Breaking Down Care Process and Patient-level Barriers to Arteriovenous Access Creation Prior to Hemodialysis Initiation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Breaking Down Care Process and Patient-level Barriers to Arteriovenous Access Creation Prior to Hemodialysis Initiation (NCT04032613), a na na study. The primary outcome is Mean Scores of a Questionnaire Evaluating Patient Confidence in Navigating Vascular Access Care Pre- to Post-program Implementation.

2. Clinical Question

3. Trial Design

This is a completed, single-group pilot study of the Vascular Access Navigation and Education Quality Improvement Program. The registry lists the allocation as NA and masking as NONE. It does not describe a randomized comparison. Participants in the program were not compared with a like-for-like control arm; instead, the principal question concerns patient confidence measured before and after participation.

The program was to be implemented in the Geisinger Danville, PA chronic kidney disease clinic. People choosing to participate in a research sub-study completed questionnaires intended to assess vascular access care knowledge and confidence before and after the quality improvement program. The registry lists University of North Carolina, Chapel Hill as the sponsor. The record gives the study start as 2019-07-30, primary completion as 2020-04-30, and status as COMPLETED.

The registry lists an enrollment of 46 and describes chronic kidney disease and chronic kidney disease requiring chronic dialysis as conditions of interest. It identifies the study as a pilot, while the phase is listed as NA. The intervention is categorized as OTHER rather than as a drug or device intervention.

The study design supports a within-participant pre/post question only for people with both evaluations. It cannot, by itself, separate a program-associated change from other changes over time, because the record describes no concurrent control group. The registry record does not report the recruitment process, eligibility criteria in detail, adherence to program activities, or the statistical plan. Those omissions limit assessment of how participants were selected and how the analysis was intended to address the design.

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:

Analysis population for the primary outcome, as defined in the registry: All Vascular Access QI program patient participants enrolled in the study who completed both the pre- and post-program evaluation questionnaires.

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 Mean Scores of a Questionnaire Evaluating Patient Confidence in Navigating Vascular Access Care Pre- to Post-program Implementation, measured over Pre- and post-intervention, a total of up to 7 months.

The primary endpoint is the mean score on a questionnaire evaluating patient confidence in navigating vascular access care before and after program implementation. It is defined for patient participants who completed both the pre-program and post-program evaluation questionnaires. The timeframe is pre- and post-intervention, up to 7 months.

Confidence was assessed with three team-developed questions, each contributing to a score on a scale from 1 to 10. Higher scores represent greater confidence in navigating the vascular access creation process. The registry describes the summary measure as a mean and the associated measure of spread as a standard deviation.

Confidence is relevant to the program's stated focus on patient-level barriers and navigation of vascular access care. As a patient-reported measure, it reflects participants' stated confidence rather than a clinical event or a direct measure of whether access was created. It therefore addresses a specific aspect of the program's rationale, not all possible effects on care or health.

The registry record does not report the pre-program mean, post-program mean, estimated change, standard deviation values, or a confidence interval for the change. It also does not report further details about how the three questions were combined into a score or whether the measure was validated. Without the posted outcome results, the magnitude and precision of any pre-to-post difference cannot be evaluated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a continuous outcome summarized with a mean and standard deviation. A continuous measure can take values along a scale rather than being limited to categories such as event versus no event. For this endpoint, the score is on a scale from 1 to 10, and higher values indicate greater confidence. A mean provides a measure of the average score in the analyzed group; a standard deviation describes the spread of individual scores around that mean.

Because confidence was assessed before and after the program, a natural general approach for this type of question is to examine within-participant changes among people with both measurements. This retains the connection between each participant's two scores. An analysis that treats the pre-program and post-program observations as independent groups would not use that pairing and could misrepresent the uncertainty. However, the registry record does not state which analysis was used, so no particular test or model can be attributed to the study.

A mean change and its uncertainty answer different questions. The estimated change describes the average direction and size of the observed shift in scores. A confidence interval describes statistical uncertainty around that estimate under the model's assumptions. A narrow interval generally indicates a more precise estimate, while a wide interval indicates less precision. Neither an estimate nor an interval establishes that the program caused a change in a single-group study. No numerical change estimate or confidence interval is reported in the registry record.

The record lists standard deviation as the dispersion measure. This is useful for describing variation in scores, but a standard deviation should not be confused with a standard error or a confidence interval. The standard deviation concerns variation among observed scores; the standard error concerns precision of an estimated quantity. Estimating uncertainty for a paired mean change requires information about the paired observations or their change scores, and the registry does not report those details.

Questionnaire scores also have measurement considerations. The three confidence questions were team-developed, according to the registry record. The record gives the score range and direction of interpretation, but does not report how individual question responses were combined, whether the questions were evaluated for reliability, or whether the score's measurement properties were assessed. These details would help readers judge how consistently and meaningfully the score captures confidence. They are not reported in the registry record.

Missing observations can affect a pre/post analysis. If some participants lack a post-program evaluation, the endpoint population defined by both completed questionnaires excludes them from the paired outcome calculation. If completion is related to confidence or other participant characteristics, the measured changes may differ from the changes that would have been observed in all program participants. This is a general concern, not a claim about what happened in this study. The registry does not report the number missing at each time point, reasons for missingness, or any imputation or sensitivity analysis.

The record lists four outcome measures and four analyses. When several outcomes or analyses are examined, the chance of at least one apparently unusual result can increase if each is interpreted without considering the set. General approaches include identifying a primary outcome in advance, defining a testing hierarchy, or adjusting inference for multiple comparisons. The registry record does not report whether these approaches were used, nor does it provide a statistical analysis plan.

The sample-size assumptions associated with the planning illustrations are described as a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. These are planning assumptions for illustrations, not a statement of the study's design or an account of its original sample-size justification. The trial itself is single-group, and the registry record does not report a sample-size justification or a planned target based on those assumptions. A sample-size illustration is not observed power and does not establish how likely the study was to detect an effect.

For general context, over-dispersion refers to variability greater than a model expects. It can make standard errors and confidence intervals too small if ignored. This issue is most often relevant to count or event models, whereas the primary outcome is a continuous questionnaire score. The registry record does not report a model or any assessment of over-dispersion, so it cannot be said to have arisen or been addressed in this analysis.

The registry lists no masking and a single-group model, with allocation recorded as NA. This design information does not specify the exact analysis method. The statistical test, covariate adjustments, treatment of repeated measures, assumptions checks, and any interim analyses are not reported in the registry record. Without those details and the outcome estimates, readers cannot independently reconstruct the primary analysis or assess its precision.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and four analyses, but the relationship between them is not reported in the registry record. The primary endpoint is identified as mean confidence before and after the program. The record does not describe the status of the other outcomes, whether analyses were planned in advance, or whether a multiplicity procedure was used. When several outcomes or tests are considered, interpreting each as if it were the only analysis can overstate the strength of evidence. Whether that concern was addressed in this study is not reported in the registry record.

The primary endpoint population includes patient participants who completed both pre-program and post-program questionnaires. This definition makes paired completion necessary for inclusion in the endpoint analysis. The registry does not report the number of participants with both evaluations, the amount of missing data at either time point, reasons for missingness, or whether participants with incomplete questionnaires differed from those included.

Missing-data methods are not reported in the registry record. It is therefore not possible to determine whether the analysis used complete pairs only, imputed missing scores, or conducted sensitivity analyses. These choices can affect both the estimate and its uncertainty, especially if the likelihood of completing follow-up is related to participants' outcomes.

The record does not report a statistical analysis plan, the exact analysis population for outcomes other than the primary endpoint, or how deviations from any planned analysis were handled. It also does not report an interim-analysis plan. These omissions do not establish that a procedure was absent; they mean its use cannot be assessed from the registry record.

11. 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 registry lists safety information for Vascular Access QI Program Patient Participants and Vascular Access QI Program Provider/Personnel Participants. For patient participants, the record lists 21 at risk for serious adverse events and 21 at risk for other adverse events; the affected counts are 0 for serious events and 0 for other events, and deaths are listed as 0. For provider/personnel participants, the record lists 25 at risk for serious adverse events and 25 at risk for other adverse events; the affected counts are 0 for serious events and 0 for other events, and deaths are listed as 0.

These are registry-reported counts, not rates calculated. The record does not provide event terms in the serious-event listing. Zero recorded affected participants does not establish that no event could occur, and it does not describe the intensity or completeness of safety monitoring. The registry record does not report detailed event definitions, follow-up by safety category, or information about events outside the listed categories.

The patient and provider/personnel entries are separate program-participant categories, not comparison arms for estimating a treatment effect. Their counts should be read as safety descriptions within the registry record, not as evidence from a controlled safety comparison.

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

This study addresses a practical question about patient confidence in navigating vascular access care around participation in a navigation and education program. Its primary measure is a questionnaire score collected before and after the program, with higher scores indicating greater confidence. The registry identifies the outcome and the population for its measurement, but it does not report the observed scores or the estimated change.

Without those results, the registry record does not establish whether mean confidence increased, decreased, or remained similar. It also does not establish the size or precision of any change. No conclusion about a statistically clear difference can be made without an estimate and its uncertainty, and no clinical interpretation of a change can be made without reported results and context for the score.

Even if a pre/post change were reported, the single-group design would describe change among measured participants rather than isolate the program's causal effect. Without a concurrent control group, other time-related influences cannot be distinguished from the program's contribution using this comparison alone. The record also does not report the number of participants completing both questionnaires, which limits understanding of how representative the endpoint population may be.

The safety record lists zero serious adverse events, zero other adverse events, and zero deaths in each of its participant categories. These figures are limited to the counts reported and do not demonstrate absence of risk. The registry does not provide the detail needed to evaluate event ascertainment or monitoring.

The results and design information therefore support a description of the study's intended question and recorded structure, but not a conclusion about efficacy, causation, or the size of any patient-reported change. The registry record does not report the primary outcome findings, missing-data handling, or the statistical analysis plan.

13. Why This Trial Matters Statistically

The study is statistically notable for asking a pre/post question in a single group while focusing on a patient-reported measure. The endpoint is confidence in navigating vascular access care, not a direct count of access procedures or a clinical outcome. Keeping that distinction clear helps align any interpretation with what the questionnaire actually measures.

The paired structure of the endpoint is important. Participants included in the primary outcome are those who completed both evaluations, so the relevant information is the relationship between each person's pre-program and post-program scores. The registry does not report the number with paired data or the resulting estimate. Those details are necessary to judge both the magnitude and precision of a change.

The study also illustrates why a pre/post difference and a causal effect are not interchangeable. A single-group design can describe change over time, but it does not provide a concurrent comparison that would help separate program effects from other influences. This limitation is central to the interpretation, independent of whether a future result is statistically precise.

For biostatistical interpretation, transparency about the analysis population, missing questionnaires, outcome construction, and handling of multiple analyses would be valuable. The record identifies four outcomes and four analyses but does not report their hierarchy or multiplicity approach. It also does not report the primary numerical results or a statistical analysis plan. Consequently, readers cannot assess whether the primary question was answered with a precise estimate or how the analysis treated incomplete observations.

The record is useful for identifying the design and outcome being studied, while its missing result and analysis details limit what can be learned about the observed data. That distinction matters: a completed registry entry is not, by itself, a report of the direction or strength of evidence for an outcome.

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 primary limitation for interpretation is that the registry record does not report numerical results for the primary confidence outcome. There is no reported pre-program mean, post-program mean, estimate of change, or uncertainty measure. The outcome's direction, size, and precision therefore cannot be evaluated.

The study has a single-group pre/post design, with no like-for-like control comparison. Any observed change would be descriptive of the measured participants over time and would not alone identify a causal effect of the program. The registry record does not describe other approaches intended to strengthen causal interpretation.

The primary outcome applies to participants who completed both questionnaires, but the number with paired responses is not reported. Nor are the missing-data amounts, reasons for noncompletion, or methods for handling missing observations. This makes it difficult to assess selection into the endpoint population.

The confidence measure uses three team-developed questions. The record states the score range and meaning of higher scores but does not report the questions' wording, scoring details, validation, or reliability. These omissions constrain interpretation of what a score difference represents.

The record lists four outcome measures and four analyses without describing their hierarchy, statistical methods, or multiplicity handling. It does not report the statistical analysis plan, covariate adjustments, assumptions checks, or interim analyses. Finally, safety entries provide affected counts but not event terms, definitions, or detailed monitoring information. These gaps limit independent assessment of both the outcome analysis and safety reporting.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Breaking Down Care Process and Patient-level Barriers to Arteriovenous Access Creation Prior to Hemodialysis Initiation — NCT04032613.
• Registry record last updated 2021-01-28; status last verified 2020-08.
• Results first posted 2020-12-17.
• 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 record describes a completed pilot study of the Vascular Access Navigation and Education Quality Improvement Program in a chronic kidney disease clinic in Geisinger Danville, PA. It lists an enrollment of 46, a single-group model, no masking, and allocation recorded as NA. The sponsor is University of North Carolina, Chapel Hill. The study start is listed as 2019-07-30 and primary completion as 2020-04-30.

The primary outcome is mean patient confidence in navigating vascular access care, assessed before and after program participation with three team-developed questions scored from 1 to 10. The endpoint population is patient participants who completed both evaluations, over a timeframe of up to 7 months. The registry record does not report the primary outcome results or the analysis method.

Safety entries list zero serious adverse events, zero other adverse events, and zero deaths in the patient and provider/personnel participant categories. The record lists four outcome measures and four analyses, but does not report the analysis plan, missing-data methods, or approach to multiplicity.