This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Treatment of Acute Sinusitis (NCT00377403), a randomized phase 4 study. The primary outcome is SNOT-16 Score (Sino-Nasal Outcomes Test) at Day 3.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00377403 |
| Phase | Phase 4 |
| Condition | Acute Respiratory Infections, Acute Rhinosinusitis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 172 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Washington University School of Medicine |
| Results posted | Yes |
2. Clinical Question
Population
Adults with acute sinusitis or acute rhinosinusitis were eligible for the study. The brief summary describes adult volunteers aged 18 to 70 years old. The primary analysis included participants for whom Day 3 data were available; the registry record says telephone interviews could not be completed with 11 subjects.
Intervention
Participants in the intervention arm received amoxicillin 500mg three times a day for 10 days, in addition to symptomatic treatments. The registry lists acetaminophen, dextromethorphan hydrobromide with guaifenesin, guaifenesin, pseudoephedrine sustained action, and saline spray among the interventions.
Comparator
The comparator arm received placebo for 10 days along with symptomatic treatments. The brief summary describes pain medication, a chest decongestant, nasal decongestants, and cough medicine as available as needed. Thus, the contrast concerns adding amoxicillin to symptomatic care, not amoxicillin versus no treatment.
Primary question
The primary outcome was the SNOT-16 score at Day 3. The statistical comparison asks whether the average score differed between the amoxicillin and placebo arms among participants with Day 3 data. Lower SNOT-16 scores correspond to less impact from sinus-related symptoms on the measure.
This question focuses on a short-term, patient-reported quality-of-life measure. It does not directly test every outcome named in the study summary: recurrence, satisfaction with care, functional status, and direct treatment costs are described as areas of interest, but no secondary results are posted in the registry record. The posted primary contrast is between two treatment strategies that both include symptomatic treatments. Any interpretation therefore applies to the comparison as recorded and to the Day 3 score, rather than to all possible effects of treatment or the full course of illness.
3. Trial Design
The registry identifies NCT00377403 as a Phase IV randomized clinical trial titled Treatment of Acute Sinusitis. Its official title describes a randomized clinical trial evaluating guidelines for acute rhinosinusitis. The study is recorded as completed, with a parallel-group model and quadruple masking. The sponsor was Washington University School of Medicine. The recorded start was 2006-10 and the primary completion was 2009-05.
There were two arms. The intervention arm received amoxicillin 500mg three times a day for 10 days in addition to symptomatic treatments. The comparator, titled Symptomatic Treatments Only, received placebo for 10 days in addition to symptomatic treatments. The brief summary describes symptomatic medicines as pain medication, a chest decongestant, nasal decongestants, and cough medicine as needed. It also names a planned group of 200 adult volunteers, aged 18 to 70 years old, while the recorded enrollment is 172. The registry record does not explain the difference between the planned number in the summary and the enrollment figure.
The primary posted outcome is the SNOT-16 score at Day 3, assessed by telephone. The registry reports available data for 81 participants in the intervention arm and 74 in the symptomatic-treatments-only arm. It also states that telephone interviews could not be completed with 11 subjects. The posted comparison is a mean difference with a confidence interval, and the sponsor’s analysis is identified as an ANOVA. Additional details about the randomization procedure, concealment, the precise masking roles, and the trial’s original statistical design assumptions are not reported in the registry record. The record also does not describe how treatment adherence was assessed.
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
| Stage | Intervention Arm | Symptomatic Treatments Only |
|---|---|---|
| STARTED | 85 | 81 |
| Day -3 Assessment | 81 | 74 |
| Day 7 Assessment | 80 | 75 |
| Day 10 Assessment | 81 | 71 |
| Day 28 Assessment | 82 | 77 |
| COMPLETED | 81 | 74 |
| NOT COMPLETED | 4 | 7 |
Reasons for not completing this period:
| Reason | Intervention Arm | Symptomatic Treatments Only |
|---|---|---|
| Unable to contact for telephone intervie | 4 | 7 |
Analysis population for the primary outcome, as defined in the registry: We analysed all participants for whom we had data at Day 3. We were unable to complete the telephone interview with 11 subjects.
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.
| Characteristic | Unit | Intervention Arm | Symptomatic Treatments Only | Total |
|---|---|---|---|---|
| Participants analysed | 85 | 81 | 166 | |
| Age Continuous | years | 32 (18 to 69) | 31 (18 to 66) | 32 (18 to 69) |
| Sex: Female, Male: Female | Participants | 54 | 52 | 106 |
| Sex: Female, Male: Male | Participants | 31 | 29 | 60 |
6. Primary Endpoint
The registry lists the primary outcome as SNOT-16 Score (Sino-Nasal Outcomes Test) at Day 3, measured over 4 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the SNOT-16 score at Day 3. SNOT-16 is a brief, disease-specific quality-of-life instrument for acute and chronic rhinosinusitis. It contains 16 sinus-related symptom items, administered by telephone. For each item, the respondent rates how much it was a problem, taking account of both severity and frequency. The response choices range from no problem to severe problem, and the overall score is the mean across the items. The score ranges from 0, indicating minimal impact, to 3, indicating significant impact.
This measure is used to represent the burden of sinus-related symptoms from the participant’s perspective, rather than relying only on a clinical sign or a clinician’s assessment. A Day 3 score makes the primary question a short-term comparison after treatment began. It is not a measure of long-term recurrence, satisfaction, cost, or every aspect of daily function, although the brief study summary mentions these as outcomes of interest. No secondary outcomes are posted in the registry record.
Because the endpoint is continuous, the reported arm values are means with standard deviations, and the comparison is expressed as a mean difference. A mean describes the average score in each group; the standard deviation describes how spread out individual scores are around that group’s mean. These summaries help characterize both the average symptom-related quality-of-life score and the variability among participants with available Day 3 data.
7. Results Posted in the Registry
- Symptomatic Treatments Only: mean 1.14 versus 1.12 on control; difference 0.02 (95% CI -0.15 to 0.19), standardized effect d = 0.04; z-test p = 0.820.
Mean difference: Symptomatic Treatments Only
95% CI: -0.15 to 0.19
Recalculated from the posted summary statistics
8. Statistical Interpretation
The posted Day 3 mean SNOT-16 score was 1.12 in the amoxicillin-plus-symptomatic-treatments arm and 1.14 in the symptomatic-treatments-only arm. The reported mean difference was 0.02. In the context of this scale, the two group averages are close, and the point estimate represents a small separation between them. The registry’s reported ANOVA p-value is 0.83. The unadjusted recalculation from the posted summaries gives p = 0.82. Both values are consistent with substantial uncertainty about whether the underlying group means differ.
The 95% confidence interval for the mean difference extends from -0.152 to 0.192 when expressed to three decimal places. It includes zero, so the posted result does not distinguish a difference in either direction from no mean difference. The interval also shows that the estimate is not highly precise: differences on either side of zero remain compatible with the data under the assumptions behind the interval. The fact that the point estimate is close to zero is not by itself proof that the treatment strategies have the same average outcome.
The outcome is a score for which higher values indicate more impact from symptoms. The intervention arm’s mean was slightly lower than the comparator arm’s mean, but the small observed separation and interval spanning zero do not establish a clear between-group difference. The p-value should not be read as the probability that the treatment has no effect, nor as a measure of the size or importance of any difference. It summarizes how unusual the observed data would be under the statistical model’s null hypothesis of no difference, subject to the model assumptions.
The analysis is based on participants with Day 3 data, not every enrolled participant. The registry says 11 subjects did not complete the telephone interview, and the analysis population is described as all participants for whom Day 3 data were available. How missing Day 3 scores were handled beyond restricting the analysis to available data is not reported in the registry record. This matters because the interpretation relies on the observed participants representing the treatment groups adequately for the question being asked.
These findings describe one short-term endpoint in a trial of two strategies that both included symptomatic treatments. They do not establish whether the groups differed on recurrence, satisfaction, costs, longer-term quality of life, or other outcomes. No secondary results are posted in the registry record. The result is therefore best understood as an imprecise estimate of the difference in Day 3 average SNOT-16 scores among participants with available measurements, rather than a broad conclusion about all effects of the treatment strategies.
9. Statistical Methods Explained
The primary outcome is continuous: each participant has a SNOT-16 score, and the registry reports a group mean and standard deviation. The sponsor’s posted comparison is an analysis of variance, or ANOVA, with a p-value of 0.83. The posted summaries also permit a simple unadjusted comparison of the two means. That recalculation gives a mean difference of 0.02, a 95% confidence interval from -0.152 to 0.192 when rounded to three decimal places, and p = 0.82. The registry reports no discrepancy flag, and the sponsor’s own result remains the primary reported analysis.
What does a mean difference describe?
A mean difference compares the average outcome in one group with the average in another. Here, the arm means are 1.12 for the intervention arm and 1.14 for the symptomatic-treatments-only arm, and the reported mean difference is 0.02. The difference is expressed in SNOT-16 scale units. It does not describe how much every participant changed, nor does it show the distribution of individual responses. Two groups can have similar means while individual scores vary substantially within each group.
The standard deviations are 0.54 and 0.55. In general, a standard deviation describes the spread of observations around a group mean. These values provide context for the amount of participant-to-participant variation relative to the difference between the means. They are not standard errors of the means and should not be interpreted as confidence limits for a group average.
What does the confidence interval add?
In general, a confidence interval is a range of estimates compatible with the observed data under a statistical model and its assumptions. The 95% interval for this mean difference runs from -0.152 to 0.192 after expressing the endpoints to three decimal places. Since it includes zero, the data do not establish a nonzero mean difference at the conventional two-sided 0.05 significance level. The interval also gives more information than a p-value alone by showing the direction and scale of differences that remain compatible with the observed results.
A confidence interval is not a statement that there is a 95% probability that the fixed treatment effect lies in this particular interval. In general, the confidence level describes the long-run coverage of the method when its assumptions hold. The interval is based on a simple unadjusted comparison of the posted group summaries, rather than on a reconstruction of every detail of the trial’s analysis plan.
How should the p-values be understood?
The registry reports an ANOVA p-value of 0.83. The unadjusted recalculation gives p = 0.82. In general, a p-value assesses how compatible the observed data are with a null model of no difference, assuming that model and the analysis assumptions are appropriate. A large p-value does not prove that the groups are identical, and it is not the probability that the null hypothesis is true. The p-values do not convey the magnitude of the mean difference or the range of effects compatible with the data; the estimate and confidence interval provide that information.
The two p-values are close, but they arise from different descriptions of the analysis: the registry’s own ANOVA and a simple unadjusted recalculation from posted summary statistics. No discrepancy is recorded. The sponsor’s analysis is therefore the reported trial result, while the recalculation is a transparent check based on the available summary data. Details such as any covariates included in the ANOVA, diagnostics, or adjustments are not reported in the registry record.
What assumptions matter for a mean comparison?
In general, a two-group mean comparison relies on the suitability of the data and model for estimating a difference in means. Relevant considerations include the independence of participant observations, the distribution of outcomes and residuals, and whether the uncertainty estimate handles variability appropriately. The registry identifies an ANOVA but does not report diagnostic checks, transformations, covariate adjustment, or the precise variance assumptions. The recalculation uses the posted means, standard deviations, and group sizes; it is not an adjusted analysis.
In general, over-dispersion is a concern when data vary more than a statistical model expects. It is especially relevant for count outcomes when a simple count model understates variability. This endpoint is a continuous score, so count-model over-dispersion is not the central issue for the posted mean comparison. The broader lesson is that uncertainty estimates depend on whether the model represents the observed variability adequately; the registry record does not report diagnostic results that would allow that assessment.
What does the analysis population represent?
The record says the analysis included all participants for whom Day 3 data were available, and that 11 subjects could not be reached for the telephone interview. This is an available-case analysis for the endpoint as described. In general, analyzing only observed outcomes can yield a biased estimate if missingness is related to treatment or to the unobserved outcome. The record does not state whether missingness was assessed, whether any imputation was used, or whether a sensitivity analysis was performed. The observed-data comparison should therefore be interpreted with that limitation in mind.
Overall, the methods support a focused reading: the posted result estimates a difference in average Day 3 SNOT-16 scores for participants with observed scores, with a confidence interval that includes zero. The analysis does not, by itself, answer questions about other outcomes or resolve the uncertainty created by missing measurements.
10. Confidence Intervals and Precision
The estimated mean difference is 0.02 SNOT-16 units. Its 95% confidence interval ranges from -0.152 to 0.192 when expressed to three decimal places. This interval spans zero and includes estimates in both directions. The result is therefore compatible with a modestly lower mean score in one arm or a modestly higher mean score, as well as a difference close to zero. The point estimate alone gives a narrower impression than the interval does.
In general, a confidence interval communicates precision by showing the range of values that remain compatible with the data and the method’s assumptions. A narrow interval indicates greater precision than a wide interval. The interval is relatively broad in relation to the small point estimate, so the data do not pinpoint the mean difference closely. It does not support interpreting the near-zero estimate as proof that the treatment strategies have exactly the same average score.
The posted arm means and standard deviations are 1.12 with a standard deviation of 0.54 for the intervention arm, and 1.14 with a standard deviation of 0.55 for symptomatic treatments only. The comparison uses Day 3 data from 81 and 74 participants, respectively. Precision is influenced by the amount of variability and the number of observed outcomes, as well as by the analysis method. The registry does not provide a separate interval for each arm mean, and those should not be inferred from the comparison interval.
The sponsor’s ANOVA p-value is 0.83, while the unadjusted recalculation gives p = 0.82. Neither p-value replaces the confidence interval. The interval gives the range and direction of the estimated contrast; the p-value summarizes compatibility with a null model. Both are consistent with the same general reading: the posted data do not give a precise estimate establishing a between-arm difference on this endpoint.
11. 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.
| Effect to detect | Participants per arm, 80% power | Participants per arm, 90% power |
|---|---|---|
| 100% of the observed effect | 11,648 | 15,594 |
| 75% of the observed effect | 20,708 | 27,721 |
| 50% of the observed effect | 46,592 | 62,373 |
The sample-size figures are planning illustrations based on the observed mean difference, not the trial’s original design calculations. They are stated as participants per arm for 80% power and participants per arm for 90% power. These are not total event counts; the event-count convention applies to time-to-event outcomes, whereas this continuous outcome uses participants per arm.
The listed planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set as a stated fraction of the observed effect. The listed rows consider 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. Under those scenarios, the figures for 80% power are 11,648, 20,708, and 46,592 participants per arm, respectively. For 90% power, the corresponding figures are 15,594, 27,721, and 62,373 participants per arm.
In general, a power target describes the chance that a planned study will detect an effect of a specified size if that effect is truly present and the model assumptions hold. The 80% and 90% columns therefore illustrate different design targets: the 90% target calls for more participants than the 80% target for the same assumed effect. Smaller effects are harder to distinguish from random variation, so planning for a smaller effect requires more participants. The figures are especially sensitive to the observed effect used as their starting point.
These numbers are not observed power and do not describe the achieved power of this completed trial. They are hypothetical planning calculations based on a very small observed difference. The trial’s original sample-size justification, target power, and design assumptions are not reported in the registry record. The planned count described in the brief summary and the recorded enrollment do not reveal the original statistical assumptions.
12. 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 z1−α/2 = 1.960) and the desired power (z1−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
- Observed difference Δ = 0.020; pooled standard deviation σ = 0.545.
- n = 2 × (1.96 + 0.842)2 × 0.5452 / 0.0202 = 11,647.8, rounded up to 11,648 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 <- 0.0199999999999998 # observed difference in means
sigma <- 0.544794138730192 # 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(377403)
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 = 11,648 (80% power), 15,594 (90% power)
75% of observed effect: n per arm = 20,708 (80% power), 27,721 (90% power)
50% of observed effect: n per arm = 46,592 (80% power), 62,373 (90% power)
power.t.test: 11648.7
Simulated power at n = 11,648 per arm: 0.806 (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.
13. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| ANOVA | not reported | 0.830 |
The registry reports the sponsor’s analysis as an ANOVA, with a p-value of 0.83 for the comparison of the two groups. The recalculation from the posted means, standard deviations, and group sizes is an unadjusted comparison. It gives a mean difference of 0.02, a 95% confidence interval from -0.152 to 0.192 when expressed to three decimal places, and p = 0.82.
The recalculated p-value is close to the sponsor’s reported p-value. The registry record does not mark a discrepancy. The sponsor’s analysis should therefore be treated as the reported trial analysis; the recalculation is a straightforward check based on summary statistics and should not be mistaken for a replacement analysis. The registry does not report enough detail to reproduce the ANOVA fully, including whether it included covariates or used any other adjustments.
Both analyses indicate that the posted data do not establish a difference in average Day 3 SNOT-16 score. The confidence interval from the recalculation shows the range of estimates compatible with that unadjusted method, while the sponsor’s p-value reports the result of the recorded ANOVA. Similar p-values do not imply that the methods are identical, and neither result establishes that the groups are equivalent.
14. Multiplicity, Missing Data and Analysis Populations
The registry record posts one outcome measure and one analysis for this comparison. No secondary outcome results are posted in the registry record, although the brief summary describes interest in functional status, symptoms, recurrence, satisfaction with care, and direct treatment costs. The record does not explain whether other outcomes were collected but not posted, or whether a formal hierarchy of outcomes was specified.
Multiplicity arises in general when many outcomes, time points, subgroup comparisons, or statistical tests are examined. The more tests considered, the greater the chance that at least one appears statistically notable by chance if no adjustment or prespecified interpretation plan is used. The registry does not report a multiplicity adjustment, an endpoint hierarchy beyond the identified primary outcome, or a broader analysis plan. It would therefore be inappropriate to assume either that multiplicity was handled or that it was not relevant to analyses beyond the one posted.
For the primary outcome, the record states that the analysis used participants for whom Day 3 data were available. It also says that the telephone interview could not be completed with 11 subjects. The arm-level outcome summaries include 81 participants in the intervention arm and 74 in the symptomatic-treatments-only arm. The registry does not describe the characteristics of participants with missing scores, reasons for each missing interview, or whether missingness differed by arm.
In general, missing outcome data can affect an estimated group difference if the participants with observed measurements do not represent the full randomized groups. The record does not report imputation, weighting, sensitivity analyses, or an intention-to-treat analysis for this endpoint. It also does not state how participants were handled if they discontinued treatment but still had an outcome measurement. The analysis population is therefore best described using the registry’s available-Day-3-data wording, without assuming a broader population or missing-data method.
Further details about the randomization procedure, allocation concealment, planned interim analyses, stopping rules, covariate adjustment, and trial-specific sample-size justification are not reported in the registry record. These absences limit how fully the analysis can be audited from the posted information. They do not change the arithmetic of the posted summary comparison, but they constrain interpretation of its assumptions and relationship to any original protocol plan.
15. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Intervention Arm | 0 | 85 | 0.0% |
| Symptomatic Treatments Only | 0 | 81 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Intervention Arm | 39 of 85 |
| Symptomatic Treatments Only | 36 of 81 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Intervention Arm | Symptomatic Treatments Only |
|---|---|---|---|
| Other non-serious adverse events | General disorders | 39 of 85 | 36 of 81 |
The registry lists serious adverse events in 0 of 85 participants at risk in the intervention arm and 0 of 81 participants at risk in the symptomatic-treatments-only arm. These are the serious-event figures recorded for the groups. The registry does not list any serious adverse-event terms. Death counts are not reported in the registry record.
The record also lists other adverse events in 39 of 85 participants at risk in the intervention arm and 36 of 81 at risk in the symptomatic-treatments-only arm. These are counts of participants affected, as presented in the registry, and should not be confused with the number of individual events if a participant could experience more than one event. No further description of the other adverse events is posted in the registry record.
These safety figures should be read with their recorded denominators. The denominators for the adverse-event summaries differ from the available Day 3 outcome counts, and the registry does not explain the relationship between those populations. The listed absence of serious events does not establish that no harms occurred outside the reported collection or reporting period. The record does not give event timing, severity details for other events, or a comparison adjusted for exposure. These data describe the posted counts only.
16. What the Result Does, and Does Not, Mean
The primary result is a comparison of average Day 3 SNOT-16 scores between two randomized groups receiving symptomatic treatments, with either amoxicillin or placebo added. The means were 1.12 and 1.14, and the reported mean difference was 0.02. The sponsor’s ANOVA p-value was 0.83. The unadjusted recalculation has a 95% confidence interval from -0.152 to 0.192 when rounded to three decimal places, and p = 0.82. The interval includes zero and allows differences in either direction.
This means that the posted primary analysis does not establish a difference in average Day 3 SNOT-16 score. It does not demonstrate that the two treatment strategies are identical, because the confidence interval remains compatible with a range of possible mean differences. Nor does the result establish that either strategy is effective or ineffective. The statistical comparison alone is not a clinical recommendation.
The endpoint concerns disease-specific quality of life at an early time point. It does not answer whether treatment strategies differ in recurrence, satisfaction with care, cost, later symptoms, or other outcomes. The brief summary refers to these topics, but secondary outcome results are not posted in the registry record. It also does not report longer-term follow-up results beyond the primary endpoint information available.
The estimate describes participants with Day 3 outcome data. The record notes 11 subjects whose telephone interviews could not be completed. Because the handling and possible impact of missing data are not described beyond using available Day 3 observations, the result should be interpreted as an observed-data comparison rather than assumed to represent every enrolled participant without qualification.
The findings are specific to the recorded comparison: amoxicillin plus symptomatic treatments versus placebo plus symptomatic treatments. They do not isolate the effect of symptomatic medicines, since those were part of both arms, and they do not establish effects for treatment schedules or populations not described in the record. The confidence interval, missing-data information, and limited set of posted results all help define how far the conclusion can reasonably extend.
17. Why This Trial Matters Statistically
This trial illustrates why an estimate, its uncertainty, and the analysis population should be read together. The two group means are close, but the confidence interval is more informative than the point estimate alone: it includes zero and still permits a range of differences in either direction. A near-zero estimate should not be turned into a claim of equivalence when no equivalence margin or equivalence analysis is reported in the registry record.
It also demonstrates the distinction between a trial’s reported analysis and a simple recalculation from summary statistics. The sponsor’s ANOVA gives p = 0.83, while the unadjusted summary-statistic calculation gives p = 0.82. The close results offer a useful consistency check, but the methods are not necessarily identical. The registry record does not give enough detail to reproduce the sponsor’s full model.
The endpoint is patient-reported and specific to sinus-related quality of life. Its interpretation depends on the scale, timing, and participants who contributed measurements. A Day 3 score answers a focused short-term question; it is not a substitute for results on the other outcomes described in the study summary. The available-case analysis and the uncompleted interviews are also part of the statistical interpretation, not merely administrative details.
Finally, the sample-size illustrations show how strongly planning can depend on the effect size being targeted. They are not evidence about achieved power or the trial’s original design. The original design assumptions are not reported in the registry record. Together, these features make the study useful for understanding the limits of inference from a small observed mean difference, a confidence interval spanning zero, and incomplete reporting of the broader analysis plan.
18. 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 primary analysis is described as including participants with Day 3 data, and 11 subjects could not complete the telephone interview. The registry does not report reasons for missing interviews, comparisons between participants with and without outcome data, or sensitivity analyses. The available-data analysis may not represent every enrolled participant if missingness is related to outcome or treatment.
The registry provides an ANOVA p-value but not a full statistical analysis plan or enough detail to reconstruct the sponsor’s model. Whether covariates, transformations, or other adjustments were used is not reported in the registry record. The randomization procedure, allocation concealment, and the specific roles covered by quadruple masking are also not described. The original sample-size justification and planned power are not reported.
Only one outcome measure and one analysis are posted. The study summary mentions several additional areas of interest, but their results are not reported in the registry record. The available result is consequently limited to the Day 3 SNOT-16 score and should not be generalized to those unposted outcomes. The record also does not provide a detailed account of adherence, treatment discontinuation, or protocol deviations.
The study’s brief summary describes 200 planned volunteers, while the recorded enrollment is 172; the reason for this difference is not reported in the registry record. The adverse-event denominators differ from the Day 3 outcome counts, and the record does not explain the relationship between those populations. Serious-event counts are listed, but further safety detail for other events is not posted, and death counts are not reported in the registry record.
These reporting limitations restrict assessment of the assumptions and generalizability of the result. They do not erase the posted comparison, but they make it important to interpret it narrowly as an available-case estimate for the recorded primary endpoint.
19. Related Tutorials
20. Related Statistical Calculators
21. Sources
- ClinicalTrials.gov: Treatment of Acute Sinusitis — NCT00377403.
- Registry record last updated 2012-12-28; status last verified 2012-12.
- Results first posted 2011-06-29.
- 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.
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22. Record Summary
NCT00377403 is a completed Phase IV randomized, quadruple-masked, parallel-group trial sponsored by Washington University School of Medicine. The registry records enrollment of 172 and compares amoxicillin plus symptomatic treatments with placebo plus symptomatic treatments. The recorded study start was 2006-10, with primary completion in 2009-05.
The primary outcome is the Day 3 SNOT-16 score. The posted means were 1.12 in the intervention arm and 1.14 in the symptomatic-treatments-only arm. The sponsor’s ANOVA p-value was 0.83; an unadjusted recalculation gives a mean difference of 0.02, a 95% confidence interval from -0.152 to 0.192 when expressed to three decimal places, and p = 0.82. The interval includes zero, and the estimate is not precise enough to establish a difference in average score.
The analysis used available Day 3 data, with 11 incomplete telephone interviews noted. Secondary results and several details of the original statistical plan are not reported in the registry record.