R ESEARCH A RTICLE Reliability of Height and Weight Measurements Collected by Physical Education Teachers for a School-Based Body Mass Index Surveillance and Screening System STEPHANIE S. BERKSON, PhD, MPH a JANICE ESPINOLA, MPH b KATHERINE A. CORSO, MPH c HOWARD CABRAL, PhD, MPH d ROBERT MCGOWAN, EdD e VIRGINIA R. CHOMITZ, PhD f ABSTRACT BACKGROUND: To address the obesity epidemic among children and youth, school-based body mass index (BMI) screening and surveillance is proposed or mandated in 30 states. In Cambridge, MA, physical education (PE) teachers are responsible for these measurements. This research reports the reliability of height and weight measures collected by these PE teachers. METHODS: Using Bland-Altman plots, mean absolute differences, and intraclass correlation coefficients (ICC), we estimated intra- and inter-rater reliability among PE teachers in a controlled setting and PE teacher-vs-expert inter-rater reliability in a natural classroom setting. We also qualitatively assessed barriers to reliability. RESULTS: For the controlled setting, of 150 measurements, 3 height (2.0%) and 2 weight (1.33%) measurement outliers were detected; intra-rater mean absolute differences for height/weight were 0.52 inches (SD 1.61) and 0.8 lbs (SD 3.2); intra- and inter-rater height/weight ICCs were ≥0.96. For the natural setting, of 105 measurements, 1 weight measurement outlier (0.9%) was detected; PE teacher-vs-expert-rater mean absolute differences for height/weight were 0.22 inches (SD 0.21) and 0.7 lbs (SD 0.8), and ICCs were both 0.99. Equipment deficiencies, data recording issues, and lack of students’ preparation were identified as challenges to collecting reliable measurements. CONCLUSION: According to ICC criteria, reliability of PE teachers’ measurements was ‘‘excellent.’’ However, the criteria for mean absolute differences were not consistently met. Results highlight the importance of staff training and data cleaning. Keywords: growth and development; obesity; school health services; public health; child and adolescent health. Citation: Berkson SS, Espinola J, Corso KA, Cabral H, McGowan R, Chomitz VR. Reliability of height and weight measurements collected by physical education teachers for a school-based body mass index surveillance and screening system. J Sch Health. 2013; 83: 21-27. Received on September 17, 2011 Accepted on March 4, 2012 T he prevalence of childhood and adolescent obesity increased at alarming rates during the 1980s and 1990s and continued to stay high during the first decade of the 21st century. 1,2 These trends threaten to diminish the health and life expectancy of current and future generations. 2 The Institute of Medicine and the American Academy of Pediatrics recommend the routine tracking of body mass index (BMI) in all children and adolescents as an obesity a Lecturer, (sshapi5@uic.edu), University of Illinois at Chicago, School of Public Health, Community Health Sciences, Institute for Community Health, 70 E. Brookline Street #3, Boston, MA 02118. b Epidemiologist/Biostatistician, (espinola@helix.mgh.harvard.edu), Massachusetts General Hospital, Emergency Medicine, 326 Cambridge Street, Suite 410, Boston, MA 02114. c Project Manager, (katherine_corso@rocketmail.com), Brigham and Women’s Hospital, Center for Surgery and Public Health, Department of Surgery, 75 Francis Street, Boston, MA 02115. prevention strategy. 3 School-based BMI surveillance and screening are approaches used to fulfill this recommendation. BMI surveillance in public schools is intended to assess childhood obesity in a population, whereas BMI screening is intended to detect those at risk for weight-related health problems (for further clinical assessment) and to provide families with personalized health information about their child. 4 Starting with Arkansas in 2003, states have Journal of School Health • January 2013, Vol. 83, No. 1 •  2013, American School Health Association • 21