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 Subacromial Methylprednisolone Versus Ketorolac for Shoulder Impingement (NCT03913702), a randomized phase 2 study. The primary outcome is American Shoulder and Elbow Surgeon (ASES).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03913702 |
| Phase | Phase 2 |
| Condition | Subacromial Impingement, Subacromial Impingement Syndrome |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | The University of Texas Medical Branch, Galveston |
| Results posted | Yes |
2. Clinical Question
Population
People with subacromial impingement or subacromial impingement syndrome were the intended population. The registry record reports an enrollment of 1, but the primary outcome entry states “No data collected.” Further details about participant characteristics or eligibility are not reported in the registry record.
Intervention
The ketorolac group was assigned a subacromial injection of ketorolac 60mg (2ml + 8ml lidocaine 1%). The record identifies ketorolac as a non-steroidal anti-inflammatory drug.
Comparator
The methylprednisolone group was assigned a subacromial injection of methylprednisolone 80mg (1ml + 9ml lidocaine 1%). The record identifies methylprednisolone as a steroid. Further details about administration procedures are not reported in the registry record.
Primary question
The intended comparison was between the two injections for shoulder impingement, using the American Shoulder and Elbow Surgeon (ASES) score at 12 weeks as the primary outcome. The score is described as ranging from 0 to 100, with 0 indicating the worst shoulder condition and 100 the best. No primary outcome data were collected, so the clinical question remains unanswered by the posted results.
3. Trial Design
The registry identifies this as a phase 2, randomized, double-blind, parallel-group trial. In a randomized design, eligible participants are assigned to treatment groups using a random allocation process; the record does not report how the sequence was generated or how assignments were concealed. Double blinding indicates that masking was intended, but the identities of the people masked and the procedures used to maintain masking are not reported in the registry record. A parallel design assigns participants to one group rather than having each participant receive both interventions.
The trial began on 2019-09-09, and the primary completion date is listed as 2022-11-02. Its status is terminated. The reason for termination and any effect of termination on the planned procedures are not reported in the registry record. Enrollment is listed as 1. That figure describes enrollment, not a completed comparison with outcome data.
The two intervention descriptions specify subacromial injections of ketorolac 60mg with 8ml lidocaine 1%, or methylprednisolone 80mg with 9ml lidocaine 1%. Other details about the injection protocol, participant follow-up, or treatment adherence are not reported in the registry record.
The primary outcome was ASES at 12 weeks. The record also lists ASES and range of motion among the secondary outcomes, with ASES appearing twice in that list. There are 4 outcome measures recorded, but no analyses are listed. The record does not provide a statistical analysis plan or explain how the listed outcomes were to be combined or prioritized beyond naming the primary outcome.
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: Early termination due to inadequate patient enrollment.
Overall Study
| Stage | Ketorolac | Methylprednisolone |
|---|---|---|
| STARTED | 1 | 0 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: No data collected.
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 participant enrolled in the protocol.
| Characteristic | Unit | Ketorolac | Methylprednisolone | Total |
|---|---|---|---|---|
| Participants analysed | 1 | 0 | 1 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | 0 | 1 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 1 | 0 | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 1 |
6. Primary Endpoint
The registry lists the primary outcome as American Shoulder and Elbow Surgeon (ASES), measured over 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the American Shoulder and Elbow Surgeon (ASES) self-assessment score at 12 weeks. The registry describes the score as applicable to people with shoulder pathology and ranging from 0 to 100. It states that 0 indicates the worst shoulder condition and 100 indicates the best shoulder condition. A self-assessment can capture a participant’s report of their shoulder condition, which is relevant to evaluating a shoulder-related intervention.
The description also says that a higher pain score indicates more pain and a lower pain score indicates less pain. This wording conflicts with the stated interpretation of the ASES scale, where a higher score indicates a better shoulder condition. The registry record does not clarify this inconsistency, so the direction of the ASES score should not be inferred from the pain-score wording.
The record gives no unit, summary parameter, or dispersion measure for the primary outcome, and it states “No data collected.” Thus, there is no reported score, change, between-group estimate, or uncertainty measure with which to assess the intended comparison. The endpoint is identified, but its observed result is not available in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a randomized comparison of ketorolac and methylprednisolone injections, but it does not report collected primary outcome data. Consequently, there is no posted ASES result at 12 weeks for either group and no treatment contrast to interpret. The intended endpoint is identifiable; the result of that endpoint is not.
Without outcome observations, the record cannot establish the size or direction of a difference between the groups. It also provides no confidence interval or other measure of precision, and no inferential analysis or p-value is listed. These are not merely missing details around an otherwise interpretable estimate: the primary outcome entry explicitly states “No data collected.” The randomized design alone cannot supply an effect estimate when outcome data are absent.
The enrollment figure is 1. It should not be treated as an analyzed sample or as evidence that both groups contributed outcome information. The safety entries list 1 participant at risk in the ketorolac group and 0 in the methylprednisolone group. Those figures do not establish a comparative safety profile, particularly because the record does not provide a primary outcome result or an analysis of safety comparisons.
The trial status is terminated, but the reason for termination is not reported in the registry record. The record also does not explain whether termination occurred before or after any planned follow-up procedures, or whether any data were collected for outcomes other than the primary outcome. Those uncertainties cannot be resolved from the posted information.
Planning illustrations are described as using a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. However, numerical planning results are not reported in the registry record, and the primary outcome entry provides no observed effect to interpret. Such illustrations are planning exercises, not observed power and not evidence about the treatment comparison. In short, the registry describes the question and intended design but reports no primary outcome result from which efficacy or comparative benefit can be assessed.
9. Statistical Methods Explained
The record specifies random allocation, double masking, and a parallel-group structure, but does not report the statistical procedures used to analyze outcomes. The following concepts are general explanations of how such trial methods are commonly interpreted; they do not describe unreported procedures as though they were used in this trial.
What random allocation is intended to do
In general, random allocation assigns participants to groups by chance. It is used to reduce systematic differences between groups at the point of assignment, including differences that may be known or unknown. It does not guarantee that groups will be similar in every respect, especially when the number enrolled is limited. Here, the registry lists enrollment of 1 and does not report the allocation sequence, allocation concealment, or how group assignment occurred. The randomized label therefore describes the registered design, not a basis for assuming that a balanced comparison was achieved.
What masking can and cannot tell readers
In general, masking is intended to limit the influence of treatment knowledge on care, participant reports, or outcome assessment. The record calls the trial double-blind but does not state which people were masked or how masking was implemented. The designation should not be expanded into assumptions about participants, clinicians, assessors, or analysts. Nor does masking itself establish that outcome data were collected or that an analysis was performed.
How a treatment contrast would be interpreted
For a score such as ASES, a trial analysis might compare group summaries at the specified follow-up or compare change from an earlier measurement, depending on the protocol and statistical plan. In general, an estimated difference describes the observed contrast under the chosen analysis. A confidence interval expresses uncertainty around an estimate: narrower intervals indicate greater precision, while wider intervals indicate less precision. A confidence interval does not correct for missing data or bias, and it cannot be calculated from an absent endpoint result. The registry record reports no ASES observations, group estimate, confidence interval, or analysis method.
A p-value, when reported, measures how compatible the data are with a specified statistical model and null hypothesis. It is not the probability that a treatment is effective, nor does it describe the size or clinical importance of an effect. No p-value or inferential analysis is reported in this record. Since no primary outcome observations are available, there is no reported comparison whose statistical significance or precision can be interpreted.
Why the analysis population matters
In general, an analysis population identifies which participants contribute to a particular analysis. An intention-to-treat approach typically analyzes participants according to their assigned groups, while other approaches may restrict analysis based on treatment received or availability of measurements. These choices can affect interpretation. The registry record does not describe an analysis population or state how participants with missing measurements would have been handled. With the primary outcome marked “No data collected,” the record does not identify a group of participants contributing ASES results.
Why multiplicity and dispersion can matter
When a study examines multiple outcomes, time points, or comparisons, the chance of a false-positive finding can increase if many tests are considered without an appropriate plan. Statistical methods may control or otherwise address multiplicity, but the approach depends on the planned questions and analysis. The record lists ASES and range of motion as secondary outcomes, with ASES repeated, and records 4 outcome measures. It does not report a multiplicity strategy or analyses.
Dispersion describes how much participant measurements vary around a group summary. For continuous outcomes, measures such as a standard deviation can help characterize that variation and the precision of estimates. The registry does not report a dispersion measure for the primary endpoint. More generally, over-dispersion occurs when observed variability exceeds what a chosen model assumes; if relevant, it can make standard errors and inference unreliable unless the model accounts for it. The record does not identify an outcome model or provide data that would allow assessment of dispersion.
How to read the planning assumptions
The record describes planning illustrations based on a fraction of an observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are planning assumptions, not a report of the trial’s own design justification. The record does not report a sample-size justification, the target effect used for the trial, or numerical planning results. In general, a sample-size calculation estimates how many participants would be needed under stated assumptions; it is not a measure of the power achieved after a trial is completed. Planning illustrations should therefore not be interpreted as observed power or as evidence that the treatment groups differed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists ASES as the primary outcome at 12 weeks. It also lists ASES twice among the secondary outcomes, along with range of motion, and records 4 outcome measures. These entries indicate that more than one outcome measure was registered, but they do not specify the full analysis structure, the number of planned tests, or how outcome definitions correspond to the listed measures.
Multiplicity refers generally to the increased risk of false-positive findings when several statistical tests are conducted. A prespecified hierarchy, adjustment procedure, or other strategy can help address that issue. The registry record does not report a multiplicity strategy, and it lists 0 analyses. There are no posted outcome comparisons for which multiplicity-adjusted or unadjusted results can be evaluated.
The primary outcome entry states “No data collected.” The registry does not report whether any secondary outcome data were collected, how missing measurements would be handled, or whether participants would be excluded from particular analyses. An analysis population is also not described. These omissions matter because the interpretation of a treatment contrast depends on which participants and measurements contribute to it, and how unavailable measurements are treated.
The reason for termination and the relationship between termination and missing outcome information are not reported in the registry record. It is therefore not possible to determine whether the absent endpoint data reflect incomplete follow-up, a decision not to collect data, or another circumstance. No statistical analysis plan is reported, so planned handling of missing data and outcome multiplicity remains unknown.
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 |
|---|---|---|---|
| Ketorolac | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ketorolac | 0 of 1 |
| Methylprednisolone | 0 of 0 |
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 |
|---|---|
| Ketorolac | 0 of 1 |
| Methylprednisolone | 0 of 0 |
The registry safety entries list the ketorolac group with 1 participant at risk and 0 serious adverse events, 0 other adverse events, and 0 deaths. The methylprednisolone group is listed with 0 participants at risk and 0 serious adverse events, 0 other adverse events, and 0 deaths. These are the posted counts, not estimates from a comparative safety analysis.
The groups do not have matching at-risk counts in the safety record. In particular, a group listed with 0 participants at risk cannot provide a meaningful comparison with the group listed with 1 at risk. Zero recorded events should not be read as proof that an event cannot occur, and these entries do not establish that the treatments have equivalent safety. With such limited and uneven safety information, event rates or comparative risks cannot be interpreted from the record.
No serious adverse event terms are listed. The registry does not provide further detail about how adverse events were collected, the period of safety follow-up, or the criteria used to classify events. The safety counts therefore describe only what is entered in the record; they do not support a broader conclusion about safety.
12. What the Result Does, and Does Not, Mean
The posted record establishes that investigators planned a phase 2 randomized, double-blind, parallel-group comparison of subacromial ketorolac and methylprednisolone for shoulder impingement. It identifies ASES at 12 weeks as the primary endpoint and describes the intended injections. These details define the study question and registered design, but they are not findings about the relative effects of the treatments.
The primary outcome entry says “No data collected,” and the record lists 0 analyses. There is consequently no observed ASES result, estimated group difference, confidence interval, or statistical test to interpret. The record cannot show whether the groups differed, how large a difference might have been, or how precise an estimate would be. It also cannot support a conclusion that the treatments are similar or different.
The enrollment figure is 1, and the safety record lists 1 participant at risk for ketorolac and 0 for methylprednisolone. Those entries do not amount to a balanced outcome comparison. The absence of listed adverse events in the posted counts cannot establish the absence of risk or demonstrate comparable safety.
The trial is marked terminated. The reason for termination, missing-data procedures, analysis populations, and statistical analysis plan are not reported in the registry record. The record also contains inconsistent wording about whether higher ASES-related scores indicate a better shoulder condition or more pain; it does not resolve that inconsistency.
These limitations concern what can be concluded from the registry record, not a judgment about why the trial ended or what the treatments would do in other settings. The appropriate statistical reading is that the intended comparison is described, but no primary outcome result is available to answer it.
13. Why This Trial Matters Statistically
This trial illustrates a distinction that is central to clinical-trial interpretation: a registered design is not the same as an analyzable result. Randomization and masking describe intended safeguards against bias, while an endpoint and follow-up time define what investigators planned to measure. None of those design features can replace the outcome observations needed to estimate a treatment contrast.
The record makes the gap especially clear by naming ASES at 12 weeks as the primary outcome while stating “No data collected.” Without measurements, readers cannot assess the effect’s direction, magnitude, or precision. A result without an uncertainty measure can be difficult to judge; when there is no result at all, those inferential questions cannot be answered.
The safety entries also show why denominators matter. Event counts have meaning only in the context of the people at risk and the way events were collected. Here, the at-risk counts differ between groups, and the registry does not report additional safety methods. The counts should not be converted into a comparative claim.
Finally, the record identifies missing information that is statistically consequential: no analysis plan, no analysis population, no missing-data approach, no multiplicity strategy, and no reason for termination. These details are needed to distinguish prespecified analyses from post hoc choices and to understand how incomplete information could affect estimates. Transparent registration supports sound interpretation, but the registered design cannot answer the clinical question in the absence of posted outcome data.
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 principal limitation is that the primary outcome is explicitly recorded as “No data collected.” No ASES values or treatment-effect estimates are reported, so the intended comparison cannot be evaluated statistically. The record lists enrollment of 1 and 0 analyses; it does not report an analyzed population or participant-level outcome information.
The trial is marked terminated, but the reason for termination is not reported in the registry record. The record does not explain whether termination affected planned recruitment, follow-up, or outcome collection. It also does not report a sample-size justification, a statistical analysis plan, analysis populations, missing-data procedures, or a multiplicity approach.
The outcome description has an internal inconsistency: it describes higher ASES scores as indicating a better shoulder condition, but also says higher pain scores indicate more pain and lower pain scores indicate less pain. The registry record does not clarify how the pain wording relates to the ASES score.
Safety interpretation is limited by the posted at-risk counts of 1 for ketorolac and 0 for methylprednisolone, with zero events listed in both groups. Further safety collection and follow-up details are not reported. The registry also lists ASES twice among secondary outcomes without explaining the distinction between those entries. These limitations constrain interpretation to the registered design and the limited posted counts, rather than a treatment-effect or comparative-safety conclusion.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Subacromial Methylprednisolone Versus Ketorolac for Shoulder Impingement — NCT03913702.
- Registry record last updated 2025-01-03; status last verified 2024-12.
- Results first posted 2025-01-03.
- 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
NCT03913702 is registered as “Subacromial Methylprednisolone Versus Ketorolac for Shoulder Impingement,” with the official title “Subacromial Injection of Methylprednisolone Versus Ketorolac to Treat Shoulder Impingement: a Double-blind Randomized Controlled Trial.” The sponsor is The University of Texas Medical Branch, Galveston.
The record describes a phase 2, randomized, double-blind, parallel-group trial with enrollment of 1. It lists a start date of 2019-09-09, a primary completion date of 2022-11-02, and a terminated status. The primary endpoint is ASES at 12 weeks, but the primary outcome entry states “No data collected.” The record lists 0 analyses and does not report a treatment-effect estimate or statistical analysis plan.