Congenital hypothyroidism screening program in iran; a systematic review and metaanalysis
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Yousef Veisani1, Kourosh Sayehmiri2, Shahab Rezaeian3
1Student Research Committee.
Insights
Newborn screening for congenital hypothyroidism (CH) in Iran identified an incidence of 2/1000 neonates. Further research is needed to optimize TSH cut-off levels for accurate recall rates.
Area of Science:
- Neonatal screening
- Endocrinology
- Public health
Background:
- Congenital hypothyroidism (CH) can cause intellectual disability if not treated promptly.
- Early detection through newborn screening and timely thyroid hormone replacement is crucial for normal cognitive development.
Purpose of the Study:
- To systematically review and evaluate the national CH screening program results across Iranian provinces.
- To assess the incidence and recall rates of CH in Iran.
Main Methods:
- A systematic literature review of national and international databases (PubMed, Scopus, Web of Science, etc.).
- Meta-analysis of 25 studies involving 1,425,124 neonates using random-effects models.
- Exploration of heterogeneity using meta-regression.
Main Results:
- The pooled recall rate for TSH ≥5mIU/L was 0.014 (95% CI: 0.013-0.015).
- The overall incidence of CH was determined to be 2 per 1000 neonates (95% CI: 0.002-0.002).
- No significant increase in CH incidence over time was observed (P=0.08).
Conclusions:
- The current TSH cut-off of ≥5mIU/L for recalling neonates has a low positive predictive value (14%).
- Further research is required to establish more accurate TSH thresholds for neonatal recall.
- Optimizing screening criteria can improve the efficiency and accuracy of CH detection programs.
Objective:
Unrecognized congenital hypothyroidism (CH) leads to mental retardation. Newborn screening and thyroid therapy started within 2 weeks of age can normalize cognitive development. In this systematic review, the local results of the national CH screening program in different provinces in Iran are reviewed and evaluated.
Methods:
Literature on the CH screening, the national databases including SID, Medlib, Iran Medex, Magiran as well as international databases including PubMed/Medline, ISI Web of Knowledge and web of science, EMBASE, SCOPUS and Google Scholar. Appraisal was guided by a checklist assessing clarity of aims and research questions. The 95% confidence intervals were calculated by I-square models. Meta regression was introduced to explore the heterogeneity between studies.
Findings:
We identified 25 samples including 1425124 neonates in our country. Data were Meta analyzed using random-effects models, and we found a TSH levels of 19633 babies in the first sampling were greater than the cut-off level (TSH ≥5mIU/L). The pooled recall rate was 0.014 (95 % CI: 0.013 - 0.015). According to Meta analysis the overall incidence of CH was 2/1000 (95% CI: .002 - .002). The incidence of CH did not appear to be increasing over time (P=0.08).
Conclusion:
Considering TSH ≥5mIU/L as a cut-off point for recalling neonates and low positive predictive value (14%) of this point shows that more investigation and research is needed for establishing accurate level of TSH as a criterion for recalling patients.
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