Integrated Care for Patients With High Risk Substance Use and Psychiatric Disorder With Chronic Direct Acting Antiviral Treatment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Integrated Care for Patients With High Risk Substance Use and Psychiatric Disorder With Chronic Direct Acting Antiviral Treatment (NCT02648022), a randomized na study. The primary outcome is Sustained Viral Response (SVR).

2. Clinical Question

The clinical question concerns a care-support approach alongside antiviral treatment, rather than a comparison of antiviral drugs. The integrated-care intervention combined mental health support and case management; the registry does not separate the contributions of those components. The study also tracked adherence to prescribed therapy in medical records. Its secondary outcomes included treatment initiation and completion, and completion of the planned duration using an 80% cutoff. The posted primary result describes the proportion achieving sustained viral response in each group. The registry record does not report a separate population definition beyond the high-risk substance use and psychiatric disorder context, nor does it report the specific clinical criteria used to identify eligible patients.

3. Trial Design

The registry describes a randomized, parallel-group trial with no masking. It lists enrollment as 83 and status as completed. The record gives a start of 2012-01 and primary completion of 2013-01. The phase is listed as NA. The sponsor is the VA Office of Research and Development.

Participants were assigned to integrated care or usual care. The integrated-care arm received brief mental health interventions and case management in a collaborative treatment environment. Usual care was the standard hepatitis C care at each clinic. The registry says usual-care patients were evaluated by the clinic treatment team, usually consisting of clinical nursing staff, the treating physician, and a clinic psychiatrist or psychologist. It does not describe the randomization sequence, allocation concealment, or whether assignment was stratified by clinic or another factor; these details are not reported in the registry record.

The study addressed antiviral therapies initiated in 2011, according to the brief summary. The primary endpoint was sustained viral response, with a stated timeframe of up to 24 weeks. The endpoint description also says final SVR data consisted of viral tests conducted at 6 months after therapy ended. The relation between that description and the timeframe label is not further clarified in the registry record.

Group results are posted for the primary endpoint and for completion of planned treatment duration using an 80% cutoff. Treatment initiation and completion is listed as a secondary outcome, but its result is not reported in the registry record. The original sample-size justification and the trial's planned statistical analysis details are not reported in the registry 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.

Before assignment: 83 patients were consented but only 79 were randomized. 4 participants were withdrawn.

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 Sustained Viral Response (SVR), measured over up to 24 weeks.

The primary endpoint is the proportion of participants achieving sustained viral response, or SVR. The registry says adherence to prescribed therapy and SVR were tracked using medical records. It further notes that viral load at 4, 12-and 24-weeks during treatment initiation had been shown to predict final SVR, and describes final SVR data as viral tests conducted at 6 months after therapy termination. The endpoint timeframe is listed as up to 24 weeks.

SVR is used as a treatment outcome because it records a virologic result after antiviral therapy has ended, rather than only documenting that treatment was started or taken. In general, a binary endpoint such as SVR classifies each participant as having or not having the outcome, then reports the proportion with the outcome in each group. That makes the result directly interpretable as a group-level event proportion. The registry record does not report the laboratory threshold used to define SVR, how missing viral tests were classified, or additional endpoint adjudication rules.

The posted group values are 30.0 for Integrated Care and 12.8 for Usual Care, expressed as percentages of participants. These percentages describe the observed proportions in the trial groups; they do not alone establish how precisely the group difference has been estimated. Precision is assessed using the comparison estimate and its confidence interval.

7. Results Posted in the Registry

• Integrated Care: 30.0% (12/40) versus 12.8% (5/39) on control; risk difference 17.2 percentage points (95% CI -0.5 to 34.8), risk ratio 2.34 (0.91–6.02); unadjusted two-proportion z-test p = 0.063.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Percentage of Participants That Completed Planned Duration of Treatment Using a Cutoff of 80%

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Integrated Care: 77.5% (31/40) versus 64.1% (25/39) on control; risk difference 13.4 percentage points (95% CI -6.5 to 33.2), risk ratio 1.21 (0.91–1.61); unadjusted two-proportion z-test p = 0.190.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Integrated Care and the control. The interval gives the range of effects that remain compatible with the data.

The available secondary-outcome results follow the same broad numerical direction as the primary result: the posted comparison for planned treatment duration is higher in Integrated Care. That alignment can be viewed as a consistent direction across the outcomes with reported numerical comparisons, but it does not independently establish an effect. The secondary comparison is imprecise, and its confidence interval includes no difference.

The registry lists treatment initiation and completion as a secondary outcome, as well as completion of planned duration using an 80% cutoff. Numerical results for the initiation-and-completion outcome are not reported in the registry record. Consequently, the available record does not support a full assessment of whether all secondary outcomes tell a consistent story.

Secondary results generally carry less weight than a prespecified primary endpoint because they may involve additional opportunities to find an apparently notable result. When multiple outcomes or comparisons are examined, the chance of at least one result appearing unusual by chance can increase. Statistical approaches can account for this, but the multiplicity plan for this trial is not reported in the registry record. The posted secondary comparison is described as an unadjusted recalculation, and no multiplicity adjustment is reported.

The secondary findings can provide context about treatment completion, but should not be used to override the uncertainty in the primary comparison. Nor should an unreported outcome be treated as showing no difference: without its result and analysis details, its direction and precision cannot be assessed. Overall, the secondary record is incomplete, and the available result is best interpreted as supportive descriptive context rather than conclusive evidence.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percentage of Participants With Treatment Initiation and Completion
• Percentage of Participants That Completed Planned Duration of Treatment Using a Cutoff of 80%

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary: each participant either achieved SVR or did not, according to the registry's endpoint definition. For binary outcomes, common summaries include the event proportion in each group and a comparison between those proportions. The posted arm values are proportions expressed as percentages. Comparisons can then be reported on an absolute scale, such as a risk difference, or a relative scale, such as an odds ratio.

What does a risk difference describe?

A risk difference subtracts one group's event proportion from the other's. It is an absolute measure: it describes how far apart the proportions are, in the units of the outcome proportion. A risk difference of zero corresponds to equal proportions. The unadjusted recalculation for SVR is 0.172, with a confidence interval from -0.005 to 0.348. Because that interval includes zero, the posted summaries do not pin down whether the underlying difference is positive, zero, or slightly negative. The point estimate is not the only relevant number; its uncertainty matters to interpretation.

What does an odds ratio describe?

An odds ratio compares the odds of an event between groups. An odds ratio of one represents equal odds; values on either side represent different relative odds. The registry reports an odds ratio of 2.91 with a 95% confidence interval from 0.92 to 9.27 and p = 0.07. The interval includes one, which is the null value for this measure. Odds are not the same as probabilities, so an odds ratio should not be described as a direct increase in the percentage achieving SVR.

Why can the two comparison measures differ?

The risk difference and odds ratio use different scales and answer related but distinct questions. Their values cannot be compared as if they were the same quantity. In addition, the registry's reported odds ratio comes from an analysis described as linear regression, whereas the recalculated risk difference is an unadjusted calculation from the posted group summaries. The recalculation does not adjust for covariates or reproduce an individual-level model. The registry record does not report further model details, such as included covariates or model diagnostics.

What does a confidence interval contribute?

A confidence interval gives a range of estimates compatible with the data under the calculation's assumptions. It helps show precision: a narrow interval indicates greater precision than a wide interval. It does not mean there is a specified probability that the fixed true effect lies within the particular interval. For this trial, the SVR intervals extend across the relevant null values, so the point estimates should not be treated as precise evidence of a group difference.

Why do p-values need context?

A p-value describes how inconsistent the observed data are with a specified null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of a difference. The registry reports p = 0.07 for its odds-ratio analysis; the unadjusted risk-difference recalculation gives p = 0.063. The trial's own significance threshold and testing plan are not reported in the registry record. The sample-size planning illustration separately lists a two-sided significance level of 0.05, but that is an assumption of the planning illustration, not evidence of the trial's original analysis plan.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability is greater than a model assumes. If a model treats observations as more independent or less variable than they really are, standard errors and confidence intervals can be too optimistic. This issue can arise in clustered or otherwise dependent data. The registry record does not describe a clustering structure or report an over-dispersion assessment, so it is not possible to say whether it affected this analysis.

The reported and recalculated results should therefore be read as different statistical summaries of the trial data, with different methods and scales. Neither result supplies details absent from the registry, such as handling of missing endpoint data, adjustment variables, or the prespecified testing approach.

11. Confidence Intervals and Precision

Precision is reflected in the width of a confidence interval. A range that spans a broad set of plausible effects leaves more uncertainty about the size and direction of the comparison than a narrow range. For the primary SVR endpoint, the unadjusted recalculated risk difference is 0.172, with a confidence interval from -0.005 to 0.348. This interval includes zero, the value corresponding to no absolute difference between the proportions. It is compatible with a small negative difference and with positive differences of varying size.

The registry's reported odds ratio is 2.91, with a 95% confidence interval from 0.92 to 9.27. The interval covers the null odds ratio of one and extends across a wide range of relative effects. Thus, although the point estimate favors higher odds in Integrated Care, the uncertainty is considerable. The risk-difference interval and odds-ratio interval cannot be compared numerically because they use different scales.

For the secondary planned-duration outcome, the recalculated risk difference is 0.134, with a confidence interval from -0.065 to 0.333. That interval also includes zero. Its width signals uncertainty about the magnitude of the difference, not evidence that the groups were identical. The registry does not report confidence intervals for the arm percentages themselves.

Confidence intervals describe sampling uncertainty under the methods and assumptions used. They do not account automatically for every possible source of bias, including missing data, outcome misclassification, or incomplete reporting. The registry record does not give enough information to assess those issues fully. The broad intervals are an important reason to avoid treating the point estimates as precise estimates of an underlying effect.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are planning illustrations computed from the observed effect, not the trial's own design. The listed assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. The trial's original design assumptions are not reported in the registry record.

For each stated effect size, the 80% power column gives the number of participants per arm that the planning calculation estimates would be needed to have an 80% chance of detecting that effect under the listed assumptions, if the effect is present. The 90% power column gives the corresponding planning estimate for a higher chance of detection. These are design concepts, not guarantees that a future study will detect an effect.

The planning rows use 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. For the primary endpoint, the corresponding figures are 89 and 118 participants per arm for 100% of the observed effect; 146 and 195 for 75%; and 301 and 402 for 50%, for 80% and 90% power respectively. Smaller effects require more participants under these assumptions because they are harder to distinguish from random variation.

For the secondary planned-duration outcome, the corresponding figures are 180 and 240 participants per arm for 100% of the observed effect; 331 and 443 for 75%; and 767 and 1,027 for 50%, again for 80% and 90% power respectively. These estimates depend on the observed effect used as their starting point, which is uncertain in a trial with imprecise results. The planning figures are not observed power; they are illustrations of sample sizes under stated assumptions.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.128; treatment proportion p₁ = 0.300; average p̄ = 0.214.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5801 = 1.1370.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.5672 = 0.4774.
4. n = (1.1370 + 0.4774)² / (0.1718)² = 88.3, rounded up to 89 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.128205128205128                          # control proportion
p1 <- 0.3                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(2648022)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 89 (80% power), 118 (90% power)
 75% of observed effect: n per arm = 146 (80% power), 195 (90% power)
 50% of observed effect: n per arm = 301 (80% power), 402 (90% power)
power.prop.test: 88.3 
Simulated power at n = 89 per arm: 0.809 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry's own primary analysis reports an odds ratio of 2.91, with a 95% confidence interval from 0.92 to 9.27 and p = 0.07. It describes the method as linear regression. That is the sponsor-reported analysis recorded for the primary comparison.

The recalculation from the posted group summaries uses an unadjusted risk difference: 0.172, with a confidence interval from -0.005 to 0.348 and p = 0.063. The two results differ in measure and method. The registry result is an odds ratio from its reported analysis; the recalculation is an absolute difference based on the arm-level event summaries. They are not duplicate estimates and should not be expected to match numerically.

The registry record does not report further details of the regression model, such as whether it adjusted for covariates, how missing data were handled, or whether the analysis followed an intention-to-treat approach. The record does not flag a discrepancy between the reported analysis and the recalculation. Both summaries point toward a higher outcome in Integrated Care, while their confidence intervals include their respective null values. The registry analysis should be understood as the sponsor's own reported model, and the recalculation as a simple unadjusted complement rather than a replacement for it.

15. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when researchers assess more than one outcome, comparison, subgroup, or analysis. Repeated testing can increase the chance of an apparently unusual result even when there is no underlying effect. Prespecified plans and suitable adjustments can help control that issue, but the registry record does not report a multiplicity strategy or identify which outcomes, if any, were designated for formal confirmatory testing beyond naming the primary outcome.

The record lists two secondary outcomes, but numerical results are posted for only the planned-duration outcome. Results for treatment initiation and completion are not reported in the registry record. It also lists three outcome measures and one analysis, but does not provide enough detail to establish the complete set of analyses conducted. Without a complete outcome and analysis record, selective reporting cannot be assessed from the registry entry alone.

Missing-data methods and analysis populations are also not reported in the registry record. It is not clear how participants without a final viral test were handled, whether all randomized participants were included in the primary comparison, or whether any exclusions occurred after assignment. These details matter because incomplete outcome ascertainment can affect group proportions and the precision of a comparison. The posted arm denominators describe the analyzed endpoint summaries, but do not by themselves explain the status of every randomized participant.

The record does not report an intention-to-treat or per-protocol designation, imputation method, sensitivity analysis, or interim-analysis plan. These details should not be inferred from the randomized design or the reported analysis. Their absence limits the ability to evaluate how robust the estimates are to missing outcomes, alternative analysis populations, or repeated looks at the data. The confidence intervals describe uncertainty under the reported calculations, but they do not resolve these reporting gaps.

16. 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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: hospitalization (20.0%), death (7.7%).

The registry lists serious adverse events for both groups. In Integrated Care, serious events are recorded for 8 participants among 40 at risk; in Usual Care, they are recorded for 6 participants among 39 at risk. Other adverse events are listed as 0 among 40 at risk in Integrated Care and 0 among 39 at risk in Usual Care. These are descriptive registry counts, not a randomized comparison with a reported statistical analysis.

The most frequent serious-event terms listed are Hospitalization at 20.0% and Death at 7.7%. The registry does not provide the context needed to interpret those terms as arm-specific rates or to link them to the serious-event counts. Death fields for the groups are not reported in the registry record, so the term listing should not be used to infer a separate count of deaths by group.

The registry does not state whether events were judged related to the intervention, how event terms were coded, or the period over which adverse events were collected. These figures therefore describe what is recorded, but do not establish that integrated care caused or prevented an adverse event. Differences in the number of recorded events should be interpreted cautiously, particularly without event definitions, follow-up details, or a comparative safety analysis.

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

The posted primary outcome shows a higher observed SVR percentage in Integrated Care than in Usual Care. The recalculated risk difference and the registry's odds ratio both point in that direction. However, the confidence intervals include their respective null values and extend across a broad range of possible effects. The data therefore do not provide a precise estimate of the size of any group difference.

This result does not establish that integrated care caused improved SVR. Randomization supports a comparative design, but interpretation also depends on allocation procedures, follow-up, missing outcomes, and analysis choices. Several of those details are not reported in the registry record. The result also does not identify which part of the intervention package, if any, accounts for the observed pattern: brief mental health interventions and case management were delivered together.

The observed percentages are not a guarantee of what would occur in another clinical setting. The record describes a particular group of patients with high-risk substance use and psychiatric disorders receiving direct-acting antiviral treatment, but it does not give detailed eligibility criteria, clinic characteristics, or antiviral regimen information. Generalizing beyond the population and care context described in the registry should therefore be cautious.

The secondary planned-duration outcome offers context about treatment completion, but its imprecision and the absence of results for another listed secondary outcome limit the broader picture. The safety entries are descriptive and do not provide a causal comparison. Overall, the posted data support a cautious reading: the observed direction favors Integrated Care on the reported efficacy outcomes, while uncertainty and gaps in registry detail prevent a firm conclusion about the magnitude, reliability, or wider applicability of that pattern.

18. Why This Trial Matters Statistically

This trial is statistically informative because it compares a bundled care-support approach with usual care in a population described as having high-risk substance use and psychiatric disorders while receiving antiviral treatment. The primary endpoint is an event proportion with direct clinical interpretation, and the registry provides group-level values as well as a sponsor-reported model result. Those features allow readers to consider both an absolute comparison and an odds-based comparison.

It also illustrates why direction and certainty are separate questions. Both the posted arm proportions and the primary comparison estimates lean toward Integrated Care, yet the confidence intervals include the null values and remain broad. A point estimate alone can make an effect appear more settled than it is; uncertainty intervals show that plausible effects span a wide range.

The trial also underscores the distinction between a sponsor's reported analysis and an unadjusted recalculation from summary data. Each answers a related question, but they use different statistical scales and methods. The recalculation can aid interpretation of the posted proportions, while it cannot substitute for model details or participant-level analyses that are not in the registry record.

Finally, the record highlights the importance of complete reporting. The absence of details about missing outcomes, analysis populations, multiplicity, and the original sample-size plan constrains how strongly the findings can be interpreted. These are not merely technical omissions: they affect how readers judge precision, robustness, and the completeness of the evidence. The trial is therefore a useful example of reading an encouraging numerical pattern alongside substantial statistical uncertainty and reporting limitations.

19. 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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

The registry record gives limited information about trial conduct beyond randomization, parallel groups, and no masking. The randomization sequence and allocation concealment are not reported in the registry record. Masking was none, which means participants and care teams were not masked according to the record; the record does not clarify whether outcome assessment or analysis was masked.

The intervention combined brief mental health interventions and case management. The record does not report treatment fidelity, the amount or timing of contact, or which components participants received. Usual care could vary across clinics because it is described as the standard care at each clinic. The registry does not provide clinic-level details that would allow this variation to be assessed.

Details about the hepatitis C treatment regimens, eligibility criteria, baseline characteristics, and recruitment setting are not reported in the registry record. The endpoint description refers to SVR testing after therapy, but the laboratory threshold and handling of missing final viral tests are not given. The registry also does not explain the relationship between the up to 24 weeks timeframe label and its description of final viral testing at 6 months after therapy termination.

The primary comparison is imprecise, and the registry does not provide the original sample-size justification or full statistical analysis plan. It does not report the missing-data approach, analysis population, model covariates, or multiplicity plan. Numerical results are also absent for one listed secondary outcome. These limitations restrict assessment of possible bias, robustness, and completeness; they do not by themselves show that the reported results are invalid.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Integrated Care for Patients With High Risk Substance Use and Psychiatric Disorder With Chronic Direct Acting Antiviral Treatment — NCT02648022.
• Registry record last updated 2016-05-20; status last verified 2016-05.
• Results first posted 2016-05-20.
• 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.

23. Record Summary

This completed randomized, parallel-group trial compared integrated care with usual care for patients with chronic hepatitis C and high-risk substance use and psychiatric disorders receiving direct-acting antiviral treatment. Integrated care consisted of brief mental health interventions and case management; usual care was the standard clinic approach. The record lists enrollment as 83, no masking, and a start of 2012-01 with primary completion in 2013-01.

The primary outcome was sustained viral response. The posted percentages were 30.0 for Integrated Care and 12.8 for Usual Care. The registry-reported odds ratio was 2.91, with a 95% confidence interval from 0.92 to 9.27 and p = 0.07. The unadjusted risk-difference recalculation was 0.172, with a confidence interval from -0.005 to 0.348 and p = 0.063. Both comparisons are uncertain, with intervals including their null values.

The registry also posts a planned-treatment-duration outcome, but does not report results for treatment initiation and completion. Details on missing-data handling, analysis populations, multiplicity, and the original sample-size plan are not reported in the registry record.