Improving Accuracy of Linear Growth Measurements

A survey study of pediatric and family primary care practices in 8 areas of the United States found that 70% employed inaccurate techniques for measuring children.¹ As follow-up, Lipman et al analyzed the effectiveness of an intervention aimed at improving the accuracy of linear growth measurements. From the 259 prior practice responders, 8 per geographic area were randomly recruited and divided into intervention and control arms of the trial of 55 practices (44 pediatric and 11 family practice). Practices cared for an average of 4000 children, and employed an average of 3.6 staff responsible for the measurements (21% RNs, 23% LPNs, 56% nurses’ aides/medical assistants) with an average of 8.2 years experience. At baseline, correct overall measurement technique was demonstrated on 30% of measurements. Proper equipment was used in 58% of standing measured children and in 18% of recumbently measured children. The measurements differed by an average of 1.2 cm within the same child by study staff (differences ranged up to 12.1 cm). The intervention group received: a written pre-test of knowledge of growth measurement, a slide presentation and handouts on both proper measuring techniques and the physiology/pathophysiology of growth disorders, the installation of accurate measuring equipment and demonstration (plus return demonstration) on the correct measurement of height and length, and a written post-test assessment. The control group received no intervention.  Measurement techniques were re-evaluated after 3 and 6 months in both groups. Accurate measurement in the control group remained at 37% at 3 months and 34% at 6 months. The intervention group increased the accuracy of the measurements to 55% at 3 months and 70% at 6 months. At conclusion, the intervention group’s mean difference in measurement from study staff decreased to 0.5 cm.

Lipman TH, Hench KD, Benyi T, et al. A multicentre randomised controlled trial of an intervention to improve the accuracy of linear growth measurement. Arch Dis Child. 2004; 89:342–346.

Editor’s Comment: Growth is the single most important indication of a child’s health.² Growth monitoring is an integral part of pediatric care. The American Academy of Pediatrics has recommended that height and weight be measured at least at birth; age 2–4 days; 1, 2, 4, 6, 9, 12, 15, 18 and 24 months; and yearly through age 21.³ It is disheartening that Lipman et al found high prevalence of incorrect techniques among pediatric and family practices. Even more disheartening is that 10% of pediatric practices and 40% of family practices did not measure children at every well-child visit.¹ This is a worldwide problem with a lack of equipment or trained personnel, inaccurate plotting and misunderstanding of the reference curves.⁴ Likewise, a study of an academic pediatric clinic found that 35% of well-child encounters failed to plot growth measurements and/or document a growth abnormality.⁵ This study demonstrated that an intervention program can effectively improve the accuracy of growth measurement in clinical practices, and that the improvement increased with time. Thus, rather than forgetting the lessons learned, continued use of proper technique and proper equipment reinforced and improved performance. The most common reason for practices refusing to participate in this interventional study was “provider unwillingness due to low importance assigned to linear measurements.”  The importance of proper technique and equipment cannot be overemphasized as lack of these may lead to missed or delayed recognition of growth failure or can lead to unnecessary investigation and specialist referrals. As the authors pointed out, the current average inaccuracy exceeds the difference between the defined cut-offs for normal and abnormal growth velocities. (See Online Resources at www.GGHjournal.com for links to growth charts.)

http://gghjournal.com/resources.cfm

http://www.cdc.gov/growthcharts/

Adda Grimberg, MD

References - (linked to )

1. Lipman TH, Hench K, Logan JD, DeFazio DA, Hale PM, Singer-Granick C. J Pediatr Health Care. 2000;14:166–171.
2. Tanner JM. Clin Endocrinol Metab. 1986;15:411–451.
3. American Academy of Pediatrics Policy Statement - Committee on Practice and Ambulatory Medicine. Recommendations for Preventative Pediatric Health Care. Pediatr. 2000;105:645.
4. de Onis M, Wijnhoven TM, Onyango AW. J Pediatr. 2004; 144:461–465.
5. Chen RS, Shiffman RN. Clin Pediatr. 2000;39:97–102.