Ropinirole for the Treatment of Muscle Cramps in Patients With Cirrhosis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Ropinirole for the Treatment of Muscle Cramps in Patients With Cirrhosis (NCT03176966), a randomized phase 4 study. The primary outcome is Frequency of Muscle Cramps as Assessed by Patient Survey.

2. Clinical Question

The clinical question is a comparison between two active interventions rather than a comparison with no treatment or placebo. The trial was randomized and used a crossover model, so the planned treatment pattern involved participants receiving both interventions in different orders. One sequence began with vitamin E and switched to ropinirole; the other began with ropinirole and switched to vitamin E. The posted primary outcome summaries compare participants’ survey results after each intervention period.

The registry record describes the study aim as comparing efficacy for muscle cramps in cirrhotic patients. The outcome itself is a patient-reported frequency score, not a count of cramps recorded continuously or an assessment by a clinician. The registry record also lists a secondary survey outcome for muscle cramp severity. Details beyond the scale and outcome descriptions, including a ropinirole dose and a fuller explanation of the severity score, are not reported in the registry record.

3. Trial Design

This was a Phase 4 randomized, unmasked crossover trial listed as completed. Enrollment was 31. The registry record gives a start date of 2016-09-02 and a primary completion date of 2021-10-22. Vanderbilt University Medical Center is listed as the sponsor.

The crossover structure used two treatment sequences: vitamin E followed by ropinirole, and ropinirole followed by vitamin E. The arm descriptions say participants switched interventions after 3 months. The primary frequency survey was completed at the end of 3 months on a study intervention. The listed regimen for vitamin E was 400 IU nightly; ropinirole was described as taken nightly, but its dose is not reported in the registry record.

Randomization means assignment to a treatment sequence was randomized, but the method used to generate or conceal that assignment is not reported in the registry record. Masking is listed as none. The registry record therefore does not describe participants or study personnel as blinded to which intervention was being taken.

A crossover design can allow comparisons of interventions within the same participant, which may account for stable differences between individuals. In general, that design also makes the timing and order of treatment important: period effects or effects that persist after switching can complicate interpretation. The registry record does not report a washout period, a planned adjustment for treatment sequence or period, or an analysis using paired participant-level observations. Those details should not be inferred from the design label alone.

The posted primary outcome results include survey data from n=14 after vitamin E and n=13 after ropinirole. The population description separately says that 23 participants received vitamin E and 26 received ropinirole. The registry record does not explain why the analysis counts are smaller than the numbers who received each intervention. Enrollment and the number receiving each intervention are not interchangeable with the number contributing to a particular outcome analysis.

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: 31 subjects were consented and randomized. 1 subject became ill after randomization and was unable to participate so only 30 subjects took a first dose of assigned drug.

Baseline to 3 Months (1st Intervention)

Reasons for not completing this period:

3 Month to 6 Months (2nd Intervention)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Of the 23 participants who received Vitamin E, data was analyzed for those who completed the survey at the end of each specific crossover period (n=14). Of the 26 participants who received Ropinirole, data was analyzed for those who completed the survey at the end of each specific crossover period (n=13).

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: One subject was consented and randomized to Ropinirole then Vitamin E but became ill and withdrew prior to first dose of drug.

6. Primary Endpoint

The registry lists the primary outcome as Frequency of Muscle Cramps as Assessed by Patient Survey, measured over 3 months.

The primary endpoint is the frequency of muscle cramps assessed by patient survey at the end of 3 months on each study intervention. The registry record describes a frequency scale from 0 to 3: 0 means once weekly or less, while 3 means multiple episodes a day. The endpoint is reported as a mean score with a standard deviation for each intervention.

This measure was chosen to capture how often participants experienced cramps during the intervention period. A survey can collect a participant’s account of symptoms that may not be observed during a clinic visit. In general, a bounded score also simplifies the comparison of reported frequency across treatment periods, although the scale’s ordered categories do not necessarily represent equal changes in symptom frequency from one point to the next.

The recorded endpoint is a score, not a direct count of individual cramp events. Its interpretation depends on participants understanding and completing the survey consistently. The registry record does not report the survey’s validation, recall period, missing-item rules, or whether a particular score change was considered clinically important. The frequency scale’s endpoints are described, but the registry record does not further define how intermediate values map to specific frequencies.

The primary results compare the mean frequency scores after vitamin E and ropinirole. The reported mean difference is ropinirole relative to vitamin E. This is a summary of the posted outcome data; it does not by itself describe the experience of every participant or establish how meaningful a score difference might be to patients.

7. Results Posted in the Registry

• Ropinirole Taken Nightly for 3 Months: mean 1.23 versus 1.14 on control; difference 0.09 (95% CI -0.84 to 1.02), standardized effect d = 0.07; z-test p = 0.850.

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.

Muscle Cramp Severity as Assessed by Patient Survey

• 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:
  • Ropinirole Taken Nightly for 3 Months: mean 6.00 versus 6.57 on control; difference -0.57 (95% CI -3.33 to 2.19), standardized effect d = -0.16; z-test p = 0.686.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ropinirole Taken Nightly for 3 Months and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary outcome concerns muscle cramp severity, while the primary outcome concerns frequency. Across the posted mean contrasts, the numerical direction is not the same for the two survey measures: the frequency contrast is higher after ropinirole, while the severity contrast is lower after ropinirole. These are separate scales and should not be combined into a single overall treatment effect. The registry record does not provide enough detail about the severity scale to translate its score into a specific degree of symptom change.

The secondary result does not materially settle the primary question. Both outcomes are based on survey scores after 3 months on an intervention, and both are reported from limited outcome analysis counts. The primary result remains the designated frequency comparison; a secondary endpoint can provide additional context, but it does not replace or validate the primary analysis on its own.

In general, unadjusted secondary results carry less weight when several outcomes or comparisons may be examined. If each is considered separately without an adjustment or a prespecified hierarchy, the chance of finding an apparently notable result by chance can increase. The registry record does not report a multiplicity strategy, and it lists no reported analyses. The secondary result should therefore be treated as exploratory context rather than a confirmatory finding.

The differing directions across frequency and severity also illustrate why outcomes should be interpreted according to what each measure captures. A change in how often cramps occur and a change in perceived severity are related questions, but one does not necessarily predict the other. The registry record does not report a combined endpoint or a rule for resolving disagreement between the survey measures.

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

• Muscle Cramp Severity as Assessed by Patient Survey

9. Statistical Interpretation

10. Statistical Methods Explained

What does the mean summarize?

The primary outcome is treated as a continuous measure in the posted analysis, and each intervention is summarized by a mean and standard deviation. In general, a mean is the arithmetic average of recorded scores. It describes the center of the observed scores but does not show their full distribution. A standard deviation describes how spread out scores are around the mean; it is not the uncertainty of the mean itself. The outcome values are bounded by the survey’s 0-to-3 frequency scale, so they are also constrained by the response options.

For the primary outcome, the reported mean is 1.14 after vitamin E and 1.23 after ropinirole. Their reported standard deviations are 0.99 and 1.42, respectively. These summaries describe the analyzed survey responses for each intervention period. They do not indicate that each participant had a score equal to the group mean, and they do not show how individual scores changed between periods.

What does the mean difference represent?

The posted comparison is expressed as a mean difference, with ropinirole compared with vitamin E. Its estimate is 0.09. The positive sign means the ropinirole group-period mean is higher on the coded frequency scale than the vitamin E mean. Because higher scale values correspond to more frequent cramps in the registry’s scale description, the direction is toward a higher average frequency score after ropinirole in these summaries. This direction is a description of the posted averages, not a conclusion that an intervention caused a change.

In general, a difference in means puts the group contrast on the original outcome scale, which can be easier to interpret than a standardized measure. Its practical importance still depends on the scale, the uncertainty around the estimate, and whether a meaningful threshold was defined. The registry record does not report a threshold for a clinically important frequency-score difference.

What does the p-value say?

The unadjusted p-value for the primary comparison is 0.85. In general, a p-value describes how compatible the observed data are with a specified null hypothesis under a statistical model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. A large p-value does not prove that there is no difference; it can also occur when data are too limited or variable to estimate a contrast precisely.

The word unadjusted matters because the value is not described as corrected for multiple comparisons. The registry record does not report a multiplicity plan or a sponsor-reported analysis. The p-value should therefore be read as a result for the posted primary comparison, not as a complete account of the study’s analysis strategy.

How should the crossover structure affect the reading?

In general, a crossover trial records outcomes after participants receive different interventions in sequence. The participant can serve as their own comparison, and a suitable analysis can account for the relationship between measurements from the same participant. That relationship is important: observations from one person across periods are not necessarily independent.

The posted comparison is a simple unadjusted recalculation from the separate summary statistics. It does not use participant-level paired differences or model the crossover structure. Consequently, it cannot account for within-participant correlation, period effects, sequence effects, or possible carryover. These are not claims that such effects occurred; they are features that a summary-statistics calculation cannot assess. The registry record does not report a crossover-specific analysis, and no reported analyses are listed.

Random assignment to sequence can help balance groups, but it does not remove the need to analyze a crossover trial in a way that reflects its repeated measurements. The sequence descriptions establish that participants were intended to switch interventions, but they do not provide the participant-level data needed to reconstruct paired treatment effects. The posted unadjusted comparison should therefore be treated as a descriptive contrast from the available summaries, rather than a substitute for a model that accounts for the design.

What role do the standard deviations play?

In general, greater variability in outcome scores makes a mean difference harder to estimate precisely, particularly when outcome counts are limited. The standard deviations describe variation among analyzed scores. They do not show whether the same participants’ scores moved in a consistent direction across treatment periods. For a crossover question, the variability of within-participant differences can differ from the variability of each period’s scores considered separately.

The posted comparison uses a pooled standard deviation for its standardized effect summary, but that standardized summary is not the main clinical endpoint. Standardization expresses a mean difference relative to variability and can help compare results measured on different scales. It does not replace interpretation on the original 0-to-3 frequency scale, and it does not account for crossover pairing when calculated from separate group summaries.

These methods explain the posted summaries, not an undocumented trial analysis. The statistical analysis plan, treatment of missing outcomes, adjustment strategy, and prespecified significance threshold for the original trial are not reported in the registry record. The registry record does list a planning illustration based on the observed effect; that illustration is separate from the trial’s original design and from the observed outcome analysis.

11. Confidence Intervals and Precision

The reported interval for the primary mean difference runs from a negative lower bound to 1.02. It includes zero, meaning that the posted interval is compatible with no mean difference as well as with differences in either direction. The point estimate, 0.09, is only one location within that interval; it should not be read as an exact or highly certain estimate of the underlying contrast.

A confidence interval is generally a range of values compatible with the observed data under a statistical model. A narrower interval indicates greater precision, while a wider interval indicates more uncertainty. The confidence level for the posted intervals is not reported in the registry record, so no particular confidence percentage should be attached to them.

For the primary outcome, the interval extends across both negative and positive values and reaches 1.02 at its upper end. This breadth limits the precision with which the size and direction of a difference can be described. The interval also does not establish that all values it covers are clinically important or plausible for every participant; it describes uncertainty in an estimated mean contrast under the calculation’s assumptions.

The crossover structure is relevant to precision. The posted interval is based on separate group summary statistics, and the recalculation does not use the pairing of outcomes within participants. A crossover analysis that used participant-level data could produce a different estimate of uncertainty. The record does not provide the paired data or a reported crossover analysis needed to assess that possibility.

Precision should be considered alongside the outcome counts: n=14 after vitamin E and n=13 after ropinirole. The registry record does not explain missing survey data or show whether the analyzed participants differed from those who received each intervention. The interval therefore reflects the posted calculation and its available summaries, not uncertainty about all possible sources of bias or missingness.

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 table and curve are planning illustrations derived from the observed effect, not a description of the trial’s original design. The listed quantities are participants per arm, not total events. The assumptions stated for the illustration are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The target effect in each row is a stated fraction of the observed effect.

The 80% power column gives the estimated number of participants per arm under those assumptions for a planned study to have an 80% chance of detecting the chosen effect if that effect is the true one and the model assumptions hold. The 90% power column gives the corresponding planning count for a 90% chance. These are design calculations, not results from the completed trial and not observed power.

Each row uses a different effect size for planning. Planning for 100% of the observed effect uses the full observed contrast as the target; the other rows plan for smaller fractions of it. Smaller effects are harder to distinguish from random variation, so they require more participants under the same assumptions. The table and curve are ways to see how planned sample size changes as the target effect and desired power change.

The illustration is based on a simple two-arm framework. It does not reproduce the randomized crossover design or incorporate participant-level correlation between treatment periods. It should not be interpreted as a recommended size for a future crossover trial without a design and analysis plan suited to that question. The original trial’s sample-size justification and design assumptions are not reported in the registry record.

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 = 0.090; pooled standard deviation σ = 1.216.
2. n = 2 × (1.96 + 0.842)² × 1.216² / 0.090² = 2,863.4, rounded up to 2,864 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 <- 0.0900000000000001                      # observed difference in means
sigma <- 1.21553445035507                     # 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(3176966)
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 = 2,864 (80% power), 3,834 (90% power)
 75% of observed effect: n per arm = 5,091 (80% power), 6,815 (90% power)
 50% of observed effect: n per arm = 11,454 (80% power), 15,334 (90% power)
power.t.test: 2864.4 
Simulated power at n = 2,864 per arm: 0.801 (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 two outcome measures, including the primary frequency measure and a secondary severity measure. It lists no reported analyses. A multiplicity plan, such as a hierarchy of testing or adjustment for examining more than one outcome, is not reported in the registry record. The unadjusted p-values should not be interpreted as evidence that a family of outcomes was controlled for false-positive findings.

Handling of missing outcome data is also not reported in the registry record. The primary outcome description states that 23 participants received vitamin E and that data were analyzed for those who completed the survey at the end of each specific crossover period, with n=14 reported. It states that 26 participants received ropinirole; the corresponding analyzed count in the posted primary outcome results is n=13. The reason for the differences between numbers receiving an intervention and numbers analyzed is not reported in the registry record.

The record does not state whether missing survey responses were imputed, whether participants were excluded for other reasons, or how incomplete crossover sequences were handled. It does not describe an intention-to-treat, per-protocol, or other analysis population. It is therefore not possible to determine from the registry record whether the posted outcome summaries represent all randomized participants, all participants who received treatment, or a defined subset based on completion.

The crossover design makes incomplete periods potentially important because a participant may contribute a result for one intervention but not the other. The record does not report how such cases were handled or whether the analysis required a complete pair of treatment-period surveys. Without that information, the posted summaries cannot establish how missingness may have affected the treatment contrast.

These omissions limit assessment of the analysis plan and the risk of bias. They do not establish that a particular missing-data or multiplicity problem occurred; they mean that the relevant methods are not reported in the registry record.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hepatic encephalopathy (4.3%).

The registry record reports serious adverse events for 1 of 23 participants at risk in the vitamin E group and 0 of 26 at risk in the ropinirole group. It reports other adverse events for 1 of 23 at risk with vitamin E and 3 of 26 at risk with ropinirole. Deaths are listed as 3 in the vitamin E group and 1 in the ropinirole group.

The registry record lists hepatic encephalopathy as a serious adverse event term at 4.3%. It does not provide enough detail in this summary to determine the timing, duration, clinical course, or relationship of each event to study treatment. The at-risk counts and event counts describe what the record reports; they do not establish that an intervention caused or prevented an event.

These are descriptive safety figures from the recorded groups, not a formal comparative safety analysis. The registry record does not report statistical comparisons for adverse events, an attribution assessment, or details needed to interpret deaths in relation to treatment periods and crossover order. The groups also had different numbers recorded at risk. As with any trial summary, the event counts should be read in the context of the recorded exposure and follow-up information, which is limited in the registry record.

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

The primary result describes the average patient-reported cramp-frequency score after each intervention period among the participants whose survey data were analyzed. The means were 1.14 after vitamin E and 1.23 after ropinirole, with a reported mean difference of 0.09 for ropinirole relative to vitamin E. The interval includes zero, and the unadjusted p-value is 0.85. Together, these statistics do not show a clear separation in the posted mean scores.

That conclusion is narrower than saying the interventions have the same effect. The result does not establish equivalence, because an equivalence margin and a corresponding analysis are not reported in the registry record. It also does not prove that either intervention has no effect. Lack of a clear difference in this comparison can reflect uncertainty, and the interval indicates that the estimate is not precise enough to support a definitive statement about the size of the contrast.

The reported comparison is an unadjusted recalculation from separate group summaries. It does not account for the crossover pairing, and the registry record lists no reported analyses. A model using participant-level repeated measurements could address aspects of the design that these summaries cannot, but its result is not available in the registry record. Missing-data methods and the original analysis plan are also not reported.

The endpoint is a survey score with a stated range and frequency anchors. It is not a direct count of events or a measure of every dimension of cramp experience. The secondary severity measure addresses a separate aspect of symptoms and has limited interpretive detail in the record. The posted results should therefore be understood as survey-based group summaries, rather than a complete account of symptom experience or a demonstration of an individual participant’s response.

These findings do not provide medical advice and do not establish that ropinirole or vitamin E works or does not work. They describe what was recorded for this trial and how uncertain the posted comparison is. The results apply most directly to the analyzed survey observations from patients with cirrhosis and muscle cramps; the registry record alone does not establish how they generalize to other populations or settings.

17. Why This Trial Matters Statistically

This trial is statistically notable because it uses a randomized crossover design to compare two active interventions, while the posted treatment contrast is reconstructed from separate group summaries. The design and the available analysis summaries therefore do not line up fully: the crossover structure involves repeated outcomes within participants, but the recalculation cannot use paired observations. That distinction affects what the estimate and its uncertainty can represent.

The primary outcome is a patient-reported frequency score on a bounded scale. Its mean difference is easy to state on the original scale, but a mean contrast alone does not show the distribution of individual responses or whether changes were consistent across participants. The absence of a reported clinically meaningful threshold also makes the practical interpretation of the score difference less settled than its numerical direction.

The outcome analysis counts are smaller than the numbers reported as having received each intervention, and the reasons are not stated. In a crossover study, missing a survey in one period may affect whether a participant can contribute a paired comparison. Without the missing-data rules, participant-level analysis, and crossover model, the registry record leaves important questions about the analysis population and precision unresolved.

The record also illustrates why a planning illustration based on an observed effect should be distinguished from an original trial design calculation. The planning assumptions are stated for the illustration, but the original sample-size justification is not reported. Readers can use the illustration to understand how target effects and desired power affect planned enrollment, but not as evidence about the trial’s original rationale.

Overall, the statistical importance lies in reading the estimates within the limits of the posted design details, outcome counts, and analysis reporting. The primary contrast is not clearly separated from zero, but uncertainty and missing methodological details preclude stronger claims.

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 trial information in the registry record. First, the study is listed as unmasked. Because the outcomes are patient-reported surveys, awareness of the intervention could potentially influence reporting. The record does not describe procedures to reduce that possibility.

Second, the crossover schedule makes treatment order, period effects, and possible carryover relevant. The registry record describes switching after 3 months but does not report a washout period or a reported analysis that adjusts for period or sequence. This does not demonstrate that carryover or period effects occurred; it means their handling cannot be assessed from the record.

Third, the posted outcome counts are n=14 after vitamin E and n=13 after ropinirole, while the population description reports more participants received each intervention. Reasons for the difference, missing-outcome handling, and the definition of the analysis population are not reported. Incomplete data could affect both the estimate and how well it represents the randomized population.

Fourth, the posted comparison is an unadjusted recalculation based on separate summary statistics. It cannot account for within-participant pairing in a crossover study. The registry record lists no reported analyses, so a sponsor-reported crossover model or sensitivity analysis is not available for comparison.

Finally, the primary measure is a survey score, and the record does not report a clinically important threshold or detailed validation information. Ropinirole dose and fuller details of the severity measure are also not reported in the registry record. These limits constrain interpretation of the treatment contrast and its relevance beyond the analyzed survey observations.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Ropinirole for the Treatment of Muscle Cramps in Patients With Cirrhosis — NCT03176966.
• Registry record last updated 2022-10-31; status last verified 2022-09.
• Results first posted 2022-10-31.
• 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

NCT03176966 is a completed Phase 4 randomized, unmasked crossover trial sponsored by Vanderbilt University Medical Center. It enrolled 31 patients with cirrhosis and muscle cramps and compared ropinirole with vitamin E in two treatment sequences. The registry record lists a start date of 2016-09-02 and a primary completion date of 2021-10-22.

The primary endpoint was patient-survey frequency of muscle cramps after 3 months on each intervention. The posted means were 1.14 after vitamin E and 1.23 after ropinirole, with a mean difference of 0.09 and an unadjusted p-value of 0.85. The reported interval includes zero. The comparison is an unadjusted recalculation from posted summaries, and the registry record lists no reported analyses.

The registry record also posts a secondary severity outcome and adverse-event counts. It does not report the original sample-size justification, missing-data methods, a multiplicity plan, or details of a crossover-specific analysis.