Early diagnosis and specialist care in the management of congenital hypothyroidism

ABSTRACT

Background. Newborn screening for congenital hypothyroidism (CH) in the Philippines was introduced in 1996. It is universally accepted that early detection through newborn screening and timely treatment can improve the physical and neuro-cognitive development of patients. As of December 2010, the prevalence of CH is 1 in 3,324 among 2,389,959 newborns screened. Objective. We sought to evaluate the role of timing of diagnosis, compliance with treatment, and specialist care on growth and development (mental and physical) of patients with congenital hypothyroidism detected through newborn screening. Methods. Of the 326 patients identified through newborn screening between July 1996-December 2008 at the Newborn Screening Center-National Institutes of Health, 86 patients participated in the study. With the parents' or guardians' consent, general physical examination and neuro-cognitive evaluation were done; FT4 and TSH were determined. Prevalence of poor control of disease (high TSH with normal or low FT4 or normal TSH with low FT4), stunting, and cognitive delay were each estimated at 95% confidence level and the associations of early diagnosis, initial and continuing specialist care with these conditions were determined by multiple logistic regression analyses. Results. The prevalences (95% confidence interval) were poor control of disease 63% (52-73%), stunting 24% (15-34%) and neuro-developmental delay 17% (8-25%). Delay in one aspect of neuro-development was seen in 54% (43-66%). Early diagnosis was protective against poor control of disease (adjusted Odds Ratio, ORa=0.24 [CI 0.08-0.77]). Trends towards protection were seen for initial and continuing specialist care. For delay in at least one cognetive aspect, early diagnosis was found to be protective (ORa=0.19 [CI 0.05-0.76]); results for specialist care were inconclusive. For stunting, low parent education was found to be a risk factor. (ORa of 5.45 [CI 1.3-22.7]). Conclusion. Fifty-four percent of the study patients had delay in one aspect of neuro-development. While other factors play a role in the outcome of CH, early diagnosis and treatment were shown to be protective of patients from poor control of disease and cognitive delays. Observed trends of positive benefits of specialist care at onset and continuing medical management, and the association of low parent education with poor growth should be considered in drafting specific guidelines for the long term follow-up care and monitoring of CH patients detected through newborn screening. The low percentage of participation and incomplete retrieval of information are major limitations of this retrospective study. This stresses the need for better monitoring tools that will ensure proper tracking, medical care and evaluation of CH patients.