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Document set current to 30 July 2026
Evidence synthesis · §4

Percentage weight change as a surrogate outcome — summary of findings

Outcome-by-outcome summary with effect, certainty and the reason for each downgrade.

Document identifier
CEI-ES-019/4
Series
Evidence synthesis
Version
2.3
Published
26 Jan 2026
Last reviewed
26 Jan 2026
Next review
26 Jul 2027
Identifier
10.71829/cei.syn.19
Certainty
Low
Cycle
2026 Q1
Review type
Methodological review
Search executed
17 Nov 2025

§4Summary of findings

§4.1Summary of findings

Table 7. Summary of findings for Percentage weight change as a surrogate outcome.

OutcomeParticipants (studies)Effect as reportedCertaintyReason for downgrade
Percentage change in body weight from baselineThe outcome the Institute designates as anchor for this indication.34,324 (24)Low certainty evidence indicates that percentage weight change is an imperfect surrogateLowrisk of bias, publication bias
Discontinuation for adverse eventsReported as a summary-of-findings row rather than in a tolerability annex, following a public submission.27,586 (24)Reported per contributing trial; see the included-studies tableLowinconsistency
Serious adverse eventsEvent counts are low; the estimate is imprecise by construction.29,039 (22)Reported per contributing trial; see the included-studies tableVery lowinconsistency, publication bias
Any adverse eventAscertained by spontaneous report in the contributing trials.25,676 (22)Reported per contributing trial; see the included-studies tableVery lowimprecision, publication bias
Proportion achieving ≥5 %, ≥10 %, ≥15 % and ≥20 % weight reductionA secondary outcome for this indication. Its hierarchical position within each contributing trial is recorded on that trial's abstract where the Institute holds it.26,707 (23)Reported as a secondary outcome in a subset of contributing trialsVery lowinconsistency, indirectness
Change in waist circumferenceA secondary outcome for this indication. Its hierarchical position within each contributing trial is recorded on that trial's abstract where the Institute holds it.24,238 (23)Reported as a secondary outcome in a subset of contributing trialsVery lowrisk of bias, indirectness
Certainty ratings describe confidence in the effect estimate for the stated outcome. They are not recommendations and do not transfer between outcomes.

§4.2Forest plot

Contributing estimatesPoint estimates with confidence intervals for each contributing study, plotted against the line of no effect.0.50.751Ratio measure, log scale (1 = no effect)Contributing studyEstimate (95 % CI)ATTAIN-12025 · n=not held1.03 (0.81 to 1.25)ATTAIN-22025 · n=not held0.80 (0.64 to 0.96)ECNO-PH3-CN-OBESITY2025 · n=6640.64 (0.48 to 0.80)GLORY-12025 · n=6100.82 (0.66 to 0.98)REDEFINE-12025 · n=3,4170.72 (0.58 to 0.87)REDEFINE-22025 · n=1,2060.88 (0.70 to 1.05)SOUL2025 · n=9,6500.70 (0.52 to 0.88)SURMOUNT-52025 · n=7510.72 (0.57 to 0.87)SURMOUNT-KOA2025 · n=not held0.90 (0.80 to 0.99)SURPASS-CVOT2025 · n=13,2990.84 (0.63 to 1.04)Pooled estimate0.83 (0.73 to 0.93)
Study estimatePooled estimate
Figure 1. Illustrative. Contributing estimates plotted against the line of no effect. The point estimates and intervals are the Institute's standardised representation of the contributing evidence on a common ratio scale, generated deterministically from the record identifiers; they are not the published estimates, which appear in their own units in the included-studies table and on each trial abstract. The figure is published to convey the dispersion of the evidence base, not to supply a number.

§4.3Certainty assessment for the anchor outcome

Certainty assessment by domainDowngrading decision recorded for each certainty domain.Certainty domainNo concernSeriousVery seriousEffect on ratingRisk of biasdowngrade one levelInconsistencyno downgradeIndirectnessno downgradeImprecisionno downgradePublication biasdowngrade one levelTotal downgrading: 2 levelsLow certainty
Figure 2. Domain-by-domain certainty assessment for the anchor outcome of this review.

Table 8. Reasoning recorded against each certainty domain for the anchor outcome.

DomainRatingReasoning
Risk of biasSeriousContributing trials are sponsor-conducted and one is open-label.
InconsistencyNo concernNo serious concern identified in this domain.
IndirectnessNo concernNo serious concern identified in this domain.
ImprecisionNo concernNo serious concern identified in this domain.
Publication biasSeriousToo few contributing studies for a formal assessment; the risk cannot be excluded.
Overall: Low certainty. Confidence in the effect estimate is limited. The true effect may be substantially different from the estimate.

References cited on this page

References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.

  1. Lincoff AM, Brown-Frandsen K, Colhoun HM, Deanfield J, Emerson SS, Esbjerg S, Hardt-Lindberg S, Hovingh GK, Kahn SE, Kushner RF, Lingvay I, Oral TK, Michelsen MM, Plutzky J, Tornøe CW, Ryan DH. Semaglutide and cardiovascular outcomes in obesity without diabetes. New England Journal of Medicine 2023;389(24):2221–2232. doi:10.1056/NEJMoa2307563 · PMID 37952131

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