We found that growth-faltering was common in urban, largely minority, underserved pediatric practices. Only 8% of the children with growth-faltering received subspecialist care (endocrinology or gastroenterology). It was notable that, compared with non-Hispanic white children, the black children were less likely to see a subspecialist, particularly an endocrinologist. Thus, the majority of children with growth-faltering were managed by their primary care pediatricians. Thyroid-function testing was the most frequently obtained endocrine-related diagnostic test. Pediatricians ordered GH/IGF axis tests twice as frequently for short boys than for short girls and chromosome testing for only 1.4% of the short girls.
A significant gender disparity was found in the proportion of growth-faltering children whose pediatricians ordered GH/IGF axis testing; the rate for boys was double that for girls. Both the children receiving GH/IGF testing and those with endocrine appointments tended to be older than the rest of the growth-faltering population. Taken together, these findings suggest that diagnosis of GH deficiency can be delayed or missed, especially among girls. Prompt diagnosis is needed for the timely initiation of GH therapy, which is critical for final height outcome.10
The importance of GH for cardiovascular,11
health is evident even in the pediatric population and supports the need for timely diagnosis and treatment.
The greater frequency of chromosome testing for girls relative to boys with growth-faltering was expected; Turner syndrome is a genetic condition that occurs in girls only and leads to a reduction in mean final height of 13 to 19 cm relative to the unaffected local female population.16,17
However, chromosome testing was obtained for only 1.4% of the growth-faltering girls, and 35% of these girls were at least 12 years old. These results concur with those of a review from the Turner Syndrome Clinic at the University of North Carolina. Short stature was found to be the key to diagnosis in childhood and adolescence; despite the salience of gonadal dysgenesis as a characteristic feature of this syndrome, no diagnosis was made on the basis of delayed puberty alone. Nonetheless, for the girls at the University of North Carolina Turner Syndrome Clinic, the mean delay to diagnosis after their height had fallen to below the 5th percentile was still 5.2 years.18
Even if we were to multiply 1.4% by a factor of 6 (our 3-year window of observation is one-sixth of the 18 years of pediatric care), 8.4% still falls far short of current recommendations to test chromosomes for every girl with unexplained growth failure to improve the timely diagnosis and medical care of Turner syndrome.18,–21
Timely diagnosis is important for the initiation of proper monitoring and treatment of syndrome-associated complications such as renal and cardiac congenital malformations, neurosensory hearing loss, and neurocognitive issues.22,23
Ongoing surveillance for patients with Turner syndrome is needed, even for those without congenital heart disease, because of the increased incidence of life-threatening aortic dissection.19,21,23,–27
The overall standardized mortality ratio for women with Turner syndrome was calculated as 2.86 (95% confidence interval: 2.18–3.55).24
Thus, preventive measures such as more aggressive management of hypertension (also an associated feature of Turner syndrome), avoidance of vigorous isometric exercise, and monitoring for aortic dilation have been recommended for women with Turner syndrome to prevent dissection.21,23
Similar to GH deficiency, delayed diagnosis of Turner syndrome limits the effectiveness of GH therapy in improving adult height.28
Although it is undesirable to do so, pediatric endocrinologists often compensate for late diagnoses by withholding estrogen replacement and epiphyseal closure for several years to increase the time for GH therapy to have an effect. Thus, to compound the psychosocial stress of dealing with the new diagnosis, these girls and their parents are presented with the dilemma of choosing between increased adult height and timely pubertal development. The growing appreciation for the need for age-appropriate sex hormone production for bone health29
adds to the adverse consequences of a late diagnosis of Turner syndrome. Turner syndrome is a known risk for osteoporosis, and low cortical bone mineral density is apparent even before puberty in these girls.27
However, when Turner syndrome is diagnosed at younger ages, GH therapy can lead to normal adult height with timely initiation of estrogen replacement.30,31
Thus, it is particularly concerning that 35% of the girls with growth-faltering and chromosome testing in our study were already at least 12 years old.
There are several limitations to our study. First, the frequencies of diagnostic testing and subspecialist evaluations were likely underestimates, because our population was followed longitudinally for 3 years, not their entire childhood. However, because all ages from 6 months to 20 years were represented without selection, it would be expected to produce a proportionate sampling of the entire frequencies. Second, although the majority of children in these primary care practices obtain subspecialist care within the same pediatric network, data of those who sought subspecialists at other institutions were not captured. These missed subspecialist appointments were not expected to be skewed along race or gender characteristics.
The converse limitation also holds and is important when comparing these results to those from analyses of children who were seeking short-stature evaluation in our endocrinology clinic.1
Our endocrinology clinic received referrals from all 33 primary care practices within our pediatric network as well as nonaffiliated regional and national pediatric and family care practices. The pediatric network spans 3 states in the Delaware Valley and represents racially and socioeconomically heterogeneous populations. Because of the temporal sequence by which the primary care practices adopted the electronic health records system, 3-year longitudinal data were available only for 4 urban, predominantly black and Medicaid-insured practices. The excess of boys seen among the predominantly white children who received short-stature evaluations in our endocrine clinic1
was not evident among the children who were receiving endocrine care in this current study. However, a significant racial disparity was found: there was an underrepresentation of black children among those with growth-faltering who saw an endocrinologist. Thus, to further examine the interactions between race, insurance, and gender among children who received subspecialty endocrine care for growth-faltering, additional studies comparing urban to nonurban, predominantly white, privately insured primary care practices is planned as sufficient electronic longitudinal data become available.