Outcomes
Primary outcome. THI score14. The comparison of
the THI score change between study groups was assessed before and after
treatment. The THI consists of a 25-item questionnaire to classify
participants into functional, emotional, and catastrophic subscales.
Each item is scored on a Likert-scale from 0 to 4 (0 = ‘no,’ 2 =
‘sometimes,’ 4 = ‘yes’), resulting in a score ranging from 0 to 100. The
severity levels are considered mild between 18 and 36, moderate between
38 and 56, severe between 58 and 76, and catastrophic above
7815.
The THI score is one of the most used scoring system to assess the
effect of an intervention in tinnitus.
Secondary outcome. Participants’ impression of
improvement. These outcomes were assessed by the Clinical Global
Impression of Improvement (CGI-I), which consists of a 7-point Likert
scale ranging from ‘very much worse’ to ‘very much
improved’16and one question regarding the participant’s perceived improvement
resulting in a polar yes-no response. Both outcomes were measured after
treatment. These outcomes were chosen to support the THI, other
questionnaires were avoided so as not to compromise participants’
retention.
Adverse events and adherence were also assessed in the final visit. The
most common side effects of betahistine are nausea, dyspepsia, and
headache13.