Section II · Last reviewed 2026-05-16
Scientific basis
The primary publications that empirically underpin the Dutch Protocol, plus methodological criticism and replication attempts.
Summary
The evidence base of the Dutch Protocol rests on a small number of cohort and follow-up studies from the VUmc / Amsterdam UMC group between 1998 and 2014, supplemented by international replication attempts. This section provides a summary per study (design, sample, outcome, limitations) and addresses the methodological criticism of Biggs, Levine, Abbruzzese and others.
Critical note
The primary studies in this section are — without exception — observational cohort studies without a control group, almost all from a single research group (VUmc / Amsterdam UMC). Independent replication attempts (Costa 2015, Carmichael 2021) do not confirm the original findings. NICE (2020), SBU (2022) and the University of York reviews for the Cass Review (2024) classify the cumulative evidence base as "very low certainty" according to GRADE.1
Subpages
- Cohen-Kettenis & van Goozen 1998 — first case report
- Delemarre & Cohen-Kettenis 2006 — protocol description
- de Vries et al. 2011 — first follow-up
- de Vries et al. 2014 — the "Amsterdam study"
- Steensma et al. 2013 — desistance in children
- Follow-up studies overview
- Methodological criticism — Biggs, Levine, Abbruzzese
- Sample size and attrition
- Replication attempts
- WPATH SOC and the Dutch Protocol
Related
- People index — who the authors are.
- Original publications — chronological list with PMID.
- Timeline — publications in chronological context.
- Evaluations — what independent evaluators concluded about this evidence.
- FAQ · Glossary
Footnotes
- Taylor J, Mitchell A, Hall R, et al. Interventions to suppress puberty in adolescents experiencing gender dysphoria. Arch Dis Child. 2024 (University of York / Cass Review systematic review).