The Symptom Burden Questionnaire™ for Long COVID

The University of Birmingham’s Centre for Patient-Reported Outcomes Research (CPROR) have designed the Symptom Burden Questionnaire™ for use in research and clinical care to enable patients to report symptoms and help develop new treatments for Long COVID leveraging Aparito’s Atom5™ eCOA platform.

The approach used to develop the Symptom Burden Questionnaire™ tool appears in the BMJ titled “Development and validation of the symptom burden questionnaire for long covid (SBQ-LC): Rasch analysis”

Hughes S E, Haroon S, Subramanian A, McMullan C, Aiyegbusi O L, Turner G M et al. Development and validation of the symptom burden questionnaire for long covid (SBQ-LC): Rasch analysis BMJ 2022; 377 :e070230 doi:10.1136/bmj-2022-070230

The University of Birmingham’s release notes the tool “was developed with extensive patient input following regulatory guidance, meaning its scores may be used to support regulatory decisions around the approval of new therapies for Long COVID and by policymakers.”

The study was carried out in partnership with Aparito and funded by the National Institute for Health Research (NIHR) and UK Research and Innovation (UKRI).

Abstract: Development and validation of the symptom burden questionnaire for long covid (SBQ-LC): Rasch analysis

Objective To describe the development and validation of a novel patient reported outcome measure for symptom burden from long covid, the symptom burden questionnaire for long covid (SBQ-LC).

Design Multiphase, prospective mixed methods study.

Setting Remote data collection and social media channels in the United Kingdom, 14 April to 1 August 2021.

Participants 13 adults (aged ≥18 years) with self-reported long covid and 10 clinicians evaluated content validity. 274 adults with long covid field tested the draft questionnaire.

Main outcome measures Published systematic reviews informed development of SBQ-LC’s conceptual framework and initial item pool. Thematic analysis of transcripts from cognitive debriefing interviews and online clinician surveys established content validity. Consensus discussions with the patient and public involvement group of the Therapies for Long COVID in non-hospitalised individuals: From symptoms, patient reported outcomes and immunology to targeted therapies (TLC Study) confirmed face validity. Rasch analysis of field test data guided item and scale refinement and provided initial evidence of the SBQ-LC’s measurement properties.

Results SBQ-LC (version 1.0) is a modular instrument measuring patient reported outcomes and is composed of 17 independent scales with promising psychometric properties. Respondents rate their symptom burden during the past seven days using a dichotomous response or 4 point rating scale. Each scale provides coverage of a different symptom domain and returns a summed raw score that can be transformed to a linear (0-100) score. Higher scores represent higher symptom burden. After rating scale refinement and item reduction, all scales satisfied the Rasch model requirements for unidimensionality (principal component analysis of residuals: first residual contrast values <2.00 eigenvalue units) and item fit (outfit mean square values within 0.5 -1.5 logits). Rating scale categories were ordered with acceptable category fit statistics (outfit mean square values <2.0 logits). 14 item pairs had evidence of local dependency (residual correlation values >0.4). Across the 17 scales, person reliability ranged from 0.34 to 0.87, person separation ranged from 0.71 to 2.56, item separation ranged from 1.34 to 13.86, and internal consistency reliability (Cronbach’s alpha) ranged from 0.56 to 0.91.

Conclusions SBQ-LC (version 1.0) is a comprehensive patient reported outcome instrument developed using modern psychometric methods. It measures symptoms of long covid important to people with lived experience of the condition and may be used to evaluate the impact of interventions and inform best practice in clinical management.