Treating Hypothyroidism in Adults: A Systematic Review and Quality Appraisal of Clinical Practice Guidelines Using AGREE II and AGREE-REX

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Stacy Kozak, Julie Babione, Diane Lorenzetti, Sana Ghaznavi, Doreen Rabi

PROSPERO 2026 CRD420251131419. Available from https://www.crd.york.ac.uk/PROSPERO/view/CRD420251131419.

Review title

Treating Hypothyroidism in Adults: A Systematic Review and Quality Appraisal of Clinical Practice Guidelines Using AGREE II

Condition or domain being studied

Hypothyroidism; Guidelines

This review will focus on clinical guidelines and consensus statements related to the use of combination therapy for treatment of hypothyroidism in adults.

Rationale for the review

This review will update the 2015 systematic review of Clinical Practice Guidelines’ Recommendations on Levothyroxine Therapy Alone versus Combination Therapy (LT4 and liothyronine (LT3)) for Hypothyroidism (Kraut et al 2015) as heterogeneity in recommendations, clinical practices, and patient preference remains. This review will also add a quality assessment of guidelines using AGREE II, and AGREE REX.

Review objectives

What are the current recommendations in clinical practice guidelines and consensus statements regarding the use of combination therapy (LT4 + LT3) and desiccated thyroid extract (DTE)?

What is the quality of these guides overall and what is the quality of the recommendation regarding combination therapy in the treatment of hypothyroidism in adults?

Keywords

Hypothyroidism; Clinical practice guideline; Guidelines; Clinical Practice Guidelines; AGREE II; Consensus statements

Country

Canada

ELIGIBILITY CRITERIA

Population

Included

  • Original and current Clinical Practice Guidelines or Consensus Statements addressing hypothyroidism in adults
  • Published 2014 or later
  • Available in English

Excluded

  • Clinical Practice Guidelines focusing solely on central, subclinical, or congenital hypothyroidism or those focused on hypothyroidism related to pregnancy or infertility
  • Reviews, summaries, secondary analyses, or studies about guidelines
  • Guidelines published prior to 2014, or older versions of existing guidelines
  • Conference abstracts

Intervention(s) or exposure(s)

Included

Guidelines

Recommendations for combination therapy in clinical practice guidelines or consensus statements

Comparator(s) or control(s)

This review does not have any comparators

Study design

Only non-randomized study types will be included.

Included

Clinical Practice Guidelines

Consensus Statements

Context

Clinical Practise Guidelines and Consensus Statements for the treatment of hypothyroidism in adults published in English in 2014 or later. Extraction will include recommendations about combination therapy and the evidence underlying those recommendations. Quality appraisal using AGREE II and AGREE REX will also be completed.