Study to Evaluate the OrthoCor Active System for Pain Relief: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate the OrthoCor Active System for Pain Relief (NCT05244187), a randomized na study. The primary outcome is Primary Safety EndPoint.

2. Clinical Question

The registry record frames the study as a prospective, multi-center, randomized evaluation of the device for pain relief. Its posted primary outcome, however, is a safety measure: the count of participants with adverse events. The stated endpoint does not quantify pain intensity, change in pain, functional status, or the duration of pain relief. Those outcomes should not be inferred from the safety result.

The comparison is between assignment to the device and assignment to standard of care. Randomization is intended, in general, to support a fair comparison by distributing participant characteristics across groups on average. It does not guarantee that every characteristic will be balanced in a particular trial, and the registry record does not report the details needed to assess balance. The study is listed as unmasked, so the record does not describe masking of participants or study personnel.

3. Trial Design

The study is identified as NCT05244187 and titled “Study to Evaluate the OrthoCor Active System for Pain Relief.” Its official title describes a prospective, multi-center, randomized study. The record lists the design as randomized, parallel, and unmasked. It lists the phase as NA. The sponsor is Caerus Corporation.

The registry record lists enrollment as 120. The posted primary safety results describe 59 participants in the OrthoCor Active System group and 61 in the Standard of Care group. The intervention is the OrthoCor Active System, described as a device for pain relief. Standard of care is described as over-the-counter pain medication. The record does not provide further treatment instructions or details of how adherence was assessed.

The study began on 2022-11-07, had a primary completion date of 2023-10-30, and is listed as completed. The endpoint timeframe is after 2 weeks of use. The primary outcome is the number of participants with adverse events, with the population identified as ITT, or intention to treat. The posted outcome is a participant count rather than a measure of event severity or timing.

The registry record does not report the randomization sequence method, allocation concealment, site count, masking procedures beyond NONE, or the original sample-size justification. It also does not report a detailed analysis plan or an explanation of how participants with missing endpoint data were handled. These omissions limit assessment of design and analysis choices beyond the broad design labels recorded.

The record lists two outcome measures but no posted secondary outcomes. It lists no statistical analyses. The available primary result therefore supports a focused description of the reported safety endpoint and its uncertainty; it does not provide a registry-posted analysis of pain relief or other clinical outcomes.

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

Analysis population for the primary outcome, as defined in the registry: ITT

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: The numbers represent the ITT because the analyses for PP and ITT are very similar.

6. Primary Endpoint

The registry lists the primary outcome as Primary Safety EndPoint, measured over after 2 weeks of use.

The primary safety endpoint counts participants who experienced adverse events after 2 weeks of use. Its unit is participants, and its population is identified as ITT. The endpoint is binary at the participant level: each participant either had at least one adverse event recorded for the endpoint timeframe or did not. The reported group values are counts, not the total number of separate adverse-event episodes.

Counting participants with an event is a common way to summarize safety because it indicates how many people were affected, without allowing someone with multiple events to dominate the participant count. It does not, by itself, describe event type, seriousness, duration, or clinical consequences. Those details require separate reporting.

A safety endpoint is used to examine unwanted events during a study, while the broader study purpose concerns pain relief. These are different questions. A result for adverse-event occurrence cannot establish the degree of pain relief, and an equal event count does not establish that overall safety profiles are identical. Interpretation also depends on the event definitions, follow-up completeness, and methods of collection. The registry record does not report all those details.

The posted count was 2 participants in the OrthoCor Active System group and 2 in the Standard of Care group. The comparison is therefore about participant-level event occurrence during the specified timeframe. It is not a comparison of event rates over person-time, since the endpoint is reported as a participant count and no person-time measure is given.

7. Results Posted in the Registry

• OrthoCor Active System: 3.4% (2/59) versus 3.3% (2/61) on control; risk difference 0.1 percentage points (95% CI -6.3 to 6.5), risk ratio 1.03 (0.15–7.10); unadjusted two-proportion z-test p = 0.973.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a binary participant-level outcome: whether a participant had an adverse event during the stated timeframe. The registry reports counts for each group and a risk-difference comparison. In general, a risk difference subtracts the event probability in one group from that in the other, using a stated ordering of groups. A value of zero represents no difference in those probabilities. The reported estimate is 0.001. The registry comparison identifies Standard of Care as the control and OrthoCor Active System as the comparison group.

A confidence interval gives a range of values that are reasonably compatible with the observed data under the statistical model and its assumptions. It reflects uncertainty in the estimate, not a range that contains a fixed proportion of individual participants or events. In this result, the interval extends from -0.063 to 0.065 and crosses zero. That means the data are compatible with differences in either direction, as well as with little or no difference. The interval’s span conveys substantial imprecision for this comparison.

The unadjusted p-value is 0.973. In general, a p-value measures how surprising the data, or data more extreme, would be if a specified null hypothesis and analysis assumptions held. It is not the probability that a treatment has no effect, and it does not measure the magnitude or clinical importance of a difference. An unadjusted p-value also does not account for multiplicity across multiple statistical tests. The record lists no analyses, so there is no posted analysis set against which to assess whether adjustments were planned.

The record also gives a risk ratio and an odds ratio. In general, the risk ratio compares event probabilities between groups; the odds ratio compares event odds. These relative measures can be useful when the scientific question calls for a proportional comparison, while the risk difference directly describes an absolute contrast. With few events, estimates of relative effects can be unstable and their intervals can be broad. The posted relative estimates are 1.034 for the risk ratio and 1.035 for the odds ratio; their reported intervals are wide. They should be interpreted alongside, not instead of, the absolute comparison.

The primary population is identified as ITT. In general, an intention-to-treat analysis seeks to analyze participants according to their randomized group, regardless of adherence or later treatment changes. The registry record does not describe the exact implementation of the ITT population, including how missing endpoint observations were handled. An ITT label alone does not show whether every randomized participant contributed an observed outcome or how any absent values were treated.

For a binary endpoint, event counts and group sizes determine the observed proportions, but the posted interpretation should use the estimates and intervals calculated for the registry result rather than treating counts alone as conclusive. In general, sparse-event data can yield wide confidence intervals because a small change in the event count can materially change the estimated probability. This is one reason why equal counts do not guarantee a precise estimate of the between-group contrast.

General methods also distinguish statistical significance from clinical importance. A p-value does not say whether a difference would matter to participants, and a confidence interval can include both small and larger effects. Assessing clinical importance typically requires an appropriate prespecified threshold and knowledge of the outcome’s meaning. No such threshold or equivalence margin is reported in the registry record.

The registry’s sample-size planning illustration is calculated from the observed effect, not from the trial’s original design assumptions. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. In general, a normal approximation uses a mathematical approximation to estimate the sampling behavior of a statistic. These planning assumptions describe the illustration only. The trial’s own sample-size justification, original effect target, and statistical plan are not reported in the registry record.

The record lists no statistical analyses and no posted secondary outcomes. It does not report whether interim analyses were planned or conducted, or how multiplicity was addressed. Those points cannot be inferred from the primary result. The posted comparison is described as unadjusted; no adjusted model or covariate analysis is reported.

10. Confidence Intervals and Precision

The precision of the primary safety comparison is best judged by the confidence interval, not by the equality of the observed counts alone. The reported risk-difference estimate is 0.001, with an interval from -0.063 to 0.065. Because the interval crosses zero, it is compatible with a difference favoring either group and with no difference. Its width indicates that the estimate is uncertain.

The group counts are small in relation to the range of differences represented by the interval, and only 2 participants in each group were reported to have an event. In general, estimates based on sparse events tend to be sensitive to individual observations. The observed result therefore provides limited precision about the difference in underlying event probabilities, even though the counts match.

The reported risk ratio is 1.034 and the odds ratio is 1.035. The registry’s intervals for these relative measures are wide, also signaling uncertainty. Relative measures can appear more dramatic or more reassuring depending on scale, so the absolute risk-difference estimate and its uncertainty remain important context.

The unadjusted p-value of 0.973 does not resolve the uncertainty. A large p-value is not evidence that the groups are equivalent; it indicates that the result does not provide clear evidence against the tested null hypothesis under the analysis assumptions. Establishing equivalence would require a prespecified acceptable difference and a suitably designed analysis, neither of which is reported in the registry record.

Precision is also limited by what is not reported: endpoint collection and adjudication details, missing-data handling, and results for secondary outcomes. The short stated timeframe limits conclusions to adverse events after 2 weeks of use. The result should therefore be read as a low-event, imprecise comparison for the specified primary endpoint, not as a precise estimate of broader safety or pain relief.

11. 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 planning figures are participants per arm, not total events. They are planning illustrations based on the observed effect rather than the trial’s original design assumptions. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. The original sample-size justification and design assumptions are not reported in the registry record.

The 80% power column describes the number of participants per arm estimated to give an 80% chance of detecting the specified effect under those assumptions, if that effect and model were correct. The 90% power column uses a higher chance of detection, and consequently the corresponding planning figures are larger. These are hypothetical planning quantities, not estimates of the trial’s chance of finding a result after it was conducted.

The rows represent planning for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. The figures rise as the assumed effect becomes smaller: detecting a subtler difference generally requires more participants, all else being equal. The listed values are 409,593 and 548,328 participants per arm for planning for 100% of the observed effect; 725,236 and 970,885 for planning for 75% of the observed effect; and 1,625,188 and 2,175,665 for planning for 50% of the observed effect, for 80% and 90% power respectively.

These calculations are not observed power. They should not be interpreted as a retrospective measure of whether the completed trial was adequately powered, nor as the trial’s original target enrollment. Because the illustration uses the observed effect, which is uncertain, the planning quantities are especially sensitive to the observed estimate. The registry record does not report an original target effect or the study’s own sample-size calculation.

12. 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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.033; treatment proportion p₁ = 0.034; average p̄ = 0.033.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.2539 = 0.4976.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.2539 = 0.2137.
4. n = (0.4976 + 0.2137)² / (0.0011)² = 409,592.6, rounded up to 409,593 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
p0 <- 0.0327868852459016                          # control proportion
p1 <- 0.0338983050847458                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(5244187)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 409,593 (80% power), 548,328 (90% power)
 75% of observed effect: n per arm = 725,236 (80% power), 970,885 (90% power)
 50% of observed effect: n per arm = 1,625,188 (80% power), 2,175,665 (90% power)
power.prop.test: 409592.6 
Simulated power at n = 409,593 per arm: 0.799 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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.

13. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes, comparisons, or analyses are tested. In general, conducting many tests can increase the chance of at least one apparently unusual result by chance. A statistical plan may address this through a prespecified primary outcome, adjustment procedures, or a defined hierarchy of tests. The registry record identifies a primary safety endpoint, lists two outcome measures, and reports no posted secondary outcomes. It lists no analyses and does not report whether multiplicity adjustments or a testing hierarchy were planned.

The primary result is labeled unadjusted. This describes the posted p-value as not adjusted, but the record does not explain the wider analysis strategy or whether other planned tests were conducted. It is therefore not possible to assess the family of comparisons, if any, that informed the result. No claim about interim analyses or stopping rules can be made because these are not reported in the registry record.

The primary population is identified as ITT. In general, intention-to-treat analysis aims to retain participants in their randomized groups. A useful assessment also requires knowing who was randomized, who contributed endpoint data, and how missing outcomes or deviations were handled. The registry record does not report missing-data counts or methods, and it does not describe exclusions from the endpoint analysis. The ITT label alone does not resolve these uncertainties.

The record does not report whether the event endpoint was assessed by blinded reviewers, how adverse events were elicited, or whether definitions were standardized across sites. The study is listed as unmasked, but that label does not establish how endpoint collection was conducted. These omissions matter because ascertainment and follow-up can influence which events are detected and recorded.

Without a posted analysis plan, missing-data description, and secondary outcome results, the reported primary comparison should be interpreted as the result available in the registry, rather than as a complete account of every planned analysis. These limitations do not change the reported counts, but they constrain conclusions about robustness and the broader set of outcomes.

14. 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 non-serious adverse event terms

The registry’s serious adverse event figures report 0 serious events in the OrthoCor Active System group and 0 in the Standard of Care group. The number at risk is listed as 59 and 61, respectively. The record also reports 0 deaths in each group. These are the posted serious-event and death counts; they are distinct from the primary endpoint’s count of participants with any adverse event.

For the primary endpoint, 2 participants in each group were reported to have adverse events after 2 weeks of use. The serious adverse event figures do not mean that no adverse events of any kind occurred: the posted other-adverse-event counts are 2 in each group. Counts alone do not describe event type, severity below the serious threshold, duration, or clinical consequences.

Zero observed serious events in these groups does not prove that serious events cannot occur or that the groups have identical risks. In general, when events are rare, a study may observe none even when the underlying risk is not zero. The registry record does not report additional detail about collection methods or longer-term follow-up, so these figures describe only the recorded study period and categories.

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

The central descriptive finding is that the registry reports 2 participants with adverse events in each group after 2 weeks of use. The estimated risk difference is 0.001, with a confidence interval from -0.063 to 0.065, and the unadjusted p-value is 0.973. The estimate is near zero, but the interval allows for differences in either direction and is too broad to support a precise claim that the groups have equivalent safety outcomes.

The result does not establish that the OrthoCor Active System has no safety risks, nor that its safety profile matches standard of care. It also does not establish that the device is safer or less safe. Equal event counts in this study are a sample observation, and the uncertainty around the estimated difference remains important. A formal equivalence or non-inferiority conclusion would require a specified margin and an analysis designed for that purpose; neither is reported in the registry record.

The primary endpoint concerns adverse events, not pain relief. Although pain relief is part of the study title and summary, no pain-relief result is posted among the described outcomes. The safety finding cannot be used to infer whether participants experienced pain improvement, whether any improvement differed between groups, or whether effects continued after the stated 2-week timeframe.

The result also does not describe the nature or seriousness of the two primary-endpoint events in each group. Separate registry figures record no serious adverse events and no deaths in either group, but those counts do not characterize all possible harms or establish long-term safety. The available information is a bounded snapshot of the reported endpoint and period.

In practical statistical terms, the record supports a cautious summary: observed participant counts were equal, but the estimated difference is imprecise and the posted outcome scope is limited. Conclusions about other outcomes, longer follow-up, or broader patient populations are not supported by this primary safety comparison.

16. Why This Trial Matters Statistically

This trial illustrates why a simple count comparison and an uncertainty interval answer different questions. The posted counts are equal, but the risk-difference interval extends on both sides of zero and is wide. The counts describe what happened in the study groups; the interval indicates how uncertain the estimated contrast remains. Reporting both prevents a reader from treating matching counts as proof of identical underlying risks.

It also demonstrates the limits of interpreting a large p-value. The unadjusted p-value of 0.973 does not show that the groups are equivalent, and it does not measure the probability that a difference exists. The meaning of a nonsignificant comparison depends on the estimate, uncertainty, design, outcome definition, and any prespecified threshold for a meaningful difference. The registry record does not report an equivalence margin.

The endpoint distinction matters as well. The study’s title and summary concern pain relief, but the posted primary result is a safety count. This makes it important to separate a study’s broad purpose from the specific outcome for which results are available. A safety endpoint cannot substitute for a pain-relief result, and the absence of posted secondary results leaves those questions unresolved in this record.

Finally, the planning illustration shows how strongly sample-size estimates can depend on the effect assumed for planning. Smaller assumed effects require more participants under the stated assumptions. Since the calculation is based on the observed effect rather than the original design target, it is an illustration and not a retrospective assessment of trial power. This distinction helps prevent a planning calculation from being misread as a property of the completed study.

17. 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 registry record does not report the original sample-size justification or the trial’s own statistical plan. Although it provides a planning illustration based on the observed effect, that calculation cannot establish what the study was designed to detect. No equivalence or non-inferiority margin is reported, so the result should not be described as demonstrating equivalence.

The primary safety endpoint has few observed events and a broad confidence interval. This limits precision and makes the estimate sensitive to individual observations. The record identifies the analysis population as ITT but does not describe missing endpoint data, exclusions, or the method used to handle missing values.

The study is listed as unmasked. The registry record does not report how adverse events were elicited, classified, or adjudicated, or whether outcome assessors were masked. It also does not provide detailed participant characteristics, site-level results, adherence information, or treatment-use details. Those omissions limit assessment of comparability and endpoint ascertainment.

The endpoint timeframe is after 2 weeks of use. The reported safety comparison therefore does not answer questions about events beyond that timeframe. The record lists no posted secondary outcomes and no statistical analyses, so the available result does not provide a posted comparison of pain relief or other clinical measures. These limitations should be considered alongside the equal observed event counts, not treated as evidence for or against an effect.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Study to Evaluate the OrthoCor Active System for Pain Relief — NCT05244187.
• Registry record last updated 2025-02-28; status last verified 2024-07.
• Results first posted 2024-07-17.
• 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.

21. Record Summary

NCT05244187 is a completed, prospective, multi-center, randomized, parallel-group, unmasked study sponsored by Caerus Corporation. It compares the OrthoCor Active System with standard of care, described as over-the-counter pain medication. The record lists enrollment as 120 and the primary safety endpoint as the number of participants with adverse events after 2 weeks of use in the ITT population.

The posted result reports 2 participants with adverse events in each group. The estimated risk difference is 0.001, with a confidence interval from -0.063 to 0.065; the unadjusted p-value is 0.973. The record also reports no serious adverse events and no deaths in either group. These results describe the recorded safety endpoint and do not establish equivalence or answer the pain-relief question.

The registry record lists no statistical analyses and no posted secondary outcomes. Details on the original sample-size justification, missing-data handling, endpoint ascertainment, and broader analysis plan are not reported in the registry record.