Dissemination and Implementation of a Videoconference Antimicrobial Stewardship Team: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dissemination and Implementation of a Videoconference Antimicrobial Stewardship Team (NCT05319561), a randomized na study. The primary outcome is Days of Antibiotic Therapy Per 1000 Days of Care.

2. Clinical Question

The study concerns whether adding quarterly facility-level antibiotic-use reports to the VAST approach may support antimicrobial stewardship. The registry summary frames the report as a proposed way to enhance VAST efficacy. The posted primary results compare the mean rate of antibiotic therapy between VAST+ and VAST- sites; they do not report a formal estimated treatment effect, confidence interval, or hypothesis-test result.

The comparison concerns facility-level antibiotic use, not a patient-level clinical outcome. The primary measure summarizes antibiotic days relative to days of care, while secondary outcomes address broad-spectrum antibiotic days and new antibiotic prescriptions relative to days of care. The registry does not report patient-level outcomes or the clinical consequences of changes in facility prescribing.

3. Trial Design

The registry describes a randomized, parallel-group study with no masking. It lists the study status as completed and records enrollment as 8. The primary endpoint population is VA Medical Center sites only, and the record explicitly says participants were not enrolled. The relationship between the enrollment entry and the site-based endpoint is not further explained in the registry record.

The two groups are VAST+ and VAST-. Both are described as rural VA Medical Centers working with an infectious disease physician at another VA facility to discuss infectious diseases and antimicrobial use. The intervention listing names an Antibiotic Use Report. The brief summary describes the study aim as testing whether quarterly reports quantifying facility-level antibiotic use enhance the VAST approach. The registry does not provide more detail about report content or how the report was delivered.

The primary outcome covers a 15-month period following each VAST’s first meeting. The first 3 months were treated as a wash-in period; the analysis focused on the subsequent 12-month period. The posted primary group summaries are based on 4 sites in each arm. The registry record does not describe the method used to generate or conceal the random assignment, the assignment unit, or whether allocation was stratified.

The study began on 2022-03-28, with primary completion on 2025-03-31. The record lists phase as not applicable. It describes a wider project intended to expand the VAST approach to other VA Medical Centers, particularly rural facilities where infectious disease expertise may be less accessible. That context explains the implementation focus but does not establish the effect of the intervention beyond the posted site-level data.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: VA Medical Center sites only - participants were not enrolled

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.

Population: VA Medical Center sites only - participant baseline characteristics data were not collected

6. Primary Endpoint

The registry lists the primary outcome as Days of Antibiotic Therapy Per 1000 Days of Care, measured over The study period was 15 months following each the first meeting held by each VAST. The first 3 months were considered a wash-in period. Data analysis focused on the subsequent 12 month period..

The primary endpoint is Days of Antibiotic Therapy Per 1000 Days of Care, reported as days of antibiotic therapy per 1000 bed days. It is a continuous measure summarized by a mean and standard deviation for each group. The registry describes it as an overall rate of antibiotic use. A day on which any dose of an antimicrobial agent is administered counts as one day of therapy for that agent, regardless of the number of doses or dose strength.

Because it counts treatment days rather than doses, this measure captures both how many prescriptions are issued and how long they continue. The denominator, bed days of care, provides a facility-use basis for expressing the rate and supports comparisons across facilities. The registry notes that the measure accounts for dose adjustments, such as those for people receiving dialysis, and is used to benchmark use, follow prescribing trends, and assess stewardship efforts.

The analysis period was the 12 months after a 3-month wash-in within a 15-month period following each VAST’s first meeting. The primary measure is a facility-level utilization outcome, not an individual patient outcome. The registry does not report a confidence interval or adjusted model estimate for the group comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous, and the registry reports a mean and standard deviation for each group. These summaries describe the central level and variability of site-level antibiotic use during the analysis period. A mean is the arithmetic average of the observations represented in a group summary. A standard deviation describes how dispersed those observations are around the mean. Neither statistic, on its own, quantifies uncertainty in the difference between group means.

What would a confidence interval add?

General statistical explanation: A confidence interval for a group contrast expresses uncertainty about the estimated difference, under the assumptions of the analysis. Its width reflects both the variability in the data and the amount of information available. A narrow interval indicates greater precision than a wide interval, but interpretation also depends on the range of effects that would matter in context. The registry record does not report a confidence interval for this primary comparison, so its precision cannot be evaluated from an interval estimate.

Why does the site-level unit matter?

The endpoint population is VA Medical Center sites only, and the posted group summaries list 4 sites per arm. The record says participants were not enrolled. Thus, the outcome summaries concern facility-level rates rather than individual patient measurements. General statistical explanation: When treatment or implementation is organized at the facility level, observations from people or care episodes within a facility may be correlated. The facility, rather than each underlying encounter, may be the relevant independent unit for a comparison. The registry does not describe the randomization unit or the statistical model, so it is not possible to determine from the record whether dependence in the data was modeled or how the site-level comparison was estimated.

Why can over-dispersion matter?

General statistical explanation: Over-dispersion occurs when observed variability exceeds what a statistical model assumes. If a model understates variability, its uncertainty estimates may be too small and its inferential conclusions too confident. The posted standard deviations differ between the two groups, and the VAST- group’s standard deviation is larger. That descriptive difference alone does not establish over-dispersion; assessing it would require the model assumptions and underlying data, which are not reported in the registry record.

What does randomization contribute?

General statistical explanation: Random assignment is intended to reduce systematic differences between comparison groups at the point of allocation. It does not guarantee that groups will be closely balanced, especially when the number of units is limited. It also does not remove uncertainty, prevent implementation differences, or resolve missing outcome information. The record identifies the study as randomized, but the procedure, allocation concealment, and any balancing factors are not reported in the registry record. Accordingly, the design label alone is not enough to assess how randomization was carried out.

How should the planning illustration be read?

The registry describes a sample-size planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It specifies that the effect to detect is a stated fraction of the observed effect and that non-time-to-event results are expressed as participants per arm. Such values are planning illustrations, not observed trial results or observed power. The registry record does not provide the resulting planning counts in the registry record used. The observed primary summaries also concern sites, whereas the planning description refers to participants per arm, so the registry does not establish how that distinction was handled for this endpoint.

No recalculated primary comparison is reported. The registry entries identify the continuous endpoint and provide group means and standard deviations, but they do not include a confidence interval or hypothesis-test result. A new contrast or test should not be inferred from the descriptive summaries alone. In particular, an unadjusted calculation would not substitute for the sponsor’s analysis if one were posted; no sponsor analysis result is included in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("VAST+", "VAST -")
n   <- c(4, 4)
m   <- c(710, 744)
sp  <- c(158, 332)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  VAST+  4  710.000  158.000  458.587  961.413
CARM  VAST -  4  744.000  332.000  215.714  1272.286

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures: the primary measure of antibiotic therapy days per 1000 days of care and two secondary measures. The secondary outcomes concern broad-spectrum antibiotic therapy days and antibiotic starts per 1000 bed days. The record states that two secondary outcomes are posted, but the analysis count is 0 and no secondary outcome estimates are included in the registry record for this account.

Multiplicity arises when several outcomes or statistical tests are considered. General statistical explanation: As the number of tests increases, the chance of at least one apparently notable result can rise if each test is interpreted independently. Researchers may specify a primary outcome, use an adjustment, or interpret secondary findings as exploratory. The registry record does not report a multiplicity strategy, a hierarchy of outcomes, or a statistical analysis plan, so it is not possible to determine how multiple outcomes were intended to be handled.

The record does not report missing-data counts, reasons for missingness, imputation methods, or sensitivity analyses. This absence does not establish that outcome data were missing; it means the handling of missing data is not reported in the registry record. The record also does not describe exclusions or define analysis populations beyond stating that the primary endpoint population is VA Medical Center sites and participants were not enrolled.

Interim analyses, stopping rules, and outcome-specific analysis populations are not reported in the registry record. No assumptions about those procedures should be inferred from the completed status. The available summaries are descriptive, and the lack of posted inferential results limits assessment of uncertainty, multiplicity, and robustness.

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

The posted primary summaries show mean antibiotic therapy rates of 710 per 1000 bed days for VAST+ and 744 per 1000 bed days for VAST-. The standard deviations are 158 and 332, respectively, and each arm summary includes 4 sites. These figures describe the observed site-level data for the analysis period specified in the registry.

They do not, by themselves, show whether an underlying group difference is precise or statistically distinguishable from chance. No confidence interval, p-value, test statistic, adjusted estimate, or formal comparison is reported in the registry record. Nor does the record provide a threshold for a clinically or operationally important change. Descriptive numerical separation should not be presented as proof of an effect.

The outcome measures antibiotic utilization, not patient health, infection outcomes, adverse consequences of prescribing, or the appropriateness of individual prescriptions. Although the registry’s background describes antimicrobial resistance and stewardship goals, the primary endpoint is not a direct measure of resistance or clinical benefit. The primary outcome also does not show whether a change in use resulted from the report, the VAST discussions, or other features of implementation.

The registry’s stated question is whether quarterly facility-level reports may enhance VAST. The group descriptions and intervention listing provide context, but the precise distinction between the arms is not fully detailed. The posted results therefore support a limited descriptive account of the two groups, not a definitive attribution of any observed difference to the report. Generalization beyond the rural VA Medical Center sites represented in these summaries is also uncertain; the record does not provide information to assess how these sites compare with other settings.

Zero adverse-event counts are listed for both groups, including serious events and deaths. The record does not explain the scope or method of adverse-event ascertainment. Those entries should be read as registry entries, not as evidence that harms were comprehensively assessed or impossible.

13. Why This Trial Matters Statistically

This study illustrates an important distinction in implementation research: the outcome is measured at the facility level, while the intervention concerns how facilities connect with infectious disease expertise and receive information about antibiotic use. The unit represented in the primary summaries is therefore the VA Medical Center site, and the registry says participants were not enrolled. Keeping that unit clear is essential when interpreting both the descriptive statistics and any intended analysis.

The primary endpoint is a utilization rate designed to reflect overall antibiotic use while accounting for days of care. Its definition counts an antimicrobial day regardless of the number or strength of doses, and the registry notes that the measure captures both prescription volume and duration. This makes it relevant to stewardship monitoring, but it remains an aggregate measure: it cannot on its own identify which prescriptions were appropriate or how individual patients fared.

The record also highlights the importance of statistical precision. Group means and standard deviations are available, but no inferential comparison or uncertainty interval is posted. A numerical difference between observed means is not a complete account of evidence, especially when the data summarize a small number of sites and observed variation differs between groups. Readers need the estimate’s uncertainty and the analysis assumptions to judge how strongly the results support a comparison.

Finally, a randomized label does not replace reporting of the allocation procedure, analysis plan, missing-data handling, and implementation details. Those details help readers assess whether the intended contrast was achieved and whether the analysis reflects the design. The registry record’s emphasis on rural access to stewardship expertise makes the question practically relevant, while the limited posted statistical detail calls for a cautious interpretation of the observed facility-level summaries.

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 main limitation for statistical interpretation is the absence of a reported inferential comparison for the primary endpoint. The record provides group means, standard deviations, and site counts, but no confidence interval, p-value, test statistic, or adjusted estimate. Without these, uncertainty around the contrast cannot be assessed from the registry entry.

The summaries are based on 4 sites in each arm, and the endpoint population is site-level rather than participant-level. The record does not report the randomization unit, the allocation procedure, or whether the analysis accounted for possible dependence among observations from the same facility. It also does not provide site-level outcome values, which would help readers understand how the summaries reflect variation across facilities.

Descriptions of the intervention and comparator are similar: both involve rural VA Medical Centers working with an infectious disease physician at another VA for regular discussions. The registry names an Antibiotic Use Report and describes quarterly facility-level reporting as the study’s hypothesis, but does not fully detail the delivered report or operational differences between arms. This limits assessment of the exact contrast represented by the comparison.

The statistical analysis plan, multiplicity approach, missing-data procedures, and outcome-specific analysis populations are not reported in the registry record. The listed secondary outcomes do not have results in the registry record for this account, and no analyses are listed. The record also does not describe adverse-event ascertainment. These reporting gaps constrain evaluation of robustness and scope; they should not be treated as proof that procedures were absent or that data were missing.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Dissemination and Implementation of a Videoconference Antimicrobial Stewardship Team — NCT05319561.
• Registry record last updated 2026-05-01; status last verified 2026-04.
• Results first posted 2026-05-01.
• 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

The registry record describes a completed randomized, parallel-group study with no masking, comparing VAST+ and VAST- rural VA Medical Center sites. It lists enrollment as 8, while specifying that the primary endpoint population is VA Medical Center sites and that participants were not enrolled. The primary measure is mean days of antibiotic therapy per 1000 bed days during the 12-month analysis period after a 3-month wash-in.

The posted primary summaries are a mean of 710 with standard deviation 158 for VAST+ and a mean of 744 with standard deviation 332 for VAST-, with 4 sites in each group. The registry does not post a formal comparison or uncertainty interval. It lists two secondary outcomes but no analyses. The study began on 2022-03-28 and reached primary completion on 2025-03-31. The record identifies an Antibiotic Use Report and frames the research question around whether quarterly facility-level reports enhance the VAST approach.