Content Validation of the Most Bothersome Symptom - Essential Tremor Questionnaire (MBS-ET): A Cognitive Debriefing Study
Author(s)
Ginny Shand, MSc.1, Elizabeth Exall, MSc1, Margaret Gerbasi, PhD2, Sarah Acaster, MSc1;
1Acaster Lloyd Consulting, London, United Kingdom, 2Sage Therapeutics, Inc., Cambridge, MA, USA
1Acaster Lloyd Consulting, London, United Kingdom, 2Sage Therapeutics, Inc., Cambridge, MA, USA
Presentation Documents
OBJECTIVES: To evaluate the content validity of the Most Bothersome Symptom - Essential Tremor Questionnaire (MBS-ET), a patient-reported outcome measure assessing symptoms and activities of daily living (ADL) impacts related to essential tremor (ET).
METHODS: Cognitive debriefing interviews were conducted with adult ET patients recruited across three iterative rounds. Structured interviews explored participant understanding and interpretation of the MBS-ET content, including instructions, item wording, response options, and the patient-relevance of concepts. Evidence-based revisions were made between rounds, with changes evaluated in subsequent interviews until no further modifications were required.
RESULTS: A total of N=10 participants were recruited (Round 1: n=4; Round 2: n=2; Round 3: n=4). Participants demonstrated good understanding of MBS-ET content across rounds. All symptom concepts were determined to be patient-relevant, with items assessing upper-limb tremor most frequently endorsed as relevant. ADL concepts also demonstrated evidence of patient relevance. The MBS-ET includes an open-text response option which allows respondents to state ‘other’ symptoms/ADL impacts that have bothered them in the past 7-days, and subsequently rate level of bother on these concepts. All participants that utilised this function understood its purpose and provided conceptually relevant responses. Minor evidence-based revisions were made across rounds. Following Round 1, the middle descriptive label (‘Bother me sometimes’) was removed from the numeric response scale utilised on two items assessing level of bother associated with symptoms/ADL impacts. Following Round 2, a 7-day recall period was added to two items assessing participants’ most bothersome symptom/ADL impact, to align with all other items. In Round 3, all content was well understood, and no further revisions were required.
CONCLUSIONS: Through iterative rounds of cognitive debriefing interviews, evidence-based revisions were made to the MBS-ET, with the revised version demonstrating good evidence of content validity. The psychometric validity of the MBS-ET should be investigated prior to use in clinical research.
METHODS: Cognitive debriefing interviews were conducted with adult ET patients recruited across three iterative rounds. Structured interviews explored participant understanding and interpretation of the MBS-ET content, including instructions, item wording, response options, and the patient-relevance of concepts. Evidence-based revisions were made between rounds, with changes evaluated in subsequent interviews until no further modifications were required.
RESULTS: A total of N=10 participants were recruited (Round 1: n=4; Round 2: n=2; Round 3: n=4). Participants demonstrated good understanding of MBS-ET content across rounds. All symptom concepts were determined to be patient-relevant, with items assessing upper-limb tremor most frequently endorsed as relevant. ADL concepts also demonstrated evidence of patient relevance. The MBS-ET includes an open-text response option which allows respondents to state ‘other’ symptoms/ADL impacts that have bothered them in the past 7-days, and subsequently rate level of bother on these concepts. All participants that utilised this function understood its purpose and provided conceptually relevant responses. Minor evidence-based revisions were made across rounds. Following Round 1, the middle descriptive label (‘Bother me sometimes’) was removed from the numeric response scale utilised on two items assessing level of bother associated with symptoms/ADL impacts. Following Round 2, a 7-day recall period was added to two items assessing participants’ most bothersome symptom/ADL impact, to align with all other items. In Round 3, all content was well understood, and no further revisions were required.
CONCLUSIONS: Through iterative rounds of cognitive debriefing interviews, evidence-based revisions were made to the MBS-ET, with the revised version demonstrating good evidence of content validity. The psychometric validity of the MBS-ET should be investigated prior to use in clinical research.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
PCR218
Topic
Patient-Centered Research
Topic Subcategory
Instrument Development, Validation, & Translation, Patient-reported Outcomes & Quality of Life Outcomes
Disease
SDC: Neurological Disorders