data: PubMed systematic search + grey literature for skin substitutes (refs #235, refs #236)

PubMed E-utilities search across 3 domains:
- clinical efficacy: 7,445 articles (MeSH skin substitutes/biological dressings + outcomes)
- cost-effectiveness: 123 articles (economics, Medicare spending, ASP)
- fraud/waste/abuse: 356 articles (billing patterns, enforcement, compliance)
- 7,817 unique articles after dedup, stored in bib.sqlite with PRISMA counts

Grey literature catalogue: 20 curated documents
- 3 OIG reports (incl. Sept 2025 payment trends)
- 4 CMS rules (CY2024-2026 OPPS/PFS, Benefit Policy Manual)
- 4 DOJ/court filings (Jenson, Gehrke/King, Vohra, national takedown)
- 3 GAO/MedPAC reports
- 4 MAC LCDs (Noridian, CGS, First Coast, Palmetto)
- 2 industry position statements

All tagged module:skin-subs with source and type tags for downstream filtering.

dev/scripts/collect_grey_lit_skin_subs.py

@@ -0,0 +1,505 @@
+"""Collect grey literature for skin substitutes research.
+
+Captures non-journal evidence: OIG reports, CMS rules, GAO/MedPAC reports,
+DOJ press releases, court filings, MAC LCDs, and industry position statements.
+
+Each document is stored in bib.sqlite with tags:
+  module:skin-subs, source:{oig|cms|gao|medpac|doj|court|mac-lcd|industry}
+
+Documents are curated — each entry below is a known, authoritative source
+identified during the skin substitutes research design phase.
+
+Usage:
+    uv run python dev/scripts/collect_grey_lit_skin_subs.py
+    uv run python dev/scripts/collect_grey_lit_skin_subs.py --dry-run
+"""
+
+from __future__ import annotations
+
+import argparse
+from dataclasses import dataclass, field
+from datetime import datetime
+
+from bib.item import Rule, Source
+from bib.store import Store
+
+# ---------------------------------------------------------------------------
+# Grey literature catalogue
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class GreyLitEntry:
+    """A single grey literature document to capture."""
+
+    title: str
+    url: str
+    source_tag: str  # oig, cms, gao, medpac, doj, court, mac-lcd, industry
+    type_tag: str  # report, rule, press-release, filing, lcd, position
+    date_published: str  # YYYY or YYYY-MM-DD
+    institution: str
+    abstract: str = ""
+    extra: str = ""
+    extra_tags: list[str] = field(default_factory=list)
+
+
+# --- OIG Reports ---
+OIG_REPORTS = [
+    GreyLitEntry(
+        title=(
+            "Medicare Part B Payment Trends for Skin Substitutes "
+            "Raise Major Concerns About Fraud, Waste, and Abuse"
+        ),
+        url="https://oig.hhs.gov/oei/reports/OEI-02-22-00340.asp",
+        source_tag="oig",
+        type_tag="report",
+        date_published="2025-09",
+        institution="HHS Office of Inspector General",
+        abstract=(
+            "Medicare spending on skin substitutes (CTPs) grew from $256M in 2019 "
+            "to over $10B by 2024. The report identifies troubling patterns: "
+            "concentration of billing among small number of providers, extremely "
+            "high per-beneficiary spending, and products with limited evidence of "
+            "clinical efficacy commanding the highest prices."
+        ),
+        extra_tags=["entity:oig"],
+    ),
+    GreyLitEntry(
+        title="Concerns About Skin Substitutes in the Medicare Program",
+        url="https://oig.hhs.gov/documents/special-advisory-bulletins/1078/SAB-Skin-Substitutes.pdf",
+        source_tag="oig",
+        type_tag="report",
+        date_published="2024",
+        institution="HHS Office of Inspector General",
+        abstract=(
+            "OIG Special Advisory Bulletin on fraud and abuse risks in the skin "
+            "substitute market, including kickback arrangements, medically "
+            "unnecessary applications, and documentation deficiencies."
+        ),
+    ),
+    GreyLitEntry(
+        title=(
+            "Medicare Improperly Paid Millions of Dollars for Skin "
+            "Substitute Products and Related Services"
+        ),
+        url="https://oig.hhs.gov/oas/reports/region5/51700028.asp",
+        source_tag="oig",
+        type_tag="report",
+        date_published="2019",
+        institution="HHS Office of Inspector General",
+        abstract=(
+            "OIG audit finding improper payments for skin substitute products "
+            "due to inadequate documentation, lack of medical necessity, and "
+            "billing errors."
+        ),
+    ),
+]
+
+# --- CMS Rules ---
+CMS_RULES = [
+    GreyLitEntry(
+        title=(
+            "CY 2026 OPPS/ASC Final Rule (CMS-1834-FC) — Reclassification of "
+            "Skin Substitutes from Drugs/Biologicals to Incident-To Supplies"
+        ),
+        url="https://www.federalregister.gov/documents/2025/11/20/2025-23371/medicare-program-changes-to-the-hospital-outpatient-prospective-payment-and-ambulatory-surgical-center",
+        source_tag="cms",
+        type_tag="rule",
+        date_published="2025-11-20",
+        institution="Centers for Medicare & Medicaid Services",
+        abstract=(
+            "CMS reclassifies skin substitutes/CTPs from drugs and biologicals "
+            "(ASP+6% payment) to incident-to supplies (flat rate $127.28/cm²). "
+            "Creates new HCPCS C5271-C5278 codes replacing Q4xxx series. "
+            "Estimated $9.4B savings over 10 years."
+        ),
+        extra=(
+            "FR Vol 90, Doc 2025-23371\n"
+            "CMS-1834-FC\n"
+            "Effective: 2026-01-01\n"
+            "Flat rate: $127.28/cm² (replaces ASP+6%)\n"
+            "New codes: C5271-C5278"
+        ),
+        extra_tags=["rule:cy2026-opps"],
+    ),
+    GreyLitEntry(
+        title=(
+            "CY 2025 OPPS/ASC Final Rule (CMS-1809-FC) — Skin Substitute "
+            "Payment Under OPPS"
+        ),
+        url="https://www.federalregister.gov/documents/2024/11/18/2024-25518/medicare-program-changes-to-the-hospital-outpatient-prospective-payment-and-ambulatory-surgical-center",
+        source_tag="cms",
+        type_tag="rule",
+        date_published="2024-11-18",
+        institution="Centers for Medicare & Medicaid Services",
+        abstract=(
+            "Discusses skin substitute payment methodology under OPPS, "
+            "creates high/low cost categories, and signals forthcoming "
+            "reclassification from biological to supply."
+        ),
+        extra_tags=["rule:cy2025-opps"],
+    ),
+    GreyLitEntry(
+        title=(
+            "CY 2024 PFS Final Rule (CMS-1784-F) — Skin Substitute "
+            "Payment Under Part B"
+        ),
+        url="https://www.federalregister.gov/documents/2023/11/16/2023-24184/medicare-and-medicaid-programs-cy-2024-payment-policies-under-the-physician-fee-schedule",
+        source_tag="cms",
+        type_tag="rule",
+        date_published="2023-11-16",
+        institution="Centers for Medicare & Medicaid Services",
+        abstract=(
+            "Discusses skin substitute billing requirements and medical "
+            "necessity documentation under Part B physician fee schedule."
+        ),
+        extra_tags=["rule:cy2024-pfs"],
+    ),
+    GreyLitEntry(
+        title="Medicare Benefit Policy Manual, Ch.15 §270 — Biological Products",
+        url="https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/bp102c15.pdf",
+        source_tag="cms",
+        type_tag="manual",
+        date_published="2024",
+        institution="Centers for Medicare & Medicaid Services",
+        abstract=(
+            "Coverage and payment policy for biological products (skin "
+            "substitutes) under Medicare Part B, including medical necessity "
+            "criteria, documentation requirements, and incident-to billing."
+        ),
+    ),
+]
+
+# --- DOJ Enforcement ---
+DOJ_ENFORCEMENT = [
+    GreyLitEntry(
+        title=(
+            "DOJ National Health Care Fraud Enforcement Action: 193 Defendants "
+            "Charged for $2.75 Billion in Fraud"
+        ),
+        url="https://www.justice.gov/opa/pr/justice-department-leads-efforts-seize-over-26-million-proceeds-connected-alleged-health-care",
+        source_tag="doj",
+        type_tag="press-release",
+        date_published="2025-06",
+        institution="U.S. Department of Justice",
+        abstract=(
+            "Largest-ever health care fraud takedown. Skin substitutes and "
+            "wound care fraud was a primary target area, with multiple "
+            "cases involving medically unnecessary applications, kickbacks, "
+            "and predatory billing patterns."
+        ),
+        extra_tags=["entity:doj"],
+    ),
+    GreyLitEntry(
+        title=(
+            "USA v. Patrick Jenson et al. (S.D. Tex. 4:25-cr-00271) — "
+            "$90M Skin Substitute Fraud"
+        ),
+        url="https://www.justice.gov/usao-sdtx/pr/podiatrist-and-three-others-charged-90-million-health-care-fraud-scheme",
+        source_tag="court",
+        type_tag="filing",
+        date_published="2025",
+        institution="U.S. District Court, S.D. Texas",
+        abstract=(
+            "Podiatry clinic billed $90M, received $45M in payments for "
+            "skin substitute products. Allegations include medically "
+            "unnecessary applications, forged documentation, and kickback "
+            "arrangements with product distributors."
+        ),
+        extra="Case: 4:25-cr-00271\nDistrict: S.D. Tex.",
+        extra_tags=["case:jenson", "entity:sdtx"],
+    ),
+    GreyLitEntry(
+        title=(
+            "USA v. Gehrke & King (D. Ariz.) — $1.2B Mobile Wound Care "
+            "Fraud Scheme"
+        ),
+        url="https://www.justice.gov/usao-az/pr/two-individuals-charged-12-billion-health-care-fraud-scheme-involving-mobile-wound-care",
+        source_tag="court",
+        type_tag="filing",
+        date_published="2025",
+        institution="U.S. District Court, D. Arizona",
+        abstract=(
+            "Mobile wound care company billed $1.2B for skin substitute "
+            "products. Defendants allegedly recruited patients from nursing "
+            "facilities, applied products without medical necessity, and "
+            "operated a nationwide kickback network."
+        ),
+        extra="District: D. Ariz.",
+        extra_tags=["case:gehrke-king", "entity:daz"],
+    ),
+    GreyLitEntry(
+        title="Vohra Wound Physicians (S.D. Fla.) — $45M FCA Settlement",
+        url="https://www.justice.gov/opa/pr/wound-care-company-and-physician-pay-455-million-resolve-false-claims-act-allegations",
+        source_tag="court",
+        type_tag="filing",
+        date_published="2024",
+        institution="U.S. District Court, S.D. Florida",
+        abstract=(
+            "Vohra Wound Physicians settled for $45M over allegations of "
+            "EMR-driven auto-upcoding of wound care services, including "
+            "skin substitute applications coded at higher complexity than "
+            "performed."
+        ),
+        extra="District: S.D. Fla.\nSettlement: $45.5M",
+        extra_tags=["case:vohra", "entity:sdfl"],
+    ),
+]
+
+# --- GAO / MedPAC ---
+GAO_MEDPAC = [
+    GreyLitEntry(
+        title=(
+            "GAO-23-105537: Medicare Part B — CMS Should Take Steps to "
+            "Better Manage Spending on New Biologicals"
+        ),
+        url="https://www.gao.gov/products/gao-23-105537",
+        source_tag="gao",
+        type_tag="report",
+        date_published="2023-04",
+        institution="U.S. Government Accountability Office",
+        abstract=(
+            "GAO report on Part B spending growth for biologicals including "
+            "skin substitutes. Recommends CMS strengthen payment controls "
+            "and evidence requirements for high-cost biological products."
+        ),
+        extra_tags=["entity:gao"],
+    ),
+    GreyLitEntry(
+        title=(
+            "MedPAC June 2024 Report to Congress, Ch.3: Medicare Part B "
+            "Drug and Biological Spending"
+        ),
+        url="https://www.medpac.gov/document/june-2024-report-to-the-congress/",
+        source_tag="medpac",
+        type_tag="report",
+        date_published="2024-06",
+        institution="Medicare Payment Advisory Commission",
+        abstract=(
+            "MedPAC analysis of Part B drug and biological spending trends, "
+            "including discussion of skin substitute market dynamics, "
+            "ASP+6% payment incentives, and recommendations for payment reform."
+        ),
+        extra_tags=["entity:medpac"],
+    ),
+    GreyLitEntry(
+        title=(
+            "MedPAC March 2025 Report to Congress — Payment for "
+            "Wound Care Products"
+        ),
+        url="https://www.medpac.gov/document/march-2025-report-to-the-congress/",
+        source_tag="medpac",
+        type_tag="report",
+        date_published="2025-03",
+        institution="Medicare Payment Advisory Commission",
+        abstract=(
+            "MedPAC analysis of the CMS reclassification of skin substitutes "
+            "and wound care products, including market impact assessment "
+            "and alternative payment recommendations."
+        ),
+        extra_tags=["entity:medpac"],
+    ),
+]
+
+# --- MAC LCDs ---
+MAC_LCDS = [
+    GreyLitEntry(
+        title="Noridian LCD L39831 — Skin Substitutes and Wound Care",
+        url="https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=39831",
+        source_tag="mac-lcd",
+        type_tag="lcd",
+        date_published="2024",
+        institution="Noridian Healthcare Solutions (MAC JE/JF)",
+        abstract=(
+            "Local Coverage Determination for skin substitute products "
+            "including coverage criteria, documentation requirements, "
+            "and coding guidance for Medicare claims."
+        ),
+        extra_tags=["entity:noridian"],
+    ),
+    GreyLitEntry(
+        title="CGS LCD L38916 — Application of Skin Substitute Grafts",
+        url="https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=38916",
+        source_tag="mac-lcd",
+        type_tag="lcd",
+        date_published="2024",
+        institution="CGS Administrators (MAC J15)",
+        abstract=(
+            "Coverage determination for skin substitute graft application "
+            "codes (15271-15278), including medical necessity criteria "
+            "and frequency limitations."
+        ),
+        extra_tags=["entity:cgs"],
+    ),
+    GreyLitEntry(
+        title="First Coast LCD L36498 — Wound Care (Skin Substitutes)",
+        url="https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=36498",
+        source_tag="mac-lcd",
+        type_tag="lcd",
+        date_published="2023",
+        institution="First Coast Service Options (MAC JN)",
+        abstract=(
+            "LCD covering wound care services including skin substitute "
+            "application, debridement, and negative pressure wound therapy. "
+            "Defines covered diagnoses and documentation requirements."
+        ),
+        extra_tags=["entity:first-coast"],
+    ),
+    GreyLitEntry(
+        title="Palmetto LCD L35041 — Wound Care",
+        url="https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=35041",
+        source_tag="mac-lcd",
+        type_tag="lcd",
+        date_published="2023",
+        institution="Palmetto GBA (MAC JJ/JM)",
+        abstract=(
+            "Coverage criteria for wound care including skin substitute "
+            "products, with specific documentation and medical necessity "
+            "requirements for the southern US jurisdictions."
+        ),
+        extra_tags=["entity:palmetto"],
+    ),
+]
+
+# --- Industry / Professional Societies ---
+INDUSTRY = [
+    GreyLitEntry(
+        title=(
+            "Alliance of Wound Care Stakeholders — Position Statement on "
+            "CMS Reclassification of Skin Substitutes"
+        ),
+        url="https://www.woundcarestakeholders.org/value-of-wound-care/skin-substitutes-ctps",
+        source_tag="industry",
+        type_tag="position",
+        date_published="2025",
+        institution="Alliance of Wound Care Stakeholders",
+        abstract=(
+            "Industry coalition position opposing CMS reclassification "
+            "from drugs/biologicals to supplies, arguing it will reduce "
+            "patient access and stifle innovation."
+        ),
+    ),
+    GreyLitEntry(
+        title=(
+            "Wound Healing Society — Guidelines for the Treatment of "
+            "Chronic Wounds with Cellular and Tissue-Based Products"
+        ),
+        url="https://onlinelibrary.wiley.com/doi/10.1111/wrr.13150",
+        source_tag="industry",
+        type_tag="position",
+        date_published="2024",
+        institution="Wound Healing Society",
+        abstract=(
+            "Clinical practice guidelines for use of CTPs (skin substitutes) "
+            "in chronic wound management, including evidence grading "
+            "and recommendations for specific product categories."
+        ),
+    ),
+]
+
+
+ALL_ENTRIES = OIG_REPORTS + CMS_RULES + DOJ_ENFORCEMENT + GAO_MEDPAC + MAC_LCDS + INDUSTRY
+
+
+# ---------------------------------------------------------------------------
+# Store integration
+# ---------------------------------------------------------------------------
+
+
+def entry_to_item(entry: GreyLitEntry) -> Source:
+    """Convert a GreyLitEntry to a bib Source item."""
+    tags = [
+        "module:skin-subs",
+        f"source:{entry.source_tag}",
+        f"type:{entry.type_tag}",
+    ]
+    if entry.date_published:
+        year = entry.date_published[:4]
+        tags.append(f"year:{year}")
+    tags.extend(entry.extra_tags)
+
+    return Source(
+        title=entry.title,
+        url=entry.url,
+        date_published=entry.date_published,
+        institution=entry.institution,
+        abstract=entry.abstract,
+        doc_type=entry.type_tag,
+        tags=tags,
+        extra=entry.extra,
+    )
+
+
+# ---------------------------------------------------------------------------
+# Main
+# ---------------------------------------------------------------------------
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="Grey literature collection")
+    parser.add_argument("--dry-run", action="store_true",
+                        help="Print catalogue only, don't write to bib.sqlite")
+    args = parser.parse_args()
+
+    print("=" * 70)
+    print("Grey Literature Collection: Skin Substitutes")
+    print(f"Date: {datetime.now().strftime('%Y-%m-%d %H:%M')}")
+    print("=" * 70)
+
+    # Catalogue summary
+    by_source: dict[str, int] = {}
+    for entry in ALL_ENTRIES:
+        by_source[entry.source_tag] = by_source.get(entry.source_tag, 0) + 1
+
+    print(f"\nTotal documents: {len(ALL_ENTRIES)}")
+    print("By source:")
+    for src, count in sorted(by_source.items()):
+        print(f"  {src:15s}: {count:>3}")
+
+    print("\nDocuments:")
+    for i, entry in enumerate(ALL_ENTRIES, 1):
+        print(f"  {i:2d}. [{entry.source_tag}] {entry.title[:70]}")
+
+    if args.dry_run:
+        print("\n[DRY RUN] Skipping bib.sqlite write")
+        return
+
+    # Store in bib.sqlite
+    print(f"\nStoring {len(ALL_ENTRIES)} documents in bib.sqlite ...")
+    store = Store()
+
+    created = 0
+    updated = 0
+    for entry in ALL_ENTRIES:
+        item = entry_to_item(entry)
+        con = store._con()
+        existing = con.execute(
+            "SELECT key FROM items WHERE url = ?", (item.url,)
+        ).fetchone()
+        if existing:
+            updated += 1
+        else:
+            created += 1
+        store.upsert(item)
+
+    print(f"  Created: {created}")
+    print(f"  Updated: {updated}")
+
+    # Verify total skin-subs grey lit
+    con = store._con()
+    total = con.execute(
+        """SELECT count(DISTINCT i.id) FROM items i
+           JOIN item_tags it ON i.id = it.item_id
+           JOIN tags t ON it.tag_id = t.id
+           WHERE t.name = 'module:skin-subs'
+           AND i.item_type = 'source'
+           AND i.url NOT LIKE '%pubmed%'"""
+    ).fetchone()[0]
+    print(f"  Total skin-subs grey lit in bib.sqlite: {total}")
+
+    store.close()
+    print("\nDone.")
+
+
+if __name__ == "__main__":
+    main()

dev/scripts/search_pubmed_skin_subs.py

@@ -0,0 +1,474 @@
+"""PubMed systematic literature search for skin substitutes.
+
+Queries NCBI E-utilities (esearch → efetch) across three domains:
+
+1. Clinical efficacy — RCTs, systematic reviews, wound healing outcomes
+2. Cost-effectiveness — health economics, Medicare spending, reimbursement
+3. Fraud/waste/abuse — billing patterns, enforcement, compliance
+
+Results are stored in bib.sqlite via the bib.store.Store with tags:
+  module:skin-subs, source:pubmed, type:{rct|review|meta-analysis|economic|policy|fraud}
+
+Respects NCBI rate limits (3 requests/sec without API key, 10/sec with).
+Set NCBI_API_KEY environment variable for higher throughput.
+
+Usage:
+    uv run python dev/scripts/search_pubmed_skin_subs.py
+    uv run python dev/scripts/search_pubmed_skin_subs.py --dry-run
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import time
+import xml.etree.ElementTree as ET
+from dataclasses import dataclass, field
+from datetime import datetime
+
+import httpx
+
+from bib.item import Source
+from bib.store import Store
+
+# ---------------------------------------------------------------------------
+# NCBI E-utilities configuration
+# ---------------------------------------------------------------------------
+EUTILS_BASE = "https://eutils.ncbi.nlm.nih.gov/entrez/eutils"
+API_KEY = os.environ.get("NCBI_API_KEY", "")
+TOOL_NAME = "stack-skin-subs"
+TOOL_EMAIL = "dev@localhost"
+RATE_LIMIT = 0.34 if not API_KEY else 0.1  # seconds between requests
+
+
+def _params(**kw: str) -> dict[str, str]:
+    """Build E-utilities query params with tool/email/api_key."""
+    base = {"tool": TOOL_NAME, "email": TOOL_EMAIL}
+    if API_KEY:
+        base["api_key"] = API_KEY
+    base.update(kw)
+    return base
+
+
+# ---------------------------------------------------------------------------
+# Search strategies
+# ---------------------------------------------------------------------------
+
+_Q_CLINICAL = (
+    '("skin substitutes"[MeSH] OR "biological dressings"[MeSH] '
+    'OR "tissue scaffolds"[MeSH] OR "bioengineered skin"[tiab] '
+    'OR "cellular tissue product"[tiab] OR "wound matrix"[tiab] '
+    'OR "skin substitute"[tiab] OR "skin substitutes"[tiab] '
+    'OR "Apligraf"[tiab] OR "EpiFix"[tiab] OR "Grafix"[tiab] '
+    'OR "DermACELL"[tiab] OR "Dermagraft"[tiab]) '
+    'AND ("wound healing"[MeSH] OR "treatment outcome"[MeSH] '
+    'OR "clinical trial"[pt] OR "randomized controlled trial"[pt] '
+    'OR "systematic review"[pt] OR "meta-analysis"[pt] '
+    'OR "efficacy"[tiab] OR "effectiveness"[tiab])'
+)
+
+_Q_COST = (
+    '("skin substitutes"[MeSH] OR "biological dressings"[MeSH] '
+    'OR "skin substitute"[tiab] OR "skin substitutes"[tiab] '
+    'OR "cellular tissue product"[tiab]) '
+    'AND ("costs and cost analysis"[MeSH] '
+    'OR "cost-benefit analysis"[MeSH] '
+    'OR "health care costs"[MeSH] OR "medicare"[MeSH] '
+    'OR "reimbursement"[tiab] OR "cost-effectiveness"[tiab] '
+    'OR "economic"[tiab] OR "spending"[tiab] '
+    'OR "average sales price"[tiab] OR "ASP"[tiab])'
+)
+
+_Q_FRAUD = (
+    '("skin substitutes"[MeSH] OR "biological dressings"[MeSH] '
+    'OR "skin substitute"[tiab] OR "skin substitutes"[tiab] '
+    'OR "cellular tissue product"[tiab] OR "wound care"[tiab]) '
+    'AND ("fraud"[MeSH] OR "waste"[tiab] OR "abuse"[tiab] '
+    'OR "inappropriate"[tiab] OR "overutilization"[tiab] '
+    'OR "billing"[tiab] OR "enforcement"[tiab] '
+    'OR "compliance"[tiab] OR "medically unnecessary"[tiab] '
+    'OR "upcoding"[tiab] OR "kickback"[tiab])'
+)
+
+SEARCHES: dict[str, dict[str, str | list[str]]] = {
+    "clinical_efficacy": {"query": _Q_CLINICAL, "tags": ["type:clinical"]},
+    "cost_effectiveness": {"query": _Q_COST, "tags": ["type:economic"]},
+    "fraud_waste_abuse": {"query": _Q_FRAUD, "tags": ["type:fraud"]},
+}
+
+
+# ---------------------------------------------------------------------------
+# Article model
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class Article:
+    pmid: str = ""
+    title: str = ""
+    abstract: str = ""
+    authors: list[str] = field(default_factory=list)
+    journal: str = ""
+    year: str = ""
+    doi: str = ""
+    pub_types: list[str] = field(default_factory=list)
+    mesh_terms: list[str] = field(default_factory=list)
+
+    @property
+    def url(self) -> str:
+        return f"https://pubmed.ncbi.nlm.nih.gov/{self.pmid}/"
+
+    def infer_type_tag(self) -> str:
+        """Infer article type from PubMed publication types."""
+        pt_lower = [p.lower() for p in self.pub_types]
+        if "meta-analysis" in pt_lower:
+            return "type:meta-analysis"
+        if "systematic review" in pt_lower:
+            return "type:review"
+        if "review" in pt_lower:
+            return "type:review"
+        if "randomized controlled trial" in pt_lower:
+            return "type:rct"
+        if "clinical trial" in pt_lower:
+            return "type:rct"
+        return ""
+
+
+# ---------------------------------------------------------------------------
+# E-utilities helpers
+# ---------------------------------------------------------------------------
+
+
+def esearch(query: str, retmax: int = 10000) -> list[str]:
+    """Search PubMed, return list of PMIDs."""
+    params = _params(
+        db="pubmed",
+        term=query,
+        retmax=str(retmax),
+        retmode="json",
+        usehistory="n",
+    )
+    resp = httpx.get(f"{EUTILS_BASE}/esearch.fcgi", params=params, timeout=30)
+    resp.raise_for_status()
+    data = resp.json()
+    result = data.get("esearchresult", {})
+    ids = result.get("idlist", [])
+    count = int(result.get("count", 0))
+    print(f"  esearch: {count} total results, retrieved {len(ids)} PMIDs")
+    return ids
+
+
+def efetch_articles(
+    pmids: list[str], batch_size: int = 100, max_retries: int = 3
+) -> list[Article]:
+    """Fetch article metadata for a list of PMIDs."""
+    articles: list[Article] = []
+    for i in range(0, len(pmids), batch_size):
+        batch = pmids[i : i + batch_size]
+        params = _params(
+            db="pubmed",
+            id=",".join(batch),
+            rettype="xml",
+            retmode="xml",
+        )
+        for attempt in range(max_retries):
+            time.sleep(RATE_LIMIT * (attempt + 1))
+            try:
+                resp = httpx.get(
+                    f"{EUTILS_BASE}/efetch.fcgi",
+                    params=params,
+                    timeout=120,
+                )
+                resp.raise_for_status()
+                articles.extend(_parse_pubmed_xml(resp.text))
+                break
+            except (httpx.RemoteProtocolError, httpx.ReadTimeout) as exc:
+                if attempt < max_retries - 1:
+                    wait = 2 ** (attempt + 1)
+                    print(f"  RETRY batch {i // batch_size + 1} "
+                          f"(attempt {attempt + 2}/{max_retries}, "
+                          f"wait {wait}s): {exc}")
+                    time.sleep(wait)
+                else:
+                    print(f"  SKIP batch {i // batch_size + 1} after "
+                          f"{max_retries} attempts: {exc}")
+        print(f"  efetch: batch {i // batch_size + 1}/{len(pmids) // batch_size + 1}, "
+              f"got {len(articles)} articles so far")
+    return articles
+
+
+def _text(el: ET.Element | None, path: str, default: str = "") -> str:
+    """Get text from an XML element, handling None."""
+    if el is None:
+        return default
+    node = el.find(path)
+    return (node.text or default) if node is not None else default
+
+
+def _parse_pubmed_xml(xml_text: str) -> list[Article]:
+    """Parse PubMed efetch XML into Article objects."""
+    root = ET.fromstring(xml_text)  # noqa: S314
+    articles: list[Article] = []
+
+    for art_el in root.findall(".//PubmedArticle"):
+        citation = art_el.find(".//MedlineCitation")
+        if citation is None:
+            continue
+
+        pmid = _text(citation, "PMID")
+        article_el = citation.find("Article")
+        if article_el is None:
+            continue
+
+        title = _text(article_el, "ArticleTitle")
+
+        # Abstract — may have multiple AbstractText elements
+        abstract_parts: list[str] = []
+        abstract_el = article_el.find("Abstract")
+        if abstract_el is not None:
+            for at in abstract_el.findall("AbstractText"):
+                label = at.get("Label", "")
+                text = "".join(at.itertext()).strip()
+                if label:
+                    abstract_parts.append(f"{label}: {text}")
+                else:
+                    abstract_parts.append(text)
+        abstract = "\n\n".join(abstract_parts)
+
+        # Authors
+        authors: list[str] = []
+        author_list = article_el.find("AuthorList")
+        if author_list is not None:
+            for au in author_list.findall("Author"):
+                last = _text(au, "LastName")
+                fore = _text(au, "ForeName")
+                if last:
+                    authors.append(f"{last} {fore}".strip())
+
+        # Journal
+        journal_el = article_el.find("Journal")
+        journal = _text(journal_el, "Title") if journal_el is not None else ""
+
+        # Year
+        year = ""
+        pub_date = article_el.find(".//PubDate")
+        if pub_date is not None:
+            year = _text(pub_date, "Year")
+            if not year:
+                medline = _text(pub_date, "MedlineDate")
+                if medline:
+                    year = medline[:4]
+
+        # DOI
+        doi = ""
+        for id_el in art_el.findall(".//ArticleId"):
+            if id_el.get("IdType") == "doi":
+                doi = id_el.text or ""
+                break
+
+        # Publication types
+        pub_types: list[str] = []
+        for pt in article_el.findall(".//PublicationType"):
+            if pt.text:
+                pub_types.append(pt.text)
+
+        # MeSH terms
+        mesh_terms: list[str] = []
+        mesh_list = citation.find("MeshHeadingList")
+        if mesh_list is not None:
+            for mh in mesh_list.findall("MeshHeading"):
+                desc = mh.find("DescriptorName")
+                if desc is not None and desc.text:
+                    mesh_terms.append(desc.text)
+
+        articles.append(
+            Article(
+                pmid=pmid,
+                title=title,
+                abstract=abstract,
+                authors=authors,
+                journal=journal,
+                year=year,
+                doi=doi,
+                pub_types=pub_types,
+                mesh_terms=mesh_terms,
+            )
+        )
+
+    return articles
+
+
+# ---------------------------------------------------------------------------
+# Deduplication
+# ---------------------------------------------------------------------------
+
+
+def deduplicate(all_articles: dict[str, list[Article]]) -> dict[str, Article]:
+    """Merge across search domains. First-seen domain tags win, extras merge."""
+    seen: dict[str, Article] = {}
+    seen_domains: dict[str, list[str]] = {}
+    for domain, articles in all_articles.items():
+        for art in articles:
+            if art.pmid in seen:
+                seen_domains[art.pmid].append(domain)
+            else:
+                seen[art.pmid] = art
+                seen_domains[art.pmid] = [domain]
+    return seen
+
+
+# ---------------------------------------------------------------------------
+# Store integration
+# ---------------------------------------------------------------------------
+
+
+def article_to_source(article: Article, domain_tags: list[str]) -> Source:
+    """Convert an Article to a bib Source item."""
+    tags = ["module:skin-subs", "source:pubmed"]
+    if article.year:
+        tags.append(f"year:{article.year}")
+
+    # Add type tag from pub types
+    type_tag = article.infer_type_tag()
+    if type_tag:
+        tags.append(type_tag)
+
+    # Add domain tags
+    tags.extend(domain_tags)
+
+    # Build author string for extra
+    author_str = "; ".join(article.authors[:10])
+    if len(article.authors) > 10:
+        author_str += f" (+{len(article.authors) - 10} more)"
+
+    extra_parts = [f"PMID: {article.pmid}"]
+    if article.doi:
+        extra_parts.append(f"DOI: {article.doi}")
+    if author_str:
+        extra_parts.append(f"Authors: {author_str}")
+    if article.journal:
+        extra_parts.append(f"Journal: {article.journal}")
+    if article.pub_types:
+        extra_parts.append(f"PubTypes: {'; '.join(article.pub_types)}")
+    if article.mesh_terms:
+        extra_parts.append(f"MeSH: {'; '.join(article.mesh_terms[:15])}")
+
+    return Source(
+        title=article.title,
+        url=article.url,
+        date_published=article.year,
+        institution=article.journal,
+        abstract=article.abstract,
+        doc_type="journal-article",
+        tags=tags,
+        extra="\n".join(extra_parts),
+    )
+
+
+# ---------------------------------------------------------------------------
+# Main
+# ---------------------------------------------------------------------------
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="PubMed skin substitutes search")
+    parser.add_argument("--dry-run", action="store_true",
+                        help="Search only, don't write to bib.sqlite")
+    args = parser.parse_args()
+
+    print("=" * 70)
+    print("PubMed Systematic Search: Skin Substitutes")
+    print(f"Date: {datetime.now().strftime('%Y-%m-%d %H:%M')}")
+    print(f"API key: {'configured' if API_KEY else 'not set (3 req/sec limit)'}")
+    print("=" * 70)
+
+    # Run all three search domains
+    all_articles: dict[str, list[Article]] = {}
+    all_pmids: dict[str, list[str]] = {}
+
+    for domain, cfg in SEARCHES.items():
+        print(f"\n--- Domain: {domain} ---")
+        print(f"  Query: {cfg['query'][:100]}...")
+        time.sleep(RATE_LIMIT)
+        pmids = esearch(cfg["query"])
+        all_pmids[domain] = pmids
+
+        if pmids:
+            articles = efetch_articles(pmids)
+            all_articles[domain] = articles
+            print(f"  Fetched {len(articles)} articles")
+        else:
+            all_articles[domain] = []
+            print("  No results")
+
+    # PRISMA counts
+    print("\n" + "=" * 70)
+    print("PRISMA Flow — Identification")
+    print("=" * 70)
+    total_identified = sum(len(v) for v in all_pmids.values())
+    for domain, pmids in all_pmids.items():
+        print(f"  {domain:25s}: {len(pmids):>5} records")
+    print(f"  {'TOTAL identified':25s}: {total_identified:>5}")
+
+    # Deduplicate
+    merged = deduplicate(all_articles)
+    duplicates = total_identified - len(merged)
+    print(f"\n  Duplicates removed:       {duplicates:>5}")
+    print(f"  Unique articles:          {len(merged):>5}")
+
+    # Type breakdown
+    type_counts: dict[str, int] = {}
+    for art in merged.values():
+        tag = art.infer_type_tag() or "type:other"
+        type_counts[tag] = type_counts.get(tag, 0) + 1
+
+    print("\n  By article type:")
+    for t, c in sorted(type_counts.items()):
+        print(f"    {t:25s}: {c:>5}")
+
+    if args.dry_run:
+        print("\n[DRY RUN] Skipping bib.sqlite write")
+        return
+
+    # Store in bib.sqlite
+    print(f"\nStoring {len(merged)} articles in bib.sqlite ...")
+    store = Store()
+
+    # Build domain→pmid mapping for tags
+    pmid_domains: dict[str, list[str]] = {}
+    for domain, articles in all_articles.items():
+        domain_tags = SEARCHES[domain]["tags"]
+        for art in articles:
+            if art.pmid not in pmid_domains:
+                pmid_domains[art.pmid] = list(domain_tags)
+            else:
+                for t in domain_tags:
+                    if t not in pmid_domains[art.pmid]:
+                        pmid_domains[art.pmid].append(t)
+
+    created = 0
+    updated = 0
+    for pmid, article in sorted(merged.items()):
+        domain_tags = pmid_domains.get(pmid, [])
+        source = article_to_source(article, domain_tags)
+        # Check if already exists by URL
+        con = store._con()
+        existing = con.execute(
+            "SELECT key FROM items WHERE url = ?", (source.url,)
+        ).fetchone()
+        if existing:
+            updated += 1
+        else:
+            created += 1
+        store.upsert(source)
+
+    print(f"  Created: {created}")
+    print(f"  Updated: {updated}")
+    print(f"  Total skin-subs PubMed articles in bib.sqlite: {created + updated}")
+    store.close()
+
+    print("\nDone.")
+
+
+if __name__ == "__main__":
+    main()