Pilot study of a smartphone-based tinnitus therapy using structured counseling and sound therapy: A multiple-baseline design with ecological momentary assessment

Abstract

Tinnitus affects a considerable part of the population and develops into a severe disorder in some sufferers. App-based interventions are able to provide low-threshold, cost-effective, and location-independent care for tinnitus patients. Therefore, we developed a smartphone app combining structured counseling with sound therapy and conducted a pilot study to evaluate treatment compliance and symptom improvement (trial registration: DRKS00030007). Outcome variables were Ecological Momentary Assessment (EMA) measured tinnitus distress and loudness and Tinnitus Handicap Inventory (THI) at baseline and final visit. A multiple-baseline design with a baseline phase (only EMA) followed by an intervention phase (EMA and intervention) was applied. 21 patients with chronic tinnitus (≥ 6 months) were included. Overall compliance differed between modules (EMA usage: 79% of days, structured counseling: 72%, sound therapy: 32%). The THI score improved from baseline to final visit indicating a large effect (Cohens d = 1.1). Tinnitus distress and loudness did not improve significantly from baseline phase to the end of intervention phase. However, 5 of 14 (36%) improved clinically meaningful in tinnitus distress (ΔDistress ≥ 10) and 13 of 18 (72%) in THI score (ΔTHI ≥ 7). The positive relationship between tinnitus distress and loudness weakened over the course of the study. A trend but no level effect for tinnitus distress could be demonstrated by a mixed effect model. The improvement in THI was strongly associated with the improvement scores in EMA of tinnitus distress (r = -0.75; 0.86). These results indicate that app-based structured counseling combined with sound therapy is feasible, has an impact on tinnitus symptoms and reduces distress for several patients. In addition, our data suggest that EMA could be used as a measurement tool to detect changes in tinnitus symptoms in clinical trials as has already been shown in other areas of mental health research.

Fig 1. CONSORT Flow Diagram.

Flow diagram of patient recruitment and dropouts. Study design: Multiple-baseline design across groups. The four groups introduced the treatment staggered in time to separate treatment effects from potential time effects and therefore enhance internal validity. Baseline length for each group was randomly selected following the Koehler-Levin procedure and patients were randomly allocated to groups. Intervention phase was the same length for all groups. Before baseline and after intervention phase, clinical questionnaires were applied.

Fig 2. Improvement of THI from begin of baseline phase to final visit.

a) Significant improvement of Tinnitus Handicap Inventory (THI) score from the begin of baseline phase to final visit of the sample. Higher scores indicate higher handicap. Dots represent means, error bars are standard errors; ** p < .001; N = 18. b) Individual THI values at baseline and final visit. The same shape represents the same individual.

Fig 3. Course of tinnitus distress and loudness for each case (EMA).

Individual courses of tinnitus symptoms that were assessed daily with Ecological Momentary Assessment over the study period. The grey area represents the baseline phase (EMA), the white area represents the intervention phase (EMA, structured counseling, sound therapy). Distress: How burdensome do you find your tinnitus at the moment? (0 not burdensome– 100 very burdensome); Loudness: How loud is your tinnitus at the moment? (0 inaudible– 100 very loud). N = 14.

Fig 4. Change of correlation between distress and loudness over the study period (EMA).

Pearson’s product-moment correlations between tinnitus distress and loudness during baseline phase (week 0) and intervention phase (week 1–12). All correlations are statistically significant (p < .001). N = 14.

Fig 5. Correlation of ΔTHI with improvement in EMA tinnitus distress.

Pearson’s product-moment correlation of ΔTHI with two EMA improvement scores: Distress trend (a) and ΔDistress (b). ΔTHI = THI begin baseline–THI final visit; Distress trend = slope of tinnitus distress during intervention phase; ΔDistress = Baseline phase–end of intervention phase. N = 14.