Samenvatting

Background Subclinical thyroid diseases are often the subject of debate concerning their clinical significance, the appropriateness of diagnostic testing and possible treatment. This systematic review addresses the variation in international guidelines for subclinical hyperthyroidism, focusing on diagnostic work-up, treatment, and follow-up recommendations. Methods Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed, Embase, and guideline-specific databases, and included clinical practice guidelines with recommendations on subclinical hyperthyroidism. Guideline recommendations were extracted, and quality assessment was performed using selected questions of the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. Results Of the 2,624 records screened, 22 guidelines were included, which were published between 2007 and 2021. Guideline quality was generally intermediate to low. Diagnostic approaches differed substantially, particularly in the extent of recommended testing. Treatment initiation depended on TSH levels, age, and comorbidities, but the level of detail regarding defining precise comorbidities varied. Recommendations for monitoring intervals for follow-up ranged from three to twelve months. Conclusions This review underscores the existing variability in (inter)national guidelines concerning subclinical hyperthyroidism. There is need for clear recommendations in guidelines considering diagnostic work-up, treatment and follow-up of subclinical hyperthyroidism. In order to establish this, future research should focus on determining clear and evidence-based intervention thresholds.