| Methods |
Randomised controlled trial. follow‐up study |
| Participants |
47 babies with congenital hypothyroidism detected by newborn screening |
| Interventions |
Participants were randomly assigned to 3 dosage arms of 37.5 mcg/day (group 1), 62.5 mcg/day for 3 days followed by 37.5 mcg/day (group 2) and 50 mcg/day (group 3) |
| Outcomes |
Neurodevelopment assessment using Mullen Scales of Early learning, Weschler Preschool and Primary Scale of Intelligence‐revised, Weschler Intelligence Scale for Children, Wide Range of Acheivement Test and Child Behavioural Checklist |
| Study details |
Participants who were on higher initial dose of 50mcg/day L‐thyroxine had higher full scale IQ scores compared to participants who were on lower initial dose of 37.5mcg/day. verbal IQ, performance IQ and achievement scores did not differ among the three groups. |
| Publication details |
J Pediatr 2005; 147:775‐80 |
| Stated aim of study |
Quote "Our goal was to compare neurodevelopmental outcomes, particularly cognition, academic achievement, and attention/behavior, among the 3 treatment groups. In addition, we investigated the effect of CH severity, differences (if any) between CH subjects and their unaffected siblings, and the effect of the timing of thyroid function normalization on neurodevelopmental outcomes in all treatment cohorts". |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
Described as randomised, but no details of method given. |
| Allocation concealment? |
Unclear risk |
Not described |
| Blinding?
All outcomes |
Unclear risk |
Did not report blinding of investigators |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
16 participants were lost to follow up and reasons were described. |
| Free of selective reporting? |
Unclear risk |
Unable to identify any selective reporting in the included trial, but did not have any access to the original trial protocols |
| Free of other bias? |
Unclear risk |
Participants were selected from a restricted geographical area in proximity to the hospital on the basis of the screening program for identifying congenital hypothyroidism babies. This may present a potential risk of bias due to pre‐selection of participants. |
