· ST-SAF-02 · v2
Borderline: within 4 points of the Likely/Uncertain boundary, so a re-grade could land either side.
The evidence agrees that muscle injury from statins rises as the dose rises, and that among the statins still in common use simvastatin sits at the top of the risk ranking. A large New Zealand study [14] shows simvastatin users on 40 mg were about five times as likely to suffer severe muscle breakdown as those on 20 mg, and a French national study [15] confirms higher-strength statins carry more risk. Where the evidence thins is the exact claim that 80 mg is the worst dose: within this set of studies no trial directly compares simvastatin 80 mg against every other statin for actual muscle-injury rates. The 80 mg point is instead supported by laboratory-style muscle measurements [1][5] and one single patient [20], rather than by head-to-head counts of real events. The panel therefore accepted the overall direction of the claim while flagging that its most specific part rests on indirect evidence.
Dose-dependence is directly demonstrated for simvastatin in [14], where 40 mg carried an adjusted odds ratio of 5.3 (95% CI 1.9-15.0) for rhabdomyolysis versus 20 mg in a cohort of 313,552 initiators. [15], a cohort of 969,460 statin initiators with 168 events, found high-potency statins associated with a hazard ratio of 1.93 (1.27-2.94) in men. Simvastatin's position as highest-risk is carried by pharmacovigilance [7], where among 10,657 rhabdomyolysis reports simvastatin had the highest reporting odds ratio of 2.20 (2.11-2.29), and by cohort data [8], where moderate-to-high-intensity simvastatin showed a hazard ratio of 1.33 (1.16-1.53) versus atorvastatin at equivalent doses. The 80 mg-specific signal rests on surrogate muscle data: [1] found 111 differentially expressed muscle genes on simvastatin 80 mg versus 5 on atorvastatin 40 mg, and [5] showed muscle ubiquinone fell significantly only in the simvastatin group. [20] is a single 80 mg rhabdomyolysis case with creatine kinase of 12,640 U/L. The contested point: The division is over the clause "highest with simvastatin 80mg": no included primary study ranks simvastatin 80 mg against all other statins for clinical muscle-injury incidence. Within this corpus dose-dependence for simvastatin is shown directly only up to 40 mg [14], and [15] names rosuvastatin 20 mg and simvastatin 40 mg, not 80 mg, as the doses with hazard ratios above 5.
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One reviewer's only job is to attack the finding. The challenges below were weighed before the grade was set.
The 80 mg-specific evidence in the included primary corpus ([1], [5]) is surrogate — muscle gene expression, ubiquinone and mitochondrial markers — not clinical myopathy or rhabdomyolysis incidence; mechanism does not establish the claimed event-rate ranking.
Dose-dependence within simvastatin is directly shown only up to 40 mg ([14]); the 80 mg rung is asserted from two RCTs that are not in the corpus, so the specific '80 mg' endpoint of the gradient is not primary-data-backed here.
Where it remains uncertain. No primary study in this corpus directly compares simvastatin 80 mg against other statins for event rates; the 80 mg point is carried only by surrogate muscle-metabolism data [1][5] and one confounded case [20].
Aleatory
Rhabdomyolysis is extremely rare: 29 cases in [14] and 168 events in [15], so estimates of the dose gradient rest on few events and wide intervals (OR 5.3, 95% CI 1.9-15.0 [14]).
Epistemic
No included primary study compares simvastatin 80 mg against all other statins at equivalent intensity for clinical myopathy incidence; the direct comparative figures sit in study-type-excluded reviews [10][11].
Inferential
Dose-dependence within simvastatin is shown directly only to 40 mg [14]; the 80 mg rung is inferred from two 80-vs-20 mg RCTs that [14] cites but are not in the corpus.
The load-bearing papers from a corpus of 20, each classified by what it does to the claim. Every DOI is taken from the corpus the claim was graded on.
Surrogate evidence that 80 mg simvastatin is distinctively myotoxic relative to atorvastatin.
“High dose simvastatin treatment resulted in 111 differentially expressed genes (1.5-fold change and p-value<0.05), while expression of only one and five genes was altered in the placebo and atorvastatin groups, respectively.”
Panel auditInternal validity: medium · scope of inference: Biochemical/transcriptomic muscle effects of high-dose simvastatin vs atorvastatin in hypercholesterolaemic patients.Key limitations: surrogate molecular outcome, not myopathy · no dose-response design · small specimen numbers
Surrogate mechanistic signal specific to simvastatin 80 mg vs atorvastatin 40 mg.
“The muscle ubiquinone concentration was reduced significantly from 39.7 +/- 13.6 nmol/g to 26.4 +/- 7.9 nmol/g (P = .031, repeated-measurements ANOVA) in the simvastatin group, but no reduction was observed in the atorvastatin or placebo group.”
Panel auditInternal validity: medium · scope of inference: Effect of high-dose simvastatin vs atorvastatin on skeletal-muscle sterol and mitochondrial markers in hypercholesterolaemic patients.Key limitations: surrogate biomarkers not myopathy · small arms · two drugs at non-equivalent doses
Supports 'highest with simvastatin' among seven current statins (cerivastatin excluded).
“Among 10 657 reports with rhabdomyolysis with statins, simvastatin was the highest risk statin in comparison with others: ROR = 2.20 (2.11-2.29).”
Panel auditInternal validity: low · scope of inference: Relative rhabdomyolysis reporting across statins in a global pharmacovigilance database.Key limitations: reporting bias · no dose information · no true incidence
3 of 20 papers shown. The full review lists all of them, with the panel’s arbitration →
Claims are graded at each quarterly release, and re-graded between releases only when a pivotal trial lands. Every change is a new version of the claim.
Both clauses point the right way on independent primary datasets, but the 80 mg-specific ranking rests on surrogate and anecdotal evidence, warranting Likely rather than Established.
Release 2026-q4 re-graded every claim from its corpus under protocol v0.19. An earlier release's grade is shown for the record; it came from an earlier protocol and is not a movement.
Assumptions that carry weight but are not themselves established.
The panel records the gap that would most move the claim, and the study that would close it.
Direct 80 mg clinical head-to-head. The claim's 80 mg endpoint is carried only by surrogate [1][5] and anecdotal [20] data; no primary study ranks 80 mg against other statins for event rates. The panel rates this the highest-importance open gap for the claim, and names the study design that would close it: A cohort or nested case-control study estimating clinical myopathy and rhabdomyolysis incidence for simvastatin 80 mg versus other statins at equivalent intensity.
Open question: Does clinical myopathy and rhabdomyolysis incidence on simvastatin 80 mg exceed that of every other statin at equivalent intensity? Why it is still open: No included primary study performs this direct head-to-head; the comparative figures sit in excluded reviews [10][11].
Priors is a sceptical first reader, not peer review, and not medical advice.
Release 2026-q4 · graded 26 Oct 2026 · protocol v0.19