title: The relation between serum and filter paper TSH level in neonates with congenital hypothyroidism.
abstract: BACKGROUND
  the aim of this study was to determine the relation between serum and filter paper thyroid-stimulating hormone (TSH) levels in neonates with congenital hypothyroidism (CH). We also tried to determine an appropriate cutoff point of filter TSH for recalling screened neonates.
  
  
  METHODS
  in this descriptive-analytic study, records of 2283 neonates who had been recalled during CH screening program in Isfahan (Iran) were studied. The relation between serum and filter paper TSH levels in the studied neonates was assessed and the best cutoff point of filter TSH and its sensitivity and specificity for proper diagnosis of CH were determined.
  
  
  RESULTS
  among the studied neonates, 103 (4.5%) were diagnosed with CH. Using receiver operating characteristic (ROC) curve, the best cutoff point for diagnosing CH was 7.5 with a sensitivity of 74.8% and specificity of 71.3%. The rates of false positive and false negative diagnoses at this cutoff point were28.7% and 25.2%, respectively. There was a significant relationship between serum and filter paper TSH levels.
  
  
  CONCLUSIONS
  the cutoff point for recall should be changed to 7.5 for appropriate screening outcome. On the other hand, considering the low cost of filter paper and importance of missing any case of CH, changing the cutoff point is not necessary. However, further studies in different parts of Iran are required to obtain more accurate results and consider all related factors.
authors.affiliation: Department of Pediatrics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali Hassan
authors.initials: AH
authors.lastname: Ayyad
authors.affiliation: Isfahan Endocrine and Metabolism Research Center and Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahin
authors.initials: M
authors.lastname: Hashemipour
authors.affiliation: General Practitioner, PhD candidate Child Growth and Development Research Center, Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Silva
authors.initials: S
authors.lastname: Hovsepian
authors.affiliation: Department of Epidemiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali Mehrabi
authors.initials: AM
authors.lastname: Kooshki
authors.affiliation: Department of Statistics and Mathematics, College of Science, Persian Gulf University, Boushehr, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Afshari
keywords: Congenital hypothyroidism; filter paper; thyroid-stimulating hormone