Network meta-analysis

HbA1c change

Type 2 diabetes (adults); background therapy: no glucose lowering drug (lifestyle only)

weeks 36 to 64 (target week 52)Hypothetical (as if everyone stayed on treatment)Doses of a drug pooledMean difference

Randomized trials

Treatments

1,321

Participants

Trial arms

In plain language

Across 3 trials with 1,321 participants, 2 of 3 treatments had a clearly better result than placebo on HbA1c change, and for 1 the evidence could not tell it apart from placebo. The most favorable estimate was for Tirzepatide injection: mean difference -1.94 percentage points (95% credible interval -2.79 to -0.72).

Lower values favor the treatment. "Clearly" means the 95% credible interval excludes no difference. These are averages across trials; they do not say how any one person will respond. Not medical advice.

Network of trials

Each circle is a treatment; each line joins treatments that were randomized against each other in at least one trial.

Node area shows participants; line width shows trials comparing two treatments directly. Blue: GLP-1 receptor agonist containing treatments; grey: comparators. Hover over or tab to a node or line for details.

Effects compared with Placebo

Mean difference in percentage points. Lower values favor the treatment.

Versus Placebo. Blue: Bayesian random effects posterior median with 95% credible interval (thick) and 95% prediction interval (dashed). Amber diamond: frequentist estimate with 95% confidence interval. Hover over or tab to a row for its values.

Effects of each treatment versus Placebo
Treatment	Bayesian MD (95% CrI)	95% prediction interval	Frequentist MD (95% CI)	Verdict
Tirzepatide injection TIRZ_SC	-1.94 (-2.79 to -0.72)	-3.17 to -0.30	-1.98 (-2.21 to -1.75)	Better
Orforglipron tablet ORFO_PO	-1.26 (-2.25 to -0.18)	-2.65 to 0.27	-1.28 (-1.53 to -1.03)	Better
Albiglutide injection ALBI_SC	-0.93 (-1.85 to 0.23)	-2.31 to 0.64	-0.94 (-1.18 to -0.71)	Unclear

Ranking

How likely each treatment is to be among the best. Rankings ignore the size of differences and their certainty, so read them with the effects above.

League table

Every treatment against every other: mean difference of the row treatment versus the column treatment, posterior median and 95% credible interval. Green: row clearly better; red: row clearly worse.

Every treatment in a row compared with every treatment in a column
Row versus column	PLACEBO	TIRZ_SC	ORFO_PO	ALBI_SC
PLACEBO	PLACEBO	1.94 0.72 to 2.79	1.26 0.18 to 2.25	0.93 -0.23 to 1.85
TIRZ_SC	-1.94 -2.79 to -0.72	TIRZ_SC	-0.68 -2.03 to 0.93	-1.01 -2.40 to 0.56
ORFO_PO	-1.26 -2.25 to -0.18	0.68 -0.93 to 2.03	ORFO_PO	-0.33 -1.91 to 1.15
ALBI_SC	-0.93 -1.85 to 0.23	1.01 -0.56 to 2.40	0.33 -1.15 to 1.91	ALBI_SC

Heterogeneity, fit and convergence

Bayesian random effects (primary)

Heterogeneity (tau): 0.325 (95% CrI 0.015 to 1.088)
Residual deviance: 6.0 for 6 data points
DIC: 12.0 (pD 6.0)
Largest R-hat: 1.002
Smallest ESS: bulk 2,208, tail 2,510
Divergent transitions: 0
Convergence: All criteria met
Priors: PR01 N(0, 5^2); PR03 N(0, 2.5^2); PR07 half normal(0, 0.5^2) on tau

Frequentist check (netmeta)

Method: inverse variance, REML, MD
Tau: 0.000
Q (total): 0.00 on 0 df
Q (between designs): 0.00

Inconsistency

Do trials comparing two treatments directly agree with the indirect evidence through other treatments?

No comparison here has both direct and indirect evidence, so inconsistency cannot be checked by node splitting; the between designs Q above is the global check.

Small study effects

A comparison adjusted funnel plot: each point is one trial comparison, centered on its own network estimate. Asymmetry can signal that small trials with unfavorable results are missing.

Fewer than ten trial comparisons, too few to judge funnel plot asymmetry.

Baseline characteristics of the trials

The baseline value of each effect modifier or prognostic factor that applies here, per trial: mean or percent over arms, weighted by the number randomized. A note under a value names a stand in (a median for a mean, 100 minus the male share, Asian subgroup rows, an all Asian site list); "not reported" means no source of the trial prints it.

Baseline effect modifiers and prognostic factors per trial
Trial	Baseline HbA1c (percent) effect modifier, prognostic factor; 3 of 3	Background glucose lowering therapy (stratum S0 to S4) effect modifier, prognostic factor; 3 of 3	Diabetes duration (years) effect modifier, prognostic factor; 3 of 3	Asian ancestry or region (percent Asian) effect modifier, prognostic factor; 3 of 3	Age (years) prognostic factor; 3 of 3	Treatment duration (weeks) effect modifier; 3 of 3
SURPASS-1 S000407	7.97	S0	4.7	35.15	54.11	40
NCT00849017 S000852	8.07	S0	3.97	2.36	52.9	156
ACHIEVE-1 S001950	7.98	S0	4.4	43.83	53.37	40

Comparability of the trials

Checked across designs (the set of treatments each trial compares) for eligibility, outcome definition and assessment, and the baseline factors above. Flags point to possible intransitivity; notes describe variation that is not tied to design.

FlagBaseline, Asian ancestry or region: design means range from 2.4 (ALBI_SC vs PLACEBO) to 43.8 (ORFO_PO vs PLACEBO) percent Asian; threshold 30
FlagBaseline, Treatment duration: design means range from 40.0 (ORFO_PO vs PLACEBO) to 156.0 (ALBI_SC vs PLACEBO) weeks; threshold 26
FlagHeterogeneity, tau above threshold: tau 0.32 exceeds the outcome threshold 0.3; the flags of this network are candidate explanations
NoteOutcome assessment, time point: selected time points span 40 to 52 weeks
NoteData handling, input conversions: arms_combined 3

Comparability items per trial
Trial	time weeks	analysis set	definition	instrument	adjudicated	proportion method	intercurrent events (discontinuation)	intercurrent events (rescue)	blinding	funding	start year	Eligibility
SURPASS-1	40	modified_itt	not stated	not stated	not stated	not stated	hypothetical	hypothetical	double_blind	industry	2019	adults; HbA1c 7.0 to 9.5 percent; BMI 23 or higher; no glucose lowering drug in prior 90 days
NCT00849017	52	modified_itt	not stated	not stated	not stated	not stated	hypothetical	hypothetical	double_blind	industry	2009	age 18 or older; HbA1c 7.0 to 10.0 percent; BMI 20 to 45; diet and exercise only
ACHIEVE-1	40	modified_itt	not stated	not stated	not stated	not stated	hypothetical	hypothetical	double_blind	industry	2023	adults with type 2 diabetes on diet and exercise alone; HbA1c 7.0 to 9.5 percent

Trial data

What each trial contributes. Arm rows give the arm value with its standard error, or events over participants; contrast rows give the mean difference on the analysis scale against the trial's first row. Flags mark converted, combined or approximated inputs.

Trial data entering this analysis
Trial	Arm	Treatment	Week	Data	Value	SE	Events / N	Flags	Source
SURPASS-1	A1+A2+A3	TIRZ_SC	40	arm, change	-1.942	0.055	355	arms_combined	registry:outcomes
SURPASS-1	A4	PLACEBO	40	arm, change	0.040	0.105	112		registry:outcomes
NCT00849017	A1	PLACEBO	52	arm, change	0.150	0.097	98		registry:outcomes
NCT00849017	A2+A3	ALBI_SC	52	arm, change	-0.794	0.068	197	arms_combined	registry:outcomes
ACHIEVE-1	A1	PLACEBO	40	arm, change	-0.150	0.113	138		registry:outcomes
ACHIEVE-1	A2+A3+A4	ORFO_PO	40	arm, change	-1.431	0.060	421	arms_combined	registry:outcomes

Rerun this analysis yourself

Remove treatments or trials and refit the frequentist and Bayesian models in your browser, with the same methods as the published analysis.

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