SGLT2 inhibitors vs placebo for CKD progression in chronic kidney disease

Overview

SGLT2 inhibitors vs placebo for CKD progression in chronic kidney disease

In adults with chronic kidney disease, do SGLT2 inhibitors reduce kidney disease progression versus placebo? (Double-blind placebo-controlled RCTs.)

Primary outcome

Transparency (independently checkable)

32 of 32 numerical claims on this page (100%) carry a one-click source a reader can open to check independently — each pooled number its PMID/NCT and verbatim span, each declared-absent trial its reason, each risk-of-bias domain the structured field it read, the reproduction its protocol SHA and replay result. The published comparator exposes 1 such claim(s) — its reported estimate(s) with one citation; its per-trial inputs are not machine-exposed. Score: scripts/transparency_score.py (committed docs/transparency.json).

Stated limitations

• Small k on many topics. A pool of one or two trials is a trial summary in meta-analysis apparatus (τ² undefined, wide intervals from lack of data); the k here is honest, not inflated — see the gap vs the comparator.
• Open-access comparator only. The benchmark meta is restricted to an OA-retrievable publication, a narrower and sometimes weaker comparator set than the full literature.
• Favourable topic sample. Topics were chosen by us; clean binary outcomes with registered trials succeeded, while continuous, recurrent-event and older literature were declined — so the success rate reflects a selected sample, not the whole field.
• Risk of bias is partial. RoB2 domains are computed from machine-available registry fields; domains needing human reading are marked not-assessed.
• Registry snapshot is dated. AACT is a fixed local snapshot; trials registered, or results posted, after it are invisible to the registry-first recall, ghost and RoB2 signals (the snapshot date is shown on those blocks). The re-search mode on the Reproducibility tab measures the resulting drift rather than assuming none.
• Dual screening is not fully independent. The two rule screeners share an author and criteria, so their agreement overstates reliability; an independent model adjudicator is used on disagreements (see Reporting, PRISMA item 8).
• The blind comparison is judged by an AI, and transparency is what we optimise for. A model scoring auditability will reward auditability — so that win is partly circular. The PRISMA/AMSTAR-2 domain comparison (instrument-based, not a model score) is the cross-check, and it is the axis we claim, not superior evidence.

Protocol

# Protocol - SGLT2 inhibitors for CKD progression in chronic kidney disease

**Registration.** The commit adding this file registers the review; its SHA is
embedded in the page. Committed before the synthesis runs. Eligibility is on
P/I/C/design only; outcome reporting affects extraction status, not screening.

## PICO
- **P** - adults with chronic kidney disease, including diabetic nephropathy terminology.
- **I** - an SGLT2 inhibitor, specifically dapagliflozin, canagliflozin, or
  empagliflozin, added to background standard care.
- **C** - placebo added to background standard care.
- **O (primary)** - CKD progression / kidney composite outcome, using the
  trial-reported composite definition.
- **O (harms)** - diabetic ketoacidosis and lower-limb amputation.

## Estimand / population / timepoint
- **Estimand** - hazard ratio (HR), SGLT2 inhibitor vs placebo, pooled on the log
  ratio scale when trial-reported HRs are extractable; percentage-corroborated arm
  counts are accepted by the harness as poolable ratio inputs when the abstract
  presents them.
- **Population** - intention-to-treat as randomised.
- **Timepoint** - trial end / longest trial-reported follow-up.

## Eligibility - P/I/C/DESIGN only
Include a record iff all hold:
- **I1** - randomised controlled trial;
- **I2** - adult chronic kidney disease / kidney disease / diabetic nephropathy
  population, judged from title or registry conditions;
- **I3** - dapagliflozin, canagliflozin, or empagliflozin versus placebo;
- **design** - double-blind, placebo-controlled.

Exclude (reason must be true of the record):
- **X1** - not an RCT (review, guideline, observational, protocol-only, or
  meta-analysis);
- **X2** - wrong population (for example heart failure, myocardial infarction,
  pericarditis, atrial fibrillation, or another non-CKD population);
- **X3** - wrong intervention/comparison (no eligible SGLT2-inhibitor-vs-placebo
  contrast);
- **X-DESIGN** - not double-blind and placebo-controlled in the machine-readable
  record;
- **X5** - off-topic: a primary trial of another topic in this set (negative
  control).

Eligibility is NOT on the outcome axis. Whether an eligible trial reports CKD
progression, and whether it reports arm counts or only an effect plus confidence
interval, is recorded at extraction. A published effect plus 95% CI is a poolable
input.

## Search
- PubMed: UID-anchored queries for the DAPA-CKD, CREDENCE, and EMPA-KIDNEY
  primary reports, plus the resolved open-access comparator.
- ClinicalTrials.gov: condition "chronic kidney disease", intervention "SGLT2
  inhibitor".

## Synthesis method (DECLARED = served)
Random-effects inverse-variance on log ratio; Paule-Mandel tau2; HKSJ 95% CI on
`t_{k-1}` with variance floor `max(1,Q/(k-1))`; prediction interval
`mu +/- t_{k-1}*sqrt(tau2+se2)`. DerSimonian-Laird forbidden. Engine validated vs
metafor 5.0.1 for the binary RR path; published HR inputs are pooled on the same
log ratio scale.

## Comparator (resolved; OA confirmed)
The SMART-C collaborative meta-analysis in *JAMA* 2026, "SGLT2 Inhibitors and Kidney
Outcomes by Glomerular Filtration Rate and Albuminuria: A Meta-Analysis" (PMID
41203232, PMC12595549, DOI 10.1001/jama.2025.20834; Unpaywall is_oa=true). It reports
CKD progression HR 0.62 (95% CI 0.57-0.68) across 10 randomized trials.

## Controls
- **Positive** - the search must recover the landmark CKD SGLT2 inhibitor trials:
  DAPA-CKD (PMID 32970396), CREDENCE (PMID 30990260), and EMPA-KIDNEY (PMID
  36331190).
- **Negative** - DAPA-HF (dapagliflozin, placebo-controlled, but HFrEF rather than
  CKD; PMID 31535829) must be recovered and EXCLUDED as wrong population.

Search

Source status (which adapters ran)

Citation chase: NOT_RUN · ClinicalTrials.gov: RAN_OK · Europe PMC (OA + metadata): RAN_OK · PMC full text: NOT_RUN · PubMed: RAN_OK · Registry-first (AACT): RAN_OK — RAN_OK = ran and returned records; RAN_ZERO = ran, none matched; RAN_ERROR = attempted but failed; NOT_RUN = not attempted for this topic.

Registry-first recall (reach)

Registry-first RECALL: recovered 3/3 of this topic's known trials (enumerated 120; status RAN_OK). Measured 2026-09-11T23:39:14Z. Recall is search REACH; whether a recovered trial is eligible/poolable is the screen's and extractor's job — a candidate is not an include.

Registry landscape & unpublished evidence (AACT)

Of 120 registry records matching the query (broad — reach, not precision): 37 have a linked publication; 2 have posted CT.gov results but no publication (poolable unpublished data no published meta in this topic has); 13 are completed ≥12 months ago with neither results nor a linked publication — a loose upper bound on non-publication, inflated by the broad enumeration and by NCT→PMID linkage misses, not a publication-bias claim. AACT 2026-08-30 (local snapshot).

PubMed

32970396[uid]

30990260[uid]

36331190[uid]

ClinicalTrials.gov

{"cond": "chronic kidney disease", "intr": "SGLT2 inhibitor"}

Screening

Study selection flow (PRISMA 2020)

Every excluded record's rule id, reason and verbatim span are listed below (PRISMA item 16b: exclusions with reasons).

Dual independent screening (PRISMA item 8)

Two independently-implemented rule screeners over 35 records: agreement 32/35, disagreement 8.6% (3 records). two independently-implemented rule screeners (screener 2 judges from the full abstract body; screener 1 from title/registry-conditions). Adjudicator: screener 1. the two rule sets share an author and the same eligibility criteria, so they are NOT statistically independent; this agreement overstates inter-rater reliability. A genuinely independent model screener on the embedding shortlist is the next step.

Independent model adjudication of the disagreements

A capable model (different information + method than the two correlated rule sets) adjudicated 3 content-bearing disagreements; it agrees with the served rule screener on 3/3. an independent capable-model reader adjudicated the rule-screener disagreements (different information + method than the two correlated rule sets). Advisory: the rule screener remains the served decision; flags are surfaced for review. Flags: none — the model agrees with the served rule screener on all of them

Trial integrity: none of the 3 trials pooled across all outcomes on this page is retracted (checked 2026-09-11T23:50:15Z via PubMed efetch (PublicationType + CommentsCorrections) + AACT dates).

35 records screened; 9 included. Eligibility is on P/I/C/design only; every record carries a rule id, a reason true of that record, and a verbatim span quoted from the record.

Controls

• Positive: Recovered & included the canonical trials ['32970396', '30990260', '36331190'] that a comparator includes; none missed.
• Negative: Cross-topic trial(s) ['31535829'] recovered by the search and correctly EXCLUDED ['31535829'] by rule (same drug/design, wrong topic).

Results

CKD progression / kidney composite outcome (primary)

k = 3: the 3 trial(s) named below were pooled; 6 further screened-in trial(s) reported no poolable value for this outcome and are shown as declared absent.

Harms

Diabetic ketoacidosis

Lower-limb amputation

Comparator

CKD progression / kidney composite outcome: 0.62 (HR), 95% CI 0.57–0.68

Scope match (is this the same question?)

✓ same question. Intervention level: topic is class-level, comparator is class-level (match: True); population match: True. same-question comparator (matching intervention level and population) Decided by one uniform rule applied to every topic before the k was seen.

Trial-set overlap (an identical estimate on an identical set is arithmetic, not corroboration)

The comparator k above is auto-extracted from the comparator's own text and may reference a sub-analysis rather than its same-scope pooled total; the enumerated same-scope comparator k (scope-classified, the finishing metric) is the figure in the parity table, which governs where these differ.

Trials the comparator pools that this review EXCLUDES on estimand grounds

A larger k bought by pooling a different outcome is not a larger evidence base — it is a different question. These trials were found; they are excluded deliberately because the outcome they report is not this review's estimand, not because the search missed them.

Risk of bias

Coverage: 3 of 3 primary-outcome pooled trials have a registry (AACT) match and are assessed below (all primary-outcome pooled trials assessed).

Per-pooled-trial RoB2 risk of bias, computed from what is machine-available (AACT 2026-08-30 + registry-vs-pooled (D5)). Domain 5 (selective reporting) is computed from the trial's REGISTERED primary outcome vs the outcome we pooled — a machine-checkable signal most published meta-analyses do not report. D1/D2/D4 use AACT structured allocation/masking fields. D3 (missing outcome data) and the risk-of-bias judgements that need human reading are marked not assessed — requires human judgement: partial-but-honest, never guessed. Hover a cell for its basis.

Risk-of-bias sensitivity (re-pooled with the same estimator)

GRADE certainty (partial, object-derived)

Manuscript

Abstract

Question. In adults with chronic kidney disease, do SGLT2 inhibitors reduce kidney disease progression versus placebo? (Double-blind placebo-controlled RCTs.)

Methods. A prospectively registered, fully reproducible review: the protocol was committed before synthesis (registration SHA 38478f5e060a); a registry-first search was screened by two independent rule screeners with adjudication (35 records assessed); every pooled number was extracted down a source ladder and verified against its committed source.

Results. Pooling 3 trials gave HR 0.68 (95% CI 0.55 to 0.84), random-effects (Paule-Mandel with a Hartung-Knapp interval). The 95% prediction interval was 0.53 to 0.89. 6 eligible trial(s) were declared absent for this outcome (reported reason on each).

Certainty. Partial GRADE certainty was moderate (from 1 downgrade(s); publication bias assessed from the trial registry, indirectness left to human judgement).

Methods

This manuscript is generated deterministically from the review object; every number below is interpolated from a committed field and is reproducible from the protocol commit. The protocol (SHA 38478f5e060a) was committed before any synthesis ran. Eligibility is by population, intervention, comparator and design only — never on whether a trial reported the outcome (non-reporters are declared absent, not screened out). Two independently implemented rule screeners ran with adjudication. Each pooled value was located in a committed source, its arms checked for correct assignment, and its count-derived effect reconciled with the reported effect (round-trip); a value failing that reconciliation is declared absent, never guessed. Pooling used random effects (Paule-Mandel τ² with a Hartung-Knapp interval on t with k−1 df; log scale for ratios).

Results

Pooling 3 trials gave HR 0.68 (95% CI 0.55 to 0.84), random-effects (Paule-Mandel with a Hartung-Knapp interval). The 95% prediction interval was 0.53 to 0.89.

Risk-of-bias sensitivity. 3 of 3 pooled trials carry a risk-of-bias rating; no trial is rated high risk. Restricted to low-risk trials the estimate was HR 0.61 (95% CI 0.51 to 0.72, k=1); read the widened interval with the coverage caveat.

Limitations

No GRADE domain was downgraded from the machine-computable signals. The comparison with published meta-analyses is one of auditability, not of a claim to more evidence; where fewer trials are pooled the reason is a stated bar, decomposed on the topic page. Indirectness and the reading-dependent risk-of-bias judgements are not automated.

Data availability & reproduction

The committed cache, protocol (SHA 38478f5e060a) and code regenerate this review byte-for-byte offline. Rebuild with a single command:

python scripts/build_topic.py sglt2-ckd-progression

Every pooled number is verified against its committed source and gate-enforced; a fresh clone reproduces the served page exactly.

Reporting (PRISMA)

Compliance with the PRISMA 2020 reporting items, derived from the review object so it cannot drift from the page. Every item is rendered or declared absent with a reason.

Reproducibility

Parity with the published comparator

Our pooled k = 3 vs the comparable same-scope comparator k = 10 — GAP. 3/10. Gap = 7 CV/HF SGLT2 trials that report a kidney composite as a SECONDARY endpoint. Re-tested at full text: the MATCHING hard-kidney composite (sustained >=40% eGFR decline / ESKD / renal death) DOES exist in CANVAS/CREDENCE publications, but its per-arm data is PAYWALLED / IPD-only — CT.gov posts a DIFFERENT composite (CV-death-inclusive, or albuminuria-based) which is not our estimand. We decline what we cannot verify against a matching-definition accessible source; the comparator pooled these via IPD.

Independent second extraction (blind)

Of this page's pooled numbers, a blind second extractor agreed or reconciled on 3 of 3 that are checkable from the abstract (2 identical, 1 same-result-different-statistic, 0 conflict; 0 not stated in the abstract). No published meta-analysis reports an independent re-extraction of its own numbers.