Adaptation and validation of a German version of the Multimorbidity Treatment Burden Questionnaire

BACKGROUND: Patients with multiple long-term conditions often face a variety of challenges arising from the requirements of their health care. Knowledge of perceived treatment burden is crucial for optimizing treatment. In this study, we aimed to create a German version of the Multimorbidity Treatment Burden Questionnaire (MTBQ) and to evaluate its validity.

METHODS: The steps to translate the MTBQ included forward/back translation, cognitive interviews (n = 6) and a pilot test (n = 7). Psychometric properties of the scale were assessed in a cross-sectional survey with primary care patients aged 65 and older with at least 3 long-term conditions (n = 344). We examined the distribution of responses, dimensionality, internal reliability and construct validity.

RESULTS: Cognitive interviewing and piloting led to minor modifications and showed overall good face validity and acceptability. As expected, we observed a positively skewed response distribution for all items. Reliability was acceptable with McDonald's omega = 0.71. Factor analysis suggested one common factor while model fit indices were inconclusive. Predefined hypotheses regarding the construct validity were supported by negative associations between treatment burden and health-related quality of life, self-rated health, social support, patient activation and medication adherence, and positive associations between treatment burden and number of comorbidities. Treatment burden was found to be higher in female participants (Mdn1 = 6.82, Mdn2 = 4.55; U = 11,729, p = 0.001) and participants with mental health diagnoses (Mdn1 = 9.10, Mdn2 = 4.55; U = 3172, p = 0.024).

CONCLUSIONS: The German MTBQ exhibited good psychometric properties and can be used to assess the perceived treatment burden of patients with multimorbidity.