LifeFlow Fluid Study- Non- Critical Pediatric Patients Having a Trans Abdominal Ultrasound: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for LifeFlow Fluid Study- Non- Critical Pediatric Patients Having a Trans Abdominal Ultrasound (NCT03712189), a randomized na study. The primary outcome is Duration- Ultrasound Ordered to Completed.

2. Clinical Question

The registry describes an unblinded, randomized comparison of fluid-delivery modalities in non-critical pediatric patients undergoing a transabdominal pelvic ultrasound. The primary outcome focuses on the time from the ultrasound order to its completion. It is a process measure tied to the imaging episode, rather than a measure of a clinical condition or a longer-term patient outcome.

The study context is specific: the brief summary describes female patients receiving intravenous fluid boluses so their bladders would be full for the planned ultrasound. The registry’s official title mentions critical and non-critical pediatric patients, while the brief summary and arm descriptions focus on non-critical patients. Additional detail about eligibility, the recruitment setting beyond the emergency department timeframe, and whether any other patient groups were enrolled is not reported in the registry record.

The comparison concerns assignment to a delivery method, not whether patients received fluid or whether the ultrasound was completed. Both arms are described as receiving intravenous fluids until the bladder was full. The posted results allow a comparison of group means, but do not establish how the methods affected outcomes beyond those recorded.

3. Trial Design

The registry describes a randomized, parallel-group study with no masking. Participants were assigned to the Alaris Pump or LifeFlow arm. The study is listed as completed, with an enrollment of 30. The posted primary-outcome summaries include 15 participants in each arm. The allocation method, sequence generation, concealment procedures, and any steps to limit bias during outcome measurement are not reported in the registry record.

The Alaris Pump arm is described as standard of care; participants received intravenous fluids through the Alaris IV Pump until their bladder was full. In the LifeFlow arm, fluids were delivered using the LifeFlow Fluid Device until the bladder was full. The listed intervention is a device. The registry labels the phase as not applicable.

The study start is listed as 2018-10-02, primary completion as 2019-05-31, and overall status as completed. The primary outcome timeframe is described as from emergency department arrival to discharge or admission, less than 12 hours. The primary measure itself is the duration from when the ultrasound was ordered to when it was completed. Two secondary outcomes are also posted: total intravenous fluid and duration to a full bladder.

The record identifies the sponsor as Children’s Hospital Los Angeles. It does not report the trial’s original sample-size assumptions, a detailed statistical analysis plan, how missing observations were handled, or the analysis population used for each outcome. The randomized design supports a comparison between assigned groups, but the small enrollment and lack of masking are important context for interpreting the estimates.

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

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 Duration- Ultrasound Ordered to Completed, measured over From ED (Emergency Department) arrival to discharge/admission, less than 12 hours.

The primary endpoint is the duration, in minutes, from the time the ultrasound was ordered to the time the ultrasound was completed. It is reported as a mean with a standard deviation for each randomized group. The timeframe is described as the period from emergency department arrival to discharge or admission, less than 12 hours.

This timing measure is relevant to the study because the interventions were different ways of delivering fluid before a planned transabdominal pelvic ultrasound requiring a full bladder. Measuring the interval from order to completion captures the overall time associated with getting the imaging study completed. It is a practical process outcome that can be compared between the two assigned fluid-delivery groups.

The endpoint does not isolate the time attributable to the device alone. The interval may reflect the broader course of care between ultrasound order and completion, and the registry does not report additional details about how other components of that interval were measured or controlled. Nor does the endpoint directly measure the quality of the ultrasound, a patient’s experience, or a later health outcome. The registry’s description therefore supports interpreting it narrowly as a comparison of mean ultrasound order-to-completion time in this study.

Using a mean summarizes the group’s average observed duration, while the standard deviation describes the spread of individual observations around that average. These summaries give useful context, but do not describe every participant’s timing or explain the reasons for variation.

7. Results Posted in the Registry

• LifeFlow: mean 114.80 versus 154.40 on control; difference -39.60 (95% CI -70.99 to -8.21), standardized effect d = -0.90; z-test p = 0.013.

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.

Total IV Fluid (mL)

• 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:
  • LifeFlow: mean 1,483 versus 1,613 on control; difference -130.20 (95% CI -606.44 to 346.04), standardized effect d = -0.20; z-test p = 0.592.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between LifeFlow and the control. The interval gives the range of effects that remain compatible with the data.

Duration- Full Bladder

• 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:
  • LifeFlow: mean 26.90 versus 61.90 on control; difference -35.00 (95% CI -59.05 to -10.95), standardized effect d = -1.04; z-test p = 0.004.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for LifeFlow than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Across the secondary measures, the posted group summaries have a broadly similar directional pattern to the primary comparison: the LifeFlow group has a lower observed mean for the duration to a full bladder and for total intravenous fluid. The secondary comparisons do not carry the same interpretive weight as the primary result. They are additional outcomes in a small study, and their relationship with the primary measure is descriptive rather than proof that one measure explains another.

These outcomes address related but distinct parts of the study process. Total fluid describes the amount administered over the stated emergency department timeframe, while duration to a full bladder describes time to a condition needed for the planned ultrasound. The primary endpoint instead measures the interval from ultrasound order to completion. A consistent direction across measures can provide context, but it does not establish a causal pathway or show that changes in one measure produced changes in another.

The registry reports unadjusted comparisons for the secondary outcomes and does not describe a multiplicity adjustment or a hierarchy for interpreting them. When several outcomes are examined, the chance of observing a seemingly notable result among them can increase. Without a stated plan for handling that issue, secondary p-values should be treated cautiously and as exploratory. The registry also does not report whether these outcomes were designated in advance as key secondary measures or how their analysis was specified.

The secondary results can help characterize the recorded study experience, but they do not independently confirm the primary comparison. Their estimates have uncertainty, and the sample size is limited. As with the primary endpoint, further interpretation is constrained by the absence of detailed analysis methods, participant-level distributions, and information about missing observations in the registry record. The overall pattern is therefore best understood as descriptive context, not as a separate confirmatory conclusion.

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

• Total IV Fluid (mL)
• Duration- Full Bladder

9. Statistical Interpretation

10. Statistical Methods Explained

The primary measure is continuous: each participant’s outcome is a duration in minutes. The registry reports the mean and standard deviation in each arm, then gives a mean difference comparing LifeFlow with the Alaris Pump. The posted estimate is -39.6 minutes. In this direction of comparison, a negative value means the LifeFlow group’s observed mean was lower. The reported 95% confidence interval is -70.99 to -8.209 minutes.

What does the mean describe?

The mean is the arithmetic average of the recorded durations within a group. It gives a single summary of the group’s center, but it can be affected by particularly long or short observations. A mean difference compares those group averages. It does not mean that every participant experienced the same difference, and it does not show the distribution of individual outcomes on its own.

The standard deviation describes how dispersed observations are around the group mean. The primary outcome standard deviations are 53.2 minutes for Alaris Pump and 31.9 minutes for LifeFlow. The standard deviation is not the uncertainty of the mean difference: it describes participant-level spread, whereas the confidence interval describes uncertainty in the estimated group contrast. The registry does not report medians, ranges, or participant-level durations, so the shape of the outcome distributions cannot be assessed from the posted summaries.

How should the confidence interval be understood?

General statistical explanation: a confidence interval is a range of values generated by a statistical procedure that, under its assumptions, reflects uncertainty in an estimated quantity. A narrower interval indicates greater precision than a wider interval on the same scale. It does not guarantee that the true value lies in the interval, and it does not account for biases or limitations that the analysis did not address. The primary interval ranges from -70.99 to -8.209 minutes, showing that the estimated direction is below zero across the interval while the magnitude remains uncertain.

What does the p-value add?

The unadjusted p-value for the primary comparison is 0.013. General statistical explanation: a p-value measures how unusual results at least as inconsistent with a specified null model would be if that model and the analysis assumptions held. It is not the probability that the null model is correct, and it does not measure the size or practical relevance of an effect. Here, it accompanies the estimated mean difference and its interval; it should not replace either one. The registry does not report a multiplicity adjustment for the comparisons.

Why can variability affect the comparison?

General statistical explanation: greater variability relative to the difference being estimated tends to make an estimate less precise. In a small study, individual observations can have substantial influence on the group summaries. The posted standard deviations provide information about spread, but without participant-level data or distributional diagnostics, it is not possible to assess unusual observations, skew, or whether a different summary would tell a different story.

Over-dispersion is a general concern when data vary more than the statistical model expects. If a model underestimates variability, its uncertainty estimates can be too optimistic. The registry does not describe a model-based analysis or report a specific assessment of over-dispersion. For this continuous endpoint, the posted summaries alone do not establish that over-dispersion occurred; it is a general consideration rather than a finding about this trial.

What analysis details are documented?

The registry identifies the primary outcome as a mean with standard deviation and posts a mean difference, confidence interval, and unadjusted p-value. It does not report the test or model used to obtain those comparison statistics, whether the analysis followed randomized assignment, whether adjustments were made, or how incomplete outcomes were treated. Those details are not reported in the registry record. The study’s original statistical plan, including any interim analyses, is also not reported in the registry record, so none should be inferred from the posted summaries.

The comparisons are presented as unadjusted. That label matters because the registry also posts secondary outcomes. Without a reported plan for handling multiple comparisons, the p-values should be interpreted as nominal results rather than as a family-wise conclusion across all outcomes. The statistical estimates are useful descriptions of the posted results, but their interpretation depends on assumptions and analysis choices that are not fully documented in the registry record.

11. Confidence Intervals and Precision

Precision concerns how tightly the data estimate the group difference. For the primary outcome, the mean difference for LifeFlow compared with Alaris Pump is -39.6 minutes, and the 95% confidence interval extends from -70.99 to -8.209 minutes. The interval indicates uncertainty in the difference’s magnitude: the estimate is not a single known quantity, even though the entire interval is below zero.

General statistical explanation: a confidence interval is a range produced by a method that, under its assumptions, conveys the uncertainty associated with an estimate. A wider interval generally indicates less precision than a narrower interval on the same measurement scale. It does not capture every potential source of error. For example, it cannot by itself account for selection problems, measurement bias, or an analysis model that does not fit the data.

The study enrolled 30 participants, with 15 in each primary-outcome arm. The observed standard deviations were 53.2 minutes for Alaris Pump and 31.9 minutes for LifeFlow. These summaries show that individual durations varied within both groups. A limited number of observations means the group means and their difference may be sensitive to the particular participants enrolled, although the registry does not provide participant-level data to examine that sensitivity directly.

The unadjusted p-value of 0.013 describes compatibility with a null comparison under the applicable test assumptions; it does not make the estimate precise or establish its practical importance. The registry does not report the test, analysis model, missing-data approach, or a prespecified threshold for an important difference. These omissions limit how fully the interval and p-value can be evaluated. The interval communicates the uncertainty in the posted estimate, while uncertainty about analysis details and study conduct remains additional context rather than something the interval resolves.

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 display is a planning illustration based on the observed effect, not the trial’s original design calculation. The registry’s original sample-size assumptions are not reported in the registry record. The stated illustration 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 the stated fraction of the observed effect. The figures for these continuous outcomes are participants per arm, not total events.

For the primary outcome, planning for 100% of the observed effect gives 20 participants per arm for 80% power and 26 participants per arm for 90% power. Planning for 75% of the observed effect gives 35 participants per arm for 80% power and 46 participants per arm for 90% power. Planning for 50% of the observed effect gives 78 participants per arm for 80% power and 104 participants per arm for 90% power.

In plain language, the 80% power column describes the planned number per arm under which the calculation would have an 80% chance of detecting the specified effect if the assumptions hold. The 90% power column gives the corresponding planning number for a higher chance of detection under those same assumptions. Smaller effects are harder to distinguish from random variation and therefore require more participants. The plotted curve illustrates that planning relationship; it does not show an observed trial result.

These counts are hypothetical planning values derived from the observed effect and stated assumptions. They are not observed power, and they do not establish that the study was designed using those assumptions. Because the observed effect comes from a small study, using it as the basis for future planning may not provide a stable estimate of the effect worth detecting. A design would need its own prespecified assumptions and rationale.

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 = -39.600; pooled standard deviation σ = 43.863.
2. n = 2 × (1.96 + 0.842)² × 43.863² / -39.600² = 19.3, rounded up to 20 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 <- -39.6                      # observed difference in means
sigma <- 43.8625694641798                     # 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(3712189)
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 = 20 (80% power), 26 (90% power)
 75% of observed effect: n per arm = 35 (80% power), 46 (90% power)
 50% of observed effect: n per arm = 78 (80% power), 104 (90% power)
power.t.test: 20.3 
Simulated power at n = 20 per arm: 0.796 (20000 replicates)

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

14. Multiplicity, Missing Data and Analysis Populations

The registry posts a primary outcome and two secondary outcomes. It gives unadjusted comparison statistics, but does not report a strategy for controlling the chance of false-positive findings across multiple outcomes. A multiplicity plan might specify a primary comparison, an order for testing outcomes, or an adjustment to inference when several comparisons are considered. No such approach is reported in the registry record.

This matters most when interpreting the secondary p-values. An unadjusted p-value applies to an individual comparison and does not account for the fact that other outcomes may also have been examined. The primary outcome is identified as primary in the registry, but the record does not describe whether the outcome hierarchy was prespecified in a statistical analysis plan or whether any other analyses were planned. The posted p-values should therefore not be treated as an adjusted set of confirmatory findings.

Information about missing data is also not reported in the registry record. The posted arm summaries include 15 participants per arm for the primary endpoint, but the record does not explain whether this reflects all randomized participants with measured outcomes, how missing measurements were handled, or whether any participants were excluded from an analysis. The secondary outcomes also have arm summaries, but details of completeness and handling of missing observations are not described.

The analysis population is not reported in the registry record. It is not specified whether comparisons were based on randomized assignment, participants who received the assigned device, or another set of participants. The registry does not describe adherence, crossover, protocol deviations, or exclusions. These are relevant details because excluding participants or analyzing them according to treatment received rather than assignment can affect the interpretation of a randomized comparison.

The record posts numerical comparisons but does not describe the statistical analysis plan, any interim analyses, or the exact test or model used. Those aspects are not reported in the registry record and should not be inferred. Their absence does not invalidate the posted summaries, but it limits assessment of whether the analysis followed a prespecified approach and how robust the results may be to alternative handling of the data.

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 serious adverse event figures list 15 participants at risk in each arm and zero participants affected by a serious adverse event in either arm. The non-serious adverse event figures likewise list 15 participants at risk in each arm and zero affected. Deaths are listed as zero in both groups. No serious adverse event terms are listed.

These are event counts as recorded in the registry. They indicate that no adverse events were reported in these categories for the listed participants; they do not establish that no event could occur or that the devices have been shown to be safe. The study enrolled 30 participants, and the record does not provide additional detail about how events were collected, how they were defined, or the duration of safety follow-up beyond the stated study timeframe.

Zero recorded events in a small study gives limited information about uncommon harms. The absence of listed events should be interpreted as a description of this trial’s registry results, not as a general conclusion about safety in other patients or settings. The adverse-event information also does not determine whether differences in event reporting or follow-up occurred between groups; those details are not reported in the registry record.

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

The result describes a comparison of two fluid-delivery approaches among participants in a randomized, unblinded study of non-critical female patients undergoing a planned transabdominal pelvic ultrasound. In the posted primary results, the LifeFlow group had a lower mean ultrasound order-to-completion duration than the Alaris Pump group. The estimated difference and confidence interval describe the size and uncertainty of that observed comparison.

The result does not show that every participant’s ultrasound was completed sooner, nor does it isolate the contribution of the delivery device from all other aspects of care. The endpoint covers the time from order to completion; the registry does not report a decomposition of that interval. It also does not show whether the observed difference was important to patients or clinicians, because an important-difference threshold is not reported in the registry record.

The study result cannot by itself establish that the same estimate would be seen in another population, hospital, or workflow. The enrollment was 30, the study was unblinded, and key details about eligibility, analysis populations, missing observations, and statistical methods are not reported in the registry record. These points constrain precision and generalizability. The posted results also do not evaluate outcomes beyond the listed measures.

The two secondary measures add information about fluid amount and time to a full bladder, but their unadjusted comparisons are not independent confirmation of the primary finding. The registry does not report a multiplicity strategy. The absence of recorded adverse events should likewise be interpreted within the limited study size and recorded follow-up rather than as evidence that adverse events cannot occur.

Overall, the registry record provides a small randomized comparison with numerical group summaries and an estimated primary difference. It supports describing what was observed in these study groups, while leaving uncertainty about the estimate’s size, its practical importance, and its applicability beyond this setting. It does not justify a broad claim about treatment benefit or harm.

17. Why This Trial Matters Statistically

This study illustrates why a randomized comparison and a numerical effect estimate are only part of statistical interpretation. The primary outcome is a time measure that connects the intervention to a care process, and the reported mean difference makes the direction and scale of the observed group contrast explicit. The confidence interval adds information that a point estimate alone cannot provide: it shows uncertainty about the magnitude of the comparison.

The study also demonstrates how easily a result can be overstated if the p-value is read in isolation. The p-value is unadjusted, the enrollment is limited, and the registry does not report the full analysis plan. A statistically notable comparison does not establish practical importance, explain the mechanism behind the result, or remove uncertainty about study conduct and generalizability. The estimates, interval, and study context need to be considered together.

The secondary measures show why multiplicity matters. Additional outcomes can help describe the intervention and its setting, but several unadjusted comparisons should not be treated as a collection of independent confirmations. A prespecified hierarchy and transparent analysis plan would help readers distinguish confirmatory questions from exploratory ones. Such details are not reported in the registry record.

Finally, the planning illustration reinforces the distinction between designing a future study and evaluating a completed one. Its participant counts are based on the observed effect and stated assumptions, rather than documented original design assumptions. The observed effect in a small study may not be a stable planning target. Statistical interpretation therefore depends not only on calculations, but on transparent design choices, uncertainty, and the limits of the recorded information.

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.

Several limitations are specific to the scope and reporting of this study. The brief summary describes non-critical female patients with a planned transabdominal pelvic ultrasound requiring intravenous fluid boluses, so the results apply most directly to that context. The official title also refers to critical and non-critical pediatric patients, but the brief summary and arm descriptions focus on non-critical participants. Whether any critical patients were included is not reported in the registry record.

The study enrolled 30 participants, with 15 per arm in the posted primary results. This is a limited number for estimating group differences and for describing uncommon adverse events. The study was unblinded, and the registry does not describe whether outcome assessment or other study procedures were protected from knowledge of assignment. The allocation method and concealment procedures are also not reported.

The primary endpoint is a process interval from ultrasound order to completion. It does not isolate time spent receiving fluids or the contribution of the device from other elements of care. The record does not report detailed operational definitions beyond the endpoint description, participant-level values, or distributional summaries beyond means and standard deviations. These omissions make it difficult to assess how individual observations shaped the group means.

The registry does not report the original sample-size justification, a detailed analysis plan, the analysis population, missing-data handling, or the method used for the comparison statistics. It also does not report a multiplicity plan for the secondary endpoints. Finally, the registry’s adverse-event entries have limited detail about collection and follow-up. These reporting gaps restrict assessment of analysis robustness and the breadth of conclusions that can be drawn from the posted results.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: LifeFlow Fluid Study- Non- Critical Pediatric Patients Having a Trans Abdominal Ultrasound — NCT03712189.
• Registry record last updated 2024-01-08; status last verified 2024-01.
• Results first posted 2021-02-21.
• 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

NCT03712189 is a completed randomized, unblinded, parallel-group study sponsored by Children’s Hospital Los Angeles. It enrolled 30 participants and compared intravenous fluid delivery using LifeFlow with delivery using an Alaris IV Pump, described as standard of care. The study context is non-critical female patients having a planned transabdominal pelvic ultrasound requiring a full bladder.

The primary outcome is mean duration from ultrasound order to completion. The posted comparison gives a lower mean in the LifeFlow group, with a mean difference of -39.6 minutes and a 95% confidence interval from -70.99 to -8.209 minutes; the unadjusted p-value is 0.013. Two secondary outcomes and adverse-event counts are also posted. The registry does not report a detailed analysis plan, original sample-size assumptions, missing-data approach, or analysis population.