Easy-BILAG: a new tool for simplified recording of SLE disease activity using BILAG-2004 index

Objective: BILAG-2004 index is a comprehensive disease activity instrument for SLE but administrative burden and potential frequency of errors limits its use in routine practice. We aimed to develop a tool for more accurate, time efficient scoring of BILAG-2004 index with full fidelity to the existing instrument.

Methods: Frequency of BILAG-2004 items was collated from a BILAG-biologics registry (BILAG-BR) dataset. Easy-BILAG prototypes were developed to address known issues affecting speed and accuracy. After expert verification, accuracy and usability of the finalised Easy-BILAG was validated against standard format BILAG-2004 in a workbook exercise of 10 case vignettes. 33 professionals ranging in expertise from 14 UK centres completed the validation exercise.

Results: Easy-BILAG incorporates all items present in 5% BILAG-BR records, plus full constitutional and renal domains into a rapid single page assessment. An embedded glossary and colour-coding assists domain scoring. A second page captures rarer manifestations when needed. In the validation exercise, Easy-BILAG yielded higher median scoring accuracy (96.7%) than standard BILAG-2004 documentation (87.8%, p=0.001), with better inter-rater agreement. Easy-BILAG was completed faster (59.5min) than the standard format (80.0min, p=0.04) for 10 cases. An advantage in accuracy was observed with Easy-BILAG use among general hospital rheumatologists (91.3 vs 75.0, p=0.02), leading to equivalent accuracy as tertiary centre rheumatologists. Clinicians rated Easy-BILAG as intuitive, convenient, and well adapted for routine practice.

Conclusion: Easy-BILAG facilitates more rapid and accurate scoring of BILAG-2004 across all clinical settings which could improve patient care and biologics prescribing. Easy-BILAG should be adopted wherever BILAG-2004 assessment is required.