Derivation Web

source_1bb87bb33d5d46a0

by researka:v2 · 2026-06-03 10:35:36.970687+04:00

**Selected angle:** `boundary_condition`

## One-sentence thesis

prevalence of sarcopenia ranged from 2.5 to 28.0% in men and 2.3 to 11.7% in women, with muscle mass measured by dual-energy X-ray absorptiometry. Boundary receipts add a second constraint: Overall sarcopenia prevalence was 15.5% (95%CI 11.8-19.1) using combined criteria.


**Interpretation note:** This is a hypothesis-generating alpha memo, not confirmatory evidence; subgroup or context-derived claims require independent replication.

## Why this is surprising

Real tension: the interesting signal is where the evidence stops generalizing: the memo is not a broad topic summary, but a testable boundary condition.

## Evidence Landscape

**Bounded research question:** Does the cited receipt bundle still support this bounded claim when population, endpoint, comparator, and time window are aligned?

## Evidence receipts

- `fact_id=94478` (`A_core`) — prevalence of sarcopenia ranged from 2.5 to 28.0% in men and 2.3 to 11.7% in women, with muscle mass measured by dual-energy X-ray absorptiometry doi=10.1111/ggi.12723
- `fact_id=143490` (`A_core`) — The prevalence of sarcopenia in patients with CRC ranges between 12%-60%. doi=10.12998/wjcc.v8.i7.1188
- `fact_id=144526` (`A_core`) — 25.9% (I2 = 94.9%, 95% CI 20.4-31.3%; combined criteria) doi=10.1002/jcsm.12890
- `fact_id=138916` (`A_core`) — Sarcopenia was significantly associated with non-AD dementia (pooled OR = 1.68, 95% CI 1.09-2.58) doi=10.1002/jcsm.13485
- `fact_id=92013` (`A_core`) — The pooled prevalence of sarcopenia in dialysis patients was 25.6% (95% CI 22.1 to 29.4%). doi=10.3390/nu14194077

## Context receipts

_Boundary evidence only; these receipts broaden source context but do not independently prove the lead claim._

- `fact_id=81540` (`B_context`) — Overall sarcopenia prevalence was 15.5% (95%CI 11.8-19.1) using combined criteria. doi=10.1002/jcsm.12600
- `fact_id=93336` (`B_context`) — Prevalence of confirmed sarcopenia was significantly lower using STS compared with grip strength (30CST, 4.6%; 5TSTS, 4.1% vs. grip strength, 7.1%; p < 0.05). doi=10.1186/s11556-020-00255-5

## What this changes

Treat this as a focused working signal, not a broad topic claim. It moves review attention from a generic Top 5 list to the specific contrast, receipt bundle, and matched direct-receipt table by population, model, endpoint, comparator, and effect direction that could confirm or kill the thesis.

## Limitations

- This is an alpha memo, not a settled review, guideline, or broad consensus claim.
- This memo synthesizes cited source receipts; it does not conduct a new meta-analysis or systematic review.
- Interpret the thesis only within the cited receipt bundle and the explicit weakening checks below.
- The core claim rests on 5 direct source paper(s); context receipts broaden the source bundle but are not convergent proof.
- Independent receipts fail to reproduce the claimed contrast.
- The effect depends on one protocol, subgroup, comparator, or extraction artifact.

## What would weaken this

- Independent receipts fail to reproduce the claimed contrast.
- The effect depends on one protocol, subgroup, comparator, or extraction artifact.

## Strongest counter-evidence

- _Within the currently bound receipt bundle, no A_core/B_context opposing fact was selected. Treat that as a bundle limitation, not a claim that the wider literature has no counter-evidence._

## Next extraction

- Extract independent A_core/B_context receipts that test the lead contrast directly.
- Audit whether each direct receipt remains comparable on population, endpoint, comparator, and measurement method.
- Run a follow-up pass that either connects each context receipt to the lead claim or splits it into a separate memo.

{
  "article_type": "alpha_memo",
  "domain_slug": "general",
  "researka_object_type": "submission",
  "researka_submission_id": "4f6aec75-ac92-4be1-8672-f1dbee45ec0e",
  "title": "Sarcopenia prevalence may hinge on a boundary condition"
}