Continuous glucose monitoring (CGM) has been demonstrated in randomized trials to improve glucose control in patients with type 1 diabetes (1), but until recently only a minority of participants in the German/Austrian Diabetes Patienten Verlaufsdokumentation (DPV) registry and the U.S.-based T1D Exchange (T1DX) registry were using CGM (2,3).
Over the past decade, both the accuracy and usability of CGM devices have improved considerably with expanded cost coverage of CGM by government statutory and private insurance. Some CGM devices are regulatory body approved for determining insulin dose in most circumstances, thereby reducing the number of fingersticks needed to monitor blood glucose. To assess change in CGM use over time across the age spectrum, we analyzed data from the T1DX and DPV registries for the years 2011, 2013, 2015, and 2017.
CGM use (including both real-time and intermittent scanning CGM) at each data collection time point were obtained from clinic medical records. The number of participants with available data on CGM usage varied slightly depending on the calendar year for both registries. In DPV, the cohort size ranged from 17,632 to 21,707 for youth (aged 2 to <18 years) and from 7,651 to 8,390 for adults aged (≥18 years). In T1DX, cohort size ranged from 8,334 to 9,184 for youth and from 7,717 to 9,759 for adults.
For T1DX, CGM use increased from 2011 to 2017 in all age-groups, with the most pronounced change occurring in the youngest patients. For DPV, CGM use increased in all youth age-groups, but there was no change among DPV adults except in the youngest group aged 18 to 26 years (Fig. 1). For youth in the DPV registry, CGM use remained steady from 2011 to 2015 with a dramatic increase from 4% to 44% occurring between years 2015 and 2017, whereas for T1DX youth, CGM use increased from 4% in 2013 to 14% in 2015 and to 31% in 2017. Among adults in the DPV registry, a dramatic increase in CGM occurred from 4% in 2015 to 30% in 2017 for individuals aged 18 to <26 years, with all other adult age-groups maintaining stable CGM usage rates at around 8% to 12%. For T1DX adults, CGM use increased steadily from 2013 to 2017 across age-groups, with a slightly higher rate of increase in younger adults. Despite the higher rate of increase (4% in 2011 to 24% in 2017), young adults had the lowest percentage of CGM use in T1DX by 2017.
Figure 1.
A: DPV and T1D Exchange pediatric (Peds) CGM use. The solid black line with solid black squares represents the cohort aged <6 years. The dotted black line with solid black diamonds represents the cohort aged 6 to <13 years. The dashed black line with solid black triangles represents the cohort aged 13 to <18 years. B: DPV and T1D Exchange adult CGM use. The solid black line with solid black squares represents the cohort aged 18 to <26 years. The dotted line with solid black diamonds represents the cohort aged 26 to <50 years. The dashed black line with solid black circles represents the cohort aged 50 to <65 years. The dashed black line with solid black triangles represents the cohort aged ≥65 years.
CGM use among youth in both registries increased from 2011 to 2017 regardless of sex, insulin delivery method, or minority status. Among DPV youth using injections for insulin delivery, CGM use increased from 3% to 35% compared with 5% to 50% among pump users. Among T1DX youth, CGM use increased from 1% to 13% among injection users and from 5% to 40% among pump users. For T1DX adults, an increase in CGM use from 2011 to 2017 was observed in both injection users (5% to 16%) and pump users (15% to 41%), with a higher rate in pump versus injection. For DPV, the pattern of CGM use over time stratified by insulin delivery method mimicked the overall cohort with minimal differences between injection users (8% to 18%) and pump users (10% to 26%).
It is important to use caution when interpreting the CGM use frequencies reported here. The T1DX registry is not population based and represents patients from specialized endocrinology clinics in the U.S.; therefore, the frequency of CGM use in the general population of patients with type 1 diabetes is likely lower than that observed for this cohort. The DPV registry is population based for the pediatric cohort and is therefore representative of CGM use for youth in Germany and Austria; however, the adult cohort covers only about 30% of the entire type 1 diabetes population.
The observed increase in CGM use over time is likely reflective of changes in insurance coverage and improvements in device technology, patient acceptability, and availability within nations. Of note, for the year 2017, CGM use in the T1DX was primarily real-time CGM (>98%), whereas CGM in the DPV was primarily intermittent scanning CGM (>80%).
These data document a significant increase in CGM use in people with type 1 diabetes in both the T1DX and DPV registries that has clinical implications for standardizing review of CGM data and delivering care in clinical practice and the future use of automated insulin delivery systems.
Article Information
Funding. The T1D Exchange is supported through The Leona M. and Harry B. Helmsley Charitable Trust. The DPV is supported through the German Center for Diabetes Research (DZD), which is funded by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung).
Duality of Interest. No potential conflicts of interest relevant to this article were reported.
Author Contributions. K.M.M. researched data and wrote and edited the manuscript. J.H. performed statistical analysis and wrote and edited the manuscript. N.F., S.E.H., M.R.R., T.D., M.A.C., E.L., D.M.M., and R.W.H. researched data, contributed to discussion, and reviewed and edited the manuscript. K.M.M. and J.H. are the guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Footnotes
This article is part of a special article collection available at http://care.diabetesjournals.org/collection/cgm-for-type1-diabetes.
Contributor Information
Collaborators: T1D Exchange Clinic Network, Ruth Weinstock, Roberto Izquierdo, Umair Sheikh, Patricia Conboy, Jane Bulger, Suzan Bzdick, Georgeanna Klingensmith, Carolyn Banion, Jennifer Barker, Cindy Cain, Kristen Nadeau, Marian Rewers, Arleta Rewers, Robert Slover, Andrea Steck, Paul Wadwa, Philip Zeitler, Guy Alonso, Greg Forlenza, Andrea Gerard-Gonzalez, Melanie Green, Susan Gross, Shideh Majidi, Laurel Messer, Tyler Reznick-Lipina, Emily Simmons, Katie Thivener, Isabel Weber, Steven Willi, Terri Lipman, Olena Kucheruk, Pantea Minnock, Cathy Carchidi, Brian Grant, Diana Olivos, Linda DiMeglio, Tamara Hannon, Carmella Evans-Molina, David Hansen, Tina Pottorff, Stephanie Woerner, Megan Hildinger, Robin Hufferd, America Newnum, Devyn Purtlebaugh, Lisa Smith, Kathleen Wendholt, Robin Goland, Rachelle Gandica, Kristen Williams, Sarah Pollack, Emily Casciano, Julia Hochberg, Cecilia Uche, Joyce Lee, Brigid Gregg, Meng Tan, Lynn Ang, Rodica Pop-Busui, Inas Thomas, Emily Dhadphale, Janet Dominowski, Ashley Garrity, Virginia Leone, Cynthia Plunkett, Brittany Plunkett, Roshanak Monzavi, Clement Cheung, Lynda Fisher, Mimi Kim, Brian Miyazaki, Pisit Pitukcheewanont, Anna Sandstrom, Juliana Austin, Nancy Change, Jennifer Raymond, Brian Ichihara, Megan Lipton, Jaquelin Flores Garcia, Satish Garg, Aaron Michels, Rachel Garcetti, Melanie Green, Raymond Gutin, Kristen Nadeau, Sarit Polsky, Viral Shah, Mary Voelmle, Lisa Myers, Gregory Coe, Jamie Demmitt, Yesenia Garcia Reyes, Dominique Giordano, Prakriti Joshee, Emily Nease, Nhung Nguyen, Joseph Wolfsdorf, Maryanne Quinn, Constance Fontanet, Susmita Mukherjee, Kathleen Bethin, Teresa Quattrin, Indrajit Majumdar, Lucy Mastrandrea, Emily Gorman, Amanda House, Sharon Michalovic, Wanda Musial, Barbara Shine, Andrew Ahmann, Jessica Castle, Farahnaz Joarder, Diana Aby-Daniel, Ines Guttmann-Bauman, Bethany Klopfenstein, Victoria Morimoto, Nancy Cady, Rebecca Fitch, Donald DeFrang, Kristin Jahnke, Claire Patoine, Vandana Raman, Carol Foster, Mary Murray, Trina Brown, Cassandra Davis, Hillarie Slater, Jennifer Langvardt, Bruce Bode, Jennifer Boyd, Joseph Johnson, Christopher Newton, Jonathan Ownby, RaShonda Hosey, Nitin Rastogi, Blake Winslett, Irl Hirsch, Anthony DeSantis, R Alan Failor, Carla Greenbaum, Dace Trence, Subbulaxmi Trikudanathan, Dori Khakpour, Pam Thomson, Lori Sameshima, Corinna Tordillos, Mark Clements, Angela Turpin, Ghufran Babar, Julia Broussard, Joe Cernich, Kavitha Dileepan, Max Feldt, Wayne Moore, Tiffany Musick, Susana Patton, Yun Yan, Sarah Tsai, Jennifer Bedard, Aliza Elrod, Lois Hester, Marissa Beidelschies, Julie de la Garza, Emily Haith, Jennifer James, Elizabeth Ramey, Jessica Slover, Armenthia Valentine, Darta Watkins, Misty Whisenhunt, Jami Wierson, Darrell Wilson, Bruce Buckingham, David Maahs, Priya Prahalad, Liana Hsu, Ryan Kingman, Ideen Tabatabai, David Liljenquist, Mark Sulik, Carl Vance, Jean Halford, Christine Funke, Yaw Appiagyei-Dankah, Emily Beltz, Karen Moran, Harold Starkman, Barbara Cerame, Daisy Chin, Laurie Ebner-Lyon, Kristen Sabanosh, Lawrence Silverman, Christine Wagner, Sunita Cheruvu, Marie Fox, Frances Melchionne, Richard Bergenstal, Marcia Madden, Thomas Martens, Amy Criego, Margaret Powers, Anders Carlson, Shannon Beasley, Beth Olson, LeeAnn Thomas, Kathleen McCann, Sean Dunnigan, Charlotte Ashanti, Jill Simmons, William Russell, Sarah Jaser, Jennifer Kelley, Faith Brendle, Lauren Williams, Kimberly Savin, Kimberly Flowers, George Williams, Emily Hamburger, Angelia Davis, Brenna Hammel, Eda Cengiz, William Tamborlane, Kate Weyman, Michelle Van Name, Neha Patel, Jennifer Sherr, Eileen Tichy, Amy Steffen, Melinda Zgorski, Lori Carria, Jennifer Finnegan, Elvira Duran, Sanjeev Mehta, Michelle Katz, Lori Laffel, Elisa Giani, Rebecca Snelgrove, Anat Hanono, Persis Commissariat, Julie Griffith, Ashley Atkins, Kara Harrington, Kenny Kim, Luisa Masclans, Nisha Naik, Louise Ambler-Osborn, Alan Schultz, Charlotte Cohen, Brittany Anderson, Janet McGill, Andrea Granados, Mary Jane Clifton, Stacy Hurst, Sarah Kissel, Carol Recklein, Davida Kruger, Arti Bhan, Terri Brown, Andreana Tassopoulos, Angela Hailey, Heather Remtema, Terra Cushman, Kupper Wintergerst, Sara Watson, Suzanne Kingery, Lauren Rayborn, Heather Rush, Michael Foster, Amy Deuser, Manuel Rodriguez-Luna, Stephanie Eubanks, Henry Rodriguez, Sureka Bollepalli, Laura Smith, Dorothy Shulman, E. Verena Jorgensen, Emily Eyth, Rachel Brownstein, Janet Rodriguez, Juanita O’Bria, Grazia Aleppo-Kacmarek, Allison Hahr, Mark Molitch, El Muayed, Daniel Toft, Candice Fulkerson, Daphne Adelman, Elaine Massaro, Kimberly Webb, Anne Peters, Valerie Ruelas, Mark Harmel, Mark Daniels, Nikta Forghani, Timothy Flannery, Christina Reh, Amrit Bhangoo, Himala Kashmiri, Keirsten Montgomery, Lien Trinh, Heather Speer, Kristen Lane, Richard Bergenstal, Thomas Martens, Marcia Madden, Margaret Powers, Amy Criego, Andes Carlson, Beth Olson, Shannon Beasley, Kathleen McCann, LeeAnn Thomas, Cassie Miller, Charlotte Ashanti, Christine Burt Solorzano, Jennifer Puskaric, Robert Benjamin, Deanna Adkins, Amber Spruill, Cathy Williams, Eva Tsalikian, Michael Tansey, Nidhi Bansl, Joanne Cabbage, Julie Coffey, Desmond Schatz, Michael Clare-Salzler, Kenneth Cusi, Becky Fudge, Mike Haller, Collette Meehan, Henry Rohrs, Janet Silverstein, Ashby Walker, Anastasia Albanese-O’Niell, Stephanie Foss, Janey Adams, Miriam Cintron, Nicole Thomas, Michael Gottschalk, Ron Newfield, Marla Hashiguchi, David Sparling, Jeanie Tryggested, Joni Beck, Joane Less, Linda Weber, Saleh Adi, Stephen Gitelman, Srinath Sanda, Jenise Wong, Mary McDonnell, Monica Mueller, Zara Izadi, Swaroop Mistry, Bryce Nelson, Lisa Looper, Carrie Frost, Maria Redondo, Sarah Lyons, Sara Klinepeter, Kelly Fegan-Bohm, Fida Bacha, Daniel DeSalvo, Ashley Butler, Marisa Hilliard, Farida Khetani, Ronald Yulatic, Robert Hudson, Laura Irvine, Sadia Zubair, Cory Pace, Abelin Pitrello, Wendy Levy, Charity Njoku, William Zipf, Jennifer Dyer, Rolando Lozano, Diane Seiple, Grant Corven, Megan Jaycox, Jamie Wood, Sarah Macleish, Rose Gubitosi-Klug, Ramon Adams, Paul McGuigan, Terri Casey, Wendy Campbell, Julie Kittelsrud, Ashutosh Gupta, Vikki Peterson, Ingrid Libman, Ana Diaz, David Jelley, Christina Crowder, Dana Greer, Julia Crawford, Sharnella Goudeau, Catherine Pihoker, Joyce Yi-Frazier, Susan Kearns, Michael Pascual, Beth Loots, Natalie Beauregard, Michael Rickels, Shannon O’Brien, Shivani Agarwal, Amy Peleckis, Cornelia Dalton-Bakes, Eileen Markmann, Guillermo Umpierrez, Andrew Muir, Clementina Ramos, Keywan Behbahani, Neil Dhruv, Nolan Gartzman, Brandon Nathan, Melena Bellin, Muna Sunni, Nancy Flaherty, Janice Leschyshyn, Kara Schmid, Darcy Weingartner, Marrissa Ludwig, Brittney Nelson, Anne Kogler, Avery Bartyzal, Anne Street, Beth Pappenfus, Jessica Sweet, John Buse, Laura Young, Katherine Bergamo, April Goley, Marian Kirkman, Jamie Diner, Alex Kass, Milana Dezube, Kathleen Arnold, Traci Evans, Sharon Sellers, Scott Blackman, Kimber-Lee Abel, Lisa Rasbach, Omar Ali, Peter Wolfgram, Rosanna Fiallo-Sharer, Joanna Kramer, Christina Beesley, Clare Bingham-Tyson, Rachel Unteutsh, David Harlan, Mary Lee, Leslie Soyka, Penny Feldman, Michael Thompson, Karen Gallagher-Dorval, Lisa Hubacz, Celia Hartigan, Carol Ciccarelli, Rachel Edelen, Michelle Edelen, Trista Borgwadt, Kirstin Stauffacher, Kelly DeGrote, Crystal Gruetzmacher, Michael Shepperd, Anuj Bhargava, Diana Wright, Kathleen Fitzgerald, Teck Khoo, Natalie Young, Lisa Borg, Kirstie Stifel, Cindy Rail, Luis Casas, Elizabeth Eidenshink, Christina Huber, Alex Rieder, Amy Tuchscherer, Megan Broadbent, Lawrence Dolan, Sarah Corathers, Jessica Kichler, Nicole Sheanon, Holly Baugh, Debbie Standiford, Tammy Weis, Catherine Fox, Carrie Schultz, Amy Ritter, Francesco Vendrame, Carlos Blashke, Della Matheson, Natalia Sanders-Branca, Justen Rudolph, Doris Biersdorf, Jane Fitch-Danielson, Dara Eckerle-Mize, Faith Brendle, Janet Fry, Dianne Davis, Cynthia Lovell, Brenna Hammel, Lauren Williams, Robert Hoffman, Monika Chaudhari, Manmohan Kamboj, Lindsey Carr, Luis Casas, Julie Blehm, Anthony Tello, Julie Ann Walter, Rhonda Ward, Megan Broadbent, Gabriel Blomquist, Maria Stewart, Paige Cross, Sarah Racki, Lindsey Sterchi, Diane Gouine, Becky Kiesow, Stephanie Welch, Athena Philis-Tsimikas, George Daily, Amy Chang, James McCallum, Isabel Garcia, Teresa Vela, Ioanna Loupasi, Rosario Rosal, Elena Toschi, Roeland Middelbeek, Medha Munshi, Christine Slyne, Astrid Atakov-Castillo, Larry Fox, Nelly Mauras, Rachel Wasserman, Ligeia Damaso, Kim Englert, Kaitlin Sikes, Kim Ponthieux, Louis Phillipson, Ashley Cohen, Gail Gannon, Larry Deeb, April Shiver, Leroy Schroeder, Wendi Schworm, Kristina Graham, Carol Levy, David Lam, Elizabeth Burtman, Camilla Levister, Selassie Ogyaadu, Heidi Gassner, Julie Duke, Leslie Touger, Dorothee Newbern, Francine Hoekstra, Katerina Harwood, Vijaya Prasad, JoAnne Daguanno, Richard Pratley, Karen Corbin, Mia Wright, Susann Nagel, Natasha Water, Matthew Ghere, Keri Whitaker, Rubina Heptulla, Ranjitha Katikaneni, Doreen Johnson-Newell, Jill Crandall, Danielle Powell, Valentin Anghel, Steven Ghanny, Javier Aisenberg, Amy Chartoff, Jennifer Sivitz, Susan Mathus, Toni-Lyn Cospito, Kathryn Thailkill, John Fowlkes, Evangelia Kalaitzoglou, Alba Morales Pozzo, and Kathy Edwards
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