Further development and validation of the Multimorbidity Treatment Burden Questionnaire (MTBQ)

Area of Science:

• Health Services Research
• Psychometrics
• Chronic Disease Management

Background:

• Multimorbidity, defined as the presence of three or more long-term conditions, affects a significant portion of the adult population.
• Assessing the treatment burden experienced by patients with multimorbidity is crucial for effective healthcare delivery.
• The Multimorbidity Treatment Burden Questionnaire (MTBQ) is a tool designed to measure this burden, but requires further psychometric validation.

Purpose of the Study:

• To conduct further psychometric testing of the Multimorbidity Treatment Burden Questionnaire (MTBQ).
• To evaluate whether reversing the MTBQ scale would reduce floor effects.
• To assess the test-retest reliability and construct validity of the MTBQ in a UK primary care setting.

Main Methods:

• A survey design was employed, recruiting adults (≥18 years) with three or more long-term conditions from UK primary care practices.
• Participants completed the MTBQ (original and reversed scale versions) and Treatment Burden Questionnaire (TBQ) at baseline and follow-up (1-4 weeks).
• Data on consultations and long-term conditions were extracted from electronic GP records. Psychometric properties including test-retest reliability (ICC) and construct validity (Spearman's rank correlation) were analyzed.

Main Results:

• 244 adults completed the baseline survey, with 225 completing follow-up. Reversing the MTBQ scale did not reduce floor effects or data skewness.
• The MTBQ demonstrated good test-retest reliability (ICC = 0.765).
• Global MTBQ scores showed significant correlations with global TBQ scores (R_s = 0.77) and weakly with consultations (R_s = 0.17) and number of GPs consulted (R_s = 0.23), but not with the number of long-term conditions (R_s = -0.063). Both questionnaires were reported as easy to complete.

Conclusions:

• The Multimorbidity Treatment Burden Questionnaire (MTBQ) exhibits good test-retest reliability and is perceived as easy to complete by patients with multiple chronic conditions.
• The findings support the use of the MTBQ in clinical and research settings for assessing treatment burden in multimorbid populations.
• Further validation, including content and internal consistency reliability, builds upon previous research, strengthening the MTBQ's utility.