Pain Outcomes of Non-opioid vs. Opioid Analgesia for Kidney Stone Surgery.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pain Outcomes of Non-opioid vs. Opioid Analgesia for Kidney Stone Surgery. (NCT03584373), a randomized phase 3 study. The primary outcome is Satisfaction With Pain Relief.

2. Clinical Question

The trial record describes a prospective randomized controlled trial comparing postoperative pain outcomes in patients undergoing ureteroscopy or percutaneous nephrolithotomy. Its primary outcome was a patient-reported satisfaction score, rather than a direct measurement of pain intensity. Participants were asked to rate satisfaction with pain relief since surgery while taking their assigned medication. The registry describes the scale as an 11-point ordinal numeric rating scale, from 0 for not satisfied with pain relief to 10 for well-satisfied; higher scores indicate greater satisfaction.

The comparison is between two assigned medication strategies, not between a medication and no pain treatment. The non-opioid strategy combined ketorolac with patient-directed acetaminophen, while the opioid strategy used Percocet. The record also lists medication use and constipation as secondary outcomes. These outcomes provide context about unused prescribed pills and a reported postoperative symptom, but they do not replace the primary satisfaction question.

3. Trial Design

The registry identifies this as a completed, randomized, parallel-group, phase 3 trial sponsored by Montefiore Medical Center. The official title describes it as prospective. The study concerns nephrolithiasis and postoperative analgesia following ureteroscopy or percutaneous nephrolithotomy. Enrollment is listed as 119. The trial start date is 2018-07-27, and the primary completion date is 2022-03-23.

Participants were assigned to non-opioid or opioid analgesia. The non-opioid arm used oral ketorolac, 10 mg every 6 hours or as needed, with acetaminophen used at the patient’s direction as needed. The opioid arm used oral Percocet, 5 mg every 4-6 hours or as needed. These are the assigned strategies described in the registry; the record does not report adherence to the medication instructions.

Masking is listed as none. This means the registry does not describe the study as blinded; it does not, by itself, establish how participants or staff were informed about assignment or how outcome collection was conducted. The registry describes random allocation and a parallel model but does not report the method used to generate or conceal the allocation sequence. Those details are not reported in the registry record.

The primary endpoint was assessed 1 week post surgery. The registry reports that data were not collected and analyzed for 7 participants lost to follow up in the non-opioid arm and 8 participants lost to follow up in the opioid arm. The outcome summaries therefore describe those with analyzed data for this endpoint, rather than all randomized participants. The method used to handle missing outcomes is not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: A total of 119 patients were consented and enrolled into the study. Of the 119 patients, 14 patients screen failed (did not meet inclusion/exclusion criteria) and were not randomized into the study. Accordingly, 105 patients were randomized into the two arms/groups for this study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Data was not collected and analyzed for the 7 participants who were lost to follow up in the non-opioid analgesia arm and 8 participants who were lost to follow up in the opioid analgesia arm.

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 Satisfaction With Pain Relief, measured over 1 week post surgery.

The primary endpoint was satisfaction with pain relief 1 week post surgery. Patients were asked to rate satisfaction with pain relief since surgery and while taking their assigned medication. The registry describes an 11-point ordinal numeric rating scale, with 0 meaning not satisfied with pain relief and 10 meaning well-satisfied. A higher score represents greater satisfaction. The posted group summaries report the mean and standard deviation of this score.

Satisfaction is a patient-reported outcome: it captures a patient’s overall appraisal of pain relief rather than pain intensity alone. It may reflect the experience of relief over the period since surgery, as framed by the survey question. This makes it relevant to a comparison of postoperative analgesia strategies, while also meaning the score should be interpreted according to what the question asks. It is not a direct measure of medication consumption, a count of pain episodes, or an objective measure of surgical recovery.

The endpoint is described as an ordinal scale, while the posted summaries and comparison use means and a mean difference. As a general statistical point, a mean can summarize an ordered rating scale, but it treats score steps as if they can be meaningfully averaged. That summary does not show the full distribution of individual responses. The registry record does not report the distribution of scores, a threshold defining a clinically important difference, or a minimally important difference for this measure.

7. Results Posted in the Registry

• Opioid Analgesia: mean 8.85 versus 8.70 on control; difference 0.15 (95% CI -0.58 to 0.88), standardized effect d = 0.09; z-test p = 0.689.

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.

Unused Medications - Proportion of Prescribed Pills Unused at 1 Week Post-Surgery

• 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:
  • Opioid Analgesia: mean 0.58 versus 0.63 on control; difference -0.05 (95% CI -0.20 to 0.10), standardized effect d = -0.14; z-test p = 0.511.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Opioid Analgesia and the control. The interval gives the range of effects that remain compatible with the data.

Rates of Constipation

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Opioid Analgesia: 37.0% (17/46) versus 25.0% (11/44) on control; risk difference 12.0 percentage points (95% CI -7.0 to 30.9), risk ratio 1.48 (0.78–2.79); unadjusted two-proportion z-test p = 0.221.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Opioid Analgesia and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists two secondary outcomes at 1 week post surgery: the proportion of prescribed pills unused and rates of constipation. Together, they address medication use and a postoperative symptom, offering context alongside the primary satisfaction score. They are not alternative measures of satisfaction and do not answer the primary question by themselves.

Across these domains, the secondary results do not form a single consistent signal about the comparative experience. Medication use and constipation are distinct outcomes, with different scales and interpretations; a pattern in one need not predict a pattern in the other. The secondary findings therefore add descriptive context rather than resolving the uncertainty around the primary outcome.

The registry reports an analysis for unused medications and no reported comparative analysis for constipation. The registry record does not report whether secondary outcome analyses were prespecified in a detailed analysis plan or whether adjustments were made for testing multiple outcomes. In general, when several outcomes are examined, the chance of at least one seemingly notable result arising by chance can increase if no multiplicity strategy is used. Without a reported adjustment or prespecified hierarchy, secondary results should carry less inferential weight than the primary outcome and be interpreted cautiously.

These outcomes should not be combined into a single overall conclusion: their measurement types differ, and no combined endpoint is reported. The secondary data can inform what was recorded in the trial, but they do not establish a definitive benefit or harm and do not override the uncertainty in the primary comparison.

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

• Unused Medications - Proportion of Prescribed Pills Unused at 1 Week Post-Surgery
• Rates of Constipation

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous in the registry’s statistical classification: it is a score summarized by a mean and standard deviation. The comparison is a difference between group means. In the recalculation, the contrast is expressed as opioid analgesia minus non-opioid analgesia, so a positive estimate means the observed mean was higher in the opioid arm. The estimate is 0.15. A mean difference keeps the result in score points, which makes its scale interpretable alongside the original rating measure.

What does a standard deviation describe?

As a general statistical concept, a standard deviation describes how spread out individual observations are around a group mean. It is not the uncertainty in the mean itself. The primary outcome standard deviations are 2.01 in the non-opioid arm and 1.49 in the opioid arm. The means are close, while the observed scores vary within each group. A group mean therefore does not imply that every participant gave a score near that mean.

What does the unadjusted comparison do?

The recalculated comparison uses the posted group summaries to estimate an unadjusted difference in means. It does not account for other variables or use participant-level data. The unadjusted p-value is 0.689. A p-value describes how compatible the observed data are with a specified null model under the test’s assumptions; it is not the probability that the null hypothesis is true, nor a measure of the size or importance of the difference. The registry’s own analysis is reported separately and should be used when describing the trial’s stated analysis.

The registry reports its analysis as a two-sided t-test. In general, a two-sided test considers departures in either direction rather than only a prespecified direction. The registry also labels the analysis as non-inferiority. Non-inferiority is not established merely because a difference is small or a confidence interval includes zero: the analysis needs a prespecified margin and a comparison with that margin. The margin and other details of the original analysis plan are not reported in the registry record.

Why does the confidence interval matter?

A confidence interval gives a range of effect estimates compatible with the data and the analysis procedure at a stated confidence level. It conveys precision as well as direction. The registry reports a 95% confidence interval from -0.89 to 0.60 for its net mean difference. Because the interval includes zero, the reported analysis does not resolve whether the mean difference is positive or negative. The interval does not prove that the groups are the same, and the registry does not provide a clinical-importance threshold for judging which values would matter to patients.

Why can a mean be used for an ordinal rating?

The satisfaction measure is described as an ordinal numeric rating scale, meaning scores have an order from less to more satisfaction. The posted analysis treats it as a continuous measure and reports means, standard deviations, and a t-test. As a general statistical point, this approach can provide a compact comparison of average scores, but it does not describe the full response distribution. A distributional summary, or an analysis designed around ordered categories, could address different features of the responses. Such alternatives are not reported in the registry record.

For a t-test, the precision of a mean comparison depends on the variability of scores and the amount of outcome data in each group. More variable scores generally make a mean difference harder to estimate precisely, while more outcome observations can improve precision. The registry record does not report whether assumptions were checked, whether any adjustment was used, or whether there were prespecified sensitivity analyses. Those omissions mean the posted summary statistics cannot answer questions about robustness to alternative analytic choices.

What does randomization contribute?

As a general design principle, random allocation aims to make assigned groups comparable in expectation, including with respect to characteristics that are not measured. It does not guarantee identical groups in a particular trial. The registry confirms randomization but does not report the sequence-generation or allocation-concealment procedures. Masking is listed as none. These features matter when assessing possible influences on care, reporting, and outcome measurement, particularly for a patient-reported endpoint.

The primary endpoint summary excludes participants for whom the registry says data were not collected and analyzed after loss to follow up. A complete-case comparison uses available outcomes, but its interpretation can be affected if outcome availability relates to satisfaction or treatment assignment. The registry record does not report how missingness was assessed or handled, whether participants were analyzed according to assignment, or what analysis population was specified.

11. Confidence Intervals and Precision

The registry’s reported 95% confidence interval for the net mean difference runs from -0.89 to 0.60. It includes zero and covers both negative and positive values. In general, a confidence interval represents the range of values compatible with the observed data and the statistical model at the stated confidence level. The breadth of an interval communicates precision: a narrower interval indicates a more precise estimate, while a wider interval leaves more uncertainty about the magnitude and direction.

The reported interval does not show that the groups are equivalent. Equivalence requires a prespecified acceptable range and an analysis showing that the interval lies within that range. Similarly, the registry’s non-inferiority label cannot be interpreted as a demonstrated non-inferiority conclusion without the margin and decision criteria. These details are not reported in the registry record.

The interval also does not identify whether any possible mean difference would be meaningful to patients. The record does not report a minimally important difference or another threshold for interpreting clinical importance. Thus, the confidence interval can be read as statistical uncertainty about the mean difference, but not as a clinical boundary between an important and unimportant effect.

Precision is affected by the amount of outcome data and the variability of scores. The registry reports that data were not collected and analyzed for participants lost to follow up in both arms. That missingness is relevant to how well the analyzed data represent the randomized groups. Without the missing-data approach or outcome information for those participants, the interval cannot address uncertainty arising from missing outcomes beyond what is reflected in 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 planning figures are participants per arm, not total participants across the trial. They are illustrations based on the observed effect, not the trial’s original design assumptions. The listed assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set at the stated fraction of the observed effect. The original trial’s sample-size justification and design assumptions are not reported in the registry record.

The 80% power column gives the number of participants per arm the illustration estimates would be needed for an 80% chance of detecting the specified effect under those assumptions, if that effect were present. The 90% power column gives the corresponding planning target for a 90% chance. These are planning probabilities under a model, not guarantees for a future study. They are not observed power.

Rows that plan for 100% of the observed effect use the observed estimate as the target; rows for 75% and 50% use smaller target effects. Smaller effects are harder to distinguish from random variation, so the illustrations require more participants per arm for those targets. The numbers should not be interpreted as evidence that the observed effect is real, nor as a retrospective account of how the completed trial was designed. They are conditional planning illustrations whose relevance depends on whether the assumptions and target effect are appropriate for a future study.

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 = 0.150; pooled standard deviation σ = 1.763.
2. n = 2 × (1.96 + 0.842)² × 1.763² / 0.150² = 2,169.4, rounded up to 2,170 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 <- 0.15                      # observed difference in means
sigma <- 1.76335424172745                     # 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(3584373)
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 = 2,170 (80% power), 2,905 (90% power)
 75% of observed effect: n per arm = 3,857 (80% power), 5,163 (90% power)
 50% of observed effect: n per arm = 8,678 (80% power), 11,617 (90% power)
power.t.test: 2170.3 
Simulated power at n = 2,170 per arm: 0.798 (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. Analyses Reported by the Sponsor

The registry reports a two-sided t-test for the primary outcome and labels it as non-inferiority. The sponsor’s reported estimate is a net mean difference of -0.14, with a 95% confidence interval from -0.89 to 0.60 and p = 0.70. The recalculation from the posted group summaries expresses the contrast in the opposite direction, opioid minus non-opioid, and estimates a mean difference of 0.15 with an unadjusted p-value of 0.689. The signs therefore reflect opposite contrast directions.

The recalculation is an unadjusted check using the posted means, standard deviations, and analyzed group sizes. It is not a replacement for the sponsor’s analysis, which is the appropriate reference for the trial’s own reported inferential result. The small numerical variation between the estimates and p-values may reflect differences in calculation or reporting conventions; the registry does not provide enough methodological detail to identify the reason.

The registry does not report the non-inferiority margin or the full analysis plan. Consequently, the sponsor’s non-inferiority label can be described, but whether the stated criterion was satisfied cannot be independently assessed from the reported estimate and interval alone.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and two secondary outcomes. It also reports a total of 7 outcome measures and 6 analyses, but it does not identify a complete hierarchy of hypotheses or describe how the reported endpoints relate to one another statistically. A multiplicity strategy, such as a prespecified ordering of tests or an adjustment for multiple comparisons, is not reported in the registry record.

As a general statistical principle, evaluating multiple outcomes can increase the chance of a positive-looking result arising by chance if each is interpreted as an independent confirmatory test. This is one reason secondary outcomes generally provide less definitive evidence than a prespecified primary outcome, especially when the handling of multiple testing is unclear. The registry’s reported non-inferiority analysis does not include the margin in the available record, so the decision rule for that analysis cannot be assessed.

For the primary endpoint, the record states that data were not collected and analyzed for 7 participants lost to follow up in the non-opioid arm and 8 in the opioid arm. The registry does not report the reason for loss to follow up, the timing of loss, or whether missingness was related to satisfaction or treatment assignment. It also does not report imputation, sensitivity analyses, or another missing-data method. This limits assessment of how missing outcomes may affect the comparison.

The analysis population is not reported in the registry record. The record does not specify whether the primary analysis followed assignment regardless of medication received, whether it was restricted to participants with available outcomes, or whether other populations were used. No assumptions about those choices should be made from the group summaries alone.

16. 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: anemia (5.6%), dysuria (3.7%), fever (2.0%), muscle cramps (2.0%), abdominal pain (2.0%).

For serious adverse events, the registry reports 5 affected participants among 51 at risk in the non-opioid analgesia group and 7 among 54 at risk in the opioid analgesia group. Deaths are listed as 0 in each group. These are counts in the registry’s safety record; the at-risk figures are not the analyzed group sizes for the primary satisfaction outcome.

The registry lists anemia at 5.6%, dysuria at 3.7%, fever at 2.0%, muscle cramps at 2.0%, abdominal pain at 2.0%, and gastrointestinal pain at 2.0% among the top serious event terms. The record does not provide enough detail to assign each listed term to a particular arm or to determine whether participants could contribute more than one event term. These percentages should therefore be read as the listed event information, not as a direct arm-to-arm comparison.

Serious adverse event counts do not by themselves establish whether an event was caused by an assigned medication. Definitions, event timing, relatedness assessments, and fuller event descriptions are not reported in the registry record. The figures describe what was recorded, not a comprehensive safety conclusion.

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

The posted primary results describe average satisfaction scores that were close between the randomized analgesia groups. The recalculated unadjusted mean difference is 0.15 in the direction of a higher average for opioid analgesia, while the registry’s own analysis reports a net mean difference of -0.14 using the opposite contrast direction. The sponsor-reported 95% confidence interval includes zero, and its p-value is 0.70. These results do not establish a clear difference between the group means.

They also do not establish that the strategies are equivalent or that non-opioid analgesia is non-inferior. The registry labels its analysis as non-inferiority, but the margin and decision criteria are not reported in the registry record. The available interval cannot be compared with an unreported margin. Nor does a lack of clear evidence of a difference prove that no meaningful difference exists.

The endpoint is satisfaction with pain relief, reported on an ordinal rating scale and summarized as a mean. It is not a direct measurement of all dimensions of pain or of medication effects beyond the survey question. The results do not establish how individual patients responded, because the score distributions are not reported. They also do not show how outcomes would differ for patient groups or procedures separately; such subgroup results are not reported.

The trial record reports missing primary outcome data among participants lost to follow up, and the missing-data method is not reported. That leaves uncertainty about how the analyzed results relate to outcomes for all randomized participants. The secondary outcomes and adverse event figures provide additional descriptive information, but they do not remove these limitations or prove a treatment effect. The findings should be understood as the reported trial results, not as medical advice or a guarantee of an individual outcome.

18. Why This Trial Matters Statistically

This trial raises a practical statistical comparison between two postoperative analgesia strategies in patients undergoing ureteroscopy or percutaneous nephrolithotomy. Its randomized design is intended to support a comparison of assigned groups, and its primary endpoint focuses on patients’ reported satisfaction with pain relief. That outcome matters statistically because it captures a patient perspective that is not identical to a clinical measurement of pain intensity or medication use.

The results also illustrate why an estimate, a confidence interval, and a p-value answer different questions. The mean difference describes the observed separation in average scores; the confidence interval conveys uncertainty about the estimate; and the p-value summarizes compatibility with a null model under the test. None alone establishes equivalence or clinical importance. The registry’s non-inferiority label makes the absent margin particularly important: without that threshold, the reported analysis cannot be fully interpreted as a non-inferiority decision.

Finally, the record highlights the need to consider outcome availability, analysis populations, multiplicity, and reporting detail. Missing primary outcomes and an unreported missing-data approach limit assessment of the primary comparison. Secondary endpoints provide context, but without a reported multiplicity plan they should not be treated as equally confirmatory. These are central statistical considerations when translating trial summaries into evidence about comparative outcomes.

19. 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 trial-specific details needed for a full assessment are not reported in the registry record. These include the original sample-size justification, the randomization sequence and concealment procedures, and the detailed statistical analysis plan. The registry lists a non-inferiority analysis but does not report the non-inferiority margin or the criteria used to interpret it.

The primary endpoint is a patient-reported satisfaction score on an ordinal scale, analyzed using means and a t-test. The registry does not report the full distribution of scores, a clinically important difference, or alternative analyses of the ordinal responses. Masking is listed as none, which is relevant when interpreting a subjective outcome, but the record does not describe survey administration or steps taken to limit assessment or reporting influences.

Data were not collected and analyzed for participants lost to follow up in both groups. The reasons for loss, missing-data method, sensitivity analyses, and analysis population are not reported. The available summary therefore cannot show how robust the result is to assumptions about missing outcomes.

The interventions also differ as strategies: one combines ketorolac with patient-directed acetaminophen, while the other uses Percocet. The registry does not report adherence, actual medication use, or whether participants received additional pain management. The summaries cannot separate the effect of each medication within the non-opioid strategy or establish that every participant followed the assigned instructions. Finally, the registry record does not report separate outcome results by procedure type, limiting assessment of whether findings differed between ureteroscopy and percutaneous nephrolithotomy.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Pain Outcomes of Non-opioid vs. Opioid Analgesia for Kidney Stone Surgery. — NCT03584373.
• Registry record last updated 2023-12-18; status last verified 2023-10.
• Results first posted 2023-12-18.
• 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.

23. Record Summary

The registry describes a completed, randomized, parallel-group, phase 3 trial sponsored by Montefiore Medical Center, comparing non-opioid and opioid analgesia after ureteroscopy or percutaneous nephrolithotomy for nephrolithiasis. Enrollment is listed as 119, masking as none, and the official title describes a prospective randomized controlled trial.

The primary outcome was satisfaction with pain relief 1 week post surgery, rated on an 11-point ordinal numeric scale and summarized by group means. The registry reports a non-inferiority analysis, but its margin is not reported. Primary outcome data were not collected and analyzed for participants lost to follow up in both arms.

The posted results also include unused prescribed pills and constipation as secondary outcomes, along with serious adverse event information. Missing-data methods, the analysis population, multiplicity handling, and several details of the original design and analysis plan are not reported in the registry record. The primary comparison describes the observed data but does not establish equivalence or a definitive non-inferiority conclusion.