The authors thank Beryl Rosenstein, M.D., for his thoughtful manuscript review; Michael Knowles, M.D., for helpful discussions; and Nulang Wang for CFTR genotyping. Special thanks to Mark D. Schluchter and to Michael Kulich for providing conversion programs for Bayes estimation of FEV1 at age 20 and for CF-specific percentiles for FEV1, respectively. The authors are indebted to the patients with CF and their families, research coordinators, and CF physicians who are participating in the CF Twin and Sibling Study. Without their commitment to CF research, this work would not have been possible.
The following individuals and Centers are participating in the CF Twin and Sibling Study:Frank Accurso, M.D., Shelley Mann, R.N., Advocate Hope Children's Hospital, Oak Lawn, IL; Steve Boas, M.D., Melinda Brechinella, R.N., Chicago CF Care Specialists, Glenview, IL; Titus Sheers, M.D., Deborah Ouellette, R.N., Children's Hospital and Medical Center of Akron, Akron, OH; James Acton, M.D., Patricia Joseph, M.D., Lorrie Duan, R.N., Children's Hospital and Medical Center of Cincinnati, Cincinnati, OH; Ron Gibson, M.D., Moira Aitken, M.D., Alan Genatossio, R.N., Children's Hospital and Medical Center, Seattle, WA; Joseph Cronin, M.D., Jeanne Smith, R.N., Children's Hospital of Buffalo, Buffalo, NY; Frank Accurso, M.D., Shelley Mann, R.N., Children's Hospital of Denver, Denver, CO; Arnold Platzker, M.D., Evelyn Hsu, R.N., Children's Hospital of Los Angeles, Los Angeles, CA; Karen Hardy, M.D., Deborah Kaley, N.P., Children's Hospital of Oakland, Oakland, CA; David Hicks, M.D., Bruce Nickerson, M.D., Candace Ramos, R.T., Children's Hospital of Orange County, Orange, CA; Ron Rubenstein, M.D., Maria Skotleski, B.S., Children's Hospital of Philadelphia, Philadelphia, PA; David Orenstein, M.D., Sandy Hurban, R.N., Elizabeth Hartigan, C.R.N.P., Children's Hospital of Pittsburgh, Pittsburgh, PA; William Gershan, M.D., Mary Ellen Freeman, C.R.N.P., Tami Miller, R.N., Children's Hospital of Wisconsin, Milwaukee, WI; Susanna McColley, M.D., Cathy Powers, R.D., Children's Memorial Medical Center, Chicago, IL; Peter Black, M.D., Lora Bear, C.R.N.P., Children's Mercy Hospital, Kansas City, MO; Karen McCoy, M.D., Terri Johnson, R.N., Columbus Children's Hospital, Columbus, OH; Craig Lapin, M.D., Connecticut Children's Medical Center, Hartford, CT; James Cunningham, M.D., Sara Scott, M.A., Cook Children's Medical Center, Fort Worth, TX; William Boyle, Jr., M.D., H. Worth Parker, M.D., Dennis Stokes, M.D., Dartmouth-Hitchcock Medical Center, Lebanon, NH; Thomas Lever, M.D., Rebecca Welch, R.N., Eastern Maine Medical Center, Bangor, ME; Arlene Stencenko, M.D., Carrie Cutchins, R.N., Emory University School of Medicine, Atlanta, GA; Tom Lahiri, M.D., Jackie Swartz, R.N., Fletcher Allen Health Care, Burlington, VT; Peter Scott, M.D., Barbara Crews, C.R.N.P., Georgia Pediatric Pulmonology Associates, Atlanta, GA; Jerrold Eichner, M.D., Laura Hodges, Great Falls Clinic, Great Falls, MT; Mary Passero, M.D., Mike Schechter, M.D., Hasbro Children's Hospital, Providence, RI; W. Stuart Warren, M.D., Melissa McClure, R.N., Hershey Medical Center, Hershey, PA; Morton Schwartzman, M.D., Joe DiMaggio Pulmonary Center, Hollywood, FL; Pamela Zeitlin, M.D., Peter Mogayzel, M.D., Michael Boyle, M.D., Johns Hopkins Hospital, Baltimore, MD; Greg Shay, M.D., Mary Seastrand, R.N., Kaiser Permanente Medical Center, Oakland, CA; Richard Cohen, M.D., Megan Danish, C.R.N.P., Kaiser-Permanente, Portland, OR; Allan Lieberthal, M.D., Joan Franco, R.N., Kaiser-Permanente, Panorama City, CA; Hank Dorkin, M.D., Monica Ulles, C.R.N.P., Massachusetts General Hospital, Boston, MA; Margaret Guill, M.D., Kathy Dyer, R.N., Medical College of Georgia, Augusta, GA; Patrick Flume, M.D., Susan Gray, R.N., Medical University of South Carolina, Charleston, SC; William Richards, M.D., Memphis Lung Physicians, South Haven, MS; Martha Morse, M.D., Julie Garcia, C.R.N.P., Methodist Children's Hospital, San Antonio, TX; Katharine Hale, M.D., Methodist Hospital, Houston, TX; Richard Honicky, M.D., Kathleen King, C.R.N.P., Michigan State University, Lansing, MI; Robert Zanni, M.D., Bridget Marra, R.N., Monmouth Medical Center, Long Branch, NJ; Stanley Fiel, M.D., Paula Lomas, R.N., Morristown Memorial Hospital, Morristown, NJ; Kathryn Moffett, M.D., Linda Baer, R.N., Mountain State CF Center, Morgantown, WV; Col. Joel Schmidt, M.D., Monica Leupold, R.N., National Naval Medical Center, Bethesda, MD; Capt. Henry Wojtczak, M.D., Naval Medical Center San Diego, San Diego, CA; Diana Lowenthal, M.D., Ingrid Gerson, B.S., Madelint Heydendael, R.N., New York Medical College, Valhalla, NY; James Royall, M.D., Oklahoma Health Science Center, Oklahoma City, OK; Chris Landon, M.D., Ann Thompson, R.N., Pediatric Diagnostic Center, Ventura, CA; Roxanne Marcille, M.D., Dan Brown, M.D., Carolyn Turner, R.N., Pediatric Pulmonary Associates, Columbia, SC; Cdr. Reese Lee, M.D., Fletcher Pierce, M.D., Portsmouth Naval Medical Center, Portsmouth, VA; Michael Konstan, M.D., Colette Bucur, R.N., Rainbow Babies and Children's Hospital, Cleveland, OH; Michelle Howenstine, M.D., Mary Blagburn, R.N., Delana Terrill, R.R.T., Riley Children's Hospital, Indianapolis, IN; Anne Devenny, M.B.Ch., Royal Hospital for Sick Children, Yorkhill, Scotland; Lucille Lester, M.D., Rush Presbyterian St. Luke's Medical Center, Chicago, IL; Maria Berdella, M.D., Patricia Walker, M.D., Elinor Langfelder Schwind, M.S., St. Vincent's Hospital and Medical Center, New York, NY; Joan DeCelie-Germana, M.D., Susan Galvin, R.N., Schneider Children's Hospital, New Hyde Park, NY; Louay Nassri, M.D., Janet Austin, R.N., Sparks Regional Medical Center, Fort Smith, AK; Suzanne Beck, M.D., Laurie Varlotta, M.D., Joanne Gambo, C.R.N.P., St. Christopher's Hospital for Children, Philadelphia, PA; Sue Goldfinger, M.D., Lisa Middleton, R.N., St. Mary's Medical Center, West Palm Beach, FL; Thomas Ferkol, M.D., Daniel Rosenbluth, M.D., Mary Boyle, R.N., St. Louis Children's Hospital and the Barnes Jewish Hospital, St. Louis, MO; Peter Holzwarth, M.D., Sumedha Ghate, M.S., St. Vincent Medical Center, Green Bay, WI; Richard Moss, M.D., Zoe Davies, C.R.N.P., Colleen Dunne, R.N., Stanford University Medical Center, Palo Alto, CA; Ran Anbar, M.D., Donna Lindner, R.N., SUNY Pediatric Pulmonary and CF Center, Syracuse, NY; Bradley Chipps, M.D., Kasey Pearson, C.R.N.P., Sutter Medical Center, Sacramento, CA; Joel Ledbetter, M.D., Karen Saranosky, N.P., TC Thompson Children's Hospital, Chattanooga, TN; David Waltz, M.D., Meredith Little, B.S., The Children's Hospital of Boston, Boston, MA; Pierre Vauthy, M.D., Mary Vauthy, N.P., Toledo Children's Hospital, Toledo, OH; Scott Bell, M.D., The Prince Charles Hospital, Brisbane, Queensland, Australia; Raymond Lyrene, M.D., Hector Guitierrez, M.D., Valerie Tarn, R.N., University of Alabama CF Center, Birmingham, AL; Wayne Morgan, M.D., Joanne Douthit, R.N., University of Arizona, Tucson, AZ; Dennis Neilson, M.D., Ph.D., University of California at San Francisco, San Francisco, CA; Terry Spencer, M.D., Lisa Magary, R.N., University of Florida, Gainsville, FL; Richard Ahrens, M.D., Mary Teresi, Pharm.D., University of Iowa Hospitals and Clinics, Iowa City, IA; Gaylin Perry, M.D., Adrienne Liebergen, M.N., A.R.N.P., University of Kansas Medical Center, Kansas City, KS; Jamshed Kanga, M.D., University of Kentucky, Lexington, KY; Brian O'Sullivan, M.D., Rhona Spaulding, C.R.N.P., University of Massachusetts Medical School, Worcester, MA; Samya Nasr, M.D., Dawn Kruse, University of Michigan, Ann Arbor, MI; Carlos Milla, M.D., Brooke Noren, R.N., University of Minnesota, Minneapolis, MN; Lynn Walker, M.D., Kim Adcock, Pharm.D., University of Mississippi Medical Center, Jackson, MS; John Colombo, M.D., Peter Murphy, M.D., Dee Acquazino, R.N., University of Nebraska, Omaha, NE; Elizabeth Perkett, M.D., Kyria Ramey, C.R.N.P., University of New Mexico Health Sciences Center, Albuquerque, NM; George Retsch-Bogart, M.D., Michael Knowles, M.D., Sally Wood, B.S., University of North Carolina at Chapel Hill, Chapel Hill, NC; David Lipson, M.D., Marianne Ferrin, C.R.N.P., University of Pennsylvania Adult CF Center, Philadelphia, PA; Richard Boswell, M.D., University of Tennessee, Memphis, TN; Rodolfo Amaro-Galvez, M.D., Bettina Hillman, M.D., University of Texas Health Center, Tyler, TX; Barbara Chatfield, M.D., Sue Griffiths, R.N., University of Utah, Salt Lake City, UT; Deborah Froh, M.D., Lauren Ahrens, R.N., University of Virginia Health System, Charlottesville, VA; Michael Rock, M.D., Linda Makholm, M.T., University of Wisconsin Hospital, Madison, WI; Tom Hazinski, M.D., Stephanie Rushing, R.N., Vanderbilt University Medical Center, Nashville, TN; Bruce Rubin, M.D., Wake Forest University, Baptist Medical Center, Winston-Salem, NC; Hugh Black, M.D., William Ashe, M.D., Western Carolina CF Center, Charlotte, NC; Maria Riva, M.D., David Doornbos, M.D., Janet Messamore, R.N., Wichita Clinic, PA, Wichita, KS; Andrew Lipton, M.D., Wilford Hall Medical Center, San Antonio, TX; Marie Egan, M.D., Tina Tolomeo, R.N., Yale University, New Haven, CT.