Pain Informed Movement for People With Knee Osteoarthritis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pain Informed Movement for People With Knee Osteoarthritis (NCT05730829), a randomized na study. The primary outcome is Percentage of Follow up.

2. Clinical Question

The trial was designed as a pilot and feasibility comparison, not solely as a test of a clinical treatment effect. Its stated aims include recruitment, adherence, timelines, data collection procedures, follow-up, required resources, and participants’ views of the programs. It also explores potential effects on pain, self-reported function, quality of life, functional leg strength, pain modulation, selected biological measures, and psychological factors.

The posted primary result is follow-up completion at 8 weeks. The registry record reports 28 participants in the pain informed movement group and 31 in the standard neuromuscular exercise group as completing follow-up. Those counts describe the recorded endpoint, not whether either program improved health outcomes. Follow-up completion is relevant to whether outcome collection can be carried out, but it is not itself a measure of pain relief or function.

The broader clinical questions are exploratory in this feasibility study. The record does not report analyses for the many potential health measures named in the trial description. Accordingly, the available comparison cannot answer whether the programs differ on those measures.

3. Trial Design

This was a randomized, double-masked, parallel-group trial recorded as completed. Its title identifies it as a pilot and feasibility randomized controlled trial for people with knee osteoarthritis. The registry lists McMaster University as the sponsor and an enrollment of 69. The phase is listed as NA. The recorded start date is 2023-04-03, and the primary completion date is 2024-12-03.

Participants were assigned to one of two programs: pain informed movement with pain neuroscience education, or standard neuromuscular exercise with standard osteoarthritis education. Both descriptions specify in-person group exercise twice weekly over 8 weeks. For the first program, the description specifies 75 minutes of exercise instruction and pain neuroscience education videos for 20 to 30 minutes per week during the first 4 weeks. For the comparator, it specifies 60 minutes of exercise instruction and standard osteoarthritis education for 15 to 20 minutes per week during the first 4 weeks. The comparator description also begins to refer to a weekly home session, but the registry text is incomplete; further details are not reported in the registry record.

The record labels the study double-masked but does not identify which people were masked or explain how masking was maintained. The randomization method, allocation concealment procedures, and original sample-size justification are not reported in the registry record. The trial’s stated feasibility aims make recruitment, adherence, data collection, follow-up, and resources important alongside the exploratory outcome comparisons.

The primary outcome is follow-up completion at 8 weeks. The available arm-level result reports 28 of 34 participants for pain informed movement and 31 of 35 for standard neuromuscular exercise. The registry reports three secondary outcome results concerning participants’ views of program usefulness and the frequency of exercise and educational sessions. Although 7 secondary outcomes are listed, numerical results for the other listed outcomes are 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: NA. we did not have any significant event prior to assignment of participants to an arm.

Overall Study

Analysis population for the primary outcome, as defined in the registry: This is the number of participants at baseline who completed the baseline assessments and enrolled in the study.

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 Percentage of Follow up, measured over 8 weeks.

The primary endpoint is the percentage of follow-up, defined in the registry as the number of participants who completed the study out of those who completed baseline assessment and enrolled. Its timeframe is 8 weeks. The posted arm results are counts: 28 participants in the pain informed movement group and 31 in the standard neuromuscular exercise group completed the study, with corresponding recorded group sizes of 34 and 35.

Follow-up completion is used as a feasibility measure. In general, retaining participants and collecting outcome data are necessary for a trial to assess its other questions. A low or uncertain follow-up rate can make later outcome comparisons harder to interpret, because the results may describe only the participants whose data were collected. The endpoint does not directly measure pain, physical function, quality of life, or satisfaction with treatment.

The registry record does not explain how it handled participants with incomplete follow-up data beyond defining the outcome as completion of the study. It does not report reasons for non-completion or provide a detailed analysis population definition. These details matter when interpreting the counts: a completion count describes recorded follow-up status, but by itself does not explain why participants did or did not complete the study.

As a pilot outcome, follow-up completion can inform the practical conduct of future research. It should not be read as evidence that one exercise program is clinically superior, or as a complete assessment of feasibility. Other feasibility domains named in the trial description include recruitment, adherence, data collection, timelines, and resources, and numerical results for several of those domains are not reported in the registry record.

7. Results Posted in the Registry

• Pain Informed Movement and Pain Neuroscience Education: 82.4% (28/34) versus 88.6% (31/35) on control; risk difference -6.2 percentage points (95% CI -22.8 to 10.4), risk ratio 0.93 (0.76–1.13); unadjusted two-proportion z-test p = 0.463.

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.

Number of Participants Who Considered the Program Useful and Very Useful

• 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:
  • Pain Informed Movement and Pain Neuroscience Education: 89.3% (25/28) versus 93.5% (29/31) on control; risk difference -4.3 percentage points (95% CI -18.6 to 10.1), risk ratio 0.95 (0.81–1.12); unadjusted two-proportion z-test p = 0.557.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pain Informed Movement and Pain Neuroscience Education and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Who Considered the Program Frequent Enough

• 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:
  • Pain Informed Movement and Pain Neuroscience Education: 85.7% (24/28) versus 80.6% (25/31) on control; risk difference 5.1 percentage points (95% CI -13.9 to 24.1), risk ratio 1.06 (0.85–1.34); unadjusted two-proportion z-test p = 0.604.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pain Informed Movement and Pain Neuroscience Education and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Who Considered the Educational Session Frequency Enough

• 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:
  • Pain Informed Movement and Pain Neuroscience Education: 85.7% (24/28) versus 80.6% (25/31) on control; risk difference 5.1 percentage points (95% CI -13.9 to 24.1), risk ratio 1.06 (0.85–1.34); unadjusted two-proportion z-test p = 0.604.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pain Informed Movement and Pain Neuroscience Education and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary results concern participants’ views of whether the program was useful or very useful, whether exercise sessions were frequent enough, and whether educational sessions were frequent enough. They provide an early, limited view of acceptability rather than a comprehensive assessment of feasibility. The direction of the estimates varies across these ratings: the usefulness estimate leans toward the comparator, while the frequency ratings lean toward pain informed movement. These are exploratory patterns, not established differences.

These results sit alongside, rather than replace, the primary follow-up outcome. Follow-up completion addresses whether participants were retained for outcome collection; acceptability ratings describe how some participants viewed aspects of the programs. A favorable rating does not establish that participants completed the study, and completion does not establish that a program was acceptable or clinically beneficial. Each outcome answers a different question.

The outcome denominators for these ratings differ from those used for the primary outcome. The registry record does not explain why those denominators differ or report how missing responses were handled. That limits interpretation of the ratings, especially if participants with missing responses had different views from those who responded.

The registry lists 7 secondary outcomes, but numerical results are not reported in the registry record for several listed measures, including recruitment, burden of study procedures, adherence, and adverse-event rates as framed in the secondary outcome list. Analyses are not reported for the posted secondary outcomes. The available values are therefore best treated as descriptive and hypothesis-generating.

Unadjusted secondary results carry less weight when several outcomes are examined without a reported multiplicity plan. In general, multiple comparisons make isolated apparent differences more likely to arise by chance. Without a stated hierarchy or adjustment, the secondary findings should not be presented as confirmatory evidence or as a basis for choosing between programs. The record does not report a prespecified strategy for controlling this issue.

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

• Number of Participants Who Considered the Program Useful and Very Useful
• Number of Participants Who Considered the Program Frequent Enough
• Number of Participants Who Considered the Educational Session Frequency Enough
• Rate of Recruitment Measured by Number of People Recruited in a Year
• Percentage of Participants Who Did Not Find the Study Procedures Burdensome (Questionnaires, Tests, Blood Draws) Measured on 0-10 Scale
• Rate of Adherence Measured by Number of Sessions Attended and Home Sessions Completed
• Rate of Adverse Events Measured by Question Regarding Symptom Flare and Seeking Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary: each participant either completed the study by the 8-week follow-up or did not, according to the registry definition. For a binary outcome, a group’s event count is interpreted alongside the group size used for that outcome. Here, the posted completion counts are 28 of 34 in the pain informed movement group and 31 of 35 in the comparator group. The comparison is expressed as a risk difference, with the pain informed movement group first and the standard neuromuscular exercise group as the reference.

A risk difference subtracts the event proportion in one group from the event proportion in the other. Its natural reference value is zero: zero means the recorded proportions are equal. A negative estimate means the event proportion is lower in the first-listed group; a positive estimate means it is higher. The posted estimate is -0.062. This is a simple unadjusted re-calculation from the posted summary statistics, not an adjusted analysis reported by the trial investigators.

The accompanying 95% confidence interval is -0.228 to 0.104. In general, a confidence interval describes the range of values reasonably compatible with the observed data under the calculation’s assumptions. It conveys uncertainty around an estimate rather than a guarantee that the true effect lies within the interval. Since this interval includes zero and spans values on both sides, the observed data leave open the possibility of a difference in either direction as well as little or no difference.

The unadjusted p-value is 0.463. In general, a p-value measures how unusual the observed data, or data more extreme, would be if the null hypothesis and statistical model were correct. It is not the probability that the null hypothesis is true, and it does not measure the size or practical importance of an effect. The registry record reports no analyses for the outcomes, so the posted comparison should be understood as a simple unadjusted re-calculation rather than a trial-reported model-based analysis.

Randomized allocation can support a fair comparison by distributing participant characteristics across groups on average, but randomization does not guarantee balance in every pilot trial. The registry record does not report the randomization sequence method, allocation concealment, baseline comparisons, covariate adjustment, or a prespecified statistical analysis plan. It is therefore not possible to assess from the record whether any adjusted or alternative analysis was planned or conducted.

The trial is described as double-masked and parallel-group. A parallel design assigns participants to one program and compares groups over the study period. General statistical practice recognizes that exercise programs can be difficult to conceal from participants and providers; however, the record does not specify who was masked in this trial, so the practical meaning of double masking cannot be assessed from the registry entry.

For secondary binary outcomes, the registry provides counts and unadjusted re-calculations of risk differences. The same basic interpretation applies: a difference of zero is the reference for equal proportions, and the sign indicates the direction of the observed group contrast. The number of participants contributing to these outcomes differs from the primary endpoint group sizes. The reasons for those denominators and the handling of missing responses are not reported in the registry record.

In general, missing outcome data can affect both precision and the meaning of a comparison. If participants with missing data differ systematically from those with observed data, the observed group proportions may not represent all randomized participants. The record does not report reasons for missing observations, imputation, sensitivity analyses, or an analysis population such as intention-to-treat. No specific missing-data method should therefore be assumed.

For planning, the registry includes illustrations based on the observed effect. These are not the original trial design calculations, and the original design assumptions are not reported in the registry record. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and a target effect set to the stated fraction of the observed effect. In general, an assumed smaller effect requires a larger sample to detect under otherwise unchanged planning assumptions.

The planning values are participants per arm, not observed power. In general, power describes the probability that a planned study will detect a specified effect under its assumptions. A post hoc power value based on an observed effect would not resolve the uncertainty already represented by the estimate and confidence interval. The planning illustrations are best read as hypothetical design aids, not as evidence that the completed pilot was adequately or inadequately powered for clinical effectiveness questions.

The registry reports no multiplicity adjustment or hierarchy for secondary outcomes. General statistical reasoning treats a collection of unadjusted tests cautiously: when many outcomes are considered, the chance of at least one apparently notable finding can increase. Here, the secondary results are exploratory, and the record does not state that they were designed to provide confirmatory evidence.

11. Confidence Intervals and Precision

The primary risk-difference estimate is -0.062, with a 95% confidence interval from -0.228 to 0.104. The interval is wide relative to the point estimate and includes zero. It also extends in both directions, so the posted result is compatible with lower follow-up completion in the pain informed movement group, little or no difference, or higher completion in that group. The data do not precisely identify the size or direction of a group difference.

In general, confidence intervals communicate precision: a narrower interval indicates less statistical uncertainty about the estimated contrast, while a wider interval indicates more. Precision depends on the amount and variability of information available, as well as the analysis method. The pilot’s recorded group sizes and the number of participants contributing to follow-up are limited, so the comparison should be treated as preliminary. The registry does not report a prespecified precision target for the primary outcome.

The unadjusted p-value of 0.463 is consistent with the interval’s inclusion of zero, but it should not replace the interval as the basis for interpretation. A p-value alone does not show which effect sizes are plausible, and a result that does not cross a conventional significance threshold does not prove equivalence. Demonstrating equivalence would require a prespecified margin and an appropriate analysis; those are not reported in the registry record.

The secondary outcomes also have uncertainty, and their intervals include values in different directions. Given their exploratory role and the absence of reported analyses or a multiplicity plan, small differences in point estimates should not be overinterpreted. The available precision is not sufficient to make strong claims about comparative acceptability, much less about the clinical outcomes named in the study description but without numerical results in the registry record.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations are planning scenarios based on the observed effect, not the trial’s original sample-size justification. The original design assumptions are not reported in the registry record. For this binary primary outcome, the planning figures are participants per arm; they are not total event counts. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each scenario sets the effect to the stated fraction of the observed effect.

The 80% power column means the number of participants per arm that the calculation estimates would be needed for an 80% chance of detecting the specified effect under those assumptions. The 90% power column gives the corresponding planning number for a 90% chance. These are prospective design quantities for hypothetical future studies, not observations from the completed trial. They are not a measure of the power achieved by this pilot; this is not observed power.

The rows use different fractions of the observed effect. In general, a smaller target effect is harder to distinguish from random variation, so it requires more participants if the other planning assumptions stay the same. The values should therefore be read as conditional illustrations: changing the target effect, significance level, allocation, or statistical method would change the planning result.

The observed effect in a small feasibility study can be unstable. Using it as a planning anchor can produce illustrations that should not be treated as a definitive sample-size recommendation. A future study would need a clinically and scientifically justified target effect, a clear primary analysis plan, and appropriate assumptions about missing data and outcome variability. Those design decisions are not reported as part of the registry’s original trial rationale.

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

Worked calculation for this trial

1. Control proportion p₀ = 0.886; treatment proportion p₁ = 0.824; average p̄ = 0.855.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.4985 = 0.9770.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4965 = 0.4179.
4. n = (0.9770 + 0.4179)² / (-0.0622)² = 503.2, rounded up to 504 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 <- 0.885714285714286                          # control proportion
p1 <- 0.823529411764706                          # 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(5730829)
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 = 504 (80% power), 674 (90% power)
 75% of observed effect: n per arm = 856 (80% power), 1,145 (90% power)
 50% of observed effect: n per arm = 1,834 (80% power), 2,454 (90% power)
power.prop.test: 503.2 
Simulated power at n = 504 per arm: 0.804 (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.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple secondary outcomes, and the trial description refers to a broad range of potential effects. The record does not report a statistical analysis plan, a hierarchy among outcomes, or a method for adjusting for multiple comparisons. Consequently, the posted secondary comparisons should be treated as exploratory. In general, testing multiple outcomes without accounting for multiplicity increases the chance of observing apparently notable results by chance. This is one reason not to interpret any single secondary estimate as definitive.

The record states that 7 secondary outcomes are listed, while numerical results are posted for only some of them. Numerical results for recruitment rate, procedure burden, adherence, and several other named measures are not reported in the registry record. The reported analysis count is zero, and no analyses are listed for the secondary outcomes. The presented estimates are simple unadjusted re-calculations from the posted summary statistics, not analyses attributed to the trial investigators.

Missing-data handling is not described. For the primary outcome, the registry defines the denominator as participants who completed baseline assessment and enrolled, and the endpoint as study completion. It does not provide reasons for non-completion, identify whether any participants withdrew, or state how incomplete records were treated. For secondary ratings, the outcome group sizes differ from the primary group sizes, but the reason and response-missingness approach are not reported.

The analysis population is also not defined in detail. The record does not state whether the comparisons use all randomized participants, participants with available outcome data, or another population. It does not report an intention-to-treat analysis, a per-protocol analysis, imputation, or sensitivity analyses. These methods should not be inferred from the group counts.

In general, complete reporting of outcome definitions, analysis populations, missing-data methods, and multiplicity plans helps readers distinguish prespecified conclusions from exploratory comparisons. Those details are not reported in the registry record, so the results are most appropriately interpreted as preliminary descriptions rather than a complete confirmatory analysis.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry reports zero serious adverse events in the pain informed movement group and zero in the standard neuromuscular exercise group. It also reports zero other adverse events in each group and zero deaths in each group. These are the posted event counts for the recorded risk groups.

These figures describe what was recorded in the registry; they do not establish that no symptoms or harms occurred. The record’s secondary outcome list separately refers to a question about symptom flare and seeking treatment, but numerical results for that measure are not reported in the registry record. The registry also does not provide descriptions of event monitoring, event definitions, severity grading, or the period over which each event category was assessed beyond the displayed group information.

In general, zero recorded events in a pilot study should be interpreted in light of the amount of information collected and the way events were defined and monitored. The available counts are not enough to establish comparative safety or rule out uncommon events. They should be read as registry-reported event counts, not as a guarantee about the programs.

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

The main result is a preliminary comparison of 8-week follow-up completion. The risk-difference estimate is -0.062, with a 95% confidence interval from -0.228 to 0.104 and an unadjusted p-value of 0.463. The estimate points toward lower completion in the pain informed movement group, but the interval is broad and includes no difference as well as effects in the opposite direction. The posted data do not establish a reliable difference between groups.

This result does not show that the programs are equivalent. A non-significant comparison is not an equivalence test, and no equivalence margin is reported. Nor does follow-up completion establish whether either program reduced pain, improved function, or changed quality of life. Those are different outcomes, and numerical results for them are not reported in the registry record.

The trial’s stated purpose includes feasibility and acceptability. The primary outcome gives information about follow-up completion, while the posted secondary ratings give limited descriptive information about program usefulness and session frequency. The registry does not report numerical results for several other feasibility measures, including recruitment and adherence. Therefore, the available record does not provide a complete account of feasibility across all the domains named by the trial.

The absence of reported serious and other adverse events is also limited to the registry counts. It does not establish that no symptoms occurred, and it does not demonstrate comparative safety. The record’s separate symptom-flare measure does not have numerical results posted.

Overall, this is best understood as an early randomized feasibility study whose posted results describe follow-up and selected participant ratings. It does not provide confirmatory evidence about clinical effectiveness, equivalence, or safety. Further interpretation would require fuller outcome reporting, clear analysis methods, and studies designed around prespecified clinical questions.

17. Why This Trial Matters Statistically

Pilot and feasibility trials address whether a larger study can be conducted and whether its procedures are workable. Statistical interpretation therefore needs to distinguish feasibility outcomes from clinical outcomes. Here, 8-week follow-up completion is the primary endpoint, while the trial description names recruitment, adherence, data collection, timelines, patient follow-up, and resources as additional feasibility questions. The distinction matters because a completion rate is informative about retention but does not answer whether a program changes pain or function.

Randomized comparison can make preliminary between-group estimates more interpretable than an uncontrolled description, but a feasibility trial may still yield wide uncertainty. The primary risk-difference interval includes zero and values in both directions. Its implication is not that the groups are proven identical; rather, the data do not precisely determine the direction or size of a difference in completion.

The study also illustrates why a collection of positive or negative secondary findings should not be treated as a substitute for a prespecified analysis. The record lists several outcomes, has no reported analyses, and does not describe a multiplicity plan. Statistical discipline requires separating exploratory signals from confirmatory findings, particularly when the outcomes address different constructs such as usefulness, exercise frequency, and educational-session frequency.

Finally, sample-size planning illustrations should be kept distinct from what the pilot observed. The illustrations use assumptions based on the observed effect and indicate hypothetical future-study requirements per arm. They are not evidence about the completed trial’s power or a justification for its original size. This distinction helps prevent a feasibility study from being judged as if it were designed to deliver a definitive clinical answer.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record leaves important details unavailable for interpreting the comparison. It does not describe the randomization procedure, allocation concealment, who was masked, or the statistical analysis plan. It also does not give the original sample-size justification or define the analysis population in detail. These omissions prevent assessment of whether the posted re-calculations match the investigators’ planned analyses.

The primary endpoint is follow-up completion, but reasons for non-completion are not reported. The record also does not explain the denominators for the secondary ratings, which differ from the primary outcome group sizes, or state how missing responses were handled. No imputation or sensitivity analysis is reported. Thus, the possibility that missing information affects the observed comparisons cannot be evaluated from the registry entry.

The study is identified as a pilot and feasibility trial, and the primary estimate has considerable uncertainty. The result should not be treated as a definitive comparison of the programs. Numerical results are not reported for several feasibility outcomes or for the potential clinical outcomes named in the trial description. The available secondary findings are also unadjusted and exploratory, with no reported multiplicity strategy.

The intervention descriptions are incomplete in the registry record. For example, the comparator description begins to mention a weekly home session but does not provide the full details. The record does not provide enough information to reconstruct all program procedures or assess adherence to each component. The adverse-event counts likewise lack detail on event definitions and monitoring. These limitations make the record useful for a preliminary statistical reading, but insufficient for a comprehensive evaluation of implementation, clinical effects, or safety.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Pain Informed Movement for People With Knee Osteoarthritis — NCT05730829.
• Registry record last updated 2026-08-28; status last verified 2024-11.
• Results first posted 2025-04-16.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT05730829 is a completed, randomized, double-masked, parallel-group pilot and feasibility trial sponsored by McMaster University. It enrolled 69 people with knee osteoarthritis and compared pain informed movement with pain neuroscience education against standard neuromuscular exercise with standard osteoarthritis education. Both programs were described as in-person group exercise over 8 weeks.

The primary outcome was follow-up completion at 8 weeks. The posted counts were 28 of 34 in the pain informed movement group and 31 of 35 in the comparator group. The unadjusted risk difference was -0.062, with a 95% confidence interval from -0.228 to 0.104 and p = 0.463. The result is uncertain and does not establish a group difference.

Three secondary outcomes have posted numerical results, while several listed feasibility and clinical outcomes are not reported in the registry record. No analyses are reported. The findings are preliminary descriptions of follow-up and selected acceptability ratings, not confirmatory evidence about clinical effectiveness, equivalence, or safety.