Visualizations to Improve Pain Communication Between Patients, Interpreters, and Providers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Visualizations to Improve Pain Communication Between Patients, Interpreters, and Providers (NCT04975789), a non-randomized na study. The primary outcome is Percentage of Eligible Patients Enrolled.

2. Clinical Question

3. Trial Design

The registry describes a completed, non-randomized, sequential study of the InfoViz pain communication tool. Masking is listed as none, and the allocation is listed as non-randomized. The registry also cautions that the study arms are not a like-for-like control comparison. The meaning and operational details of the sequential model, including how participants moved through the study groups, are not reported in the registry record.

The Usual Care Control group is described as receiving standard of care. In the InfoViz Intervention group, trained interpreters use the visualization tool before and during the clinical encounter. The intended focus is communication about pain severity, location, and quality among patients with limited English proficiency, interpreters, and providers. The record does not describe additional intervention procedures or details of how standard care was delivered.

The study start date is 2021-10-07, and the primary completion date is 2023-01-06. Its status is completed. The registry lists enrollment as 61, while the brief summary says 40 participants will be enrolled and describes participation as lasting up to 4 weeks. These are separate statements in the record; an explanation of their relationship is not reported in the registry record. The phase is listed as NA.

The primary outcome is the percentage of eligible patients enrolled, framed as a recruitment-feasibility measure. The registry lists 11 outcome measures and 0 analyses. It names communication satisfaction, pain relief, pain interference, and communication quality among the secondary outcomes. Results for these outcomes 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: Enrolled participants have an associated participant group, which includes the patient, the interpreter, and the provider.

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 Percentage of Eligible Patients Enrolled, measured over up to 1 day.

The primary endpoint is “Percentage of Eligible Patients Enrolled.” The registry describes it as a measure of recruitment feasibility: the percentage of eligible patients who enroll. This asks whether recruitment is feasible in the study setting, rather than whether InfoViz changes pain or communication outcomes.

Interpreting such a percentage requires knowing both how many eligible patients were identified and how many enrolled. The record does not report those underlying counts or an observed percentage. Although enrollment is listed as 61, that figure alone does not provide the number of eligible patients approached or the number who declined. It therefore cannot establish the recruitment percentage.

As general statistical context, a recruitment proportion can describe the yield of recruitment under the procedures used. Its precision depends on the amount of information contributing to the estimate, and uncertainty is commonly conveyed with a confidence interval. A confidence interval describes a range of values reasonably compatible with the observed data under the method’s assumptions; it does not resolve limitations in the underlying data or study design.

The endpoint is relevant to a pilot study because recruitment feasibility can inform whether and how a larger study might be organized. However, the registry record does not report a recruitment threshold, a rationale for any threshold, or an estimate with uncertainty. No conclusion about recruitment success can be drawn from the endpoint description alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a non-randomized allocation and a sequential model. It lists no masking. These are design characteristics, not descriptions of a statistical test. The record does not report the sequence procedures, the planned comparison method, adjustment variables, or a statistical analysis plan. The registry also cautions that the arms are not a like-for-like control comparison, an important qualification when interpreting any contrast between them.

General statistical context: Random allocation is one way to make comparison groups similar on average with respect to measured and unmeasured characteristics. In a non-randomized study, that balance is not guaranteed by the allocation process. Differences in patient characteristics, clinical circumstances, recruitment, or timing could therefore contribute to a group contrast. These are general issues for non-randomized comparisons, not claims that any specific imbalance occurred in this study. The registry record does not report whether such factors were measured or adjusted for.

The primary endpoint is a percentage based on eligible patients who enroll. For that quantity to be estimated, the numerator and denominator must be defined and observed. The endpoint description identifies the concept, but the registry record does not give the eligible-patient count, enrollment numerator for the measure, observed percentage, or an interval estimate. The enrollment field is not a substitute for the eligible-patient denominator. Without those details, neither the recruitment rate nor its precision can be reconstructed.

General statistical context: A confidence interval communicates sampling uncertainty around an estimate. A narrow interval indicates greater precision under the method’s assumptions, while a wide interval indicates less precision. It does not account automatically for selection bias, measurement problems, or a mismatch between the study population and a broader target population. No confidence interval for the recruitment endpoint or other outcomes is reported in the registry record.

For outcomes recorded as counts or proportions, interpretation depends on clear outcome definitions and consistent observation. The record gives names for several secondary outcomes, including satisfaction with communication, pain relief on a 5 Point Verbal Rating Scale, response to a pain interference question, and quality of communication. It does not report the analysis scale, summary estimates, or analytic approach for these outcomes. The registry lists 11 outcome measures overall, but the full outcome-level analysis details are not reported in the registry record.

General statistical context: Over-dispersion occurs when count data vary more than a chosen statistical model expects. If present and ignored, uncertainty estimates can be too small. A suitable approach depends on how counts were collected and on the data’s distribution. The registry record does not identify a count model, report evidence of over-dispersion, or describe an analysis for count outcomes. This concept is relevant only as general background; it is not evidence that over-dispersion arose in this study.

The record lists a planning-illustration convention: two-sided significance level 0.05, equal allocation between arms, a normal approximation, and effects defined as stated fractions of the observed effect. It also distinguishes participant-per-arm planning for non-time-to-event outcomes from total-event planning for time-to-event outcomes. These assumptions describe planning illustrations, not the study’s own design or a reported statistical analysis plan. Numerical illustration outputs and the effect estimates on which they would depend are not reported in the registry record. They should not be interpreted as observed power or as evidence that the study was designed to detect a particular effect.

General statistical context: A significance level is a decision threshold used in some hypothesis-testing procedures; it is not the probability that a finding is true. A normal approximation uses a mathematical distribution to estimate uncertainty or plan sample size under stated conditions. Equal allocation is a planning assumption about distributing participants between groups. Each assumption is meaningful only in relation to the calculation being made. Here, the listed conventions do not establish that those methods were used for the study’s outcome analyses.

The registry lists 0 analyses, so the record does not provide estimates, test statistics, confidence intervals, or model specifications for the outcomes. In their absence, statistical interpretation should remain at the level of the stated measures and study design. No recalculated effect is available from the registry entries described in the registry record.

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("Usual Care", "InfoViz")
n      <- c(18, 18)
events <- c(18, 18)
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  Usual Care  18  18  100.0  81.5  100.0  82.4  100.0  82.4  99.9
ARM  InfoViz  18  18  100.0  81.5  100.0  82.4  100.0  82.4  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures and identifies percentage of eligible patients enrolled as the primary outcome. It names four secondary outcomes: participant satisfaction with communication, participant pain relief measured using a 5 Point Verbal Rating Scale, participant response to a pain interference question, and quality of communication. The analysis details for the other outcome measures are not reported in the registry record.

When a study assesses multiple outcomes, multiplicity is a general statistical concern: conducting many tests can increase the chance of at least one apparently unusual result even when no underlying effect exists. Analysts may specify a primary outcome, adjust for multiple comparisons, or use other prespecified interpretive strategies. Whether any such strategy was planned or used is not reported in the registry record. The planning-illustration significance level does not establish how outcome testing was handled.

The registry lists 0 analyses. It does not report missing-data frequency, reasons for missingness, methods for handling missing observations, or sensitivity analyses. The analysis populations, including which participants contributed to each outcome, are also not reported in the registry record. These omissions prevent assessment of whether results might depend on exclusions, incomplete assessments, or different denominators across outcomes. They do not establish that data were missing; they mean the record does not describe missing-data handling.

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

The registry record establishes that the study was completed and describes its purpose: to pilot test an InfoViz tool intended to facilitate pain communication among patients with limited English proficiency, interpreters, and providers. It also identifies recruitment feasibility, measured as the percentage of eligible patients who enroll, as the primary outcome. These registry entries describe the study question and its intended measures, not an observed result.

The record does not report the observed percentage enrolled, outcome estimates, uncertainty intervals, or analyses. Therefore, it does not establish how feasible recruitment was, whether communication improved, or whether participants reported different pain relief or pain interference. The listed secondary outcomes are planned or identified measures; their presence is not evidence of a benefit or an effect.

The non-randomized, sequential design and the registry’s explicit caution that the arms are not a like-for-like control comparison also limit causal interpretation. Even if group results were available, a contrast could reflect differences between groups or other factors as well as the intervention. The registry record does not report analysis details that would clarify this issue.

In general, a pilot study can provide information about feasibility and measurement procedures, but a conclusion about a particular outcome requires reported data and an appropriate analysis. The record’s completed status alone does not supply that evidence. The findings and conclusions of this trial cannot be inferred from the intervention description, the endpoint title, or the enrollment field.

13. Why This Trial Matters Statistically

This study is statistically notable for distinguishing a feasibility question from an outcome-effect question. Its primary measure is the percentage of eligible patients who enroll. That measure concerns recruitment, while the intended intervention addresses communication about pain. Keeping those questions separate prevents a recruitment count from being mistaken for evidence about communication quality or pain outcomes.

The registry also makes an important design qualification explicit: allocation is non-randomized, the model is sequential, and the arms are not a like-for-like control comparison. Such information is essential for framing group comparisons. It cautions readers not to interpret a difference between groups as attributable to InfoViz without considering how allocation and other factors may have shaped the groups.

The listed outcomes span communication satisfaction, pain relief, pain interference, and communication quality. That range makes clear why outcome definitions, analysis plans, and multiplicity handling matter. When several outcomes are examined, readers need to know which question was primary and how other results were interpreted. The registry identifies a primary outcome but does not report analyses or a multiplicity strategy.

Finally, the record illustrates the difference between a completed study registration and a results record that supports statistical conclusions. It lists enrollment and outcome descriptions, but not the eligible-patient denominator or outcome analyses. A transparent account of estimates, uncertainty, missing data, and analysis populations would be needed to evaluate the study’s quantitative findings.

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 trial-specific limitation for interpretation is the non-randomized, sequential design. The registry itself cautions that the arms are not a like-for-like control comparison. As a result, the design description does not support treating a simple difference between groups as an isolated intervention effect. Details about how sequence and allocation operated, and whether participant characteristics were accounted for, are not reported in the registry record.

The primary recruitment endpoint is defined, but its observed percentage and the eligible-patient denominator are not reported. The registry lists enrollment as 61, while the brief summary says 40 participants will be enrolled; the relationship between those statements is not explained in the registry record. Neither statement supplies the eligible-patient count needed to interpret the recruitment percentage.

Outcome analyses are not reported in the registry record, which lists 0 analyses. The record therefore does not provide numerical findings or their precision for the primary or secondary outcomes. It also does not report missing-data handling, analysis populations, or a multiplicity approach. These gaps prevent evaluation of how complete the outcome data were or how the several outcomes were analyzed.

The study concerns a specific communication tool and a population described as patients with limited English proficiency. Eligibility criteria, setting details, and further population characteristics are not reported in the registry record, limiting assessment of how broadly any eventual findings might apply. These limitations describe what can be evaluated from the registry record; they do not establish that a particular bias or data problem occurred.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Visualizations to Improve Pain Communication Between Patients, Interpreters, and Providers — NCT04975789.
• Registry record last updated 2024-06-07; status last verified 2024-06.
• Results first posted 2024-06-07.
• 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

NCT04975789 is a completed, non-randomized, sequential study of an information visualization tool intended to support pain communication among patients with limited English proficiency, interpreters, and providers. The registry lists no masking and cautions that the arms are not a like-for-like control comparison. The intervention description says trained interpreters use InfoViz before and during the clinical encounter; the Usual Care Control group is described as receiving standard of care.

The primary outcome is the percentage of eligible patients enrolled, a recruitment-feasibility measure. The registry lists 11 outcome measures and 0 analyses. Although enrollment is listed as 61, the observed recruitment percentage and outcome analyses are not reported in the registry record. The brief summary states that 40 participants will be enrolled and that participation can last up to 4 weeks; the relationship between that enrollment statement and the listed enrollment is not explained. Statistical conclusions about feasibility, communication, or pain outcomes cannot be drawn from the reported record details.