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 Knee Arthroplasty Pain Coping Skills Training (KASTPain): A Randomized Trial (NCT01620983), a randomized na study. The primary outcome is Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01620983 |
| Phase | NA |
| Condition | Knee Osteoarthritis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 402 |
| Arms in the primary outcome | 3 |
| Lead sponsor | Virginia Commonwealth University |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerns patients undergoing knee replacement surgery who have high levels of pain catastrophizing. The registry record lists knee osteoarthritis as the condition. It says data from all subjects were included in the primary and secondary analyses, but further detail about eligibility criteria and the characteristics of participants is not reported in the registry record.
Intervention
Pain Coping Skills Training was delivered by physical therapists in eight one-hour telephone sessions over a two-month perioperative period. The stated aim was to teach skills intended to address pain-related thoughts and actions during recovery after arthroplasty.
Comparator
The trial included arthritis education and usual care as comparators. Arthritis education consisted of eight one-hour perioperative telephone sessions delivered by nurse educators. The usual-care description says participants received usual care following knee arthroplasty; additional details of that care are not reported in the registry record.
Primary question
The primary endpoint was the WOMAC Pain Scale at twelve months. The trial was designed to assess whether pain coping skills training reduced pain and improved function, and whether it was more cost effective, compared with arthritis education or usual care. The posted primary results report group means and confidence intervals, but do not report a direct comparison estimate or a test of differences between groups.
These are distinct questions. The primary endpoint addresses self-reported activity-limiting pain; functional outcomes and other measures were listed as secondary outcomes. Cost effectiveness was part of the trial's stated rationale, but a cost-effectiveness result is not reported in the registry record. The primary results therefore describe the endpoint values for each group rather than resolving every aim named in the trial description.
3. Trial Design
This was a randomized, double-masked, parallel-group trial with three arms: Pain Coping Skills Training, Arthritis Education, and Usual Care. The registry record lists enrollment of 402 and status as completed. The study start is listed as 2012-12, and primary completion as 2017-06-27. Phase is listed as NA. The sponsor was Virginia Commonwealth University.
Random allocation means assignment to study groups was intended to occur by chance, which can help make groups comparable at the start of a trial. The record does not report the randomization sequence method, allocation concealment, or the allocation ratio. Although masking is recorded as double, which roles were masked is not reported in the registry record. Those omissions make it difficult to assess the specific procedures used to reduce selection or expectation effects.
The intervention and arthritis education arms both involved telephone sessions during the perioperative period, but differed in content and in the professional delivering the sessions. The pain coping program was delivered by physical therapists and supervised by psychologists, according to the trial description. Arthritis education was delivered by nurse educators using presentation and discussion. The record describes usual care only as usual care following knee arthroplasty. It does not provide enough detail to characterize the content or consistency of usual care across participants.
The endpoint results list 130 participants for Pain Coping Skills Training, 135 for Arthritis Education, and 137 for Usual Care. These are the group counts reported alongside the primary outcome; they should not automatically be treated as the number randomized or as proof that outcome data were complete for every participant. The distinction matters because enrollment, randomized group size, and the number contributing to a particular analysis can differ. The registry record does not report a flow of participants through the trial or explain these counts in relation to missing outcome data.
The record gives no detailed protocol, sample-size justification, interim-analysis information, or statistical analysis plan. The planning assumptions associated with sample-size illustrations are not the trial's design justification and do not establish the trial's observed power.
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 | Pain Coping Skills Training | Arthritis Education | Usual Care |
|---|---|---|---|
| STARTED | 130 | 135 | 137 |
| COMPLETED | 111 | 113 | 122 |
| NOT COMPLETED | 19 | 22 | 15 |
Reasons for not completing this period:
| Reason | Pain Coping Skills Training | Arthritis Education | Usual Care |
|---|---|---|---|
| Lost to Follow-up | 8 | 4 | 9 |
| Withdrawal by Subject | 6 | 8 | 1 |
| Death | 2 | 0 | 0 |
| Physician Decision | 3 | 10 | 5 |
Analysis population for the primary outcome, as defined in the registry: Data from all subjects were included in primary and secondary analyses.
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.
| Characteristic | Unit | Pain Coping Skills Training | Arthritis Education | Usual Care | Total |
|---|---|---|---|---|---|
| Participants analysed | 130 | 135 | 137 | 402 | |
| Age, Continuous | years | 62.6 (SD 7.9) | 64.2 (SD 8.5) | 62.7 (SD 7.7) | 63.2 (SD 8.0) |
| Sex: Female, Male: Female | Participants | 94 | 85 | 88 | 267 |
| Sex: Female, Male: Male | Participants | 36 | 50 | 49 | 135 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 3 | 5 | 5 | 13 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 127 | 126 | 130 | 383 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 4 | 2 | 6 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 2 | 4 | 2 | 8 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 48 | 44 | 47 | 139 |
| Race (NIH/OMB): White | Participants | 78 | 83 | 86 | 247 |
| Race (NIH/OMB): More than one race | Participants | 2 | 1 | 1 | 4 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 3 | 1 | 4 |
| WOMAC Pain Scale | units on scale | 11.6 (SD 3.1) | 11.3 (SD 3.5) | 11.4 (SD 3.4) | 11.4 (SD 3.4) |
| WOMAC Function Scale | units on scale | 38.6 (SD 11.8) | 37.1 (SD 11.8) | 36.0 (SD 11.1) | 37.2 (SD 11.6) |
| Pain Catastrophizing Scale | units on scale | 30.4 (SD 9.6) | 30.0 (SD 9.2) | 29.7 (SD 9.2) | 30.0 (SD 9.3) |
| Six minute walk test | meters | 305 (SD 121) | 279 (SD 132) | 309 (SD 106) | 297 (SD 120) |
| Short Physical Performance Battery | units on scale | 7.6 (SD 3.2) | 7.5 (SD 2.9) | 7.9 (SD 2.6) | 7.8 (SD 2.9) |
6. Primary Endpoint
The registry lists the primary outcome as Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale, measured over twelve months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | units on scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale at twelve months. It is a self-report scale intended to quantify the extent of pain that limits activity. Its range is 0 to 20, with higher scores indicating worse activity-related pain. A group mean describes the average score among the participants represented in that group's outcome result; it does not describe every participant's score or the variation between people.
The measure is relevant to this trial because the stated clinical concern is pain after knee arthroplasty, and the intervention was intended to address pain-related responses during recovery. A standardized scale gives a consistent way to summarize reported pain across the study groups and to track the endpoint at the stated follow-up. It is not a direct measure of every aspect of recovery. The registry separately lists function and other patient-reported or performance measures as secondary outcomes.
The endpoint description identifies the scale's direction, range, and interpretation, but does not report a threshold for a clinically important difference. The posted results give means and 95% confidence intervals for each group. They do not give a direct between-group estimate, its confidence interval, or a statistical test for the primary comparison. As a result, the group summaries alone do not quantify the precision of a difference between treatment strategies.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
At twelve months, the posted mean WOMAC Pain Scale score was 3.3 for Pain Coping Skills Training, with a 95% confidence interval from 2.5 to 4.2. For Arthritis Education, the mean was 3.0, with a 95% confidence interval from 2.1 to 3.8. For Usual Care, the mean was 2.9, with a 95% confidence interval from 2.0 to 3.8. On this scale, higher scores indicate worse activity-related pain. These are group-level summaries, not individual outcomes.
A confidence interval expresses statistical uncertainty about an estimated quantity under the assumptions of the method used. Here, each interval is attached to a group mean. Its width reflects how precisely that mean is estimated; it is not the range containing most participants' scores, and it does not describe the spread of individual responses. The registry record does not report the method used to construct these intervals or provide standard deviations.
The three group intervals overlap. That observation is not itself a statistical test of the difference between groups. In general, comparison of two separate confidence intervals is not a substitute for estimating the contrast directly, because the uncertainty of a contrast depends on the variability and relationship between the estimates. The record does not report a treatment-effect estimate comparing Pain Coping Skills Training with either comparator, a confidence interval for such a contrast, or a p-value for the primary outcome. It is therefore not possible from these posted summaries to state how precisely the groups differ or whether a prespecified comparison met a statistical criterion.
The point estimates are on the same scale and are close in magnitude, but interpreting their clinical importance would require context that is not reported in the registry record, including a threshold for an important difference and the relevant comparison estimate. A lower score corresponds to less reported activity-related pain according to the scale description, but the arm means alone do not establish that one intervention caused a difference. Randomization supports causal comparisons when the analysis and follow-up are appropriately handled; the posted summaries do not show the details needed to evaluate those conditions or isolate a causal contrast.
The endpoint counts are 130, 135, and 137 in the respective groups. These counts accompany the outcome results, but the record does not explain whether they reflect all randomized participants, participants with available twelve-month scores, or another analysis set. The statement that data from all subjects were included in primary and secondary analyses does not describe the handling of missing measurements. No inference about completeness or attrition should be made solely from the counts.
The registry states that the trial was designed to evaluate pain, function, and cost effectiveness. The primary endpoint summaries address pain at twelve months. They do not by themselves answer the secondary function questions or the cost-effectiveness aim. No conclusion about those outcomes should be drawn from the primary pain means.
9. Statistical Methods Explained
What does a group mean represent?
A mean is a summary of the values observed in a group. For a continuous endpoint such as the WOMAC Pain Scale, it gives a central value in the scale's units. The mean can be useful for describing average reported pain, but it can conceal variation: participants with similar group averages may have quite different individual scores. The posted results give the means and confidence intervals, but do not report a measure of individual-level dispersion such as a standard deviation.
Because the scale runs from 0 to 20 and higher values denote worse activity-related pain, the direction of the mean has a clear interpretation. However, an average score should not be read as a diagnosis, a percentage of pain, or the experience of a typical participant without further information about the distribution. A mean also does not reveal how many participants improved or worsened over time. The registry record reports a twelve-month value, not a full trajectory of scores.
What does a confidence interval add?
In general, a confidence interval describes uncertainty around an estimate under a statistical model and its assumptions. The intervals reported for this outcome relate to each arm's mean. They are not individual score ranges and do not mean that a particular proportion of participants had values inside them. A narrower interval would indicate greater precision for the estimate, while a wider interval would indicate more uncertainty. Precision depends on factors such as variability and the amount of information available, but those features should not be reverse-engineered from the posted summaries.
The registry record does not report the procedure used to calculate the intervals. It therefore does not establish whether the interval method accounts for all aspects of the trial's design or analysis. In general, a confidence interval for a group mean answers a different question from a confidence interval for the difference between two group means. To assess a comparison, the contrast itself and its uncertainty are the most direct quantities. Neither is posted for the primary endpoint.
Why do the arm summaries not establish a comparison?
Randomized trials are generally interpreted through comparisons between assigned groups. The mean in each arm is descriptive. A treatment effect would usually be expressed as a difference or another contrast, with an interval that conveys its uncertainty. No such contrast is reported for the WOMAC Pain Scale. It would be inappropriate to create one from the arm means because the analysis method and any adjustment factors are not reported, and the record explicitly indicates that values for a two-arm continuous-endpoint comparison are missing or not estimable.
Nor does overlap between separate intervals determine whether a direct comparison is statistically significant. In general, the standard error of a difference depends on uncertainty in both group estimates and on the structure of the data. A direct comparison can also depend on whether the analysis adjusts for baseline values or other prespecified covariates. Those details are not reported in the registry record. No significance claim should be inferred from visual proximity of the means or intervals.
What does randomization contribute?
In general, random assignment is intended to reduce systematic differences between groups at the start of a trial. It helps support a causal interpretation of between-group contrasts, especially when allocation is concealed, participants are retained, and analyses follow appropriate principles. The record identifies the trial as randomized, but does not report the sequence-generation or concealment procedures. It also does not report a participant flow or enough analysis detail to determine how missing outcome data were handled. Randomization is an important design feature, but does not by itself guarantee unbiased results in every analysis.
The record describes the study as double-masked. Masking can reduce the influence of expectations or knowledge of assignment on care, outcome reporting, or assessment, depending on who is masked. Which roles were masked and how masking was maintained are not reported. The intervention formats differ, so the label alone does not show whether participants or intervention providers could distinguish assignments.
How should sample-size illustrations be understood?
In general, sample-size planning asks how much information a future study might need to detect a specified effect under stated assumptions. The registry material describes illustrations based on a fraction of the observed effect, a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. These are planning illustrations, not the trial's own design justification. They are not observed power and do not show the probability that the completed trial detected an effect. The actual illustration values are not reported in the registry record summarized for this analysis.
Observed power is not a substitute for an estimated effect and its confidence interval. After a trial, the observed estimate and its uncertainty are more informative than a retrospective power calculation. Here, the primary registry results do not include a direct comparison estimate, so the planning assumptions cannot fill that gap. No sample-size justification for the original trial is reported in the registry record.
What can be concluded from the posted method details?
The reported outcome is continuous, summarized as a mean with a 95% confidence interval, and the trial has three parallel arms. The record identifies a primary endpoint and lists secondary outcomes, but does not provide a full statistical plan, model specification, covariate adjustment, or a method for handling repeated measurements. These absences limit assessment of how the primary results were generated and how planned comparisons were prioritized. They do not invalidate the posted descriptive results, but they restrict what can be inferred from them.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six secondary outcomes: the WOMAC Physical Function Scale, 0 to 10 Verbal Pain Rating Scale, Pain Catastrophizing Scale, Global Rating of Change Scale, Six-minute Walk Test, and Short Physical Performance Battery. These sit alongside the primary WOMAC Pain Scale endpoint. Evaluating several outcomes can raise a multiplicity issue: in general, the more statistical tests conducted, the greater the chance that at least one result appears notable by chance if no adjustment or hierarchy is used. The registry record does not report a multiplicity strategy, a hierarchy of comparisons, or analysis-specific results for the secondary measures.
The record indicates that all subjects were included in primary and secondary analyses. This statement describes the intended analysis population, but does not explain whether every participant had every measurement, how missing values were handled, or whether imputation or sensitivity analyses were used. Those details are not reported in the registry record. The outcome counts should not be interpreted as evidence that there was no missingness.
Likewise, the record does not report whether analyses followed an intention-to-treat principle, how participants with incomplete follow-up were treated, or whether any per-protocol or other analysis population was used. The exact analysis model, baseline adjustment, and handling of repeated observations are also not reported in the registry record. These omissions make it difficult to assess the robustness of estimates or the consistency of analyses across endpoints.
There are no reported analysis-specific comparison results for the primary endpoint. The registry's primary group summaries are descriptive, and the absence of a reported contrast should not be filled by selecting an unplanned comparison. A prespecified analysis plan would be needed to judge which comparisons were intended and how multiplicity and missing data were addressed.
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 |
|---|---|---|---|
| Pain Coping Skills Training | 34 | 127 | 26.8% |
| Arthritis Education | 36 | 125 | 28.8% |
| Usual Care | 28 | 132 | 21.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pain Coping Skills Training | 2 of 127 |
| Arthritis Education | 0 of 125 |
| Usual Care | 0 of 132 |
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 |
|---|---|
| Pain Coping Skills Training | 8 of 127 |
| Arthritis Education | 3 of 125 |
| Usual Care | 9 of 132 |
Most frequent serious adverse event terms
| Event term | Organ system | Pain Coping Skills Training | Arthritis Education | Usual Care |
|---|---|---|---|---|
| Contralateral knee replacement | Musculoskeletal and connective tissue disorders | 12 of 127 | 13 of 125 | 7 of 132 |
| Other hospitalization | Surgical and medical procedures | 7 of 127 | 7 of 125 | 7 of 132 |
| Manipulation of index knee | Musculoskeletal and connective tissue disorders | 7 of 127 | 7 of 125 | 3 of 132 |
| venous thromboembolism | Blood and lymphatic system disorders | 3 of 127 | 2 of 125 | 3 of 132 |
| Hospitlilization | Musculoskeletal and connective tissue disorders | 0 of 127 | 2 of 125 | 5 of 132 |
| Revision of index knee | Musculoskeletal and connective tissue disorders | 3 of 127 | 3 of 125 | 1 of 132 |
| infection of knee | Musculoskeletal and connective tissue disorders | 2 of 127 | 1 of 125 | 2 of 132 |
| Hospitalization for psychological distress | Nervous system disorders | 0 of 127 | 1 of 125 | 1 of 132 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pain Coping Skills Training | Arthritis Education | Usual Care |
|---|---|---|---|---|
| psychological distress | Nervous system disorders | 5 of 127 | 2 of 125 | 8 of 132 |
| orthopaedic injury to the knee | Musculoskeletal and connective tissue disorders | 1 of 127 | 0 of 125 | 1 of 132 |
| Emergency room visity for knee pain | Musculoskeletal and connective tissue disorders | 1 of 127 | 1 of 125 | 0 of 132 |
| shortness of breath | Cardiac disorders | 1 of 127 | 0 of 125 | 0 of 132 |
Serious events with the highest arm-level rate: contralateral knee replacement (10.4%), manipulation of index knee (5.6%), other hospitalization (5.6%), hospitlilization (3.8%), revision of index knee (2.4%).
The registry reports serious adverse events and other adverse events by group, with counts of participants at risk and counts affected. For serious adverse events, the reported figures are 34 affected out of 127 at risk in Pain Coping Skills Training, 36 out of 125 in Arthritis Education, and 28 out of 132 in Usual Care. For other adverse events, the reported figures are 8 out of 127, 3 out of 125, and 9 out of 132, respectively. These are registry counts; they should not be added across arms or treated as counts of unique events.
The distinction between participants affected and event occurrences matters. One participant can experience more than one event, and the record does not specify whether each count represents people, event episodes, or another reporting convention beyond the affected count shown. The listed denominators also need not match the primary endpoint counts because safety and efficacy analyses can use different populations or follow-up rules. Further detail about ascertainment periods and definitions is not reported in the registry record.
Deaths are reported as 2 for Pain Coping Skills Training, 0 for Arthritis Education, and 0 for Usual Care. The registry also lists serious-event terms and percentages, including Contralateral knee replacement at 10.4%, Manipulation of index knee at 5.6%, Other hospitalization at 5.6%, Hospitlilization at 3.8%, Revision of index knee at 2.4%, and venous thromboembolism at 2.4%. The record does not provide an arm-specific breakdown for these listed terms in the available information. These figures describe reported events; they do not establish that an intervention caused them or permit a comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The posted primary results show average WOMAC Pain Scale scores at twelve months for each randomized group, alongside confidence intervals. Because higher scores on the scale mean worse activity-related pain, the means can be read in that direction. The group summaries are descriptive evidence about the observed endpoint values. They are not, on their own, estimates of the causal effect of pain coping skills training compared with education or usual care.
A direct treatment comparison requires an estimated contrast and its uncertainty. The registry record does not report a primary between-group estimate, its confidence interval, or a p-value. It also does not report a threshold for interpreting the size of a difference as clinically important. Without those elements, the summaries cannot establish the magnitude or precision of a comparative effect, nor whether a difference would matter to patients.
The trial's stated aims extend beyond the primary pain measure. Function was addressed through secondary outcomes, and cost effectiveness was part of the study rationale. The registry lists secondary measures but does not report their analysis-specific results in the information available for this account. A result for the primary pain scale cannot stand in for findings on walking performance, physical function, pain catastrophizing, perceived change, or cost effectiveness.
The safety figures provide counts of serious and other adverse events and deaths by group. They are useful descriptions of what was reported, but they do not establish comparative risk or causation. Definitions, event timing, and detailed arm-specific event terms are not reported in the registry record.
In general, conclusions from a randomized trial depend not only on the group summaries but also on follow-up completeness, outcome analysis, prespecified comparisons, and uncertainty. Information about missing data, the detailed statistical plan, and the roles covered by masking is not reported. The result therefore supports a careful description of the registry's posted endpoint means, not a broad claim about whether one care strategy is superior or whether it works for an individual patient.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it compares a structured behavioral program with both an active educational comparator and usual care. The formats and providers differ: pain coping skills training was delivered by physical therapists, while arthritis education was delivered by nurse educators. A comparison with education can help address whether outcomes differ between two organized perioperative programs, while a comparison with usual care addresses a different question. Those comparisons should be reported separately rather than treated as interchangeable.
The primary endpoint is a continuous patient-reported pain measure, summarized by group means and confidence intervals. This makes clear why descriptive arm values and a direct treatment contrast are not the same thing. Researchers and readers need the contrast, its uncertainty, and the analysis plan to understand how strongly the data support a comparative interpretation. The registry record reports the arm summaries but not the direct primary contrasts.
The trial also illustrates the importance of specifying how multiple outcomes are handled. Its secondary measures span physical function, pain ratings, pain catastrophizing, perceived change, and performance-based tests. In general, a broad set of outcomes can offer a more complete view of a research question, but it also requires transparent prioritization and interpretation. The registry record does not report a multiplicity strategy or analysis-specific results for those outcomes.
Finally, safety summaries and endpoint results may have different denominators, and enrollment should not be confused with the number contributing to a particular outcome. Here, the primary endpoint group counts and safety denominators are separately reported. Clear participant flow and missing-data methods would help readers understand how those populations relate. The record's omissions do not erase the descriptive results, but they matter when judging precision, bias, and generalizability.
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 main limitation of the registry results is that they report arm-level means and confidence intervals without a direct estimate comparing the groups on the primary endpoint. No comparison confidence interval or p-value is reported. As a consequence, the precision of any treatment contrast cannot be assessed from the posted results, and the mean values should not be interpreted as proof of a difference or equivalence.
The record does not report a threshold for a clinically important WOMAC Pain Scale difference. It therefore provides no stated benchmark for deciding whether a potential contrast would be meaningful to patients. The confidence intervals concern the group means, not the treatment contrasts, so they cannot fill that role.
Further limitations arise from incomplete methodological detail. The randomization procedure, allocation concealment, roles covered by double masking, analysis model, covariate adjustment, and handling of repeated observations are not reported in the registry record. The record says all subjects were included in analyses, but does not explain missing outcome data, participant flow, or the analysis population in enough detail to assess completeness. The outcome-specific counts should therefore be read as reported counts, not assumed to represent complete follow-up.
The secondary measures are listed, but analysis-specific secondary results and a multiplicity approach are not reported. Cost effectiveness was part of the stated trial purpose, but a cost-effectiveness result is not reported in the registry record. This limits the scope of conclusions that can be drawn from the available outcome information.
The record's intervention descriptions give session formats and providers, but do not fully describe all intervention content or the usual-care practices. This limits assessment of implementation and how reproducible the programs would be in other settings. The safety information also lacks reported detail on event definitions, timing, and arm-specific breakdowns for the listed serious-event terms. These limitations call for restrained interpretation of both efficacy and safety summaries.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Knee Arthroplasty Pain Coping Skills Training (KASTPain): A Randomized Trial — NCT01620983.
- Registry record last updated 2018-10-19; status last verified 2018-10.
- Results first posted 2018-10-19.
- 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
NCT01620983 is a completed, randomized, double-masked, parallel-group trial sponsored by Virginia Commonwealth University. It enrolled 402 participants and compared Pain Coping Skills Training, Arthritis Education, and Usual Care in the context of knee arthroplasty. The primary endpoint was the WOMAC Pain Scale at twelve months, a self-report measure from 0 to 20 on which higher scores denote worse activity-related pain.
The registry reports a mean and 95% confidence interval for each group: 3.3 (2.5 to 4.2) for Pain Coping Skills Training, 3.0 (2.1 to 3.8) for Arthritis Education, and 2.9 (2.0 to 3.8) for Usual Care. These summaries do not include a direct between-group estimate. The record lists six secondary outcomes and reports safety counts, but does not provide enough detail on missing data, multiplicity, or the statistical analysis plan to support broader comparative conclusions.