Approaches to Auditory Rehabilitation for Mild Traumatic Brain Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Approaches to Auditory Rehabilitation for Mild Traumatic Brain Injury (NCT00930774), a randomized na study. The primary outcome is Competence Score From the Psychosocial Impact of Assistive Devices Scale (PIADS).

2. Clinical Question

3. Trial Design

The registry record identifies NCT00930774, “Approaches to Auditory Rehabilitation for Mild Traumatic Brain Injury,” as a completed, randomized trial sponsored by the US Department of Veterans Affairs. Enrollment is listed as 99. The recorded start is 2010-10 and primary completion is 2012-10. The phase is listed as NA.

The design is labeled factorial and includes four groups: FM System, Auditory Training, FM System and Auditory Training, and Standard-of-care. This arrangement represents the two rehabilitation approaches individually, together, and neither approach beyond standard-of-care. The registry describes the device intervention as provision of an FM assistive device, the behavioral intervention as provision of auditory training, and the comparator as standard-of-care informational counseling.

Masking is listed as none. The registry does not report further details on how participants were assigned, whether outcome assessors were masked, the exact intervention content or duration, or how treatment adherence was assessed. Those details should not be inferred from the factorial label or the intervention names.

The main assessment was immediately post-intervention between weeks 8 and 12. The primary measure was perceived competence on the Psychosocial Impact of Assistive Devices Scale. Other listed outcomes cover speech-in-noise perception, auditory processing, working memory, self-report, and perceived hearing quality. The record lists six secondary outcomes, while numerical outcome details are available for only some of the listed measures. The registry does not report a longer-term follow-up assessment in the registry record for this result.

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: The number of participants analyzed differs from the number of baseline enrollees due to participant attrition. Specifically, one individual in arm 1 (FM system), eleven participants in arm 2 (Auditory training), four in arm 3 (FM system and auditory training) and three in arm 4 (standard of care) chose not to attend the follow-up visit.

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.

Population: Participants were male and female blast-exposed Veterans from the Operation Enduring Freedom/Operation Iraqi Freedom conflicts who reported difficulties hearing speech in noise/when spoken quickly/other difficult circumstances but had clinically-normal hearing.

6. Primary Endpoint

The registry lists the primary outcome as Competence Score From the Psychosocial Impact of Assistive Devices Scale (PIADS), measured over Immediately post-intervention between weeks 8 and 12.

The primary endpoint is the mean Competence score from the Psychosocial Impact of Assistive Devices Scale (PIADS), measured immediately post-intervention between weeks 8 and 12. The registry describes competence as perceived functional capability, independence, and performance. This is a patient-reported measure of perceived impact, rather than a direct test of hearing performance.

The score ranges from -3, indicating maximum negative impact, to +3, indicating maximum positive impact. Zero is the midpoint and represents no impact or no perceived change. The reported outcome is a group mean with standard deviation. The mean describes the average score in each analyzed group; the standard deviation describes variation among individual scores within that group.

This measure is relevant to the stated rehabilitation question because it captures participants’ perceptions of functional competence after intervention. It complements performance-based auditory tests, which assess different aspects of listening or cognition. A difference in group means would describe a difference in average reported competence, but by itself would not establish why that difference occurred or whether it is important to participants. The registry record does not report a threshold for a clinically meaningful difference, nor does it report a prespecified interpretation rule for PIADS score changes.

7. Results Posted in the Registry

• FM System: mean 0.56 versus 0.41 on control; difference 0.15 (95% CI -0.24 to 0.54), standardized effect d = 0.23; z-test p = 0.447.
• Auditory Training: mean 0.37 versus 0.41 on control; difference -0.04 (95% CI -0.46 to 0.38), standardized effect d = -0.06; z-test p = 0.851.
• FM System + Auditory Training: mean 0.62 versus 0.41 on control; difference 0.21 (95% CI -0.21 to 0.63), standardized effect d = 0.30; z-test p = 0.321.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Hearing in Noise Test

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • FM System: mean -8.10 versus -7.90 on control; difference -0.20 (95% CI -1.88 to 1.48), standardized effect d = -0.07; z-test p = 0.815.
  • Auditory Training: mean -8.10 versus -7.90 on control; difference -0.20 (95% CI -1.71 to 1.31), standardized effect d = -0.08; z-test p = 0.795.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between FM System and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Auditory Training and the control. The interval gives the range of effects that remain compatible with the data.

Staggered Spondaic Word Test

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • FM System: mean 5.10 versus 5.30 on control; difference -0.20 (95% CI -3.73 to 3.33), standardized effect d = -0.03; z-test p = 0.912.
  • Auditory Training: mean 2.60 versus 5.30 on control; difference -2.70 (95% CI -5.80 to 0.40), standardized effect d = -0.50; z-test p = 0.088.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between FM System and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Auditory Training and the control. The interval gives the range of effects that remain compatible with the data.

Digit Span Score Measure of Auditory Working Memory

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • FM System: mean 16.00 versus 16.40 on control; difference -0.40 (95% CI -2.83 to 2.03), standardized effect d = -0.09; z-test p = 0.747.
  • Auditory Training: mean 17.50 versus 16.40 on control; difference 1.10 (95% CI -1.19 to 3.39), standardized effect d = 0.33; z-test p = 0.347.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between FM System and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Auditory Training and the control. The interval gives the range of effects that remain compatible with the data.

The listed secondary measures span speech understanding in noise, auditory processing, working memory, self-reported cognitive symptoms, and perceived hearing qualities. Numerical results are posted for the Hearing in Noise Test, Staggered Spondaic Word Test, and Digit Span Score Measure of Auditory Working Memory. The registry lists other secondary measures, but their numerical results are not reported in the registry record among the outcome details available for this analysis.

Across the secondary results with numerical details, the group patterns do not form a consistent, decisive signal that clearly reinforces the primary competence result. The sponsor-reported overall analyses for these measures also do not identify a clear overall separation among the groups. The measures assess different constructs and use different scales, so their directions and magnitudes should not be combined into a single interpretation. They are complementary outcome domains, not interchangeable replications of the PIADS endpoint.

In general, multiple outcome measures and multiple comparisons create more opportunities for apparently unusual results to arise by chance. Unadjusted secondary estimates therefore carry less weight than a prespecified primary analysis, especially when the record does not state how multiplicity was handled. Individual numerical contrasts should be treated as exploratory rather than conclusive, and should not be selected or emphasized solely because of their direction or size.

The registry record does not report whether the secondary outcomes were prespecified in a hierarchy, whether any corrections were applied, or whether all planned secondary analyses were completed. Accordingly, the secondary findings can provide context about the range of measured outcomes, but do not resolve the uncertainty around the primary result or establish a broad pattern of intervention effects.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Hearing in Noise Test
• Staggered Spondaic Word Test
• Digit Span Score Measure of Auditory Working Memory
• Time Compressed Speech Test (TCST)
• Cognitive Self Report Questionnaire (CSRQ).
• Speech, Spatial and Qualities of Hearing Scale-comparative (SSQ-C)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, and the registry reports means and standard deviations for each group. The mean is the arithmetic average of the measured scores in the analyzed participants. The standard deviation expresses how spread out individual scores are around that average; a larger standard deviation indicates more variability in scores. It is not the same quantity as uncertainty in the group mean.

What does the overall ANOVA test?

In general, an analysis of variance (ANOVA) evaluates whether the observed group means are consistent with a common mean or whether the data provide evidence that at least one group mean differs. An overall ANOVA does not, on its own, identify which groups differ. The registry reports an ANOVA across the four primary-outcome groups with p = 0.527. The record does not report the model specification, degrees of freedom, assumptions assessment, or a fuller analysis plan.

Because the trial is labeled factorial, the arrangement of groups may also permit questions about the separate contributions of FM assistance and auditory training and whether their combination behaves differently from the individual approaches. However, the registry entries report an overall four-group ANOVA, not a factorial-effects analysis. The record does not report estimates or tests for main effects or an interaction, so those effects cannot be inferred from the four group means alone.

What are the recalculated mean differences?

The recalculated contrasts subtract the standard-of-care mean from the corresponding intervention-group mean. They are simple, unadjusted comparisons based on the posted group summary statistics. A positive estimate means that the intervention-group mean is numerically higher on the PIADS competence scale; a negative estimate means it is numerically lower. The direction is descriptive and should be interpreted in the context of the scale, whose midpoint is zero. These calculations do not adjust for other variables or for making several comparisons.

The effect-size values in the recalculation express the mean contrasts in relation to a pooled standard deviation. In general, standardizing a mean difference can help describe its size relative to observed score variation. It does not turn an imprecise estimate into a precise one, and the registry does not report a threshold for a meaningful standardized effect. The recalculated contrasts are not the sponsor’s reported analysis.

How should p-values be read?

In general, a p-value describes how unusual data at least as discrepant as those observed would be under a specified statistical model and a null hypothesis. It is not the probability that the null hypothesis is true, and it does not measure the size or importance of an effect. The sponsor’s primary p-value concerns the overall group analysis. The recalculated p-values concern separate unadjusted intervention-versus-standard-of-care contrasts. The registry record does not report whether the sponsor used a prespecified significance threshold or how multiplicity was handled.

Why does variability matter?

In general, more variability within groups makes it harder to distinguish differences in group means from random variation, particularly when the analyzed groups are limited in size. Standard deviations are substantial relative to the reported mean contrasts, and the recalculated confidence intervals reflect uncertainty in those contrasts. A nonsignificant p-value does not prove there is no difference; it may reflect a small effect, imprecise data, or both. Conversely, a numerical difference between group means is not enough to establish a reliable or important effect.

The record notes attrition in the primary outcome population, and analyzed group counts differ from baseline enrollment. The full analysis population definition, method for handling missing outcome measurements, and sensitivity analyses are not reported in the registry record. Those choices can affect how an analysis represents the randomized groups. No adjustment for baseline measurements or other covariates is described in the registry entries.

11. Confidence Intervals and Precision

A confidence interval gives a range of values compatible with the observed data under the assumptions of the analysis. In general, a narrower interval indicates greater precision, while a wider interval indicates that the estimate is less precise. A 95% confidence interval is not a guarantee that the true value lies within a particular calculated interval; it is a method with a long-run coverage interpretation under its assumptions.

For the recalculated primary contrasts, the 95% confidence intervals are -0.236 to 0.536 for FM System versus Standard-of-care, -0.458 to 0.378 for Auditory Training versus Standard-of-care, and -0.205 to 0.625 for FM System and Auditory Training versus Standard-of-care. Each interval includes zero. Thus, the results do not pin down a single direction of difference: values consistent with lower or higher mean competence are included, as is no mean difference.

The intervals also cover effects that are not close to zero, so the estimates do not precisely rule out potentially relevant differences in either direction. The registry does not report what magnitude of difference would be clinically meaningful, making it impossible to classify the interval against a stated importance threshold. The observed group standard deviations also indicate variation in individual scores, which is distinct from the uncertainty in the group mean contrasts.

The sponsor reports an overall ANOVA p-value but no confidence interval for that overall result in the registry record. The recalculated contrast intervals are unadjusted and should be interpreted as exploratory estimates alongside the sponsor’s analysis. Their precision should not be overstated, and the overlapping uncertainty across comparisons is a reason to avoid ranking the approaches by the point estimates alone.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm for the continuous-outcome comparisons, not total events. They are illustrations based on the observed effect, not the trial’s original design assumptions. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; each planning scenario uses the stated fraction of the observed effect. The trial’s own sample-size assumptions are not reported in the registry record.

The 80% power column describes the number of participants per arm that a hypothetical future two-arm study would plan for to have an 80% probability of detecting the selected effect under the stated assumptions, if that effect and the model assumptions were correct. The 90% power column uses a higher target probability of detecting that effect and therefore generally requires more participants per arm.

Rows that plan for a smaller fraction of the observed effect require more participants, because smaller differences are harder to distinguish from random variation. The figures should be read as planning illustrations tied to these particular observed estimates and assumptions, not as universal sample-size recommendations. An observed effect from a small or imprecise study can be unstable, so basing future planning directly on it may produce a misleading target. These calculations are not observed power.

The figures do not account for features not listed in the stated assumptions, such as attrition, multiplicity, a factorial-effects analysis, or other design features. The registry record does not report whether its original enrollment target was based on these endpoints or what effect size it was designed to detect.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 0.150; pooled standard deviation σ = 0.659.
2. n = 2 × (1.96 + 0.842)² × 0.659² / 0.150² = 302.7, rounded up to 303 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 0.15                      # observed difference in means
sigma <- 0.658633226669235                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(930774)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 303 (80% power), 406 (90% power)
 75% of observed effect: n per arm = 539 (80% power), 721 (90% power)
 50% of observed effect: n per arm = 1,211 (80% power), 1,621 (90% power)
power.t.test: 303.6 
Simulated power at n = 303 per arm: 0.796 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The sponsor’s reported primary analysis is an ANOVA across the four groups, with p = 0.527. The posted recalculations instead form unadjusted mean differences between each intervention group and standard-of-care, with confidence intervals and p-values derived from group summary statistics. These are different analyses and answer related, but not identical, questions: the ANOVA is an overall comparison, while the recalculations estimate specific contrasts.

The primary outcome’s discrepancy flag is false. Even so, the recalculations remain simple unadjusted re-calculations rather than a replacement for the trial analysis. The sponsor’s own analysis takes precedence. The record does not report enough detail about the sponsor’s model, covariate adjustment, or analysis population to reproduce that analysis from the registry entries.

The recalculated contrasts all have confidence intervals that include zero, and their unadjusted p-values do not establish a clear difference from standard-of-care. They should be read as supplementary descriptions of the posted means, not as independent confirmation of the sponsor’s ANOVA or as adjusted pairwise findings. No sponsor-reported pairwise estimates are reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The trial includes a primary outcome, multiple secondary outcomes, four groups, and possible comparisons among groups. Each additional outcome or comparison creates another opportunity to observe a result that appears notable by chance. In general, multiplicity procedures control or otherwise address this accumulation of statistical testing. The registry record does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a detailed prespecified analysis plan.

The sponsor’s primary report is an overall ANOVA. The additional intervention-versus-standard-of-care contrasts are unadjusted recalculations. Their p-values should not be interpreted as multiplicity-adjusted evidence. The registry entries do not establish whether the sponsor used a different approach in the original analysis, so the correction status of the sponsor’s analysis is not reported in the registry record.

Missing-data handling is also important. The primary outcome description notes participant attrition and gives arm-specific counts of participants who left: one in the FM system arm, eleven in the auditory training arm, four in the combined arm, and three in the standard-of-care arm. The analyzed group counts are reported separately from baseline enrollment. The registry record does not report the reasons for all missing measurements, whether all randomized participants were included in the analysis, the assumptions used for missing outcomes, or any imputation or sensitivity analysis.

The exact analysis population, including whether the primary analysis followed intention-to-treat principles, is not reported in the registry record. Nor are baseline adjustment, handling of protocol deviations, or methods for examining the factorial structure described in the registry entries. These omissions limit assessment of how robust the findings are to analysis choices and attrition. They do not show that a particular method was or was not used; they mean that method is not documented in the registry record.

16. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The adverse-event record lists zero serious adverse events in each group. The numbers listed as at risk are 25 for FM System, 25 for Auditory Training, 24 for FM System and Auditory Training, and 25 for Standard-of-care. For other adverse events, the record lists zero in the intervention groups and one in Standard-of-care. These counts describe the adverse-event entries recorded for the groups; they do not, by themselves, establish comparative safety.

The registry does not report deaths for these groups in the registry entries; the death entries are not populated. A missing death count should not be read as a confirmed count of zero. The adverse-event ascertainment period, definitions, severity details for the other event, and relationship of events to intervention are not reported in the registry record.

In general, the absence of recorded serious events in a trial does not rule out uncommon harms, particularly when the number of participants observed is limited. The posted figures are a description of what the record reports, not a basis for medical advice or a comprehensive safety conclusion.

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

The results describe perceived competence at the immediate post-intervention assessment and several other auditory or cognitive outcomes. For the primary measure, the group means are all above the PIADS midpoint, while the sponsor-reported overall ANOVA does not identify a clear difference among the groups. The recalculated contrasts with standard-of-care are uncertain and include no difference within their confidence intervals.

This does not establish that the interventions are equivalent. A failure to identify a clear difference is not the same as evidence that meaningful differences are absent. Demonstrating equivalence or noninferiority requires a suitable design and prespecified margins; those are not reported in the registry record. The registry also does not report a threshold for a clinically important PIADS difference.

The results do not show that every participant experienced the group average, and they do not establish the mechanism behind any individual score. Nor do they provide a basis for concluding that an intervention improves hearing or daily functioning. The primary endpoint is perceived competence, and the other outcomes represent distinct measures. The interpretation is limited to the outcomes and assessment period reported.

The registry description emphasizes difficulties in speech understanding despite normal or near-normal auditory sensitivity, but the full eligibility criteria and characteristics of the enrolled participants are not reported in the registry record. Generalizing beyond the enrolled trial population therefore requires caution. The immediate post-intervention assessment does not establish persistence of an effect at later times, and longer-term results are not reported in the registry record for this analysis.

Overall, the posted data are best understood as estimates with substantial uncertainty rather than a definitive ranking of the rehabilitation approaches. The sponsor’s reported analysis takes precedence over simple unadjusted recalculations, and the missing details about analysis populations, multiplicity, and missing data further constrain the strength of interpretation.

18. Why This Trial Matters Statistically

This trial is statistically informative because it places two rehabilitation approaches in a factorial arrangement: FM device provision, auditory training, both together, and standard-of-care counseling. Such a design can motivate questions about separate and combined intervention effects. However, the reported overall four-group ANOVA does not itself answer every factorial question. The registry record does not report main-effect or interaction estimates, making the distinction between the design structure and the analysis actually documented important.

The primary endpoint also illustrates why estimates and uncertainty matter more than a simple numerical ranking. The combined-intervention group has the highest listed mean, but its contrast with standard-of-care is imprecise and compatible with values on either side of zero. A point estimate alone cannot show whether a group difference is stable, meaningful, or attributable to the intervention.

The registry records attrition and analyzed populations that differ from baseline enrollment. This highlights the statistical importance of transparent reporting about missing outcomes and analysis populations. Without those details, readers cannot fully assess how the observed group means relate to the randomized groups.

Finally, the trial illustrates the tension between several outcome domains and multiplicity. A broad set of auditory, cognitive, and self-report measures can provide a richer picture, but multiple analyses require a clear plan for interpretation. The record’s overall pattern is not a substitute for prespecified comparisons, confidence intervals, and transparent reporting of analysis decisions. These principles are relevant to clinical research well beyond this particular intervention question.

19. 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.

The registry record does not report the full eligibility criteria, participant characteristics, allocation procedure, intervention dose, adherence, or details of masking beyond listing masking as none. These gaps make it difficult to judge how closely the enrolled population and delivered interventions correspond to the clinical context described in the trial summary.

Attrition is noted, including different numbers of participants leaving across the four arms. The reasons for attrition, timing of missing measurements, and methods for handling missing outcomes are not reported in the registry record. The primary analysis population and whether it followed an intention-to-treat approach are also not reported. These details matter because the available outcome counts do not simply reflect baseline enrollment.

The primary analysis is reported as an overall ANOVA without model details, while pairwise comparisons against standard-of-care are unadjusted recalculations from summary statistics. The factorial design is not accompanied in the registry entries by main-effect or interaction estimates. The record does not report a multiplicity strategy, a clinically meaningful difference threshold, or the trial’s original sample-size assumptions.

The primary endpoint is measured immediately post-intervention between weeks 8 and 12. The registry entries do not report longer-term outcomes or an assessment of whether perceived competence differences persist. Numerical details are also absent from the registry record for some listed secondary outcomes. These limitations restrict conclusions about longer-term effects, outcome consistency, and the applicability of findings beyond the assessed sample and time point.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Approaches to Auditory Rehabilitation for Mild Traumatic Brain Injury — NCT00930774.
• Registry record last updated 2014-06-11; status last verified 2014-06.
• Results first posted 2014-06-11.
• 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.

23. Record Summary

NCT00930774 is a completed randomized factorial trial of auditory rehabilitation approaches for mild traumatic brain injury, sponsored by the US Department of Veterans Affairs. Its four groups received an FM system, auditory training, both approaches, or standard-of-care informational counseling. The primary outcome was mean PIADS competence score immediately post-intervention between weeks 8 and 12.

The sponsor reported an overall ANOVA p-value of 0.527. The unadjusted recalculated contrasts with standard-of-care have confidence intervals that include zero. The registry also reports secondary outcomes and adverse-event counts, but important details about multiplicity, missing-data handling, analysis populations, and the original sample-size assumptions are not reported in the registry record.