COGNITIVE BEHAVIOR THERAPY FOR TINNITUS RELATED INSOMNIA: A SINGLE-CASE EXPERIMENT

Tinnitus is the perception of sound (excluding voices), often described as a
*ringing* or a high frequency tone, which occurs in the absence of an
identifiable source. Although approximately 20% of the adult population has
tinnitus, between 1-6% suffer from it (Bhatt, Lin, & Bhattacharyya, 2016; Cima,
Crombez, & Vlaeyen, 2011; Davis & Refaie, 2000; Kim et al., 2015; McCormack,
Edmondson-Jones, Somerset, & Hall, 2016). Chronic tinnitus has no cure and
sufferers typically experience severe distress and disturbances in many aspects
of daily life (Davis & Refaie, 2000; Hall et al., 2018). Insomnia is one such
complaint that is prevalent amongst tinnitus sufferers, with the underlying
mechanisms still largely unknown (Langguth, 2011). According to Harvey (2001),
insomnia may not be a secondary complaint and may be the cause, maintainer and
generator of disorders, distress and dysfunction. Given the dynamic
relationship between insomnia and tinnitus, insomnia is likely a comorbid
clinical complaint. As such, comorbid insomnia must be treated directly (Folmer
& Griest, 2000).

Recent meta-analyses have concluded that CBTi has clinically significant
effects on primary chronic insomnia (Trauer, Qian, Doyle, Rajaratnam, &
Cunnington, 2015) and comorbid insomnia (Geiger-Brown et al., 2015). Moreover,
beyond insomnia reduction, CBTi has demonstrated improvements in accompanying
complaints such as depression (Jacobs, Benson, & Friedman, 1993), generalized
anxiety disorder (Blais, Mineault, & Morin, 2000) and chronic pain (Jungquist
et al., 2010). More recently, a small trial has suggested that the same
improvements might be true for tinnitus patients with half of the participants
showing improvements in tinnitus distress (Marks, McKenna, & Vogt, 2019). The
trial was the first ever conducted with CBTi on tinnitus patients. Despite the
small number of participants (n=24) and lack of control condition, the findings
are an important first step in understanding insomnia in tinnitus patients.
Further research into the effects of CBTi on tinnitus is needed.

As an alternative and complementary approach to Randomized Control Trial (RCT),
Single-Case Experimental Design (SCED) offers high degree of internal validity,
vital for establishing causal relations between intervention and changes within
patients. SCED also enables for an in depth exploration of change mechanisms
within the intervention, allowing for the emergence and exploration of possible
mediators and moderators. This research utilizes the SCED methodology to
investigate CBTi for tinnitus patients allowing a more precise and controlled
evaluation of the treatment protocol and enabling causal relationships to be
established. A positive and reliable effect of CBTi on insomnia and tinnitus
distress may provide a concrete path to treatment and indicate future
directions for intervention designs.

Patients are required for this study as there is no reliable means of
simulating the effects of chronic subjective tinnitus in healthy participants.
Adults with chronic subjective tinnitus and sleep complaints will be recruited
to participate in this study as we are testing the degree of effectiveness of
the intervention. These treatment-seeking individuals are already recommended
CBTi by the established hospital protocol (a.k.a. treatment as usual), allowing
for a minimally invasive and burdensome study design.

Primary Objective: This study aims to investigate the positive, negative or
lack of effect that CBTi has on insomnia in tinnitus patients.

Secondary Objective(s): Investigate the positive, negative or lack of effect
that CBTi has on tinnitus experience.

The study will use a sequentially replicated SCED. This design relies on a
series of different participants undergoing the same intervention at different
time points. Each participant will act as their own control and will be
systematically assessed through daily diaries (already part of the current CBTi
intervention). The continuous assessment of each individual participant allows
for the exploration of possible relationships between each intervention
component (e.g. psycho-education, relaxation) and individual experience (e.g.
sleep quality, tinnitus distress) by pinpointing when and if change occurs at
different levels.

Data is continuously collected throughout baseline (phase A), treatment (phase
B) and follow-up (phase A`), latter analysed within and between participants,
allowing causal relations to be established. A sequentially replicated design
across subjects increases power by allowing randomization of intervention start
(phase B) for every incoming participant.

The treatment as usual for tinnitus related insomnia at Maastricht UMC+ is the
CBTi intervention (see section 5.1 and Appendix A) comprised of 9 sessions. The
first session (Session 0 in the CBTi protocol) relates to the introduction of
the sleep diary. Sessions 7 and 8 are follow-up sessions at the 1 and 3 month
marks respectively. Therefore, after the introduction of the sleep diary there
are 6 intervention sessions delivered weekly at Maastricht UMC+. Added to
treatment as usual are the tinnitus daily diary and other assessments (i.e.
ESIT-SQ, FTQ, TCS, HUI-3; see section 8.1) at T0 (screening/pre-treatment), T1
(end of session 6), T2 (1 month follow-up), and T3 (3 month follow-up).

Data collection starts immediately after Session 0. An internet-based
application purposely build for single-case experiments
(https:tamalkd.shinyapps.io/scda/ - developed by the Methodology of Educational
Sciences Research Group and Health Psychology Research Group at KU Leuven) will
randomly generate a start date for phase B. The recommended minimum number of
measurement points required for a stable baseline varies and primarily depends
on the level of variability in the dependent variable. As a minimum it is
considered that at least five data points are necessary (Kratochwill et al.,
2013) and therefore, randomization of treatment start will take place between 5
and 33 days after Session 0. The study follows a regulated randomization
(Koehler & Levin, 1998) where each participant is randomized into a schedule
that has the treatment start also randomized, increasing the possible number of
combinations and thus, increasing power. Daily data gathering halts at the last
follow-up meeting together with all final data points obtained at session 8
(the 3-month follow-up as stablished by the CBTi protocol).

The sleep diary embedded into the CBTi protocol strongly favours the
single-case methodology through its sensitivity to therapy related changes and
by its daily schedule of data gathering. A tinnitus diary is added in order to
capture any daily changes in tinnitus experience. Therefore, detailed
assessments on sleep and tinnitus experience are collected daily during phase
A, B and A`.

The treatment as usual relies on the CBTi protocol (Dutch: *Behandeling van
langdurige slapeloosheid*; Verbeek & van de Laar, 2015), which contains 9
sessions carried out by a trained therapist at Maastricht UMC+. Added to the
treatment as usual assessments (i.e. sleep diary, TQ, ISI, DBAS, TFI, and HADS)
are the tinnitus diary and questionnaires (i.e. ESIT-SQ, FTQ, TCS, HUI-3) at T0
(screening/pre-treatment), T1 (end of session 6), T2 (1 month follow-up), and
T3 (3 month follow-up). A brief summary of the sessions* aims follows:
1. Session 0: Sleep anamneses.
Exploration and discussion of sleep history and introduction to the sleep and
tinnitus diary as well as assessments (added to treatment as usual).
2. Session 1: Information and sleep hygiene.
Explanation of sleep hygiene and insomnia model (psycho-educational session)
3. Session 2: Sleeping behavior and break moments.
Introduction of two interventions/techniques for insomnia.
4. Session 3: Relaxation and cognitive therapy.
Introduction to relaxation (Jacobson*s technique) and cognitive therapy (i.e.
the role of automatic thoughts).
5. Session 4: Working with automatic thoughts.
Carrying out relaxation exercises as well as discussing other techniques (e.g.
sleep restriction). The session focuses on challenging automatic thoughts.
6. Session 5: Cognitive therapy (continuation).
Further development of cognitive therapy techniques (e.g. sleep restriction).
7. Session 6: Evaluation.
Discussion of which methods are beneficial to the patient. Administration of
assessments (i.e. FTQ, TCS, HUI-3, TQ, ISI, DBAS, TFI, and HADS) added to
treatment as usual.
8. Session 7: 1 month follow-up.
Discussion of if sleeping behavior has improved or been maintained.
Administration of assessments (i.e. FTQ, TCS, HUI-3, TQ, ISI, DBAS, TFI, and
HADS) added to treatment as usual.
9. Session 8:
End of treatment and possible scheduling of booster session or further
referral. Administration of assessments (i.e. FTQ, TCS, HUI-3, TQ, ISI, DBAS,
TFI, and HADS) added to treatment as usual.

There are minimal risks, discomfort and burden associated with the study.
Previous CBTi research has demonstrated improvement in sleep as well as
comorbidities (e.g. anxiety, depression) with no additional risks to the
individual. The sleep diary is a short assessment instrument (under 5-min
completion time), which is already an integral part of the clinical treatment.
The added tinnitus diary (also under 5-min completion time) does not
significantly increase burden. Beyond the regular clinical treatment
appointments, participants are not required to stay longer than necessary,
neither to make extra visits to the centre.