STROBE-AMS (STROBE Extension for Antimicrobial Stewardship)

What it is

— STROBE-AMS (Strengthening the Reporting of Observational Studies in Epidemiology — extension for studies on Antimicrobial resistance and antimicrobial Stewardship) is a topic-specific extension of the parent STROBE reporting guideline. It was developed by Tacconelli and colleagues (BMJ Open, 2016) through a two-round Delphi consensus and is catalogued in the EQUATOR Network library of reporting guidelines. STROBE-AMS does not replace STROBE; it layers additional, AMS-specific reporting items onto the 22-item STROBE checklist so that observational studies of antibiotic exposure, antimicrobial resistance (AMR), and stewardship interventions describe their design, microbiology, and exposure measurement with enough granularity for readers, evidence synthesists, and decision-makers to judge validity and pool results. Like all STROBE-family tools, it is a reporting instrument — a transparency contract about what an article must disclose — not an instrument for designing the study or grading its quality.

When to use

— Apply STROBE-AMS when you are reporting an observational epidemiological study (cohort, case-control, or cross-sectional) whose core scientific content concerns antimicrobial use, the selection or spread of antimicrobial resistance, or the effect of stewardship interventions, and you are writing for a peer-reviewed journal, an HTA/payer evidence package, or an evidence-synthesis input. Decision rule for choosing the right STROBE family member: use plain STROBE for a generic observational study with no AMS-specific exposure/outcome; use STROBE-AMS when the study's exposure is antimicrobial use or its outcome is resistance/stewardship effectiveness and the microbiological detail (organism, susceptibility testing, breakpoints, resistance definitions) is load-bearing; and if the study is built on routinely-collected health data (claims, EHR, registries, dispensing or microbiology databases), layer RECORD (or RECORD-PE for pharmacoepidemiology) on top, because STROBE-AMS says little about database provenance, linkage, code lists, and data cleaning. STROBE-AMS applies to the report; it is not a protocol template (use HARPER or the ENCePP checklist for that) and not a randomized-trial guideline (use CONSORT for an RCT of a stewardship intervention).

What it requires

— On top of the standard STROBE domains (title/abstract, background, objectives, design, setting, participants and eligibility, variables, data sources/measurement, bias, study size, statistical methods, descriptive and outcome results, limitations, generalizability, funding), STROBE-AMS adds AMS-specific reporting that maps onto the same validity concerns that govern any real-world-data study: (1) Exposure definition and measurement — how antimicrobial exposure was ascertained and quantified (defined daily doses, days of therapy, dispensing vs administration, look-back windows), the analogue of phenotype/algorithm specification in claims and EHR work; (2) Microbiological methods and resistance definitions — the organism(s), specimen source, susceptibility-testing method, breakpoint system (e.g., EUCAST/CLSI) and version, and the explicit rule that classified an isolate as resistant, so that the resistance "outcome" is reproducible; (3) Time relationships — the temporal ordering of exposure and resistance, which is the AMS-specific face of time-zero alignment and immortal-time avoidance; (4) Confounding and case-mix — patient- and unit-level confounders (severity, prior hospitalization, device exposure, co-medications) and how they were handled; (5) Population, denominator, and setting — the at-risk denominator and care setting that make rates interpretable and transportable. The extension's intent is that two studies reporting the "same" association can be compared only if exposure metrics, resistance definitions, and denominators are stated precisely — exactly the comparability problem that defeats naive pooling of observational estimates.

When NOT to use — limitations and common misapplications

— STROBE-AMS is a reporting checklist, with the hard limits that implies. (1) It is not a risk-of-bias instrument and not a quality score. A fully STROBE-AMS-compliant paper can still be badly confounded; appraise non-randomized AMS studies with ROBINS-I, not with checklist completeness. Do not sum ticked items into a "quality score" — STROBE's authors explicitly warn against this. (2) Completing the checklist does not make the study causal. Transparent reporting of an exposure–resistance association is necessary, not sufficient; the causal claim rests on design (active comparator, new-user, target-trial emulation), not on disclosure. (3) Wrong family member / wrong layer. Using plain STROBE where the AMS-specific microbiology and exposure items are needed under-reports the study; conversely, using STROBE-AMS alone for a study built on claims or linked EHR omits the database-provenance, code-list, and linkage reporting that RECORD/RECORD-PE exist to enforce — these are complementary, not interchangeable. (4) Wrong design entirely. STROBE-AMS is for observational designs; a cluster-randomized stewardship trial is reported with CONSORT, and a study protocol with HARPER/ENCePP. (5) Checklist-as-theater. Pointing every item at a page number while leaving the resistance definition, breakpoint version, or exposure metric vague defeats the purpose — the value is the substantive disclosure, not the cross-reference table.

How it maps to this catalog

— In this repo, STROBE-AMS's reporting demands are implemented (i.e., the underlying design/measurement work the report must describe) by these concepts: - Exposure/outcome ascertainment (antimicrobial-use metrics; resistance/infection outcome definitions): diagnosis-phenotype-algorithm-1ip-2op-time-window-rwe, claims-outcome-algorithm-ppv-sensitivity-rwe, algorithm-validation, and misclassification-bias-correction-rwe for quantifying outcome/exposure misclassification the report must acknowledge. - Design validity and confounding control the paper must report: active-comparator-new-user, target-trial-emulation, and high-dimensional-propensity-score-hdps-rwe. - Estimand and time structure (STROBE-AMS's time-relationship and effect-measure items): estimands-ate-att-intercurrent-events-rwe. - Population, attrition, and generalizability (denominator, loss to follow-up, transportability of rates): attrition-and-loss-to-follow-up-rwe, database-feasibility-attrition-funnel-rwe, and generalizability-transportability-external-validity-rwe. - Data-source provenance when the study is database-built: claims-analysis and medicare-ffs-ma-commercial-claims-differences-rwe — and, at the reporting layer, pair STROBE-AMS with RECORD/RECORD-PE.

Applied note (claims/EHR/registry RWE)

A claims- or EHR-based study of, say, fluoroquinolone exposure and subsequent resistant Gram-negative infection should, to satisfy STROBE-AMS and be appraisable, report the antibiotic exposure metric and look-back window (the diagnosis-phenotype-algorithm-1ip-2op-time-window-rwe and exposure-window logic), the validated outcome definition with its PPV/sensitivity (claims-outcome-algorithm-ppv-sensitivity-rwe, algorithm-validation), the breakpoint system/version used to define resistance, time-zero alignment and the comparator strategy (active-comparator-new-user), confounding control (high-dimensional-propensity-score-hdps-rwe), the analytic estimand (estimands-ate-att-intercurrent-events-rwe), the enrolment/attrition funnel and at-risk denominator (database-feasibility-attrition-funnel-rwe, attrition-and-loss-to-follow-up-rwe), and the database provenance, linkage, and code lists (which is where RECORD/RECORD-PE and claims-analysis carry the load STROBE-AMS does not).