Music vs. No Music During Cesarean Delivery on Patient Satisfaction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Music vs. No Music During Cesarean Delivery on Patient Satisfaction (NCT03412019), a randomized na study. The primary outcome is Patient Satisfaction.

2. Clinical Question

The trial addressed whether music during cesarean delivery was associated with a difference in patients’ reported satisfaction. The outcome was a questionnaire score rather than a direct measure of a clinical event. The posted primary comparison is the difference between the group means, with the intervention group compared against the control group.

The registry describes a randomized, parallel-group comparison and lists no masking. It reports 22 participants enrolled, while the primary outcome summaries show 10 participants in each group. Why the outcome summaries include fewer participants than the total enrollment is not reported in the registry record. Eligibility details and characteristics that would help define the population are also not reported in the registry record.

3. Trial Design

The registry lists NCT03412019 as a completed, randomized, parallel-group trial sponsored by Tufts Medical Center. The listed enrollment is 22. The study start date is 2018-02-21, and the primary completion date is 2019-08-06. The phase is listed as not applicable. Masking is listed as none, so participants and study personnel were not described as blinded in the registry record.

The intervention was a Mozart playlist selected in advance and turned on by a study investigator. The control condition involved no music. Both group descriptions include assessment of hemodynamics and anxiety, and measurement of satisfaction. The registry lists patient satisfaction as the primary outcome, assessed one day after the procedure. Patient anxiety and mean arterial pressure are listed as secondary outcomes.

The primary outcome summaries contain 10 participants in the control group and 10 in the intervention group. The registry’s overall enrollment is 22; the reason the outcome summaries contain fewer participants is not reported in the registry record. The number enrolled should therefore not be treated as the number contributing to every posted outcome.

The record lists three outcome measures and no reported analyses. It does not describe the original statistical analysis plan, the test used for the primary comparison, the method for handling missing observations, or the analysis population. The original sample-size justification and any interim analyses are not reported in the registry record. Random allocation is stated, but sequence generation and allocation concealment details are not reported 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:

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: Parturients scheduled for cesarean delivery

6. Primary Endpoint

The registry lists the primary outcome as Patient Satisfaction, measured over 1 Day.

The primary endpoint is patient satisfaction, measured with Morgan’s Maternal Satisfaction Scale for Cesarean Section (MSSCS). The registry describes a 22-item questionnaire, with each item scored on a Likert scale from 1 to 7, where 1 means strongly disagree and 7 means strongly agree. The resulting total score ranges from 22 to 154, with higher scores representing greater satisfaction. The questionnaire was scheduled for post-operative day one, during the hours of 8am-1pm.

A multi-item questionnaire can capture several aspects of a patient’s experience in a single score. Reporting the group means and standard deviations describes the average scores and the spread of scores in each group. The mean difference then expresses the contrast between those averages on the questionnaire’s scale. It does not show how every individual participant responded, nor does it establish which particular questionnaire items contributed to the group pattern.

The endpoint was chosen to address satisfaction directly, rather than treating anxiety or blood pressure as substitutes for satisfaction. Those measures are listed as secondary outcomes. The registry record does not report additional details about the questionnaire’s scoring procedures, its psychometric properties in this study population, or a threshold defining an important difference.

7. Results Posted in the Registry

• Intervention Group: mean 116.00 versus 120.00 on control; difference -4.00 (95% CI -21.16 to 13.16), standardized effect d = -0.20; z-test p = 0.648.

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.

Patient Anxiety

• 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:
  • Intervention Group: mean 2.70 versus 2.50 on control; difference 0.20 (95% CI -2.12 to 2.52), standardized effect d = 0.08; z-test p = 0.866.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Intervention Group and the control. The interval gives the range of effects that remain compatible with the data.

Hemodynamic Parameter (Mean Arterial Pressure, MAP)

• 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:
  • Intervention Group: mean 80.40 versus 82.20 on control; difference -1.80 (95% CI -18.03 to 14.43), standardized effect d = -0.10; z-test p = 0.828.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Intervention Group and the control. The interval gives the range of effects that remain compatible with the data.

Across the secondary outcomes, the posted estimates are close to zero relative to their uncertainty: neither comparison gives a clear distinction between the groups. The confidence intervals include values in both directions, and the unadjusted p-values are not small. This broad pattern is consistent with uncertainty rather than a well-resolved secondary-outcome signal.

The secondary outcomes address related but distinct questions. Anxiety is a participant-reported measure, while mean arterial pressure is a physiological measure. Neither is a substitute for the primary satisfaction endpoint. Their results can provide context about the comparison, but they do not resolve the uncertainty in the primary result or establish a mechanism for any satisfaction difference.

Secondary outcomes generally carry less evidential weight when analyses are unadjusted and the analysis plan is unavailable. Examining multiple outcomes creates more opportunities for chance findings, and the registry record does not report a method for accounting for that multiplicity. It also does not report whether the outcomes or analysis choices were prespecified in a detailed statistical plan.

The secondary pattern should therefore be interpreted as descriptive and exploratory, not as independent confirmation of the primary result. The registry record lists no reported analyses for these endpoints. The posted summaries do not establish that there were no other analyses; they establish only that no analyses are listed as reported in the record.

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

• Patient Anxiety
• Hemodynamic Parameter (Mean Arterial Pressure, MAP)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is recorded as a numerical score, and the registry reports a mean and standard deviation for each group. A mean describes the arithmetic average of observed scores. The standard deviation describes how spread out individual scores are around that average. A standard deviation is not the uncertainty in the mean itself; it describes variation among participants’ scores.

The posted comparison uses a mean difference, with the intervention group contrasted against the control group. The estimate of -4.0 is on the MSSCS score scale. A negative sign means the intervention-group mean is lower than the control-group mean under that subtraction order. The sign does not determine whether a difference is important, and the registry record does not report a threshold for a clinically meaningful change.

A confidence interval gives a range of values reasonably compatible with the data and the method used to calculate the interval. The 95% interval for the primary mean difference extends from -21.16 to 13.16. Because it includes zero, the posted data do not distinguish the estimate from no mean difference at the conventional level associated with a two-sided 95% interval. The interval’s width also communicates that the estimate is not precise. The registry record does not report the interval-calculation method or the assumptions used for the primary comparison.

The posted p-value is unadjusted. In general, a p-value compares the observed data with what would be expected under a specified null model, assuming the statistical model is appropriate. It is not a measure of the probability that the observed finding occurred by chance, and a larger or smaller p-value does not by itself describe the size of an effect. The exact test and its assumptions are not reported in the registry record. No analyses are listed as reported analyses, so the posted comparison should not be mistaken for a documented full analysis plan.

In general, standard deviations and confidence intervals can be affected by the distribution of the outcome and by the number of observations. With few observations, the data may provide limited information about the population mean and the variability around it. The primary summaries contain 10 observations per group, so precision should be judged from the interval as well as from the point estimate. The registry record does not report diagnostic checks or other details that would show how the analysis addressed distributional assumptions.

The outcome scale has a stated range of 22 to 154, but the record does not report whether any observed scores were at the scale limits. Nor does it describe how incomplete questionnaires, if any, were scored. These details matter for understanding how questionnaire responses become a total score; they are not reported in the registry record.

The planning illustrations use the observed effect as a reference and assume a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. In general, a sample-size calculation estimates how many participants would be needed to detect an assumed effect under specified design assumptions. It does not establish the assumptions used for the trial’s original design. The original sample-size justification is not reported in the registry record. The planning calculations are illustrative and do not tell how likely this completed trial was to produce a statistically significant result.

Over-dispersion is a general concern when outcomes vary more than an analysis model expects: standard errors may then be understated and intervals too narrow if the model does not account for that extra variability. The posted primary endpoint is summarized with group standard deviations, but the registry record does not report a model-based analysis or a check for over-dispersion. This general concept should not be taken as a claim that over-dispersion was present in this trial.

The record includes two secondary endpoints as well as the primary endpoint. When several outcomes are examined, the chance of at least one apparently notable result can increase if each is interpreted without accounting for the number of comparisons. This is the general multiplicity concern. The p-values are unadjusted, and a multiplicity strategy is not reported in the registry record. The secondary results should therefore be treated as less conclusive than a prespecified, appropriately analyzed primary outcome.

Random allocation can support a fair comparison by balancing prognostic factors on average, but it does not guarantee balance in a small trial. The record says allocation was randomized, while the sequence-generation and concealment methods are not reported in the registry record. With no masking listed, the groups and study personnel knew the assigned condition. The record does not report whether outcome assessment was performed independently or whether any other safeguards were used.

11. Confidence Intervals and Precision

The primary mean difference is -4.0 units, with a 95% confidence interval from -21.16 to 13.16. The interval crosses zero and covers values on both sides of the point estimate. In practical terms, the observed data are consistent with a range of possible average differences rather than a narrowly estimated contrast. The registry record does not report a threshold for deciding which differences on the MSSCS scale would be important.

The group means are 120.0 for the control group and 116.0 for the intervention group. Their standard deviations are 22.3 and 16.4, respectively. These values describe the observed score variation within the groups, while the confidence interval describes uncertainty in the between-group mean difference. They answer related but distinct questions.

Confidence intervals are often misread as containing a fixed probability that the true effect lies inside the particular interval. More generally, a 95% confidence procedure is designed to produce intervals that cover the true parameter in 95% of repeated uses under its assumptions. For this trial, the interval is a precision summary conditional on the method used. The calculation method and its assumptions are not reported in the registry record.

The interval’s breadth matters alongside its inclusion of zero: the result does not precisely determine the direction or magnitude of the underlying difference. The posted data do not prove equivalence, and they do not establish that the groups differ. A more precise estimate would require stronger information than this comparison provides; the registry record does not specify what size of difference future research should target.

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, not total events. They are illustrations based on the observed effect, rather than the trial’s original design calculation. 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 as the effect to detect.

For the primary outcome, planning for 100% of the observed effect gives 376 participants per arm for 80% power and 504 participants per arm for 90% power. Planning for 75% of the observed effect gives 669 participants per arm for 80% power and 895 participants per arm for 90% power. Planning for 50% of the observed effect gives 1,504 participants per arm for 80% power and 2,013 participants per arm for 90% power.

In plain language, 80% power describes a design that would have an 80% chance of detecting the specified effect under the planning assumptions if that effect were the true one. The 90% power column describes the corresponding chance for a design targeting 90% power. Smaller assumed effects require more participants to distinguish them from random variation, which is why the planning numbers rise as the assumed fraction of the observed effect gets smaller.

These figures are not observed power. They do not retrospectively quantify the probability that the completed trial detected an effect. The registry record does not report the trial’s own original sample-size assumptions or justification; these planning illustrations answer a different question about hypothetical future designs.

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 = -4.000; pooled standard deviation σ = 19.574.
2. n = 2 × (1.96 + 0.842)² × 19.574² / -4.000² = 375.9, rounded up to 376 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 <- -4                      # observed difference in means
sigma <- 19.5735791310634                     # 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(3412019)
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 = 376 (80% power), 504 (90% power)
 75% of observed effect: n per arm = 669 (80% power), 895 (90% power)
 50% of observed effect: n per arm = 1,504 (80% power), 2,013 (90% power)
power.t.test: 376.9 
Simulated power at n = 376 per arm: 0.804 (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. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and two secondary outcomes, for three outcome measures in total. It does not report a multiplicity strategy, such as prioritizing a sequence of tests or adjusting inference across outcomes. The posted p-values are unadjusted. In general, when several hypotheses are tested, interpreting each result as if it were the only test can overstate the strength of evidence. The secondary outcomes consequently warrant cautious interpretation, especially in the absence of a reported analysis plan.

Missing-data handling is not reported in the registry record. The primary outcome summaries include 10 participants in each group, whereas the listed overall enrollment is 22. The record does not explain the difference, identify missing questionnaires, describe exclusions, or say how incomplete outcome data were handled. It would be inappropriate to infer the reason from these counts alone.

The analysis population is not reported in the registry record. It is not stated whether participants were analyzed according to randomized assignment, whether the posted summaries include only those with observed outcomes, or whether any other population was used. The record also does not describe protocol deviations or the handling of participants who may not have received the assigned condition.

There is no reported analysis plan or list of reported analyses. Details of prespecification, interim analyses, stopping decisions, and statistical adjustment are therefore not reported in the registry record. The absence of those details limits the ability to assess how outcome selection, missingness, and multiple comparisons were handled. It does not establish that such procedures were or were not used; it means the registry record does not describe them.

15. 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 adverse-event record lists 11 participants at risk in each group. It records zero serious adverse events, zero other adverse events, and zero deaths in both the control and intervention groups. These are the counts recorded for the groups in the registry.

Zero recorded events means that no events of those listed categories appear in the posted safety figures. It does not prove that no event occurred outside the recorded data, nor does it demonstrate that the conditions are free of risk. Safety conclusions depend on the size of the groups, the completeness of event collection, and the definitions and follow-up used.

The registry record does not provide further details about adverse-event definitions, monitoring procedures, or the duration of safety follow-up. The at-risk counts differ from the 10 participants per group in the primary outcome summaries, and the reason for that difference is not reported in the registry record. The safety figures should be read as descriptive counts rather than a precise comparison of risk.

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

The posted results describe a randomized comparison of Mozart music with no music during cesarean delivery. For the primary satisfaction measure, the intervention-group mean was lower than the control-group mean by the reported estimate of -4.0 units. The confidence interval is broad and includes zero, so the trial does not precisely establish the direction or magnitude of an average difference in satisfaction.

This is not evidence of equivalence. A finding that does not clearly distinguish the groups is different from showing that any possible difference is small enough to be unimportant. The registry record does not specify an equivalence or non-inferiority margin, and the interval does not rule out differences in either direction.

The result also does not establish that music caused a particular experience for every participant. Randomization supports a group comparison, but the posted summaries describe averages, not individual responses. Masking is listed as none, and satisfaction was reported by participants who knew whether music was played. The record does not establish how this knowledge influenced responses.

The endpoint captures satisfaction at one specified post-operative assessment. It does not, by itself, answer broader questions about other outcomes, other musical selections, different delivery settings, or longer-term experiences. Those questions are not evaluated by the primary comparison as described in the registry record.

The secondary outcomes and safety counts add descriptive context but do not remove the primary result’s uncertainty. The most defensible reading is that the registry reports a small group comparison with an imprecise estimate and limited analysis details. It does not support a broad conclusion about effects in populations or circumstances beyond the study described.

17. Why This Trial Matters Statistically

This trial illustrates why an estimate and its uncertainty should be read together. The primary mean difference is a single summary of the observed group contrast, while the confidence interval communicates that the underlying difference is not precisely determined by these data. A p-value alone would not convey the range of plausible contrasts or the limits of the evidence.

It also highlights the distinction between enrollment and outcome data. The registry lists 22 participants enrolled, while the primary summaries contain 10 participants per group. Without an account of that difference, readers cannot determine from the registry record why the outcome summaries have that size or how the analysis population was defined. Transparent reporting of participant flow and missing-data handling helps readers assess that issue.

Patient satisfaction is an important kind of outcome to measure because it captures the participant’s reported experience, but it is not interpreted in the same way as a physiological measurement. The use of a named questionnaire and a stated scoring range gives context for the primary endpoint. At the same time, the record does not provide a threshold for an important score difference or additional information about questionnaire performance in this study.

Finally, the record shows how much the interpretation depends on reporting. Randomization is listed, but details of allocation, masking, the analysis plan, multiplicity, and missing-data methods are not reported. These gaps do not invalidate the posted results, but they limit assessment of how robustly the study was designed and analyzed. The trial is a useful example of the need to distinguish a descriptive result from a fully documented inferential analysis.

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 outcome summaries include 10 participants per group, and the confidence interval for the mean difference is broad. The registry lists enrollment of 22 but does not explain the difference between enrollment and the outcome counts. No participant-flow details or missing-data procedures are reported, limiting assessment of how complete the primary outcome data were.

The study is listed as unmasked. Participants knew whether music was played, and satisfaction is self-reported. The record does not report procedures intended to reduce potential effects of expectations or knowledge of assignment on questionnaire responses. This is a consideration in interpreting the endpoint, not proof that responses were biased.

The registry record does not report detailed eligibility criteria, participant characteristics, allocation procedures, or a full statistical analysis plan. It also does not report how the questionnaire was scored if responses were incomplete, or a threshold for an important difference. The absence of these details limits assessment of representativeness and analytical choices.

The primary satisfaction outcome was assessed on post-operative day one. The record does not describe later satisfaction assessments. The trial therefore addresses the stated assessment time rather than longer-term outcomes. The safety counts are descriptive, and additional information about event definitions and follow-up is not reported in the registry record.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Music vs. No Music During Cesarean Delivery on Patient Satisfaction — NCT03412019.
• Registry record last updated 2020-03-03; status last verified 2020-02.
• Results first posted 2020-03-03.
• 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.

22. Record Summary

NCT03412019 is a completed randomized, parallel-group trial sponsored by Tufts Medical Center. It compared a pre-selected Mozart playlist during cesarean delivery with no music. The registry lists enrollment of 22 and no masking.

The primary outcome was patient satisfaction measured with the Maternal Satisfaction Scale for Cesarean Section on post-operative day one. The posted group summaries include 10 participants per group. The mean difference was -4.0 units, with a 95% confidence interval from -21.16 to 13.16 and an unadjusted p-value of 0.648.

Patient anxiety and post-procedure mean arterial pressure were listed as secondary outcomes. The safety record lists zero serious adverse events, zero other adverse events, and zero deaths in each group. The registry record does not list reported analyses or provide the original sample-size justification, analysis plan, or explanations for the outcome-count difference.