Illness Management and Recovery for Veterans With Severe Mental Illness: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Illness Management and Recovery for Veterans With Severe Mental Illness (NCT00515671), a randomized na study. The primary outcome is Illness Management Ratings.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group trial with no masking listed in the registry. The registry reports total enrollment of 118 and identifies veterans with severe mental illness as the study population. Schizophrenia and schizo-affective disorder are listed conditions. The trial is marked completed, with a start date of 2008-01 and primary completion in 2012-04. Its phase is listed as NA.

The intervention was Illness Management and Recovery, a structured 9-month curriculum offered in small groups. The curriculum combines motivational, educational, and cognitive-behavioral techniques and incorporates several evidence-based practices related to education, medication adherence, social support, relapse prevention, and coping skills. The comparator was Problem Solving, described as an active control. It also met weekly in groups for 9 months, with discussion of current concerns and group support but without structured problem-solving tasks.

The primary outcome was consumer-rated illness self-management. Assessments are listed at baseline, 9 months, and 18 months, so the outcome schedule includes measurements during and after the group program. The registry also lists psychiatric symptoms measured by PANSS Total as a secondary outcome. It identifies two outcome measures and two analyses, but does not report a single primary-outcome comparison for the multiple listed time points.

Details including the randomization procedure, allocation concealment, recruitment setting, eligibility criteria, adherence to the assigned group condition, and the analysis population are not reported in the registry record. The record also does not report a detailed statistical analysis plan or the rationale used to choose the enrollment target.

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 Illness Management Ratings, measured over Baseline, 9 months, 18 months.

The primary endpoint is illness self-management measured with the consumer-rated Illness Management and Recovery Scale. The registry describes an overall score formed as the mean across all 15 items. Each item is rated on a 5-point behaviorally anchored scale, and the overall score ranges from 1 to 5. Higher scores indicate better self-management. The measure is reported in units on a scale, with the mean and standard deviation specified as the summary format.

This outcome is relevant to the intervention because IMR is designed to help people manage mental illness and pursue recovery-related goals. A consumer rating captures the participant’s view of their illness-management behaviors rather than relying only on a clinician rating. That perspective is part of what the scale is intended to assess; it does not, by itself, establish changes in symptoms or other clinical outcomes.

The registry lists baseline, 9-month, and 18-month assessments. Baseline can describe the starting measurement, while later assessments can describe ratings during or after the 9-month group program. However, the registry record does not report a single numerical contrast across those time points, or the method used to combine or compare repeated measurements. The PANSS Total is listed separately as a secondary outcome, not as the primary endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the design establish? Randomization assigns participants to study groups by chance, which is intended to make the groups comparable on average at the start of a trial. It does not guarantee that every measured or unmeasured characteristic will be balanced in a particular trial. The registry identifies this study as randomized and parallel-group, but details of the random sequence, allocation concealment, and implementation are not reported in the registry record. The record lists no masking. It does not specify which people, if any, were aware of the assigned condition beyond that designation.

What does the primary scale measure? The consumer-rated Illness Management and Recovery Scale is described as the mean across all 15 items, rated on a 5-point behaviorally anchored scale. Its stated range is 1 to 5, and higher scores indicate better self-management. A mean is a summary of the item ratings. The registry specifies a mean and standard deviation as the outcome format, but does not report the observed group means or standard deviations for the assessment times in this record.

How should a between-group estimate be understood? In general, a treatment-effect estimate compares outcomes between assigned groups. It answers a different question from whether either group changed from its own baseline. For a trial with repeated outcome measurements, an analysis may compare group ratings at a particular follow-up, compare changes from baseline, or model the pattern across assessment times. These approaches do not necessarily estimate the same quantity. The registry lists baseline, 9-month, and 18-month assessments but does not report which contrast or model was used. No particular repeated-measures method, covariate adjustment, or handling of baseline values should be inferred.

In general, a confidence interval describes a range of values compatible with the data and the assumptions of the statistical method. Its width conveys the precision of the estimate: a wider interval indicates less precision than a narrower interval. A p-value, when reported, assesses how compatible the data are with a specified null hypothesis under the analysis assumptions; it does not measure the size or practical importance of an effect. The registry record does not report confidence intervals or p-values for the primary comparison, so neither precision nor statistical evidence for a difference can be evaluated from the recorded information.

What is the role of standard deviation? In general, a standard deviation describes variation among individual measurements around a group mean. It is not the same as the uncertainty in the estimated mean or in a difference between group means. To assess the uncertainty of a treatment contrast, an analysis also needs to account for the amount of available information and its design and modeling assumptions. The record names standard deviation as the dispersion measure but does not provide the outcome values needed to interpret variability or calculate an effect estimate.

How should the planning illustrations be read? The stated planning approach uses a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It describes sample-size illustrations based on a stated fraction of the observed effect. These are planning illustrations, not observed power and not the trial’s own documented design justification. A sample-size estimate based on an observed effect is conditional on that effect estimate and the assumptions used; it cannot replace an outcome analysis or establish that the trial was adequately powered. The registry does not report the trial’s sample-size justification, and specific planning counts are not reported in the registry record.

Why can extra variability matter? In general, over-dispersion means that observed variation is greater than expected under a model’s assumptions. If a model fails to account for such variation, its uncertainty estimates can be too small and its statistical tests can be misleading. The registry does not report whether over-dispersion was assessed or relevant to the continuous illness-management outcome. No model details are available to determine how the outcome’s distribution or within-person repeated measurements were handled.

The available information therefore supports a description of the intended comparison, the scale, and the assessment schedule, but not a reconstruction of the statistical analysis. The analysis population, missing-data method, covariates, multiplicity procedure, and any interim analyses are not reported in the registry record. The record also does not report whether analyses followed assigned groups or another population definition.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is listed at baseline, 9 months, and 18 months, and the registry explicitly notes that it was not reduced to one comparison because it has several categories or time points. Multiple assessment times can create more than one possible contrast, such as a comparison at each follow-up or a comparison of change over the assessment schedule. If several contrasts are tested, the chance of at least one false-positive finding can increase unless the analysis plan addresses multiplicity. This is a general statistical concern, not a claim about what happened in this trial.

The registry record does not report a prespecified primary contrast, a multiplicity adjustment, a hierarchy of outcomes, or a strategy for selecting among time points. It lists PANSS Total as a secondary outcome, but does not describe how testing across outcomes was handled. Interim analyses and any stopping rules are not reported in the registry record.

Missing outcome measurements can also affect interpretation, especially when measurements are scheduled at different times. In general, an analysis may use assumptions about why data are missing, and different assumptions can produce different estimates. The record does not report how missing observations were handled, whether participants lost to follow-up differed from those with observed measurements, or how many participants contributed outcome data at each assessment.

The analysis population is also not reported in the registry record. It is therefore not possible to determine whether the results, if available, would describe all randomized participants, participants who attended groups, or another defined population. Without these details and the outcome results, the effects of missingness, multiplicity, and analysis-population choices cannot be assessed.

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.

The registry reports adverse-event risk sets of 60 participants in Arm 1 and 58 in Arm 2. In each arm, the recorded count affected by serious adverse events is 0, and the count affected by other adverse events is also 0. These are counts as recorded for the listed risk sets; they are not estimates of comparative risk, and no percentage or rate is reported.

A count of 0 means that no affected participants are recorded in that category in the registry entry. It should not be read as proof that no event occurred outside the reporting definitions or observation process. The record does not describe the safety observation period, event-collection procedures, attribution rules, or completeness of reporting. No serious adverse-event terms are listed.

Death counts are recorded as null for both arms. Null is not the same as a reported count of 0; death figures are not reported in the registry record. These sparse registry entries do not permit a detailed comparison of safety between the groups. They also do not describe event severity beyond the serious and other adverse-event categories or provide information about individual events.

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

The record establishes that a randomized, parallel-group study compared a structured Illness Management and Recovery program with an active Problem Solving group condition for veterans with severe mental illness. It identifies illness self-management as the primary outcome and records assessments at baseline, 9 months, and 18 months. It also identifies psychiatric symptoms measured by PANSS Total as a secondary outcome.

The record does not establish the size or direction of any difference in illness self-management. It does not report the numerical outcome results, a single comparison across the listed assessment times, confidence intervals, or p-values. It is therefore not possible to determine from the record whether ratings changed, whether the groups differed at follow-up, or how precise any difference was. The same limitation applies to the listed secondary outcome because its results are not reported in the registry record.

The study design also matters to the meaning of any eventual contrast. The comparator was an active group condition with weekly meetings for 9 months, rather than an absence of intervention or contact. A comparison between the groups would address the relative outcomes of these two conditions under the study’s implementation, not the effect of IMR relative to receiving no group support.

The recorded enrollment of 118 does not show how many participants contributed data at each assessment or whether the outcome analysis included everyone assigned to a group. The record does not report missing-data handling, the analysis population, or the detailed statistical plan. Those omissions limit judgments about precision and robustness as well as interpretation of any outcome contrast.

Thus, the registry information supports a clear account of the research question and measurement schedule, but not a conclusion about the trial’s primary findings. Missing numerical results should not be interpreted as evidence of no effect or as evidence of benefit. The record does not support a clinical recommendation.

13. Why This Trial Matters Statistically

Statistically, this trial is notable for comparing a structured recovery-oriented curriculum with an active group condition. The Problem Solving arm included weekly group meetings and group support, so the study question concerns the contrast between two forms of group programming. That distinction is important when interpreting the purpose of a randomized comparison: the estimate, if reported, would relate to the assigned conditions as implemented, rather than to IMR versus no contact.

The primary measure is a consumer-rated scale focused on illness self-management. Its content aligns with the stated focus of IMR on self-management and recovery-related goals. The assessment schedule includes baseline, 9 months, and 18 months, making the timing of the contrast important. A result at the end of the group program and a result at later follow-up would address different time-specific questions. The registry record does not specify a single contrast across these times.

The case also illustrates why an outcome label and a sample size are not enough to interpret a trial statistically. An estimate, its uncertainty, the analysis population, and the handling of repeated measurements and missing observations are all needed to judge what the data show. The registry records an enrollment of 118, but outcome estimates and key analysis details are not reported in the registry record.

Finally, planning illustrations based on an observed effect should be distinguished from design justification and from observed power. They can show how sample-size assumptions relate to a hypothetical target, but they do not establish the precision of the trial’s actual result. Without a reported primary contrast and its uncertainty, the statistical evidence from this study cannot be evaluated quantitatively.

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 central limitation for interpreting this trial from the registry record is the absence of a single reported primary-outcome comparison. Illness self-management was measured at baseline, 9 months, and 18 months, but the record does not give the group results at those times or an estimate comparing the randomized groups. The direction and magnitude of any difference, and its precision, are therefore unknown from the record.

The trial has an active group comparator, which makes the contrast specific to IMR relative to the described Problem Solving condition. The record does not report details about attendance, adherence, delivery fidelity, or exposure to the assigned programs. The IMR description identifies a structured curriculum, but the available arm description is incomplete, so the full implementation details cannot be assessed.

Important design and analysis information is also absent. Randomization procedures, allocation concealment, eligibility criteria, recruitment setting, baseline characteristics, analysis population, missing-data methods, and statistical model details are not reported in the registry record. The record does not state how multiple assessment times and outcomes were handled statistically. These omissions prevent assessment of whether results could be affected by differential follow-up, analytic choices, or selective emphasis among possible comparisons.

Safety information is limited to recorded counts in the serious and other adverse-event categories. The observation period and event-collection methods are not reported, and death counts are not reported in the registry record. The absence of outcome estimates and these design details means the record supports description of the study question, but not a full assessment of efficacy, precision, or robustness.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Illness Management and Recovery for Veterans With Severe Mental Illness — NCT00515671.
• Registry record last updated 2021-12-15; status last verified 2021-12.
• Results first posted 2014-10-10.
• 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

NCT00515671 is a completed randomized, unmasked, parallel-group trial titled Illness Management and Recovery for Veterans With Severe Mental Illness. The registry reports enrollment of 118, a start date of 2008-01, and primary completion in 2012-04. The listed conditions are schizophrenia and schizo-affective disorder.

The comparison was Illness Management and Recovery versus a Problem Solving active control, with both conditions delivered in groups for 9 months. The primary outcome was consumer-rated illness self-management, assessed at baseline, 9 months, and 18 months. PANSS Total was listed as a secondary outcome.

The record does not report a single primary-outcome comparison or numerical results for the outcomes. It also does not report the detailed analysis plan, missing-data approach, or analysis population. Adverse-event entries record 0 affected participants in the serious and other categories in both arms; death figures are not reported in the registry record.