Bridging the Evidence-to-practice Gap: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bridging the Evidence-to-practice Gap (NCT03713515), a randomized phase 4 study. The primary outcome is Implementation Fidelity - Adherence: Screening.

2. Clinical Question

The study’s stated purpose is to evaluate practice facilitation as a strategy for accelerating translation of a systems-level adherence intervention into safety-net practices. The registry record also lists change in blood pressure control and change in medication adherence as secondary outcomes. It does not report results for these outcomes. The clinical question therefore concerns the delivery and implementation of care as well as clinical measures, but the posted record does not establish whether screening, blood pressure control, or medication adherence differed between conditions.

3. Trial Design

The registry identifies NCT03713515 as a completed Phase 4 study of hypertension care, sponsored by NYU Langone Health. It reports randomized allocation, a single masking designation, and a parallel model, with enrollment of 652 participants. The study began on 2020-12-01, and its primary completion date is 2024-05-30. These design labels do not, by themselves, describe who was masked, how randomization was carried out, or which entity was assigned to a condition; those details are not reported in the registry record.

The listed intervention is ALTA, categorized as behavioral. The arm descriptions focus on practice facilitation: one arm is supported by a practice facilitator, while usual care consists of standard hypertension management without practice facilitation at that time. The usual-care description additionally states that all practice sites begin in the usual-care control condition and will receive the intervention later, using a stepped wedge design. Because the registry also labels the model parallel, the record contains design descriptions that are not fully reconciled. The sequence, timing, and analysis implications of any stepped-wedge implementation are not reported in the registry record.

The stated primary outcome is implementation fidelity—adherence: screening. It is defined as the percentage of eligible participants who were screened, with a timeframe of up to Month 12. The study description says that clinical measures at 12 months are secondary outcomes, specifically change in blood pressure control and change in medication adherence. Although the registry lists five outcome measures, it does not give results for the primary or secondary outcomes in this record. It also does not report a comparison estimate, confidence interval, or analysis population for the primary outcome. The study’s completed status indicates its registry status, but does not substitute for posted outcome findings.

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: Clinics were assigned to a Cohort which specified the timing of the Usual Care, Pre-Imp, and Intervention Periods. Participants were enrolled only during the Intervention Periods. No participants dropped out during the course of the study.

Usual Care: Months 0-3

Usual Care: Months 1-4

Usual Care: Months 2-4

Usual Care: Months 2-5

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.

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Implementation Fidelity - Adherence: Screening, measured over Up to Month 12.

The primary endpoint is implementation fidelity—adherence: screening. It measures the percentage of eligible participants who were screened, through Month 12. In general, an implementation-fidelity measure describes whether an intervention or care process is delivered as intended. Screening is a process measure: it focuses on whether eligible participants received a specified step of care, rather than directly measuring a clinical state such as blood pressure control.

That distinction suits the stated study aim of evaluating practice facilitation as a way to accelerate translation of an intervention into safety-net practices. In general, a process measure can help assess whether an implementation strategy is associated with delivery of the intended activity. It does not, on its own, establish that a clinical outcome changed, explain why screening occurred or did not occur, or demonstrate that any change was caused by practice facilitation.

The registry’s definition depends on identifying who was eligible and who was screened. Eligibility criteria, the precise screening procedure, the way screening status was ascertained, and the denominator rules for participants with incomplete information are not reported in the registry record. Most importantly, the record does not report the number or percentage screened in either condition, nor a between-condition estimate. The endpoint is therefore described, but its observed value and comparative result cannot be interpreted from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes randomized allocation, single masking, and a parallel model. In general, randomization is intended to reduce systematic differences between assigned groups by allocating participants or other units through a chance process. Its usefulness for causal comparison depends on how allocation was implemented, what unit was randomized, and whether the analysis respects that unit. The randomization unit, sequence generation, concealment procedures, and analysis approach are not reported in the registry record. The single-masking label does not identify who was masked or what information was concealed.

A parallel design generally compares conditions assigned over the same study period. The registry’s usual-care description, however, says all practice sites begin in usual care and later receive the intervention using a stepped wedge design. A stepped-wedge design generally introduces an intervention to sites in sequence, so sites may contribute observations during different conditions or periods. General statistical analyses for such designs may need to account for time and for clustering of observations within sites. The registry record also labels the model parallel, and does not explain how these descriptions fit together. The actual sequence, assignment unit, number of sites, timing of transitions, and planned model are not reported in the registry record; no particular stepped-wedge analysis can therefore be assumed.

The primary measure is binary at the participant level in the sense that a participant either meets the screening definition or does not, while the endpoint is expressed as a percentage among eligible participants. In general, a binary outcome can be summarized as a count and a proportion. A comparison may report a difference in proportions, a ratio of proportions, or another model-based contrast. The choice affects interpretation and can depend on the design and analysis plan. No primary-outcome counts, percentages, or comparative estimates are reported in the registry record, so none of these contrasts can be interpreted for this study.

For clustered or sequentially implemented studies, observations from participants at the same practice may be more alike than observations from different practices. General methods can account for this dependence through cluster-level analyses or models that represent clustering. Ignoring dependence may make uncertainty appear smaller than it is. If outcome patterns vary over calendar time, general methods may also account for period effects. These are statistical considerations, not claims about the analysis used in this trial: the analysis plan, clustering adjustments, period adjustments, and handling of repeated observations are not reported in the registry record.

In general, a confidence interval communicates precision as well as the range of effect values compatible with the data under the model. A narrow interval indicates greater precision than a wide interval, while both the estimate and interval are needed to understand the result. A p-value, when reported, addresses compatibility with a specified null hypothesis under assumptions; it does not describe the size or practical importance of an effect. The registry record posts no primary-outcome estimate, confidence interval, or p-value. Statistical significance and precision therefore cannot be assessed for the primary comparison.

The registry describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. Such illustrations are hypothetical planning calculations, not the trial’s original design justification and not observed power. The record does not report the trial’s own sample-size justification. Since the primary comparative result and observed effect are not reported in this record, the basis and numerical implications of any effect-based planning illustration cannot be independently interpreted from this record alone.

General power calculations concern the probability that a specified analysis would detect an effect of a chosen size under stated assumptions. They are not a measure of the probability that a finding is true, and they do not establish whether a completed study found an effect. Planning illustrations should not be confused with observed power, which is not a substitute for examining estimates and confidence intervals. The registry’s own description labels its calculations as planning illustrations, rather than the trial’s design calculations. No trial-specific sample-size rationale, target effect, or interim-analysis plan is reported in the registry record.

The registry lists five outcome measures and zero analyses. It does not describe a statistical analysis plan, outcome hierarchy beyond identifying the primary measure, model specification, covariate adjustment, or multiplicity procedure. It also does not report missing-data methods, sensitivity analyses, or the population included in any analysis. These details matter because the interpretation of a proportion can depend on the eligible denominator and on how unavailable screening status is handled. The record does not establish whether all enrolled participants were eligible for the primary endpoint or whether all had outcome data.

In general, over-dispersion occurs when observed variability exceeds what a chosen statistical model assumes. It can lead to understated uncertainty if not addressed. The registry record does not report a dispersion estimate or model-based analysis for the primary endpoint, so over-dispersion cannot be assessed for this trial. No model should be inferred from the fact that the endpoint is a participant count or percentage. The available record defines the measure, but not the statistical method used to analyze it.

10. Exact Estimates for Each Arm

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

R code and output

arm    <- c("Eligible Participants")
n      <- c(3103)
events <- c(1649)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Eligible Participants  3103  1649  53.1  51.4  54.9  51.4  54.9  51.4  54.9

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies implementation fidelity—adherence: screening as the primary outcome and lists change in blood pressure control and change in medication adherence as secondary outcomes. It reports five outcome measures in total, but does not provide the full outcome hierarchy or a multiplicity procedure. In general, testing multiple outcomes can increase the chance of at least one apparently notable result if no adjustment or prespecified interpretation plan is used. Whether and how that issue was addressed is not reported in the registry record.

The record lists zero analyses and does not post a comparative analysis for the primary outcome. It also does not report analysis results for the secondary outcomes. Thus, multiplicity cannot be evaluated by reviewing the reported estimates or tests, and no conclusion about adjustment should be inferred from the outcome labels alone.

Missing-data methods and analysis populations are not reported in the registry record. The primary endpoint is defined as a percentage of eligible participants who were screened, but the record does not explain how eligibility was determined for analysis, how missing screening status was treated, or whether participants with incomplete follow-up were included. It does not identify an intention-to-treat, per-protocol, or other analysis population. In general, missing outcome data can affect both the estimated proportion and its uncertainty, particularly if data availability differs across groups or relates to screening. Those possibilities cannot be assessed without the underlying data and analysis description.

The record’s skipped primary comparison leaves the central statistical question unanswered in the posted results. It does not establish that missingness or multiplicity caused the absence of an analysis. Reasons for the skipped comparison, the availability of participant-level data, and any additional analysis outside the registry are not reported in the registry record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: blood pressure related hospitalization (7.7%).

The adverse-event record lists all enrolled participants as the group at risk: 652 participants. It reports 50 participants with serious adverse events, zero with other adverse events, and zero deaths. These are the registry’s posted safety counts. They are not separated by practice-facilitation and usual-care conditions in the record, so they do not provide a randomized comparison of safety between those conditions.

The most frequently listed serious-event term is blood pressure related hospitalization, at 7.7%. That figure is reported as a term frequency; the record does not describe its calculation or give further event-level detail. It should not be read as an estimate of a difference between study arms. Nor does a zero count for other adverse events imply that no non-serious events occurred outside the registry’s recorded category or reporting scope; the meaning and collection rules for those entries are not reported in the registry record.

In general, adverse-event counts describe events recorded under the study’s reporting definitions. Their interpretation depends on the observation period, ascertainment procedures, attribution rules, and whether counts refer to participants or events. Those details are not reported in the registry record. The safety figures therefore describe what the registry posts, but do not establish whether the intervention caused an event or how event risk compares between conditions.

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

The registry record establishes that a completed randomized Phase 4 study evaluated practice facilitation in the context of a hypertension intervention intended for safety-net practices. It identifies screening fidelity through Month 12 as the primary outcome and describes blood pressure control and medication adherence as secondary outcomes. These details clarify the study question and the outcomes selected to address it.

The record does not report a primary-outcome result or an analysis comparing conditions. It also does not report secondary-outcome findings. As a result, the posted information cannot show whether screening differed between practice facilitation and usual care, how large any difference might have been, or how precisely it was estimated. The same limitation applies to change in blood pressure control and change in medication adherence. Absence of posted results is not evidence that the conditions were equivalent, and it is not evidence that practice facilitation did or did not affect the outcomes.

In general, a process endpoint can inform whether a care activity was carried out, while clinical outcomes address patient measures. The study’s choice of screening fidelity as its primary outcome aligns with its stated implementation focus, but a process result alone would not answer every clinical question. Conversely, a clinical outcome comparison would not by itself explain whether an intervention was implemented as intended. Interpreting both types of outcomes requires their observed estimates and suitable uncertainty measures, neither of which is posted for these outcomes in the registry record.

The safety counts are also limited: the registry reports 50 serious adverse events among 652 participants at risk, zero other adverse events, and zero deaths, without a displayed comparison by condition. These counts cannot establish a causal safety difference. The record’s completion status, enrollment total, and stated aims provide context, but do not replace results. The central conclusion is therefore about the limits of the posted evidence: the study question is identifiable, while its comparative outcome answer is not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically notable because its stated goal concerns implementation: whether practice facilitation can support fidelity when translating an intervention into safety-net practices. Its primary endpoint is not a direct clinical measure, but a participant-level screening process summarized as a percentage of eligible participants. That choice makes the distinction between implementation outcomes and clinical outcomes important to interpretation.

The registry also exposes a design-description issue that matters for analysis. It labels the study randomized and parallel, while the usual-care arm description refers to sites beginning in usual care and later receiving the intervention through a stepped wedge design. General statistical methods can differ according to whether assignment occurs by participant or site, whether conditions change over time, and whether observations within a practice are correlated. Since the record does not reconcile those descriptions or report the analysis model, readers cannot determine which design features the analysis was intended to represent.

The registry identifies the primary endpoint but lists zero analyses and no primary comparison. That gap is consequential: a well-defined endpoint without an estimate and uncertainty measure cannot answer the comparative question. It also illustrates why trial status and enrollment do not, on their own, provide statistical evidence about effectiveness or implementation. The record’s descriptions of secondary clinical outcomes likewise do not establish their results.

Finally, the adverse-event counts are not presented by randomized condition, and the record does not describe the statistical analysis or missing-data approach. These reporting limits constrain both effect interpretation and reproducibility. The study matters statistically as an example of the need to connect a clearly specified implementation question with a transparent design description, a prespecified analysis, and posted comparative results.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most important limitation for interpreting this trial from the registry record is that the primary endpoint is described without a reported result or analysis. No screening count, percentage, between-condition estimate, confidence interval, or p-value is posted. The secondary outcomes—change in blood pressure control and change in medication adherence—also have no reported results. The registry therefore does not support an estimate of intervention effect or its precision.

The design description is not fully clear. The registry identifies a randomized parallel study, but the usual-care description refers to all practice sites starting in usual care and later receiving the intervention using a stepped wedge design. It does not report the randomization unit, site count, transition schedule, or how the design labels were reconciled. These omissions prevent a reader from assessing whether the analysis accounted for clustering or time, if relevant.

Other trial-specific details needed for interpretation are not reported in the registry record: participant eligibility criteria, the identity of the masked party, screening ascertainment, denominator rules, sample-size justification, analysis population, missing-data approach, outcome hierarchy beyond the named primary and secondary measures, multiplicity handling, and the primary analysis method. The registry lists five outcome measures but does not provide the results for them as a set.

The safety information is limited to an all-enrolled group, with no adverse-event comparison by condition and no further description of ascertainment or reporting rules. The serious-event term blood pressure related hospitalization is listed at 7.7%, but contextual details for interpreting that frequency are not reported. These limitations are specific to the information available in the registry record and do not establish whether additional analyses or reporting exist elsewhere.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Bridging the Evidence-to-practice Gap — NCT03713515.
• Registry record last updated 2026-06-10; status last verified 2026-06.
• Results first posted 2026-06-10.
• 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.

19. Record Summary

NCT03713515 is a completed Phase 4 randomized study sponsored by NYU Langone Health, with enrollment of 652 participants and a focus on hypertension care in safety-net practices. The registry labels the model parallel and masking single. The usual-care description also refers to a stepped wedge design, a distinction the record does not reconcile.

The primary outcome is implementation fidelity—adherence: screening, defined as the percentage of eligible participants screened through Month 12. Secondary outcomes are change in blood pressure control and change in medication adherence. The registry lists five outcome measures and zero analyses; it does not report a comparative primary-outcome result or secondary-outcome findings. The listed safety figures are 50 participants with serious adverse events, zero with other adverse events, and zero deaths among 652 at risk. A serious-event term, blood pressure related hospitalization, is listed at 7.7%. These record details describe the study and posted counts, but do not provide comparative outcome estimates.