Internet-based Cognitive Behavioural Therapy for Spanish Tinnitus Sufferers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Internet-based Cognitive Behavioural Therapy for Spanish Tinnitus Sufferers (NCT04335929), a na na study. The primary outcome is Tinnitus Functional Index (TFI); Measure of Tinnitus Distress.

2. Clinical Question

3. Trial Design

This completed pilot was registered as a single-group behavioral intervention study of internet-based cognitive behavioural therapy for Spanish tinnitus sufferers. The registry lists the phase as NA, allocation as NA, and masking as none. No randomized allocation or concurrent control group is described, so the design is not a controlled comparison of treatment against another intervention or usual care.

The intervention description specifies an 8-week online program, with new modules introduced weekly and assignments to practise the techniques. The study purpose also describes guided delivery with audiological support. Further details about how the guidance and support were delivered are not reported in the registry record.

The registry lists enrollment of 46. The primary-outcome description separately states that 32 participants started the trial, 22 completed post-intervention measures, and 16 completed the 2-month post-intervention measures. These are the available participation figures; reasons for non-completion and a fuller participant-flow account are not reported in the registry record.

The primary outcome was the Tinnitus Functional Index, assessed at T0, baseline; T1, post-intervention at 8-weeks from baseline; and T2, 2-months post-intervention at 16-weeks from baseline. The record also lists measures of tinnitus cognition, depression, anxiety, insomnia, health-related quality of life, tinnitus problems, hearing problems, and sound tolerance. The statistical analysis plan, including methods for comparing measurements over time, is not reported in the registry record.

The study is marked completed, with a start date of 2020-05-04 and a primary completion date of 2020-08-14. Completion status does not establish that outcome findings or analyses are present in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 32 participants started the trial 22 participants completed the post-intervention measures 16 participants completed the 2-month post-intervention measures

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Tinnitus Functional Index (TFI); Measure of Tinnitus Distress, measured over T0: Baseline, T1: Post-intervention (8-weeks from baseline), T2: 2-months post-intervention (16-weeks from baseline).

The primary endpoint is the Tinnitus Functional Index, a 25-item questionnaire intended to measure the severity of tinnitus distress. Its total score ranges from 0-to-100, with higher scores indicating more severe distress and therefore a worse outcome. The registry description states that scores >25 indicate tinnitus is a significant problem requiring tinnitus intervention.

The measure is relevant to the stated study question because the trial aimed to assess tinnitus distress following the Spanish internet-based program. Repeated assessment at baseline, immediately after the intervention, and at follow-up can describe how scores vary over time among participants with recorded measurements. In general, a patient-reported score can capture the participant’s experience of symptoms and their impact, rather than relying only on an external clinical observation.

The registry specifies the mean and standard deviation as the primary outcome summary. These describe the average score and the spread of scores, respectively; they do not by themselves show the amount of change for each participant. The actual Tinnitus Functional Index scores, summaries at the stated timepoints, and any change estimates are not reported in the registry record. Consequently, the direction, size, and precision of any change cannot be determined from the recorded information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as continuous, summarized by a mean and standard deviation. The mean describes the arithmetic average of the scores included in a particular summary. The standard deviation describes how dispersed those scores are around their mean. Together, these quantities provide a basic description of a group’s score distribution, but they do not reveal the full distribution or how scores changed for individual participants.

What would a change estimate describe?

In general, a change estimate compares measurements taken at different times. For this study, the relevant occasions are baseline, post-intervention, and 2-month post-intervention follow-up. A within-participant change calculation would use measurements from the same participant at two occasions. A comparison of group means at different timepoints instead summarizes each occasion’s available scores and may involve different sets of participants if measurements are missing. The registry record does not report which approach, if any, was used.

Repeated observations from the same participant are usually related rather than independent. General statistical methods for repeated measurements account for this relationship when estimating changes and their uncertainty. Treating repeated measurements as if they came from unrelated participants can misstate uncertainty. The analysis method for the repeated Tinnitus Functional Index measurements is not reported in the registry record, so it is not possible to determine how this issue was addressed.

How should uncertainty be understood?

In general, a confidence interval gives a range of values compatible with the data and the assumptions of the analysis. Its width reflects statistical precision: a narrower interval indicates greater precision under those assumptions, while a wider interval indicates more uncertainty. A confidence interval is not a guarantee that the true effect lies inside the interval, and it does not address limitations such as missing data or lack of a control group. No confidence interval for the primary outcome is reported in the registry record.

A hypothesis test, when used, evaluates how compatible the observed data are with a specified null hypothesis under a statistical model. A p-value is not a measure of the size or clinical importance of an effect. It also does not establish causation. The registry record lists 0 analyses and does not report a p-value or a hypothesis-testing procedure for the primary outcome. No statistical significance claim can therefore be assessed from the record.

What can the single-group design estimate?

In general, a single-group before-and-after study can describe score patterns among participants who have measurements at the relevant occasions. Without a concurrent comparator, it cannot separate a treatment-associated pattern from changes that might have happened over the same period for other reasons. Regression to the mean is a general possibility when participants are measured after entering a study with elevated or bothersome symptoms: later scores may differ partly because unusually high measurements tend to be less extreme on repeat measurement. This is a statistical consideration, not a claim about what occurred in this trial.

The absence of a control group also means there is no direct estimate of how participants’ scores would have changed over the same period without the program. General explanations for observed change could include natural symptom fluctuation, expectations, concurrent support, or measurement variation. The registry does not report information that would quantify or distinguish these influences.

How do missing measurements affect interpretation?

The primary-outcome description reports 32 participants starting, 22 completing post-intervention measures, and 16 completing the 2-month post-intervention measures. In general, an analysis based only on participants with measurements at each occasion can be biased if completion is related to symptoms, response, or other participant characteristics. The direction of any such bias cannot be known from completion counts alone.

Common analytic approaches may use only complete observations, or may use statistical models or imputation to make use of incomplete records under stated assumptions. Each approach has conditions and limitations. The registry record does not state whether missing measurements were excluded, imputed, or handled with a repeated-measures model, and it does not describe assumptions about why data were missing. The analysis population is also not reported in the registry record.

What do the planning calculations mean?

In general, sample-size planning asks how many participants an imagined study would need under specified assumptions about the effect to detect, variability, significance level, and allocation. Such calculations are planning illustrations, not observed power and not a test of the current trial’s findings. The registry description states that the planning illustration uses a two-sided significance level of 0.05, equal allocation between two hypothetical arms, a normal approximation, and fractions of an observed effect. It does not make those hypothetical assumptions a feature of this single-group trial. The planning figures cannot supply a missing effect estimate or substitute for a reported analysis.

The registry lists nine outcome measures, with the Tinnitus Functional Index designated as primary and measures of tinnitus cognition, depression, anxiety, insomnia, health-related quality of life, tinnitus problems, hearing problems, and sound tolerance also listed. In general, evaluating many outcomes can raise multiplicity concerns: the chance of at least one apparently notable result can increase when many hypotheses are tested. A prespecified primary outcome and a declared strategy for secondary outcomes can help readers understand which findings are confirmatory and which are exploratory. The multiplicity strategy is not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists nine outcome measures. The primary measure is the Tinnitus Functional Index. The secondary measures cover tinnitus cognition, depression, anxiety, insomnia, health-related quality of life, tinnitus problems, hearing problems, and sound tolerance. Considering multiple outcomes can create multiplicity concerns if many statistical tests are conducted: a notable finding among many tests may occur by chance. In general, a prespecified primary outcome and a stated approach to secondary analyses help clarify how such findings should be interpreted. The registry record does not report a multiplicity adjustment or a statistical plan for the secondary outcomes.

The registry lists 0 analyses. It does not report outcome estimates, hypothesis tests, or confidence intervals for the primary or secondary measures. The record therefore does not allow readers to assess how results across outcomes were handled or whether any analyses were designated as exploratory.

For the primary measure, the registry states that 32 participants started the trial, 22 completed post-intervention measures, and 16 completed the 2-month post-intervention measures. Reasons for missing measurements, the timing of withdrawals, and the approach to missing data are not reported in the registry record. The record also does not identify an analysis population, such as whether analyses included all participants who started or only those with complete measurements.

In general, complete-case summaries can be difficult to interpret if completion is related to participants’ outcomes or characteristics. Methods that use incomplete data also rely on assumptions, which should be made explicit. Because neither the handling method nor its assumptions are reported, the potential influence of missing data on any outcome estimate cannot be assessed.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry reports 0 serious adverse events among 32 participants at risk in the internet-based cognitive behaviour therapy group. It also reports 0 other adverse events among 32 participants at risk and 0 deaths. No serious adverse event terms are listed.

These figures describe the safety entries in the registry record; they are not evidence that an event was impossible or that the intervention has no risks. In general, an event count is interpreted in light of how events were defined, how they were sought, the observation period, and how completely they were reported. Those details are not reported in the registry record. The figures should therefore be read as no events recorded in the listed categories, rather than as a comprehensive estimate of risk.

The safety counts do not provide a comparison with an untreated or alternative-treatment group. Because the trial is single group, the record cannot establish whether any event was caused by the intervention or compare event rates between interventions. The registry’s adverse-event entries also do not describe non-serious symptoms or other tolerability information beyond the reported count for other adverse events.

12. What the Result Does, and Does Not, Mean

The registry record documents a pilot study of an 8-week Spanish-language internet-based cognitive behavioural therapy program for tinnitus, delivered with guidance and audiological support as described in the study purpose. It identifies the Tinnitus Functional Index as the primary measure and specifies assessments at baseline, post-intervention, and follow-up. These details show what the study set out to assess, but do not establish what happened to participants’ scores.

The record does not report primary-outcome values, changes, or uncertainty estimates. It therefore does not show whether average tinnitus distress scores rose, fell, or remained similar over time. Missing outcome estimates should not be interpreted as a finding of no change. The listed completion counts show that fewer participants completed measures at later assessments than started the trial, but the record does not explain the reasons or the effect of missing data on results.

The design also limits what any within-group change could mean. In general, without a concurrent comparator, changes over time cannot be attributed specifically to the intervention. Other influences may produce changes over the same period, and the record does not report information that would separate those explanations. Thus, even if numerical before-and-after scores were available, they would not by themselves establish a causal treatment effect.

The stated study purpose includes feasibility and tinnitus-related comorbidities, and the registry lists secondary measures for those domains. However, feasibility findings and numerical results for the secondary outcomes are not reported in the registry record. The available information cannot establish whether participants found the program acceptable, whether the program was practical to deliver, or whether secondary measures changed.

The appropriate interpretation is limited to the registered design, measures, participation counts, and adverse-event entries. The record does not provide sufficient statistical results to judge the magnitude or precision of outcome changes, and it does not support a conclusion about efficacy. The study’s pilot designation and single-group structure are important context for understanding its intended role and the limits of any inference.

13. Why This Trial Matters Statistically

This trial illustrates why a clear outcome schedule and a reported analysis are both necessary for interpreting a clinical study. The registry identifies the Tinnitus Functional Index as the primary measure and specifies baseline, post-intervention, and follow-up assessments. It also gives completion counts for the later assessments. These details help define the intended measurement framework, but without score summaries and estimates they cannot answer whether tinnitus distress changed or how uncertain any change might be.

The single-group structure is statistically important. A within-group pattern can describe what happened among participants with measurements, but it cannot provide the same causal comparison as a design with a concurrent control group. In general, change over time may reflect the intervention, other experiences during the study, or variation in measurement and symptoms. The design does not separate those possibilities.

The participation counts also make missing-data reporting consequential. The registry records fewer completed measures at later timepoints than the number who started. Readers need to know how missing observations were handled and whether the analysis included all relevant participants, because choices about incomplete records can affect both estimates and uncertainty. Those analytic details are not reported in the registry record.

Finally, the registry lists a primary outcome alongside secondary measures and notes no analyses. This makes clear the difference between registering what a study intends to measure and reporting the statistical evidence from those measurements. The record is useful for understanding the study’s question and structure, but outcome estimates and transparent methods are needed for statistical interpretation.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several limitations are specific to the information recorded for this trial. The design is single group, with allocation listed as NA and masking listed as none. There is no concurrent control group, so the record cannot support a controlled estimate of intervention effect or distinguish intervention-associated change from other changes over time.

The registry lists enrollment of 46, while the primary-outcome description says 32 participants started the trial. It reports that 22 completed post-intervention measures and 16 completed the 2-month post-intervention measures. The record does not reconcile the enrollment and started figures, describe reasons for non-completion, or provide a full participant-flow account. It also does not report how missing outcome data were handled.

Most importantly for statistical interpretation, the registry lists 0 analyses and does not report Tinnitus Functional Index scores, changes, confidence intervals, or hypothesis tests. Numerical findings for the listed secondary measures are also not reported in the registry record. The direction and precision of outcomes therefore cannot be assessed.

The record does not report the statistical analysis plan, the analysis population, any multiplicity strategy, or the assumptions used for missing data. Further participant characteristics, eligibility details, and details of intervention guidance are not reported in the registry record. The adverse-event entries do not provide additional detail about event definitions or ascertainment. These omissions constrain interpretation; they do not establish that the study did or did not encounter issues in those areas.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Internet-based Cognitive Behavioural Therapy for Spanish Tinnitus Sufferers — NCT04335929.
• Registry record last updated 2021-08-06; status last verified 2021-07.
• Results first posted 2021-07-19.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

This completed single-group behavioral study assessed an 8-week internet-based cognitive behavioural therapy program for Spanish tinnitus sufferers. The registry lists enrollment of 46 and reports that 32 participants started, 22 completed post-intervention measures, and 16 completed the 2-month post-intervention measures. The primary outcome was the Tinnitus Functional Index, measured at baseline, post-intervention, and follow-up.

The record lists 0 analyses and does not report outcome estimates or statistical tests. It records 0 serious adverse events, 0 other adverse events, and 0 deaths in the intervention group. The study’s design, outcome schedule, participation counts, and safety entries are recorded, but the available information does not establish the direction or precision of changes in tinnitus distress.