Music Therapy in Sickle Cell Pain Mixed Methods Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Music Therapy in Sickle Cell Pain Mixed Methods Study (NCT02270060), a randomized na study. The primary outcome is Change (Post - Pre) From Baseline in Visual Analog Scale of Pain Intensity (VASPI) of Memorial Pain Assessment Card.

2. Clinical Question

3. Trial Design

The registry record describes a completed randomized, single-masked, parallel-group study with enrollment of 60 and three groups: music therapy, music listening, and control. Each group has posted results for 20 participants. The start is recorded as 2014-09 and primary completion as 2016-05. The study phase is listed as NA. The identity of the masked party is not reported in the registry record, so the masking description cannot be interpreted more specifically.

The music therapy arm received one 20-minute session with a music therapist. The session used specially composed music tailored to a participant’s preferences, with an iPad. The music listening arm listened to preferred music on an iPod touch for the same duration without a therapist present. The control arm received standard care and waited in the treatment room or bay for twenty minutes. This three-arm structure allows the posted results to be read as comparisons of therapist-led music therapy and music listening, each against standard care.

The primary outcome was change from baseline in Visual Analog Scale of Pain Intensity, measured at baseline and at the end of the 20-minute intervention, up to 120 minutes following randomization. The study also named pain relief, mood, Tursky scale change, length of stay, amount of hydromorphone, and numeric pain rating as secondary outcomes. The registry record does not report the original protocol’s detailed statistical analysis plan, the intended sample-size rationale, handling of missing observations, or the identity of the masked party. The stated study purpose also included assessing feasibility, but feasibility results are not reported in the registry record.

Although the study is labeled randomized, details of sequence generation, concealment, and any stratification are not reported in the registry record. The posted results give means, standard deviations, and group sizes for the continuous outcome measures. No sponsor-reported analyses are listed in the record for the posted outcomes; the comparisons discussed in this analysis are simple unadjusted recalculations from the group summaries.

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.

Before assignment: Following verbal consent on the day of an ACC visit, an RN escorted the participant into the ACC to receive standard care that included vital signs, a lab draw, assessment by a nurse practitioner, and scheduled analgesics. The assigned study condition occurred one hour after participants' first dose of analgesics.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All participants who participated in the music therapy intervention.

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Change (Post - Pre) From Baseline in Visual Analog Scale of Pain Intensity (VASPI) of Memorial Pain Assessment Card, measured over Baseline and at end of 20-minute intervention, up to 120 minutes following randomization.

The primary endpoint is change from baseline in the Visual Analog Scale of Pain Intensity (VASPI) on the Memorial Pain Assessment Card. It is a continuous score on a scale whose minimum is 0 and maximum is 10; higher scores represent worse pain intensity. Because the outcome is expressed as post-intervention score minus baseline score, a negative change corresponds to a lower score at the later measurement than at baseline. That direction describes the scale arithmetic, not a conclusion about the clinical importance of the change.

The registry specifies measurement at baseline and at the end of the 20-minute intervention, up to 120 minutes following randomization. This captures short-term change around the intervention rather than a longer-term outcome. The registry lists the primary population as all participants who participated in the music therapy intervention. It does not provide further detail about how that population label relates to the three reported arms or how missing measurements were handled.

General: A continuous change score can summarize both the direction and average size of change, while retaining variation among participants. The standard deviation describes that variation within a group. These measures are useful for comparing average short-term changes across randomized groups, but interpretation still depends on the scale’s meaning, the precision of the comparison, and the completeness of the outcome data. The registry record does not state a threshold for a clinically important difference on this scale, so the posted estimates alone do not establish whether an observed difference would be important to patients.

7. Results Posted in the Registry

• Music Therapy Group: mean -1.92 versus -1.19 on control; difference -0.73 (95% CI -1.84 to 0.38), standardized effect d = -0.41; z-test p = 0.197.
• Music Listening Group: mean -1.92 versus -1.19 on control; difference -0.73 (95% CI -2.05 to 0.59), standardized effect d = -0.34; z-test p = 0.279.

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.

Change (Post - Pre) From Baseline in Visual Analog Scale of Pain Relief (VASPR) of Memorial Pain Assessment Card

• 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:
  • Music Therapy Group: mean 2.05 versus 0.45 on control; difference 1.60 (95% CI 0.26 to 2.94), standardized effect d = 0.74; z-test p = 0.019.
  • Music Listening Group: mean 0.86 versus 0.45 on control; difference 0.41 (95% CI -1.55 to 2.37), standardized effect d = 0.13; z-test p = 0.682.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Music Therapy Group than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Music Listening Group and the control. The interval gives the range of effects that remain compatible with the data.

Change (Post- Pre) From Baseline in Visual Analog Scale of Mood (VASMOOD) of Memorial Pain Assessment Card

• 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:
  • Music Therapy Group: mean 2.33 versus 0.74 on control; difference 1.59 (95% CI 0.33 to 2.85), standardized effect d = 0.78; z-test p = 0.014.
  • Music Listening Group: mean 0.96 versus 0.74 on control; difference 0.22 (95% CI -1.14 to 1.58), standardized effect d = 0.10; z-test p = 0.751.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Music Therapy Group than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Music Listening Group and the control. The interval gives the range of effects that remain compatible with the data.

Change (Post - Pre) From Baseline in Tursky Scale of Memorial Pain Assessment Card

• 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:
  • Music Therapy Group: mean -0.80 versus -0.50 on control; difference -0.30 (95% CI -0.98 to 0.38), standardized effect d = -0.27; z-test p = 0.390.
  • Music Listening Group: mean -0.35 versus -0.50 on control; difference 0.15 (95% CI -0.92 to 1.22), standardized effect d = 0.09; z-test p = 0.784.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Music Therapy Group 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 Music Listening Group and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes add several perspectives on short-term change, including pain relief, mood, and Tursky scale scores. Across the posted group summaries, music therapy has positive mean changes for pain relief and mood, while the music listening and control groups also have positive mean changes on those measures. The unadjusted comparisons show a more distinct separation from control for music therapy on pain relief and mood than for music listening. For the Tursky measure, the comparison intervals include zero. This broader pattern is not identical to the primary pain-intensity result, whose comparison intervals also include zero.

These outcomes relate to the primary endpoint but are not interchangeable with it. Pain intensity, pain relief, mood, and Tursky scores capture different aspects of the assessment; a result for one measure does not automatically establish a corresponding result for another. The registry record does not specify the direction or clinical importance threshold for every secondary scale, so the numeric changes should be interpreted using the posted scale descriptions rather than assuming that a larger change always represents a better outcome.

The registry lists secondary outcomes for length of stay, amount of hydromorphone, and numeric pain rating, but numeric results for those outcomes are not reported in the registry record. The stated study purpose also included feasibility, covering delivery, acceptability, and usefulness, but feasibility results are not reported in the registry record.

General: Secondary findings are often considered supportive or exploratory when a trial evaluates several outcomes and comparisons. Without a reported multiplicity plan, unadjusted p-values do not account for the opportunity to observe nominally notable results across multiple tests. This matters even when an individual interval excludes zero. The secondary pattern can help describe what the study measured, but it carries less confirmatory weight than a primary analysis specified and interpreted under a reported analysis plan. No such sponsor-reported analyses are listed in the registry record.

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

• Change (Post - Pre) From Baseline in Visual Analog Scale of Pain Relief (VASPR) of Memorial Pain Assessment Card
• Change (Post- Pre) From Baseline in Visual Analog Scale of Mood (VASMOOD) of Memorial Pain Assessment Card
• Change (Post - Pre) From Baseline in Tursky Scale of Memorial Pain Assessment Card
• Length of Stay in Minutes
• Amount of Hydromorphone
• Change (Post - Pre) From Baseline in Numeric Pain Rating (NPR)

9. Statistical Interpretation

10. Statistical Methods Explained

General: The methods below explain the statistical ideas used to read continuous outcome summaries and unadjusted comparisons. They do not describe an analysis plan beyond what the registry record states. The record lists means and standard deviations for the groups, plus recalculated differences and confidence intervals; it does not report sponsor-conducted analyses.

What does a mean change represent?

A mean change is the average of participant-level changes over the measurement period. For this primary outcome, change is defined as the post-intervention score minus the baseline score. Since higher pain-intensity scores represent worse pain, a negative mean change describes a lower average score at the later measurement. The mean condenses the group’s observed changes into one value; it does not imply that every participant changed by that amount or even in the same direction.

The standard deviation describes how dispersed individual changes are around the group mean. Larger dispersion means individual changes varied more. It is not the same quantity as the uncertainty in the estimated group mean or in a difference between groups. The posted group standard deviations are 1.88 for music therapy, 2.5 for music listening, and 1.69 for control on the primary outcome. They show that participant outcomes varied within each group, but they do not alone tell whether the group means differ convincingly.

How should a mean difference be read?

The recalculated mean difference compares a group’s mean with the control group’s mean. For the primary comparisons, the estimate is -0.73 for music therapy versus control and -0.73 for music listening versus control. A negative estimate means that the intervention group’s average change score is lower than the control group’s average change score. Because the outcome is change in a pain-intensity score, the sign can be understood alongside the scale direction, but it does not establish clinical importance.

These comparisons are unadjusted: they use the posted group summaries rather than a model that accounts for baseline covariates or other factors. General: Adjustment can be useful when an analysis plan specifies relevant baseline variables or design features, but no adjusted results are reported in the registry record. It is not possible to infer what adjustment the trial intended or whether a different prespecified method would produce the same estimate.

What does a confidence interval add?

A confidence interval describes statistical uncertainty around an estimate under the assumptions of the calculation. The primary music therapy versus control interval runs from -1.838 to 0.378, and the music listening versus control interval runs from -2.053 to 0.593. Both include zero, the value corresponding to no mean difference. They also span values on either side of zero, so the posted summaries are compatible with more than one direction of the underlying group difference.

General: A confidence interval is not a guarantee that the true value lies inside its particular endpoints, and it does not assign a probability to each possible effect. Its width is informative about precision: wider intervals indicate more uncertainty in the estimate. Interpretation should consider the estimate and interval together, rather than relying only on a p-value or the sign of the point estimate.

What is the role of the p-value?

The unadjusted p-values for the primary comparisons are 0.197 and 0.279. In general, a p-value measures how unusual data at least as incompatible with a specified null model would be if that model and the calculation assumptions held. It is not the probability that the null hypothesis is true, nor does it measure the size or importance of a difference. Here, the confidence intervals include zero and the p-values do not provide a clear distinction from no difference under the unadjusted comparisons.

The registry does not state whether its original analysis used these tests, a different model, or a multiplicity adjustment. The comparisons are explicitly recalculated from summary statistics and should be treated as descriptive, unadjusted evidence. A more detailed sponsor analysis, if one exists outside this record, is not reported in the registry record.

Why does variation matter?

General: Greater participant-to-participant variation makes it harder to estimate a group average precisely when group sizes are held fixed. Variation can reflect real differences among participants, measurement noise, or both. With 20 participants reported in each group, estimates can remain uncertain when individual outcomes vary. This is one reason that point estimates alone should not be treated as conclusive.

General: Over-dispersion refers to greater variability than a model assumes. When present, it can make standard errors too small and confidence intervals too narrow if the model does not account for it. The registry record does not report a model-based dispersion assessment, so over-dispersion should not be asserted as a feature of this trial. The posted standard deviations simply describe the observed spread of the continuous measures.

How do secondary outcomes fit?

General: Secondary outcomes can provide complementary descriptions of participants’ experiences or resource use, but interpreting many outcomes and comparisons increases the chance of finding nominally notable results by chance. A multiplicity plan can control how such repeated testing is interpreted. No such procedure is reported in the registry record. The pain relief and mood p-values therefore need cautious interpretation, particularly because they are unadjusted and sit alongside several other named outcomes.

In summary, the available methods support reading group means, standard deviations, mean differences, confidence intervals, and unadjusted p-values as descriptive summaries of the posted data. They do not establish the trial’s original sample-size justification, full analysis plan, missing-data strategy, or analysis population beyond the primary population wording. Those details are not reported in the registry record.

11. Confidence Intervals and Precision

The primary comparison estimates a mean difference of -0.73 for music therapy versus control. Its 95% confidence interval extends from -1.838 to 0.378. The interval includes zero and includes negative as well as positive values. In practical statistical terms, the point estimate favors a lower change score in the music therapy group, but the data do not pin down the difference precisely enough to rule out no difference or a difference in the other direction.

For music listening versus control, the estimated mean difference is also -0.73. Its 95% confidence interval runs from -2.053 to 0.593. This interval is wider than the interval for the music therapy comparison and also includes zero. The spread of the possible values represented by each interval is an important part of the result: a single point estimate cannot convey the uncertainty evident in these comparisons.

General: A confidence interval’s precision depends on the amount of information in the data and the variability of the outcome, as well as on the calculation method. Small groups and dispersed outcomes commonly leave more uncertainty than large, consistent datasets. The reported standard deviations and 20 participants per group provide context for why these estimates should not be read as exact quantities.

The registry record does not state a threshold for a clinically important difference in pain intensity. Therefore, even apart from whether an interval includes zero, the clinical meaning of values within it cannot be determined from the record alone. The confidence intervals quantify statistical uncertainty under the recalculation, not the probability that a particular value is clinically meaningful. They should be considered with the short measurement window, outcome scale, and limitations of the reported analysis.

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 sample-size figures are planning illustrations expressed as participants per arm, not total event counts. They are based on the observed effect and assume a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The planning scenarios use the stated fraction of the observed effect. These are calculation assumptions for the illustrations; the trial’s original design assumptions are not reported in the registry record.

The 80% power column gives the estimated number of participants per arm for a future comparison to have an 80% chance of detecting the specified effect under the stated assumptions, if that effect and the calculation model were correct. The 90% power column gives the corresponding planning target for a higher chance of detection under those assumptions. Neither figure describes what power the completed trial actually had. This is not observed power.

Rows based on 100% of the observed effect use the full effect estimate from the posted comparison. Rows based on 75% or 50% of the observed effect plan for smaller effects. Smaller effects are harder to distinguish from random variation, so they require more participants under the same assumptions. For example, the music therapy versus control primary comparison gives 95 participants per arm for 80% power at 100% of the observed effect, and 377 participants per arm for 80% power at 50% of that effect. These figures are not proposed enrollment targets for this study; they are illustrations tied to the recalculated estimate.

Planning calculations are sensitive to the assumptions used, including the assumed effect and variability. The registry record does not report that its original enrollment was chosen using these illustrations, nor does it report the original sample-size justification. The displayed planning figures should therefore be used to understand how assumptions affect future study size, not to judge whether the completed study was appropriately planned.

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 = -0.730; pooled standard deviation σ = 1.788.
2. n = 2 × (1.96 + 0.842)² × 1.788² / -0.730² = 94.1, rounded up to 95 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 <- -0.73                      # observed difference in means
sigma <- 1.78752622358387                     # 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(2270060)
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 = 95 (80% power), 127 (90% power)
 75% of observed effect: n per arm = 168 (80% power), 225 (90% power)
 50% of observed effect: n per arm = 377 (80% power), 505 (90% power)
power.t.test: 95.1 
Simulated power at n = 95 per arm: 0.799 (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 record lists one primary outcome and several secondary outcomes, and it includes multiple group comparisons for some measures. It does not report a strategy for controlling multiplicity, such as a hierarchy among outcomes or an adjustment to account for repeated comparisons. The recalculated secondary p-values are unadjusted. When multiple outcomes or comparisons are considered, some nominally small p-values may occur by chance even if no underlying differences exist. This general concern makes the secondary findings less conclusive than a result interpreted under a documented multiplicity plan.

The registry does not list sponsor-reported analyses for these outcomes. It also does not describe the exact statistical model, whether baseline values were included as covariates, or whether any adjustment for design features was prespecified. Those details are not reported in the registry record. The simple comparisons from group means and standard deviations should not be mistaken for a complete analysis plan or a substitute for an unreported sponsor analysis.

Missing-data procedures are also not reported in the registry record. It is not stated whether outcome values were missing, how any missing measurements were handled, or whether sensitivity analyses were conducted. The group summaries list 20 participants in each arm, but those counts alone do not establish that every participant had every outcome measured at every time point.

The primary outcome description names its population as all participants who participated in the music therapy intervention. Further detail about the analysis population, including whether all randomized participants were analyzed in their assigned groups, is not reported in the registry record. The record does not explain how participants who might have stopped or not completed a session would be treated in an analysis. It also does not report subgroup analyses or interim analyses. These omissions limit the ability to assess how the posted summaries relate to the original trial protocol and intended inferential approach.

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 registry reports zero serious adverse events among the 20 participants at risk in each of the music therapy, music listening, and control groups. It also reports zero other adverse events among the 20 participants at risk in each group, and zero deaths in every group. No serious adverse event terms are listed.

These figures are event counts in the registry record, not a complete description of every possible safety outcome. A zero count means that no events in the specified category are reported for the listed group; it does not show that every possible symptom or harm was actively sought, or that an event could not occur in a larger or longer study. The record does not provide further detail about adverse-event definitions, collection procedures, or follow-up duration for safety reporting.

Safety counts should also be considered separately from the pain outcome comparisons. They do not resolve uncertainty about the primary endpoint or establish that one group is safer than another. The registry’s zero counts are a concise description of what is recorded, with the limits of that reporting in mind.

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

The posted results describe average short-term changes in pain intensity after randomization to music therapy, music listening, or standard care. For the primary comparison, the recalculated mean difference between music therapy and control is -0.73, and the confidence interval includes zero. The music listening comparison has the same point estimate and a confidence interval that also includes zero. These data therefore leave uncertainty about whether the group differences reflect a true difference rather than chance variation.

The point estimates for both music groups are in the direction of a lower pain-intensity change score than control. That direction is worth describing, but it is not enough to conclude that the intervention produced a reliable or clinically important difference. The trial’s reported group sizes are small, the confidence intervals are broad, and the registry record does not define a clinically important difference for the scale.

The secondary results include nominally notable unadjusted comparisons for music therapy on pain relief and mood, but multiple outcomes were assessed and no multiplicity procedure is reported. Other secondary comparisons do not show the same pattern, and numeric findings for several listed outcomes are not reported in the registry record. These secondary data should be viewed as context for the primary result rather than as independent confirmation.

The study was designed to examine a single session and short-term measurements, with assessment at the end of the 20-minute intervention, up to 120 minutes following randomization. The findings do not establish longer-term effects, and they do not resolve the feasibility aims because feasibility results are not reported in the registry record. The posted results also do not establish what would happen in other populations or settings.

General: A trial estimate is one contribution to evidence, not a guarantee of an outcome for an individual. The registry record supports a cautious description of short-term group summaries and their uncertainty. It does not justify medical advice or a definitive claim that music therapy does or does not reduce pain.

17. Why This Trial Matters Statistically

This study is statistically informative because it distinguishes a therapist-led music session from preferred-music listening without a therapist and from standard care. The three-arm randomized design makes those contrasts relevant to the study question, while the equal posted group sizes allow readers to compare the reported means and variability across arms. The design also highlights why comparator choice matters: a comparison against standard care asks a different question from a comparison against music listening.

The primary result illustrates the difference between a point estimate and a precise conclusion. Both music-group comparisons have a negative estimated mean difference from control, yet each confidence interval includes zero. The estimates therefore offer a direction and approximate scale for the observed differences, but substantial uncertainty remains. Statistical interpretation is not settled by the sign of an estimate alone.

The secondary measures show another important statistical issue. Some unadjusted results for pain relief and mood appear more distinct from control than the primary pain-intensity result, while other measures do not show the same pattern. Without a reported multiplicity plan, those findings need cautious interpretation. This is a practical example of why prespecified outcomes, transparent reporting, and a stated analysis strategy matter when a study evaluates several measures.

Finally, the planning illustrations demonstrate how sample-size requirements change when a study aims to detect a smaller effect. They are planning examples based on observed estimates, not a retrospective measure of trial quality or a statement of observed power. The registry record’s missing details about its original sample-size justification and analysis plan also show how incomplete methodological reporting limits independent assessment. Together, the results offer a clear case for reading estimates, uncertainty, outcome scope, and reporting limitations as a connected whole.

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 most direct limitation is the size and scope of the posted dataset: 20 participants are reported in each group, and the primary outcome is measured over a short period, ending at the 20-minute intervention endpoint and extending up to 120 minutes following randomization. These results do not describe longer-term outcomes. The registry record does not report whether follow-up beyond that window was planned or collected.

The study evaluates a single session. Its results therefore do not describe repeated sessions or a longer course of music therapy. The population is adults with sickle cell disease, and applicability beyond the studied population is not established by these results. Although the study purpose included intervention feasibility, feasibility findings are not reported in the registry record.

The primary comparison intervals include zero, and the recalculated comparisons are unadjusted. The registry does not report the original sample-size rationale, full analysis plan, multiplicity procedure, missing-data approach, or details of sequence generation and allocation concealment. It labels masking as single but does not identify the masked party. The primary population wording also does not explain in detail how the reported groups were included in analyses.

Numeric results are not reported for several listed secondary outcomes, including length of stay, amount of hydromorphone, and numeric pain rating. The registry record also does not state a clinically important difference for the primary scale. These reporting gaps limit conclusions about clinical importance, completeness of outcomes, and robustness to alternative analyses. The recalculated estimates are useful summaries of posted statistics, but they cannot fill in those missing protocol and analysis details.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Music Therapy in Sickle Cell Pain Mixed Methods Study — NCT02270060.
• Registry record last updated 2019-08-21; status last verified 2019-08.
• Results first posted 2019-07-15.
• 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

NCT02270060 is a completed randomized, single-masked, parallel-group study of music therapy in adults with sickle cell disease. Enrollment was 60, with 20 participants reported in each of three arms: a single 20-minute music therapy session, 20 minutes of preferred-music listening without a therapist, and standard care.

The primary outcome was change from baseline in pain intensity on the Visual Analog Scale of Pain Intensity, measured at the end of the intervention, up to 120 minutes following randomization. Recalculated unadjusted comparisons of both music groups with control have confidence intervals that include zero. Secondary results show some nominal differences for pain relief and mood, but no multiplicity plan is reported. Results for several listed outcomes and feasibility are not reported in the registry record.

The record reports zero serious adverse events, zero other adverse events, and zero deaths in each group. Important details of the original sample-size rationale, analysis plan, missing-data handling, and masking are not reported in the registry record.