Improving Cancer Pain Management Through Self-Care: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Improving Cancer Pain Management Through Self-Care (NCT00708019), a randomized na study. The primary outcome is Average Pain Intensity Score.

2. Clinical Question

The study also aimed to determine whether pain management behaviors learned by patients and family caregivers continued after the intervention stopped. How that persistence was defined or assessed is not reported in the registry record. The posted primary outcome is average pain intensity; the listed secondary outcome is Worst Pain Intensity Score.

3. Trial Design

This was a randomized, parallel-group trial with no masking indicated in the registry record. Enrollment was 185. The record lists 92 participants in the Low Dose arm and 93 in the High Dose arm. Both groups received the PRO-SELF PLUS Pain Management Program, with the planned difference being the amount of contact with the intervention nurse over 10 weeks: 8.0 hours for Low Dose and 12.3 hours for High Dose.

The record describes the study as phase NA and lists it as completed. The recorded start was 2007-12, and primary completion was 2012-12. The sponsor is the University of California, San Francisco. These details identify the setting and structure recorded for the trial; they do not establish how consistently participants received the intended intervention or completed outcome assessments. Adherence, treatment fidelity, and departures from assigned intervention are not reported in the registry record.

The primary endpoint was average pain intensity, assessed using a daily numeric rating scale running from 0 (no pain) to 10 (worst pain imaginable). The primary outcome description says change from enrollment to the end of the study, at 10 weeks, was evaluated between the intervention groups. However, the posted results contain arm-specific estimates and confidence intervals rather than an estimable between-group contrast. The statistical test, model, adjustment variables, and analysis population are not reported in the registry record.

Random assignment can support a fair comparison when the allocation process is implemented as intended and outcomes are analyzed appropriately. It does not by itself resolve questions about missing outcome data, adherence, or the precision of a treatment contrast. Those details are not reported in the registry record, so the design features alone cannot establish the size or certainty of a difference between intervention doses.

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

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 Average Pain Intensity Score, measured over 10 weeks.

The primary endpoint was Average Pain Intensity Score. It represents average pain assessed on a numeric rating scale from 0 (no pain) to 10 (worst pain imaginable). The registry record says pain was measured daily and that change from enrollment to the end of the study, at 10 weeks, was evaluated between the two intervention groups.

Using a continuous score preserves gradations in reported pain rather than reducing responses to categories such as improved or not improved. A group mean can describe the central level of the measure, while a confidence interval conveys uncertainty around an estimate. The endpoint is relevant to the study’s stated aim of evaluating pain management and its hypothesis about a decrease in pain intensity. The registry record does not explain the rationale for choosing this endpoint over other measures, or specify how daily ratings were combined into an average.

The posted arm-level estimates are 1.192 for Low Dose, with a 95% confidence interval from 0.452 to 1.932, and 1.304 for High Dose, with a 95% confidence interval from 0.54 to 2.069. The registry record does not state the sign convention for the reported change estimates. Therefore, the positive values alone do not indicate whether pain increased or decreased. More importantly, the record does not provide an estimable difference between arms, so these values do not answer the primary comparative question by themselves.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the reported outcome represent?

The primary outcome is continuous: it is a numeric score, rather than a count or a yes-or-no event. The registry record identifies the reported measure as a mean and describes a daily rating scale from 0 (no pain) to 10 (worst pain imaginable). The study’s primary outcome description concerns change between enrollment and 10 weeks. A mean summarizes the center of a set of values, but it does not show how individual participants’ ratings were distributed. The record does not explain how daily observations were combined, or whether all scheduled ratings contributed to each participant’s outcome.

General statistical context: a continuous endpoint can be analyzed in several ways, including comparing group means or modeling repeated measurements over time. These approaches can account for the data structure differently. The registry record does not report which model or method was used, so no particular analytic approach should be inferred from the arm-level means alone.

How should the confidence intervals be read?

The Low Dose estimate is 1.192, with a 95% confidence interval from 0.452 to 1.932. The High Dose estimate is 1.304, with a 95% confidence interval from 0.54 to 2.069. A confidence interval expresses the statistical uncertainty around an estimate under the assumptions used to calculate it. In repeated use of the same method, intervals constructed in this way have a stated long-run coverage property. It does not mean there is a 95% probability that this particular interval contains the true value.

These intervals describe each arm’s estimate, not the difference between the arms. For a comparative question, the direct estimate of the difference and its confidence interval are the most relevant quantities. Those are not reported as estimable in the registry record. The arm-level intervals cannot be used to recover a valid treatment contrast without additional information about the analysis and the relationship between the estimates.

Why is a direct contrast important?

Randomized studies are designed to compare groups, and the central quantity is generally the difference in outcomes between assigned groups. A direct contrast estimates that difference and communicates its precision. The posted record has an estimate and confidence interval for each arm, but no estimable two-arm comparison for the continuous endpoint. It therefore does not quantify the comparative effect of the higher dose versus the lower dose. No p-value for that contrast is reported.

General statistical context: a p-value, when reported, measures how incompatible observed data are with a specified null hypothesis under a statistical model. It is not a measure of the size or clinical importance of an effect. A confidence interval for a direct contrast is often more informative because it conveys both the estimated direction and the range of values compatible with the analysis. Neither is available for the primary comparison in this registry record.

What can randomization and allocation tell us?

The record identifies the trial as randomized and parallel, with the two dose groups reported separately. Randomization is intended to make groups comparable on average at the point of assignment, including with respect to characteristics that may not have been measured. It does not guarantee identical groups in a particular trial, and it does not prevent bias from missing outcomes, deviations from assignment, or other issues after randomization. Allocation concealment and the specific randomization procedure are not reported in the registry record.

The trial was listed as having no masking. Knowledge of assignment can affect participant reports, intervention delivery, or outcome assessment, particularly when the outcome is self-reported. This is a general methodological consideration, not evidence that such effects occurred in this trial. The registry record does not describe procedures intended to reduce their influence.

What can be said about sample size and statistical planning?

The record reports total enrollment of 185 and arm counts of 92 and 93. A sample size describes how many people were enrolled or assigned; it does not by itself establish whether a study had enough precision to answer its question. That depends on factors such as the expected effect, variability, missing data, and the analysis plan. The study’s sample-size justification, target effect, assumptions, and planned power are not reported in the registry record. No claim about observed power can be drawn from enrollment or from the posted arm-level estimates.

General statistical context: planning calculations can illustrate how many participants might be needed under stated assumptions, but such illustrations are not a measure of what a completed trial actually achieved. Their usefulness depends on assumptions that must be made explicit. The registry record does not provide the study’s original planning rationale or a posted comparative estimate that would support a precision assessment for the primary question.

What remains unknown about the analysis?

The record reports no analyses and marks the two-arm continuous comparison as having values that are missing or not estimable. It does not describe a model, test, covariate adjustment, handling of repeated daily ratings, or analysis population. It also does not explain whether the posted arm-level estimates came from all randomized participants, a subset with observed outcomes, or another population. These omissions prevent a detailed assessment of how the estimates were produced and whether the analysis followed a prespecified plan.

General statistical context: over-dispersion matters most for count data, where observed variability can exceed what a simple count model assumes. The primary endpoint is described as a continuous mean, not a count outcome. The registry record does not report a dispersion estimate or analysis details that would justify applying a particular variance model. Statistical methods should be interpreted from the recorded endpoint and the analysis actually reported, rather than inferred from general possibilities.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome, Average Pain Intensity Score, and one secondary outcome, Worst Pain Intensity Score. It reports no analyses. The secondary outcome’s result is not reported in the registry record, and no analysis plan describing how primary and secondary outcomes were handled is reported.

When a study assesses more than one outcome or conducts multiple comparisons, the chance of obtaining a nominally notable result by chance can increase. Statistical plans sometimes address this by identifying a primary outcome in advance, adjusting significance thresholds, or treating secondary analyses as exploratory. The registry record does not report whether any multiplicity strategy was planned or used. The presence of a single listed primary outcome does not reveal whether additional analyses were conducted or how they were interpreted.

Missing-data handling is also not reported. The enrollment counts do not establish how many participants contributed to the primary outcome at 10 weeks, whether daily ratings were incomplete, or how any missing observations were handled. The record does not report an intention-to-treat analysis, a per-protocol analysis, imputation, or sensitivity analyses. These are not assumptions that can be filled in from the randomized design alone.

The analysis population is not reported in the registry record. It is therefore unclear whether the arm-level estimates include all randomized participants, only participants with observed outcomes, or another defined group. The absence of an estimable direct comparison further limits assessment: the record does not provide a treatment contrast or its uncertainty for the primary endpoint. These gaps concern what can be evaluated from the record; they do not establish that a particular method was or was not used outside the information recorded.

11. Safety Results

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

Other (non-serious) adverse events

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

For Low Dose, the registry record lists 92 participants at risk for serious adverse events and 0 with a serious adverse event. It also lists 92 at risk for other adverse events and 0 affected. For High Dose, the record lists 93 participants at risk for serious adverse events and 0 with a serious adverse event, and 93 at risk for other adverse events and 0 affected.

These figures describe the adverse-event counts posted in the registry record. They do not describe the nature, timing, duration, or method of collecting adverse events, none of which is reported there. The record does not list serious adverse-event terms. Death counts are not reported in the registry record; the corresponding entries are unavailable, not zero.

A recorded count of zero should be read as no events reported in that category for the listed group, not as proof that no events occurred under every definition or during every period of observation. The registry record does not provide follow-up completeness or additional detail needed to evaluate how comprehensively safety events were captured. These counts alone also do not establish a comparative safety difference between the two groups.

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

The posted results allow a limited description of the primary outcome by group. The Low Dose estimate is 1.192, with a 95% confidence interval from 0.452 to 1.932; the High Dose estimate is 1.304, with a 95% confidence interval from 0.54 to 2.069. The endpoint is described as change in average pain intensity from enrollment to 10 weeks, using a 0-to-10 rating scale. The registry record does not state the sign convention for change, so the estimates cannot be translated into a direction of change from the numeric values alone.

The central question was whether the change differed between the intervention doses. The record does not provide an estimable between-group comparison, so the size and precision of any difference cannot be established from these results. The record also does not report a p-value for the primary contrast. This is not the same as evidence that there was no difference, and it is not evidence that the higher dose produced a greater decrease. The stated hypothesis remains a hypothesis, rather than a conclusion supported by an estimable comparative result.

The findings do not establish whether participants maintained pain management behaviors after the intervention stopped. Although this was an aim described for the study, relevant estimates are not reported in the registry record. The listed secondary outcome, Worst Pain Intensity Score, also has no posted result in the record. Consequently, the available results do not resolve that secondary question either.

The reported adverse-event counts are zero in the serious and other event categories for both arms, among the listed participants at risk. The record does not supply event descriptions or follow-up detail, and death counts are not reported. These safety entries should be understood as registry reporting, rather than as a complete account of all possible outcomes.

Overall, the record gives arm-level summaries and basic trial characteristics, but leaves the key comparative result unavailable. It does not support a claim that either dose is more effective, nor does it establish equivalence. Such conclusions would require a valid between-group estimate with suitable uncertainty and sufficient information about the analysis and outcome data.

13. Why This Trial Matters Statistically

This trial poses a useful statistical question about comparing different doses of a behavioral, psychoeducational intervention. Because both groups received the program, the intended comparison concerns the incremental difference associated with the higher versus lower dose, rather than the program versus no intervention. That distinction matters when describing what a randomized comparison can answer.

The registry record makes the gap between arm-level summaries and a treatment contrast visible. Each group has a posted estimate and confidence interval for Average Pain Intensity Score, but the primary comparison is marked as not estimable or missing. Without the direct contrast, readers cannot quantify the difference between intervention doses or judge its precision. The example underscores why comparative estimates are central in randomized trials, rather than relying on separate group summaries.

The record also illustrates the limits of a stated hypothesis. The study description anticipates a greater decrease with the higher dose, but a hypothesis does not constitute a result. The recorded sign convention for change is absent, and the between-group estimate is unavailable. Keeping these distinctions clear avoids interpreting a planned direction as an observed conclusion.

Finally, the record shows why trial design and outcome reporting must be read together. Randomization and enrollment counts describe important features of the study, but they do not reveal how missing ratings were handled, which participants contributed to the analysis, or how the primary contrast was modeled. The absence of those details constrains statistical interpretation. The result is not a basis for declaring the doses equivalent or different; it demonstrates the importance of reporting an interpretable contrast and its uncertainty.

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 important limitation for interpreting the primary question is that the registry record does not provide an estimable between-group comparison for Average Pain Intensity Score. Arm-specific estimates are posted, but no direct contrast, confidence interval for the contrast, or p-value is available. As a result, the comparative question cannot be answered from the posted primary results.

The sign convention for the change estimates is not stated. Although the endpoint description identifies change from enrollment to 10 weeks, the positive arm-level values cannot be labeled as increases or decreases without knowing how change was calculated. The record also does not explain how daily ratings were combined, how many observations contributed, or how repeated measurements were analyzed.

Additional statistical details are absent: the analysis population, missing-data methods, model specification, covariate adjustment, and prespecified analysis plan are not reported in the registry record. The method of randomization and allocation concealment are also not described. The trial is listed as open-label, but the record does not describe how awareness of assignment was addressed in outcome assessment or intervention delivery.

The registry record lists Worst Pain Intensity Score as a secondary outcome without a posted result. It also describes an interest in whether learned behaviors continued after the intervention stopped, but does not report results for that question. Safety reporting is limited to counts, without event terms or further collection and follow-up details; death counts are not reported.

These limitations concern the information available in the registry record. They do not establish that unreported analyses or procedures were absent from the full study, but they do limit independent evaluation of the posted findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Improving Cancer Pain Management Through Self-Care — NCT00708019.
• Registry record last updated 2016-05-05; status last verified 2016-04.
• Results first posted 2016-05-05.
• 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

NCT00708019, titled Improving Cancer Pain Management Through Self-Care, is recorded as a completed randomized, open-label, parallel-group study sponsored by the University of California, San Francisco. Enrollment was 185, with 92 participants in Low Dose and 93 in High Dose. The intervention was the PRO-SELF PLUS Pain Management Program, with 8.0 hours of nurse contact over 10 weeks for Low Dose and 12.3 hours for High Dose.

The primary outcome was Average Pain Intensity Score on a 0-to-10 scale, assessed daily, with change from enrollment to 10 weeks described as the comparison of interest. The record posts arm-level estimates and 95% confidence intervals, but no estimable two-arm comparison. The secondary outcome listed is Worst Pain Intensity Score, with no result posted. Statistical analysis details, missing-data handling, analysis populations, and results addressing continued use of learned behaviors are not reported in the registry record.