3. PARS-6 (Practitioner Allegiance Risk Scale): A Six-Item Instrument for Screening Allegiance Bias — Resolving a Documented Source of Between-Study Variance in Intervention Research Synthesis — Pre-Submission Registration

PARS-6 (Practitioner Allegiance Risk Scale): A Six-Item Instrument for Screening Allegiance Bias — Resolving a Documented Source of Between-Study Variance in Intervention Research Synthesis A field-agnostic allegiance screening instrument for use across all intervention domains This component contains all materials for PARS-6 (Practitioner Allegiance Risk Scale), an original six-item binary screening instrument for investigator allegiance bias in systematic reviews and meta-analyses, developed within the MBM Lifespan Series and submitted for independent validation to Systematic Reviews (BMC) (Gopurala et al., 2026). PARS-6 addresses a documented gap in evidence synthesis methodology: no structured, field-agnostic instrument existed for screening investigator allegiance bias — a recognised source of between-study heterogeneity not captured by RoB 2 or ROBINS-I. Studies scoring ≥4/6 on PARS-6 are designated high-allegiance-risk and modelled separately in a prespecified sensitivity analysis; PARS-6 scores are reported for all included studies regardless of threshold. The instrument is offered for open adoption across intervention research fields. Items cover: tradition affiliation; funding source; COI disclosure; allegiance to comparator (highest inter-rater disagreement item — automatic third-party adjudication); intervention development role; and prior public advocacy (operationalised as prior to data collection commencement, not prior to publication). A three-option decision rule (present / unreported / confirmed absent) governs scoring of unreported items. Files in this component: PARS6_Methods_Instrument.docx (submitted for independent peer review to Systematic Reviews (BMC)); PARS6_Figure.pptx (application flowchart); PARS6_IRR_Coding_Sheet.xlsx (four-sheet inter-rater reliability workbook); PARS6_IRR_Analysis.R (base R reliability analysis script); PARS6_Retrospective_Application_Protocol.docx (JAMA/Lancet validation pathway); PARS6_Reviewer1_Briefing.docx; PARS6_Reviewer2_Briefing.docx. Developed by: Gopurala B, Gopurala OV, Gopurala S, Walsh C. MBM Lifespan Series Vol II · 2026.