This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Oral Ketorolac for Arthroscopic Rotator Cuff Repair (NCT03967847), a randomized phase 3 study. The primary outcome is Postoperative Visual Analog Scale Scores.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03967847 |
| Phase | Phase 3 |
| Condition | Rotator Cuff Tear, Postoperative Pain |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 44 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University Hospitals Cleveland Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
People undergoing arthroscopic rotator cuff repair in a trial concerning rotator cuff tear and postoperative pain. The registry lists an enrollment of 44. It does not report further eligibility details or a fuller description of the people included in the outcome analyses.
Intervention
The listed intervention is ketorolac. The registry’s summary describes the investigators’ aim as examining intravenous and oral ketorolac as an adjunct to a standard-of-care pain protocol. However, the arm descriptions are blank, so the treatment assignment details and the route or timing used for each arm are not reported in the registry record.
Comparator
The comparator is labelled Control. The registry’s summary refers to a standard-of-care pain protocol, but the control-arm description does not specify its components. The details needed to establish precisely how the control care differed from ketorolac treatment are not reported in the registry record.
Primary question
The primary endpoint is postoperative Visual Analog Scale pain scores, recorded as medians with inter-quartile ranges. The registry describes a scale from 0 to 100, with a smaller score considered better, and says participants were assessed at a single time point up to 8 weeks. The clinical question is whether the posted pain-score summaries differ between the ketorolac and control groups. The registry record does not provide an estimable two-arm comparison or a reported analysis for this endpoint, so the summaries alone do not establish the size or precision of a treatment contrast.
3. Trial Design
The registry describes NCT03967847 as a completed, randomized, parallel-group, phase 3 trial. Masking is listed as none. University Hospitals Cleveland Medical Center is identified as the sponsor. The stated enrollment is 44. The registry lists rotator cuff tear and postoperative pain as the conditions under study.
The record gives a start date of 2019-02-11 and a primary completion date of 2020-10-14. These registry dates describe the trial record; they do not by themselves explain when individual participants were enrolled, treated, or assessed. The registry’s brief summary says the investigators aimed to examine intravenous and oral ketorolac as an adjunct to standard-of-care postoperative pain care, with the hypothesis that adding ketorolac would reduce postoperative opioid consumption. Opioid consumption is not the posted primary endpoint described in the results information summarized in the registry record.
The intervention listing names Ketorolac, while the two arms are labelled Control and Ketorolac. The arm descriptions are blank. Consequently, details such as dose, route by arm, duration, accompanying analgesia, and the specific control regimen are not reported in the registry record. Randomization is reported, but the method used to generate the allocation sequence, any allocation-concealment procedures, and the reason masking was not used are not reported in the registry record.
The primary outcome is postoperative Visual Analog Scale scores, expressed as medians and inter-quartile ranges, at one single assessment time point up to 8 weeks. A secondary outcome records participants with retear of rotator cuff repair at 6 months. The results information gives different recorded participant counts for these outcomes, but the registry does not explain the analysis populations or the reasons for those differences. The record labels the study completed; it does not provide further detail about adherence, withdrawals, or the conduct of follow-up.
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
| Stage | Control | Ketorolac |
|---|---|---|
| STARTED | 21 | 23 |
| COMPLETED | 21 | 23 |
| NOT COMPLETED | 0 | 0 |
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: 44 patients were enrolled/randomized but only 39 patients were included for final analysis because of incomplete data collection
| Characteristic | Unit | Control | Ketorolac | Total |
|---|---|---|---|---|
| Participants analysed | 19 | 20 | 39 | |
| Age, Continuous | Years | 55.7 (SD 12.9) | 55.7 (SD 8.2) | 55.7 (SD 10.5) |
| Sex: Female, Male: Female | Participants | 8 | 5 | 13 |
| Sex: Female, Male: Male | Participants | 11 | 15 | 26 |
| Race/Ethnicity, Customized: White | Participants | 12 | 15 | 27 |
| Race/Ethnicity, Customized: Black | Participants | 7 | 5 | 12 |
| Race/Ethnicity, Customized: Hispanic | Participants | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Asian | Participants | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Other | Participants | 0 | 0 | 0 |
| BMI | kg/m^2 | 29.2 (SD 6.1) | 32.9 (SD 6.5) | 31 (SD 6.3) |
| Smoker | Participants | 4 | 3 | 7 |
6. Primary Endpoint
The registry lists the primary outcome as Postoperative Visual Analog Scale Scores, measured over participants were assessed at one single time point up to 8 weeks..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | score/units on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the postoperative Visual Analog Scale score. The registry describes the scale as ranging from 0 to 100 and states that a smaller score represents a better outcome. A Visual Analog Scale is a way to record a participant’s rating of a subjective experience such as pain on a defined continuum. It converts that rating into a score that can be summarized across participants, while the meaning of a given score still depends on the assessment context and timing.
The registry reports a median and an inter-quartile range for each arm. The median is the middle value in an ordered set of observations; the inter-quartile range describes the span between the lower and upper quartiles and indicates the spread of the central portion of the observed scores. These summaries are useful when the score distribution may not be well represented by a mean and standard deviation, or when the aim is to describe a typical score and its spread.
The stated assessment was made at one single time point up to 8 weeks. The precise timing within that window and the rationale for choosing the assessment time are not reported in the registry record. The record gives arm-specific summaries, but not an estimated between-arm contrast or its confidence interval. Therefore, the posted medians describe the observed scores in each arm; they do not, on their own, quantify the uncertainty around a treatment comparison or establish whether a difference is compatible with chance variation.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome summaries show a median postoperative score of 30.0 in the Control arm, with an inter-quartile range from 15.0 to 50.0, and a median of 20.0 in the Ketorolac arm, with an inter-quartile range from 8.75 to 32.5. Because lower scores are defined as better on this scale, the observed median is lower in the Ketorolac arm. This is a descriptive contrast between the posted arm summaries, not a reported estimate of the treatment effect.
The registry does not provide a reported comparative analysis for the primary endpoint. It does not give a confidence interval or a p-value for the difference in postoperative scores. Without those quantities, the precision of the between-arm contrast cannot be assessed from the registry results. The overlap between the reported inter-quartile ranges is not a substitute for a confidence interval or a formal comparison: inter-quartile ranges describe the distribution of individual scores within arms, whereas uncertainty around a treatment contrast concerns the estimated difference between arms.
For the secondary retear outcome, the posted counts are 3 participants in Control and 2 in Ketorolac, with 11 participants recorded in each arm for that outcome. The registry reports a risk difference of -0.091, with a confidence interval from -0.439 to 0.257, and an unadjusted p-value of 0.611. The interval spans values on both sides of no difference, so the result is imprecise and does not isolate a clear direction for the underlying contrast. The p-value is not evidence that the groups are equivalent; it describes the compatibility of the data with a specified no-difference comparison under the analysis used.
The primary outcome and secondary outcome address different questions and have different assessment times. The pain-score summaries concern a single assessment up to 8 weeks; the retear outcome is recorded at 6 months. The retear result therefore does not fill the gap left by the absent primary-endpoint comparison. Nor does the registry’s hypothesis about postoperative opioid consumption establish a result for opioid use: no opioid-consumption endpoint is included in the posted results.
Overall, the record offers descriptive pain-score summaries and an imprecise secondary comparison. It does not report enough inferential information for a firm conclusion about the primary pain-score contrast. These results describe the registry record and should not be interpreted as a recommendation about postoperative care.
9. Statistical Methods Explained
The registry reports a randomized, parallel-group design with no masking. Randomization is intended, in general, to make treatment groups comparable on average by assigning treatment through a chance-based process rather than by selecting treatment according to participant characteristics. This does not guarantee that the groups will look alike in a particular trial, especially when the amount of outcome information is limited. The method used to generate or conceal the allocation is not reported in the registry record.
What do the primary summaries describe?
The primary outcome is summarized using a median and an inter-quartile range in each arm. In general, the median identifies the central observation after values are ordered. It is less influenced by unusually high or low observations than the mean. The inter-quartile range describes the range from the lower quartile to the upper quartile, giving a sense of the spread among the central observations. These summaries are descriptive: they characterize the recorded scores in each group but do not, by themselves, estimate the uncertainty around the difference between groups.
For the Visual Analog Scale, the registry specifies a range from 0 to 100 and states that smaller scores are better. The Control median is 30.0 and its inter-quartile range is 15.0 to 50.0; the Ketorolac median is 20.0 and its inter-quartile range is 8.75 to 32.5. The registry gives no primary-endpoint confidence interval, p-value, or other comparative estimate. A reader should not infer a statistically tested treatment contrast from the fact that the two medians differ.
What does a confidence interval mean?
In general, a confidence interval is a range of values generated by a statistical procedure to express uncertainty in an estimated quantity. For a group contrast, it indicates which values are reasonably compatible with the data and the assumptions of that procedure. Its width is affected by the amount and variability of outcome information and by the analysis method. It is not a range containing a stated percentage of individual participant outcomes, and it does not remove uncertainty about bias, missing outcomes, or whether the analysis assumptions are appropriate.
The secondary retear result includes a risk difference estimate and confidence interval. The point estimate is -0.091 and the interval is -0.439 to 0.257. In general, a risk difference compares the proportions with an event between groups on an absolute scale. The interval crosses zero, the value that corresponds to no difference on this scale. Its breadth indicates that the registry result is compatible with a range of contrasts, rather than tightly determining the direction or magnitude. The registry also reports an unadjusted p-value of 0.611. A p-value is not the probability that the treatment has no effect, nor does it measure the clinical importance of an effect.
Why does event rarity and over-dispersion matter?
General statistical considerations are important when outcomes are counts or binary events. When events are uncommon and the numbers of observations are limited, estimates can be unstable: a small change in the observed event count may have a noticeable effect on a group contrast. A normal approximation may also be less reliable for sparse data than methods designed for small samples. Over-dispersion, in general, means that the observed variation is greater than a model’s assumptions allow. If present and unaccounted for, it can make uncertainty estimates too narrow. The registry does not report a diagnostic assessment of dispersion or enough detail to evaluate model assumptions for the retear analysis.
The sample-size illustrations in the registry are based on the observed retear effect, not on the trial’s own design justification. The stated assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation; the illustrations consider fractions of the observed effect. In general, such figures describe planning scenarios under specified assumptions. They are not observed power, do not show that the completed trial had a particular probability of detecting an effect, and should not be read as a recommended design without considering the outcome, assumptions, and intended analysis. The trial’s original sample-size justification is not reported in the registry record.
What can be inferred from an unadjusted secondary analysis?
An unadjusted comparison is a result reported without an adjustment for multiple outcome testing or other stated covariates. The secondary retear result is explicitly described as unadjusted, and the registry does not report a multiplicity procedure. In general, when several outcomes or comparisons are examined, the chance of at least one apparently notable result can increase if each is judged independently. This is why secondary analyses are often treated as exploratory unless a prespecified testing strategy is available. Here, the registry record does not give the full statistical plan, so the intended hierarchy of outcomes and analyses cannot be evaluated.
For the primary pain endpoint, the registry provides descriptive summaries but no reported analysis. For the secondary endpoint, it provides a comparative estimate but no reported analysis details beyond the unadjusted result. The statistical plan, the handling of missing data, the analysis populations, and any sensitivity analyses are not reported in the registry record. Those omissions limit how fully the estimates can be checked and interpreted.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies postoperative Visual Analog Scale scores as the primary outcome and lists retear of rotator cuff repair as a secondary outcome. It does not report a full statistical analysis plan, the planned testing hierarchy, or whether any multiplicity adjustment was intended. The secondary comparison is identified as unadjusted. Without the prespecified analysis strategy, it is not possible to determine how the reported secondary result fits into the trial’s intended confirmatory or exploratory framework.
Multiplicity matters in general when researchers examine multiple outcomes, time points, subgroups, or statistical contrasts. Each additional analysis can create another opportunity for a result that appears unusual under a no-effect assumption. Adjustment procedures can control some forms of this error, but they may also change the precision or interpretation of results. The appropriate approach depends on the study question and the prespecified plan. No such adjustment procedure is reported in the registry record, so the unadjusted secondary p-value should not be treated as though it had been adjusted for a wider set of possible analyses.
The registry does not report how missing outcome data were handled, whether participants were analyzed according to randomized assignment, or which analysis population was used for each endpoint. The primary results list 19 participants in Control and 20 in Ketorolac, while the retear results list 11 in each arm. These recorded counts differ by outcome, but the reason is not reported in the registry record. It is not possible to establish from the posted results whether the difference reflects follow-up availability, an analysis restriction, or another cause.
Missingness can affect interpretation if the likelihood of having an outcome recorded is related to treatment assignment or the outcome itself. General methods for addressing missing data rely on assumptions, and sensitivity analyses can help assess how conclusions might change under alternatives. The registry does not report a missing-data method or sensitivity analysis. It also does not describe a prespecified intention-to-treat, per-protocol, or other analysis population. These omissions make it difficult to assess the potential for bias from incomplete outcome reporting or to reproduce the analyses.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Control | 0 | 19 | 0.0% |
| Ketorolac | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Control | 0 of 19 |
| Ketorolac | 0 of 20 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Control | 16 of 19 |
| Ketorolac | 9 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Control | Ketorolac |
|---|---|---|---|
| Drowsiness | Nervous system disorders | 4 of 19 | 1 of 20 |
| Nausea/Vomiting | Gastrointestinal disorders | 2 of 19 | 2 of 20 |
| Constipation | Gastrointestinal disorders | 3 of 19 | 0 of 20 |
| Dizziness | Nervous system disorders | 3 of 19 | 0 of 20 |
| Insomnia | Nervous system disorders | 1 of 19 | 2 of 20 |
| Headache | Nervous system disorders | 0 of 19 | 2 of 20 |
| Abdominal Pain | Gastrointestinal disorders | 0 of 19 | 1 of 20 |
| Diarrhea | Gastrointestinal disorders | 1 of 19 | 0 of 20 |
| Rash | Skin and subcutaneous tissue disorders | 0 of 19 | 1 of 20 |
| Dry mouth | Gastrointestinal disorders | 1 of 19 | 0 of 20 |
The registry reports no serious adverse events in the recorded groups: 0 among 19 participants at risk in Control and 0 among 20 participants at risk in Ketorolac. It also reports no deaths in either group. These are the recorded counts in the safety results; they do not establish that serious events could not occur or that the groups have equivalent safety profiles.
For other adverse events, as categorized in the registry, 16 of 19 participants at risk are recorded as affected in Control and 9 of 20 in Ketorolac. The registry does not provide the event terms or a detailed definition of this “other” category in the information available for this analysis. The counts should therefore be interpreted according to the registry’s broad category, not as a description of particular symptoms or diagnoses. The record lists no top serious adverse-event terms.
Safety counts depend on how events were defined, collected, and attributed, and the registry does not report those details. The denominators and counts describe the posted record; they are not a basis for medical advice or a definitive comparison of harms. In general, absence of recorded serious events in a trial does not rule out uncommon risks, particularly when the number of observed participants is limited.
12. What the Result Does, and Does Not, Mean
The primary result is descriptive: the posted median pain score is 30.0 in Control and 20.0 in Ketorolac, and the scale defines smaller values as better. The corresponding inter-quartile ranges describe the spread of recorded scores in each arm. These values do not establish that the treatment caused a difference. The registry does not report a comparative estimate, confidence interval, or p-value for the primary endpoint, so the precision and statistical compatibility of a between-arm effect cannot be assessed from the posted primary summaries.
The secondary retear comparison is also uncertain. Its confidence interval includes values on both sides of no difference, and the unadjusted p-value is 0.611. This does not prove that the groups are the same, nor does it demonstrate a treatment benefit or harm. It indicates that the posted data, analyzed as reported, do not tightly determine the direction or magnitude of the difference.
The results do not answer every question raised by the trial’s stated aims. The brief summary refers to postoperative opioid consumption, but the posted outcome information described in the registry does not include an opioid-consumption result. The record also does not specify enough about the treatment regimens or statistical procedures to determine the exact contrast being estimated or to evaluate all analytic assumptions.
In general, an observed group difference is not automatically a causal effect. Randomization can support causal interpretation when assignment, follow-up, outcome measurement, and analysis are appropriately conducted, but details about these procedures are incomplete in the registry record. The results should therefore be understood as the reported observations and estimates, with the stated limitations, rather than as proof that ketorolac does or does not work. They do not provide medical advice or establish what treatment should be used for an individual.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction in clinical statistics: arm-level outcome summaries are not the same as an estimate of the treatment contrast. A median and inter-quartile range describe the recorded score distribution in each group. To judge the uncertainty in a difference between groups, readers also need an appropriate comparative estimate and its uncertainty, or another clearly reported inferential analysis. The primary outcome has descriptive summaries, but that comparative information is not reported in the registry record.
The secondary retear result shows why estimates should be read together with their uncertainty. The registry reports a point estimate, a confidence interval that crosses zero, and an unadjusted p-value. The point estimate alone cannot convey how uncertain the comparison is, while the p-value alone cannot indicate the range of plausible effects or clinical importance. Sparse event outcomes can be especially difficult to estimate precisely, a general issue that matters when interpreting small clinical trials.
The record also highlights the value of transparent reporting. Clear arm descriptions, outcome timing, analysis populations, missing-data methods, and a prespecified statistical plan help readers understand what was compared and how conclusions were reached. When those details are absent, uncertainty concerns not only the numerical precision of an estimate but also how completely the analysis can be evaluated.
Finally, planning illustrations based on an observed effect are not evidence of the completed trial’s power. They depend on assumptions and an effect size chosen for the illustration. Keeping planning calculations separate from observed results helps prevent a common interpretive error: treating retrospective sample-size scenarios as proof that a trial could or could not detect a meaningful effect. This distinction is useful when reading registry results across clinical areas.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary endpoint is reported only as arm-level medians and inter-quartile ranges. The registry does not provide a comparative estimate or uncertainty measure for the primary contrast, which prevents a direct assessment of its precision. The assessment is described as a single time point up to 8 weeks, but the exact timing within that window is not reported in the registry record. The record also does not explain whether all participants were assessed at a common time.
The trial is listed as randomized and unmasked, but details of sequence generation, allocation concealment, and outcome-assessment procedures are not reported in the registry record. The arm descriptions are blank, and the control regimen and ketorolac dose, route by assigned arm, and treatment duration are not specified. The summary mentions intravenous and oral ketorolac as part of the investigators’ aim, but the intervention details do not establish how these were implemented in the compared arms.
The number of participants recorded for the outcomes differs: the primary summaries list 19 in Control and 20 in Ketorolac, while the 6-month retear outcome lists 11 in each arm. The registry does not explain the differences or report a missing-data strategy, analysis population, or sensitivity analysis. This limits evaluation of whether outcome availability could have affected the findings.
The retear estimate is based on the posted event counts and has a wide confidence interval spanning both directions. Its p-value is unadjusted, and the registry does not report a multiple-testing plan or complete statistical analysis plan. The posted results also do not include the opioid-consumption outcome named in the trial summary. Together, these reporting gaps limit the strength and scope of conclusions that can be drawn from this registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Oral Ketorolac for Arthroscopic Rotator Cuff Repair — NCT03967847.
- Registry record last updated 2022-05-10; status last verified 2022-04.
- Results first posted 2022-05-10.
- 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.
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18. Record Summary
NCT03967847 is listed as a completed, randomized, unmasked, parallel-group, phase 3 trial sponsored by University Hospitals Cleveland Medical Center, with enrollment of 44. The study concerns ketorolac as an adjunct to postoperative pain care following arthroscopic rotator cuff repair.
The primary endpoint is postoperative Visual Analog Scale scores, summarized by medians and inter-quartile ranges at a single assessment time point up to 8 weeks. The posted medians are 30.0 for Control and 20.0 for Ketorolac, with smaller scores defined as better. No comparative primary-endpoint analysis is reported. The secondary endpoint records retear at 6 months and includes an unadjusted risk-difference analysis, with substantial uncertainty.
The registry does not report the full treatment regimens, statistical analysis plan, missing-data handling, or analysis populations. Safety results record no serious adverse events or deaths in either group; other adverse-event counts are reported without detailed event terms. These results should be read as registry findings with important limits on interpretation.