7.
        8. Matkovic V. Nutrition, genetics and skeletal development. J Am Coll Nutr 1996;15 (6):556-69.
        9. Bailey D. The Saskatchewan Pediatric Bone Mineral Accrual Study: bone mineral acquisition during the growing years. Int J Sports Med 1997;18 Suppl 3:S191-4.
        10. Barr S, McKay H. Nutrition, exercise, and bone status in youth. Int J Sport Nutr 1998;8:124-42.
        11. French SA, Fulkerson JA, Story M. Increasing weight-bearing physical activity and calcium intake for bone mass growth in children and adolescents: a review of intervention trials. Prev Med 2000;31:722-31.
        12. Ribot C, Tremollieres F, Pouilles JM. Late consequences of a low peak bone mass. Acta Paediatr Suppl 1995;411:31-5.
        13. Riis B, Hansen MA, Jensen AM, Overgaard K, Christiansen C. Low bone mass and fast rate of bone loss at menopause: equal risk factors for future fractures: a 15-year follow-up study. Bone 1996;19:9-12.
        14. Seeman E,  Tsalamandris C, Formica C, Hopper JL, McKay J. Reduced femoral neck bone density in daughters of women with hip fractures: the role of low peak bone density in the pathogenesis of osteoporosis. J Bone Miner Res 1994;9:739-43.
        15. Johnston CC Jr, Slemenda CW. Risk assessment: theoretical considerations. Am J Med 1993;95 (5A):S2-5.
        16. Matkovic V, Kostial K, Simonovic I, Buzina R, Brodarec A, Nordin BE. Bone status and fracture rates in two regions of Yugoslavia. Am J Clin Nutr 1979;32:540-9.
        17. Hui SL, Slemenda CW, Johnston CC Jr. Baseline measurement of bone mass predicts fracture in white women. Ann Intern Med 1989;111:355-61.
        18. Wasnich R, Ross PD, Davis JW, Vogel JM. A comparison of single and multi-site BMC measurements for assessment of spine fracture probability. J Nucl Med 1989;30:1166-71.
        19. U.S. Department of Agriculture, Agricultural Research Service. Food and nutrient intakes by children 1994-96, 1998. Beltsville (MD): ARS Food Surveys Research Group;1999.
        20. Albertson AM, Tobelmann RC, Marquart L. Estimated dietary calcium intake and food sources for adolescent females: 1980-92. J Adolesc Health 1997;20:20-6.
        21. Zive MM, Nicklas TA, Busch EC, Myers L, Berenson GS. Marginal vitamin and mineral intakes of young adults: The Bogalusa Heart Study. J Adolesc Health 1996;19:39-47.
        22. Simons-Morton BG, O扝ara NM, Parcel GS, Huang IW, Baranowski T, Wilson B. . Res Q Exerc Sport 1990;61(4):307-14.
        23. Pate R, Long B, Heath G. Descriptive epidemiology of physical activity in adolescents. Pediatr Exerc Sci 1994;6:434-47.
        24. Sallis JF. Epidemiology of physical activity and fitness in children and adolescents. Crit Rev Food Sci Nutr 1993;33 (4-5):403-8.
        25. Duke J, Huhman M, Heitzler C. Physical activity levels among children aged 9-13 years — United States, 2002. MMWR Morb Mortal Wkly Rep 2003;52 (33):785-8.
        26. Myers L, Strikmiller PK, Webber LS, Berenson GS. Physical and sedentary activity in school children grades 5-8: the Bogalusa Heart Study. Med Sci Sports Exerc 1996;28 (7):852-9.
        27. Trost SG, Pate R, Sallis JF, Freedson PS, Taylor WC, Dowda M, et al. Age and gender differences in objectively measured physical activity in youth. Med Sci Sport Exerc 2002;34 (2):350-5.
        28. Grunbaum J, Kann L, Kinchen SA, Williams B, Ross JG, Lowry R, et al. Youth risk behavior surveillance — United States, 2001. MMWR Surveill Summ 2002;51 (4):1-62.
        29. Andersen RE, Crespo CJ, Bartlett SJ, Cheskin LJ, Pratt M. Relationship of physical activity and television watching with body weight and level of fatness among children: results from the Third National Health and Nutrition Examination Survey. JAMA 1998;279 (12):938-42.
        30. Working for children and families: safe and smart after-school programs. U.S. Department of Education. U.S. Department of Justice; Washington (DC): 2000.
        31. Contento I, Balch GI, Bronner YL, Paige DM, Gross SM, Lytle LA et al. Nutrition education for school-age children. J Nutr Ed 1995;27:298-311.
        32. Stone EJ, McKenzie TL, Welk GJ, Booth ML. Effects of physical activity interventions in youth. Review and synthesis. Am J Prev Med 1998;15 (4):298-315.
        33. Lytle L, Achterberg C. Changing the diet of America's children: what works and why? J Nutr Ed 1995;27 (5):250-60.

        Back to top

         



         



        The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors’ affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.


         Home 

        Privacy Policy | Accessibility

        CDC Home | Search | Health Topics A-Z

        This page last reviewed March 30, 2012
        Centers for Disease Control and Prevention
        National Center for Chronic Disease Prevention and Health Promotion
         HHS logoUnited States Department of
        Health and Human Services



         
        国产精品久久久久久一级毛片