Piloting "Positive Peer Journaling" a Journaling Practice to Support Recovery From Addiction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Piloting "Positive Peer Journaling" a Journaling Practice to Support Recovery From Addiction (NCT03903159), a na na study. The primary outcome is Treatment Retention.

2. Clinical Question

The study also aimed to observe whether PPJ was associated with improvement in hypothesized outcomes, including reduced recurrence of substance use, and to explore possible mediators such as mood and satisfaction with recovery. These are stated objectives, not evidence that changes were observed. Numerical results for those outcomes are not reported in the registry record.

3. Trial Design

This was a completed, single-group behavioral pilot sponsored by the University of Minnesota. The registry lists an enrollment of 15, a phase of NA, allocation of NA, and masking of NONE. The intervention arm is called the Treatment Group and received Positive Peer Journaling (PPJ). No separate control or comparison arm is listed, so the design does not support a randomized, between-group treatment contrast.

The registry lists the study start as 2019-01-29 and primary completion as 2019-09-30. Its stated main objective was development of PPJ and assessment of feasibility, acceptability, and the logistics of treatment delivery. A further objective was to observe whether PPJ was associated with changes in hypothesized outcomes. Treatment retention and reduced recurrence of substance use are identified as primary outcomes in the study summary; mood and satisfaction with recovery are given as examples of hypothesized mediators.

The registry lists four outcome measures and zero analyses. It does not report a statistical analysis plan, a sample-size justification, or numerical results for the retention endpoint. Information on recruitment procedures, eligibility criteria, intervention dose, adherence, and the handling of departures from treatment is not reported in the registry record. Consequently, the design can be described from the registered features, but details needed to assess implementation and analysis cannot be filled in from the 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.

Overall Study

Reasons for not completing this period:

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 Treatment Retention, measured over 8 weeks.

The primary endpoint is Treatment Retention, measured as the percentage of participants who either remained in treatment at the host facility until the end of the study or left the residential treatment facility on good terms during the study. The stated timeframe is 8 weeks. This definition combines continued treatment at the facility with a specified type of departure; it is not simply a measure of remaining in residence for the entire period.

Retention is relevant to the study’s stated objective of examining treatment engagement during recovery support. As a binary percentage endpoint, it describes the proportion meeting the registry’s retention definition rather than the duration of treatment or the quality of the journaling experience. General statistical interpretation: an endpoint definition needs to be applied consistently to each participant before the percentage can be estimated, and the number meeting the definition and the denominator are needed to understand that estimate.

The registry record does not report the observed percentage, participant count meeting the definition, or an uncertainty interval. It also does not report how cases with incomplete follow-up were classified. Thus the endpoint’s intended meaning is specified, but its observed value and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What the endpoint represents. Treatment Retention is recorded as a percentage of participants, with an endpoint definition that counts those retained until the end of the study or those who left the residential facility on good terms during the study. Statistically, this is a binary outcome: each participant either meets the stated definition or does not, once the rule is applied. The group percentage describes how often that defined outcome occurred in the analyzed participants. The registry record does not give the number meeting the definition, the denominator used for the percentage, or the resulting estimate.

What an estimate and its uncertainty mean. General statistical explanation: a sample percentage is an estimate of the proportion in the population represented by the study, subject to uncertainty because it is based on a finite set of participants. A confidence interval expresses uncertainty around an estimate under a specified statistical model and procedure. A narrow interval would indicate greater precision than a wide interval, but precision is not the same as freedom from bias. No confidence interval or other uncertainty measure for retention is reported in the registry record.

Why the design matters. The registered model is single group, with no listed comparator. The study can therefore describe outcomes among the participants who received PPJ if those results are reported, but cannot estimate a randomized contrast between PPJ and another condition. General statistical explanation: comparison groups help distinguish an intervention-associated outcome from changes that might occur over time or alongside usual care. Without such a group, observed changes cannot be attributed to PPJ on the basis of this design alone. The registry record does not report an alternative causal analysis.

How to read the planning assumptions. The registry record includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. It specifies participants per arm for non-time-to-event outcomes. These are planning assumptions, not a description of the completed single-group study’s allocation. The record does not report the observed effect or the numerical planning outputs in the registry record for this analysis. Such illustrations cannot be interpreted as observed power, actual enrollment requirements, or evidence that a design with two arms was used.

What over-dispersion means in general. General statistical explanation: in count or rate data, over-dispersion means that variability is greater than the model’s basic assumptions allow. If ignored, standard errors can be too small and uncertainty can appear less than it is. The registry identifies the primary endpoint as a percentage, not as a count or rate model, and does not report an over-dispersion assessment or a fitted model. No claim about such a model can be made for this study.

Multiplicity and model choice. General statistical explanation: when several outcomes or statistical tests are examined, the chance of finding at least one apparently notable result by chance can increase. A prespecified hierarchy or multiplicity adjustment can address some of this issue, but the choice depends on the analysis plan and research question. The registry lists four outcome measures and zero analyses. It does not report a multiplicity procedure, a primary-versus-secondary testing hierarchy, or the statistical methods used for any outcome. It would therefore be inappropriate to infer which tests were run or how their results were handled.

What is needed for reproducible interpretation. General statistical explanation: a complete account would ordinarily identify the analysis population, endpoint coding, handling of incomplete observations, estimator, uncertainty method, and any planned adjustment or sensitivity analysis. The registry record does not report these details for the retention outcome. Their absence means the registered description is insufficient to reproduce or independently evaluate a numerical estimate. This is a limitation of the information in the record, not proof that a particular analysis was or was not performed outside what the record lists.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Treatment Group")
n      <- c(15)
events <- c(11)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Treatment Group  15  11  73.3  44.9  92.2  48.0  89.1  47.6  89.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and zero analyses. It does not report a statistical analysis plan, a hierarchy of outcomes, or a method for addressing multiplicity. General statistical explanation: examining multiple outcomes can increase the chance that some result appears noteworthy by chance, so interpretation depends on which outcomes were designated primary and how testing was planned. The study summary identifies treatment retention and reduced recurrence of substance use as primary outcomes, but the record does not provide an inferential testing plan or numerical outcome results.

The registry does not report the analysis population for the retention endpoint. It does not say whether the percentage was intended to include all enrolled participants, only participants with an observed outcome, or another defined group. It also does not explain how missing follow-up, withdrawal, or incomplete endpoint information was handled. Because the outcome definition includes both remaining in treatment and leaving on good terms, the classification rules for each participant would be important to interpretation; those operational details are not reported in the registry record.

General statistical explanation: excluding participants with missing information can change an estimated percentage if their outcomes differ from those observed. Methods for handling missing data rely on assumptions, and those assumptions should be described rather than inferred. No missing-data method, sensitivity analysis, or analysis-population definition is reported. The absence of these details prevents assessment of whether incomplete observations could affect the retention estimate.

12. 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 serious-adverse-event entry lists the Treatment Group with 10 participants at risk, zero participants with a serious adverse event, zero participants with other adverse events, and zero deaths. These are the figures recorded for the safety entry. They are distinct from the study’s enrollment of 15, and the registry record does not explain why the risk count differs from enrollment.

These entries describe reported counts; they do not establish that no adverse events occurred outside the categories or reporting period captured by the registry. The record does not provide event-level descriptions, observation time for the safety figures, collection procedures, or an explanation of the at-risk population. The absence of listed serious events or deaths should therefore be read narrowly as the recorded counts, not as proof of an absence of risk.

General statistical explanation: safety counts are easier to interpret when the population under observation, follow-up duration, event definitions, and completeness of reporting are clear. These details are not reported in the registry record. The safety entry also does not permit comparison with another group because none is listed.

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

The record establishes that a completed pilot of Positive Peer Journaling was registered as a single-group study with an enrollment of 15. Its main stated focus was development of the intervention and assessment of feasibility, acceptability, and treatment-delivery logistics. Treatment retention was identified as a primary endpoint over 8 weeks, using a definition that includes continued treatment through study end or departure from the facility on good terms.

The record does not report the numerical retention result, the number meeting the endpoint, or uncertainty around an estimate. It also does not report numerical findings for recurrence of substance use, mood, or satisfaction with recovery. Therefore, the registered information does not show whether these outcomes changed or how precisely any change was estimated. Objectives and outcome definitions are not substitutes for outcome results.

The single-group design also limits what could be learned about cause and effect. Without a listed comparator, an outcome among participants receiving PPJ cannot be contrasted with an outcome under a different condition. Any observed change, if reported elsewhere, would not by itself isolate the contribution of journaling from other influences.

The registry’s safety entry records zero serious adverse events, zero other adverse events, and zero deaths among 10 participants at risk. The entry does not explain the at-risk count or describe the scope and completeness of safety monitoring, so those counts should be interpreted as registry-reported figures rather than a comprehensive safety conclusion.

Overall, the record describes a pilot intended to develop and assess delivery of PPJ, but does not provide the outcome values needed to judge retention or the hypothesized recovery outcomes. It cannot support a conclusion about intervention effectiveness or comparative benefit.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between a pilot’s stated aims and the evidence needed to evaluate an outcome. The registry describes development, feasibility, acceptability, and delivery logistics as central objectives, while also naming retention and recurrence of substance use as outcomes of interest. These goals are related, but they require different forms of evidence: information about whether an intervention can be delivered is not the same as a precise estimate of an outcome or a comparative estimate of an intervention effect.

The registered single-group design also makes the comparison question explicit. A within-group outcome can describe what occurred among participants receiving PPJ, but without a comparator it cannot identify what would have occurred under another condition. This matters when readers encounter an intervention described as being associated with an outcome: association, change over time, and causal effect are not interchangeable interpretations.

The registry specifies a primary retention definition and timeframe, which helps clarify what the outcome was intended to capture. Yet the numerical result, denominator, uncertainty, and missing-data handling are not reported. These details are essential for judging both the size and reliability of an estimate. The discrepancy between enrollment of 15 and the safety entry’s 10 participants at risk also illustrates why population definitions should be clear and outcome-specific.

For statistical readers, the record therefore highlights the value of complete reporting: endpoint counts and estimates, uncertainty, analysis populations, missing-data procedures, and the distinction between pilot objectives and confirmatory comparisons. In their absence, restraint in interpretation is not a judgment about the intervention; it is a recognition of what the registered evidence can and cannot establish.

15. 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.

Several limitations specific to this study follow from the registered information. First, the study is listed as single group, with no comparator arm. That design does not provide a like-for-like control comparison and cannot separate an intervention-associated outcome from other influences on participants’ recovery or treatment retention.

Second, although the primary endpoint and its 8-week timeframe are defined, the registry record does not report the retention percentage, the number of participants meeting the endpoint, or an uncertainty interval. Numerical results for the other stated outcomes are also not reported. This prevents assessment of magnitude, direction, and precision.

Third, enrollment is listed as 15, while the safety entry lists 10 participants at risk. The record does not explain the relationship between these counts. It also does not report the denominator used for the primary endpoint, the analysis population, or whether all enrolled participants had outcome data.

Fourth, endpoint classification and missing-data handling are not described. The retention definition includes both staying through study end and leaving on good terms, but the record does not give operational rules for classifying these circumstances or explain how incomplete follow-up was handled. The analysis plan, sample-size justification, multiplicity approach, and statistical methods are not reported in the registry record.

Finally, the registry lists zero analyses, which limits the statistical detail available in the record. These limitations concern the information and design documented there; they do not establish that unreported procedures or analyses were never conducted elsewhere.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Piloting "Positive Peer Journaling" a Journaling Practice to Support Recovery From Addiction — NCT03903159.
• Registry record last updated 2021-08-26; status last verified 2021-08.
• Results first posted 2021-08-26.
• 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.

19. Record Summary

NCT03903159 is a completed University of Minnesota single-group behavioral pilot of Positive Peer Journaling for addiction recovery in a rural Minnesota community. The registry lists enrollment of 15, allocation NA, masking NONE, a start date of 2019-01-29, and primary completion on 2019-09-30.

The study’s stated objectives include development of PPJ and assessment of feasibility, acceptability, and treatment-delivery logistics. Treatment Retention is the primary endpoint, defined as the percentage retained through the end of the study or leaving the residential facility on good terms during the 8 weeks.

The registry lists four outcome measures and zero analyses. Numerical results for retention and the other stated outcomes are not reported in the registry record. The safety entry lists 10 participants at risk, zero serious adverse events, zero other adverse events, and zero deaths.