Depression and Pain Perseverance Through Empowered Recovery Intervention: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Depression and Pain Perseverance Through Empowered Recovery Intervention (NCT04091347), a randomized na study. The primary outcome is Pain Intensity as Assessed by the Patient Reported Outcomes Measurement Information System (PROMIS).

2. Clinical Question

The clinical question is whether the DAPPER intervention is associated with a change in reported pain intensity over the study period compared with the wait-list condition. This is a question about the groups and outcome as defined in the registry, not a conclusion about treatment benefit. The record identifies a randomized, double-masked, parallel trial, but does not state who was masked or provide the detailed allocation procedure.

The study also concerns depressive symptoms, frailty, and aging, and the brief description emphasizes both pain and mood. However, the listed primary outcome is pain intensity, not a combined pain-and-mood score. The registry lists salivary measures of IL-6, IL-8, IL-1 Beta, and TNF-Alpha as secondary outcomes. Their inclusion does not replace the primary pain-intensity question, and numerical results for those measures are not reported in the registry record.

3. Trial Design

The registry identifies DAPPER as a randomized, double-masked, parallel-group behavioral study. It lists 34 participants as enrolled and marks the study completed. The registry dates are 2020-01-02 for study start and 2023-11-30 for primary completion. These dates describe the registered study timeline; they do not provide the timing of each participant’s follow-up or explain the length of the overall recruitment period.

Participants in the intervention arm were to receive DAPPER for 12 weeks. The description says the intervention included 8 nurse visits in participants’ homes. The wait-list control group had outcomes measured without receiving DAPPER at that time, and was to complete the intervention after the intervention group had completed it. The record does not say whether the wait-list participants’ later intervention period contributed to the primary comparison.

The primary outcome was assessed at baseline and 12 weeks. The registry reports that 23 participants completed the intervention and that the primary measure was completed at both time points by 13 participants assigned to the intervention group and 10 assigned to the control group. The record does not explain why this measure’s participant count differs from the total enrollment, or describe how participants without both measurements were handled in an analysis.

Although the record labels the study double-masked, it does not identify which people were masked or explain how masking was maintained. It also does not report details of the randomization sequence or concealment. The phase is listed as NA. A detailed protocol, statistical analysis plan, sample-size justification, interim analysis plan, and planned analysis population are not reported in the registry record. These omissions limit the extent to which the registered design can be compared with the analysis actually performed.

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: A total of 23 participants completed the intervention. Participants who completed this measure at baseline (pre intervention) and post intervention (12 + weeks), (13 participants in the intervention group and 10 in the control group).

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 Pain Intensity as Assessed by the Patient Reported Outcomes Measurement Information System (PROMIS), measured over Baseline and 12 weeks.

The primary endpoint is pain intensity measured with the Patient Reported Outcomes Measurement Information System (PROMIS) Intensity measure. The registry describes a score on a 0-10 scale and states that higher scores indicate more pain intensity. The outcome was scheduled at baseline and 12 weeks. The registry does not report a numerical mean, standard deviation, change score, or group contrast for this endpoint.

A patient-reported measure records the participant’s own assessment rather than an observer’s judgment. In general, a pain-intensity score can express how strongly a person experiences pain at a particular assessment, while repeated measurements can describe how scores change over time. For a randomized comparison, interpretation depends on a clearly specified contrast: for example, a comparison of follow-up scores or a comparison of change from baseline. The registry record does not identify a single contrast of that kind in its posted primary outcome results.

The measure is relevant to the study question because the intervention description concerns pain as well as mood, and pain intensity is explicitly designated as the primary outcome. The listed scale direction gives a reader a way to interpret the meaning of a score if numerical results are available: larger scores represent greater reported intensity. It does not, on its own, reveal whether scores changed, whether groups differed, or how precisely any difference was estimated. The registry record also does not state a threshold for a clinically important change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the outcome as continuous and describes it using a mean and standard deviation. A mean is a measure of the center of a set of scores; a standard deviation describes how dispersed individual scores are around that mean. In general, those summaries can help readers understand both the typical score and the variability among participants. They do not alone describe a randomized group contrast, and the registry record does not post the primary outcome means or standard deviations.

What does a comparison need to specify?

With measurements at baseline and follow-up, an analysis might compare follow-up scores between randomized groups, compare within-person changes, or model both time points together. These approaches answer related but not identical questions and rely on different assumptions. In general, a within-person change uses the pairing of a participant’s measurements, whereas a comparison of follow-up scores asks how the groups differ at the later assessment. A model using both time points can represent the repeated observations and the group-by-time pattern. The registry record does not specify which of these approaches was planned or used.

The registry says the primary outcome was measured at baseline and 12 weeks, and notes that the primary outcome has several categories or time points and was not reduced to one comparison. It does not report an estimate for any particular contrast. A reader therefore cannot infer that one time point, one change definition, or one analysis was the intended basis for a primary conclusion.

How should uncertainty be understood?

In general, a confidence interval presents a range of estimates compatible with the observed data under the model and its assumptions. A narrower interval indicates greater precision than a wider interval, while an interval spanning values in different directions can indicate uncertainty about the direction of a contrast. The registry record does not report a confidence interval for the primary outcome. There is therefore no reported interval with which to assess precision.

A hypothesis test is another way to summarize data relative to a specified null hypothesis. A p-value is calculated under assumptions and describes how unusual the data would be if that null hypothesis and model were true. It is not the probability that the null hypothesis is true, nor a measure of the importance of an observed difference. The registry record reports no primary comparison test or p-value. It also does not report a planned significance threshold for the primary analysis.

What does the planning information mean?

The study record includes a general sample-size planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It describes the target effect as a stated fraction of the observed effect. Those assumptions describe a planning calculation, not the trial’s observed result, and the planning figures are not observed power. The registry does not report the trial’s own sample-size justification or state that these illustration assumptions formed its original design plan.

In general, a sample-size calculation asks how many participants would be needed under chosen assumptions to detect a specified effect with a chosen operating characteristic. Its result depends on the assumed effect, variability, allocation, and analysis method. A planning illustration based on an observed effect is particularly dependent on that effect estimate, which may be imprecise in a small study. It should not be read as proof that the study had a particular probability of detecting an effect, and it does not substitute for the missing primary estimate and confidence interval.

What can the reported counts tell us?

The registry lists 34 enrolled, 23 intervention completers, and 23 participants with a baseline and post-intervention primary measure, split as 13 in the intervention group and 10 in the control group. These are descriptive counts, not analysis results. In general, fewer observations can make estimates less precise, and incomplete measurement can introduce bias if the likelihood of missing data is related to outcomes or participant characteristics. The record does not describe a missing-data method or the reasons participants did not contribute both measurements.

The record identifies a parallel randomized design. In general, random assignment is intended to make groups comparable at the start with respect to measured and unmeasured factors, on average. That design advantage depends on preserving the randomized comparison in the analysis and appropriately handling missing outcomes. The registry record does not say whether the primary analysis followed assignment regardless of intervention completion, or whether it was restricted to completers. The analysis population and details needed to evaluate that choice are not reported.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 15 outcome measures and identifies four secondary salivary outcomes: IL-6, IL-8, IL-1 Beta, and TNF-Alpha, each described as a saliva measure. It reports zero analyses. The primary outcome is described as having several categories or time points and is not reduced to one comparison. The record does not provide a complete list of planned contrasts or explain how results across outcomes and time points were to be interpreted.

In general, examining many outcomes or comparisons creates a multiplicity issue: even if each test uses the same threshold, the chance of at least one apparently notable result can increase as more tests are considered. Prespecifying a primary contrast and describing any adjustment or hierarchy can help readers distinguish confirmatory questions from exploratory ones. The registry record does not report a multiplicity procedure, a hierarchy among secondary outcomes, or an analysis plan for selecting among time points. This absence means a reader cannot determine how any possible collection of comparisons was intended to control false-positive findings.

For the primary measure, the record reports paired availability at baseline and post-intervention for 13 participants in the intervention group and 10 in the control group. It does not give the count at each time point separately, the pattern of missingness, or reasons for missing measurements and noncompletion. It does not report imputation, a likelihood-based approach, or another method for handling missing data. In general, missing-data methods rely on assumptions about why outcomes are absent; those assumptions should be stated and considered alongside observed counts.

The registry also does not identify an intention-to-treat analysis, a per-protocol analysis, or another analysis population. It is therefore not possible to tell whether participants were analyzed according to randomized group, according to intervention completion, or under another rule. These omissions leave uncertainty about how the observed participants were selected for any analysis. The record does not report enough information to assess whether missingness or the choice of analysis population could have affected a comparative result.

11. 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’s adverse-event counts list 17 participants at risk in each arm. In the intervention arm, 0 participants were reported as affected by a serious adverse event, 0 by another adverse event, and 0 deaths were listed. The wait-list control arm likewise lists 0 serious adverse events, 0 other adverse events, and 0 deaths among 17 participants at risk. The record does not list serious-event terms.

These are the counts recorded in the registry; they should be read as reports of no affected participants in the listed categories, not as proof that the intervention or study conditions carry no risk. In general, zero recorded events in a limited group cannot rule out events that were uncommon, occurred outside the reporting period, or were not captured under the registry’s reporting process. The registry record does not describe the adverse-event collection method, the period of risk assessment, or how events were attributed to an intervention.

Counts at risk are not the same as evidence that every participant had complete safety follow-up. The record does not explain whether all participants were observed for the same duration or whether safety data were missing. The adverse-event figures are therefore descriptive and should be interpreted with the study’s size and the lack of reporting detail in mind. They do not answer the primary pain-intensity question.

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

The registry record establishes that DAPPER was a randomized, double-masked, parallel behavioral study with a wait-list control and a primary outcome focused on pain intensity. It describes an intervention lasting 12 weeks, including 8 home nurse visits, and identifies baseline and 12-week assessment of the PROMIS Intensity measure. It also reports enrollment and measure-completion counts. These details describe the study that was registered; they are not a numerical estimate of the intervention’s comparative effect.

The registry does not report primary outcome means, changes, a between-group estimate, a confidence interval, or a test result. As a result, it cannot establish whether the groups’ pain-intensity scores differed, the direction or size of any difference, or how precisely such a difference could be estimated. The fact that the study was randomized does not fill in those missing results. Randomization describes an allocation approach; it does not itself supply an outcome contrast.

The outcome description says higher PROMIS Intensity scores indicate more pain intensity. That direction would help interpret a reported score or contrast, but no such numerical result is available in the registry record. Likewise, the safety counts report no affected participants in the listed categories, but they do not establish an absence of all possible harms or provide a complete account of safety follow-up.

The record should not be read as demonstrating either benefit or lack of benefit. A missing comparative estimate is not evidence that the groups were the same, just as a study’s completion status is not evidence that its primary objective was met. The available information supports a description of the design and recorded participant counts; it does not support a conclusion about the intervention’s effect on pain intensity. Further interpretation would require the outcome results and enough analysis detail to understand how those results were obtained.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of why trial registration and outcome reporting answer different questions. The registry identifies a randomized design, a defined comparator, a primary patient-reported outcome, and assessments planned at baseline and 12 weeks. Those details help readers understand the intended comparison. Yet without a numerical result and an analysis description, the registry record cannot show the estimated difference or its uncertainty.

The study also highlights the importance of specifying a single primary contrast when an outcome has multiple categories or time points. A clear definition allows readers to distinguish the main planned question from other possible comparisons. Here, the record notes that the primary outcome has several categories or time points and is not reduced to one comparison. It does not report how those measurements were to be combined or prioritized in an analysis.

The participant counts matter statistically because the primary measure was completed at both stated time points by 13 intervention participants and 10 control participants, while enrollment was 34. These numbers make transparent that the available paired measurement group is limited. In general, a limited amount of information can lead to imprecise estimates, and incomplete outcome data may affect interpretation depending on why data are missing. The reasons and analysis handling are not reported in the registry record.

Finally, the listed salivary outcomes and the absence of reported analyses illustrate why a number of registered measures cannot be treated as a set of findings. Clear reporting of estimates, uncertainty, analysis populations, and multiplicity decisions is necessary for a reader to distinguish planned measurement from evidence. The registry contains design and outcome descriptions, but the primary comparative evidence is not reported.

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 most direct limitation for interpreting this trial is that the registry record does not report numerical results for the primary pain-intensity outcome. It gives no mean scores, standard deviations, change estimates, between-group contrast, confidence interval, or p-value. Without these, readers cannot assess the direction, magnitude, or precision of the primary comparison.

Outcome availability is described for 23 participants with both baseline and post-intervention measurements, with 13 in the intervention group and 10 in the control group. The registry does not explain why the count is lower than the total enrollment of 34, give the reasons for incomplete measurement or intervention noncompletion, or describe how missing data were addressed. It also does not identify the analysis population. These omissions prevent assessment of whether the reported measurement group represents all randomized participants in a way that preserves the intended comparison.

The intervention is described as lasting 12 weeks and including 8 nurse visits at home, but the record does not provide further information about delivery, adherence, or variation in exposure. Although the study is labeled double-masked, the people masked and the masking procedures are not reported. Details of random sequence generation and allocation concealment are also not reported in the registry record.

The registry lists 15 outcome measures, including salivary inflammatory markers, but reports zero analyses and does not give a multiplicity plan. It notes that the primary outcome has multiple categories or time points without reducing them to one comparison. A sample-size justification and detailed statistical analysis plan are not reported. The study’s results therefore cannot be evaluated against a prespecified analysis from the registry information alone.

The enrolled population is specifically described as African American women aged 50 years and older with depressive symptoms, pain, and mobility difficulty. Conclusions about other populations or circumstances cannot be drawn from this record. These limitations concern the information available in the registry and should not be mistaken for evidence that a particular result occurred.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Depression and Pain Perseverance Through Empowered Recovery Intervention — NCT04091347.
• Registry record last updated 2025-11-19; status last verified 2025-11.
• Results first posted 2025-06-29.
• 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.

18. Record Summary

NCT04091347 is the completed, randomized, double-masked, parallel DAPPER behavioral study. Its official title identifies it as a pilot study. The record lists 34 participants enrolled and an intervention lasting 12 weeks, described as including 8 nurse visits in participants’ homes. The comparator was a wait-list control that was to receive the intervention after the intervention group completed it.

The primary outcome was PROMIS pain intensity, assessed at baseline and 12 weeks on a 0-10 scale, with higher scores indicating more pain intensity. The record says 23 participants completed the intervention and reports paired outcome measurement for 13 intervention participants and 10 control participants. It lists 15 outcome measures, including four salivary cytokine measures, but reports zero analyses. Numerical primary outcome comparisons, an analysis plan, missing-data procedures, and a sample-size justification are not reported in the registry record.