title: Transient hypothyroidism at 3-year follow-up among cases of congenital hypothyroidism detected by newborn screening.
abstract: OBJECTIVE
  To investigate the rate of transient thyroid deficiency and treatment compliance among cases with congenital hypothyroidism diagnosed and followed-up after age 3 years by newborn screening (NBS).
  
  
  METHODS
  Cases detected by Michigan NBS between October 1, 2003, and December 31, 2007, and followed-up after age 3 years were included. The χ(2) and Fisher exact tests were used to test differences among followed and lost cases. Logistic regression models were used to investigate predictors of treatment cessation.
  
  
  RESULTS
  Roughly 45% of eligible cases were lost to follow-up, and disease state (transient or permanent congenital hypothyroidism) could not be determined for 12 cases (7.9%). Of the 72 followed cases, 34 (47%) were considered permanent congenital hypothyroidism based on thyroid imaging findings (n = 7) or an increase in medication dosage over time (n = 27). One-quarter of followed cases with congenital hypothyroidism were no longer being treated, and of these, just over 83% stopped treatment without medical supervision. Of 23 cases that underwent a medically supervised trial without thyroid hormone medication, treatment was reinstated in 20. Laboratory confirmation of euthyroidism was available for 6 of 18 cases clinically deemed transient. After adjustment, black race was the strongest predictor of treatment cessation (OR, 9.86; 95% CI, 1.82-53.31). Treatment cessation was also more common among low birth weight infants and those admitted to the neonatal intensive care unit at birth.
  
  
  CONCLUSIONS
  We recommend that NBS programs include long-term follow-up through at least age 3 years to determine treatment compliance and disease permanence. Further research is needed to determine ideal follow-up program operations and reassessment methods for congenital hypothyroidism disease permanence. Guidelines that provide evidence-based reassessment methods would be beneficial for the healthcare providers of children with congenital hypothyroidism.
authors.affiliation: Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Detroit, MI 48201, USA. sKorzeni@med.wayne.edu
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Korzeniewski
authors.forename: Violanda
authors.initials: V
authors.lastname: Grigorescu
authors.forename: Mary
authors.initials: M
authors.lastname: Kleyn
authors.forename: William I
authors.initials: WI
authors.lastname: Young
authors.forename: Gretchen
authors.initials: G
authors.lastname: Birbeck
authors.forename: David
authors.initials: D
authors.lastname: Todem
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Nigel
authors.initials: N
authors.lastname: Paneth
mesh_terms: D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology* / Q000517:prevention & control*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055118:Medication Adherence; D015997:Neonatal Screening; D013997:Time Factors