The Healthy Short Child: How Much Testing?

William T. Basco, Jr., MD, MS

November 26, 2013

Low Incidence of Pathology Detection and High Cost of Screening in the Evaluation of Asymptomatic Short Children

Sisley S, Trujillo MV, Khoury J, Backeljauw P
J Pediatr. 2013;163:1045-1051

Study Summary

Guidelines published in 2008^[1] suggest a standard panel of screening laboratory and radiologic tests for all patients with short stature (< 2 SD below the mean) if the patient's history and physical examination do not identify a specific diagnosis. The recommended tests include the following:

• Complete blood count;
• Basic metabolic panel;
• Erythrocyte sedimentation rate;
• Calcium and phosphorus levels;
• Serum albumin level;
• Alkaline phosphatase level;
• Tissue transglutaminase level;
• Immunoglobulin A assessment;
• Growth factor profile;
• Thyroid tests;
• Karyotype (for girls); and
• Bone age.

The current study was conducted to identify how often the recommended screening procedure identifies a pathologic diagnosis. The researchers added a cost analysis to their investigation.

The study involved a cohort of children who were referred for short stature to a single pediatric endocrinology clinic during 2008-2011. Children were included if their height was < 3rd percentile; previous height velocity was < 5 cm/yr; and if no diagnosis could be made after history, review of systems, and physical examination.

Ultimately, the researchers identified 235 children for analysis. In addition to body measurement data, data on parental stature, and typical clinical data, they evaluated the yield of the screening tests recommended in the 2008 guidelines.

Study Findings

Of the 235 children, 72.8% were boys, and the mean age of referral was 10 years. Tanner stage I pubertal development was exhibited at the time of the first evaluation of 60.6% of the children, and 24.9% exhibited Tanner stage II. The average height SD was -2.5.

Three (1.3%) of the children in the study were identified as having short stature due to a pathologic diagnosis. One child had confirmed celiac disease, another child had a possible insulin-like growth factor-1 receptor defect, and the third had an abnormal tissue transglutaminase level that could not be confirmed.

Among the 232 children who did not have a pathologic diagnosis, 36% were diagnosed with idiopathic short stature. Another 41% were diagnosed with constitutional growth delay and 23% with familial short stature.

Among all of the children, the average percentage of recommended tests completed was 64.3%, with the average cost of testing amounting to $1341 for each patient. This resulted in a cost of $105,000 per pathologic diagnosis identified. If the patients had completed all of the recommended testing, the cost would have averaged $2385 per patient.

The investigators concluded that healthy children with short stature do not warrant broad screening, and they instead urge moving toward an approach that is patient-specific.

Viewpoint

The value of this report for general pediatric providers is to remind us of the short stature screening that can be completed in the primary care setting. In an accompanying editorial,^[2] Dr. Rogol argues that the primary care provider and his or her long-term knowledge of the patient may be the best test for identifying a cause of short stature. However, both the study authors and the editorialist suggest that the menu of screening laboratory tests should be shortened on the basis of the child's history.

I would bet that the data to help us accomplish that are available, although they are probably isolated in individual pediatric endocrine clinics across the country. If these data could be pooled, it would be a relatively simple (but admittedly time-consuming) analytic effort to identify which of these suggested screening laboratory tests have the highest overall yield, and even prioritize them according to the presenting scenario. For example, do the highest yield tests vary by the age of the patient? Or do tests have different yields if the parents are of normal vs short stature?