Information Visualizations to Facilitate HIV-related Patient-provider Communication in New York City (Info Viz: HIV-NYC): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Information Visualizations to Facilitate HIV-related Patient-provider Communication in New York City (Info Viz: HIV-NYC) (NCT04102540), a na na study. The primary outcome is Mean CD4 Count.

2. Clinical Question

The study addressed whether an infographic intervention could be piloted in the context of HIV-related patient-provider communication. Its design also included interviews to explore participants’ perceptions of communication using infographics and clinical team members’ perspectives on the infographics’ clinical utility. The registry record does not report the findings of those interviews.

This is a descriptive question about measurements collected over time in one group, not a direct comparison of the intervention with an untreated or alternative-treatment group. The record lists additional outcomes related to knowledge, satisfaction with care, self-efficacy, medication adherence, health status, and health literacy. It does not report results for those outcomes either.

3. Trial Design

The registry describes a completed mixed-methods pilot with a single-group pretest-posttest design. The listed enrollment was 32. Participants received health education using infographics at a study visit scheduled immediately after a regularly scheduled clinic visit. Assessments were planned at enrollment and at 3- and 6-month follow-up visits. The brief description also outlines in-depth interviews with a selection of participants and follow-up interviews with clinical team members.

The study had no randomized allocation and no masking. The record lists the allocation as NA and the masking as none. It identifies one intervention group rather than a parallel control group. Consequently, measurements before and after the intervention describe change over time within the group; they do not provide a randomized comparison that isolates the intervention’s effect from other influences.

The registry lists the study as completed and identifies Columbia University as the sponsor. The recorded start date is 2019-10-07, and the primary completion date is 2020-07-29. The phase is listed as NA. The intervention is categorized as other. The record describes the project as a pilot intended to test the infographic intervention and explore views about communication and clinical utility.

Two participants were withdrawn by the principal investigator and were not included in analyses, according to the primary endpoint description. The record does not explain the reason for withdrawal, specify when it occurred, or give the number contributing data at each assessment. It also does not report the detailed eligibility criteria, recruitment procedures, or the operational schedule beyond the visits described.

The record does not report a formal statistical analysis plan, a sample-size justification for the completed single-group study, or procedures for handling repeated measurements. These omissions limit the extent to which the intended analysis can be reconstructed from the registry description.

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: 2 participants were withdrawn by the PI and were not included in analyses.

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: Two participants were removed from the study by the PI. Their information was not included in the calculations of participants' characteristics at baseline.

6. Primary Endpoint

The registry lists the primary outcome as Mean CD4 Count, measured over Baseline, 3-, and 6-months.

The primary endpoint is mean CD4 count, measured in cells/mm^3 at baseline and at the 3- and 6-month follow-up assessments. The registry describes the endpoint as the mean Cluster of Differentiation 4 (CD4) count at each time point and identifies standard deviation as its measure of dispersion. The record does not report the actual means, standard deviations, participant counts at each assessment, or a numerical estimate of change over time.

A mean describes the arithmetic center of a set of measurements. A standard deviation describes how dispersed individual measurements are around that mean. These are general statistical interpretations of the endpoint’s stated summary measures; they do not establish what the observed CD4 values were in this study.

Repeated measurement of the same endpoint can describe how group measurements vary across scheduled visits. A baseline value provides a reference for interpreting later measurements, while follow-up values describe the group at subsequent assessments. However, the registry record does not explain why CD4 count was selected as the primary endpoint or specify the clinical interpretation intended by the investigators. That rationale is not reported in the registry record.

The endpoint description notes that two participants were withdrawn by the principal investigator and were not included in analyses. It does not state how missing measurements at individual visits were handled or whether all remaining participants contributed data at every time point. Without the reported endpoint values and analysis details, the precision and pattern of the measurements cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean with a standard deviation describe?

The primary endpoint is a continuous measurement summarized as a mean and standard deviation at baseline and at follow-up. In general, a mean represents the arithmetic average of observed values. A standard deviation describes how much individual observations vary around that average. Together, these summaries can convey the group’s central value and the spread of measurements, but neither alone describes every feature of the data distribution. The registry record does not report the actual summaries for this endpoint.

A mean at each visit is a descriptive summary for that visit. Comparing visit-specific means can describe how the group-level average varies over time. It is not the same as presenting each participant’s trajectory, nor does it by itself quantify uncertainty in an estimated change. To interpret a change estimate, readers generally need information about the estimate’s precision, such as a confidence interval, and a clear account of the analysis used. The registry record does not report a change estimate, confidence interval, or statistical test for the primary endpoint.

How does repeated measurement affect analysis?

When people are measured at more than one visit, measurements from the same person are generally related. General statistical methods for repeated measurements account for that within-person relationship when estimating change or comparing visits. Treating all visit measurements as if they came from unrelated people can misrepresent the amount of information in the data. The record gives the planned assessment times but does not identify a repeated-measures model, a paired analysis, or another specific method. None should be assumed.

Repeated visits also raise practical questions: which observations are included, how incomplete follow-up is handled, and whether the analysis uses all available measurements or only participants with complete records. Those choices can affect both the estimate and its uncertainty. The registry record states that two participants were withdrawn by the principal investigator and were not included in analyses, but it does not describe the handling of other missing or incomplete observations.

What does a confidence interval convey?

In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the method used. A narrower interval indicates greater precision under those assumptions; a wider interval indicates less precision. It does not correct for biases in the study design or turn an uncontrolled comparison into a randomized one. No confidence interval for the primary endpoint is reported in the registry record, so the precision of any estimated change cannot be evaluated.

A p-value, when reported, addresses how compatible the data are with a specified statistical model or null hypothesis. It does not measure the size or importance of an effect, and it does not establish causation. The registry record does not report a p-value for the primary endpoint. Without an estimate and its uncertainty, significance language would not provide a useful substitute for the missing results.

Why does the single-group design matter?

General statistical interpretation of a single-group pretest-posttest study focuses on describing outcomes over time within the enrolled group. The baseline assessment can serve as a reference, but there is no parallel control group to represent the course of outcomes in the absence of the intervention. Any change could reflect the intervention, other changes over time, or a combination of influences. The study description does not support attributing a change solely to the infographics.

The record lists a planning illustration based on a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. It distinguishes participant counts per arm for non-time-to-event calculations from total event counts for time-to-event calculations. These are planning assumptions, not evidence that the completed trial used a two-arm design. The actual study is described as single-group, and the record does not report the sample-size justification for its own design or the resulting planning counts. Such illustrations are not observed power and do not indicate the probability that the intervention produced an effect.

General sample-size planning asks how much information a proposed design may need to estimate or detect a specified effect under stated assumptions. Its result depends on those assumptions and on the design. A planning calculation based on two arms does not describe the enrollment or analysis of a single-group pilot. The registry record does not report a prespecified effect target for the completed study, a rationale for enrollment of 32, or an account of whether enrollment was chosen for quantitative precision, feasibility, or another purpose.

How should dispersion be interpreted?

The endpoint names standard deviation as its dispersion measure. In general, dispersion indicates variation among observations and can help readers understand whether a mean represents values clustered closely together or values spread more widely. It is not the same as the standard error, which concerns the precision of an estimated mean. The record does not report either the standard deviations or the standard errors, so the observed spread and precision are unknown.

Some continuous outcomes can have distributions for which a mean and standard deviation give an incomplete picture, particularly when values are highly skewed or unusually dispersed. General analysis may then consider distributional diagnostics or alternative summaries and models. The record does not provide individual-level data, distributional information, or the analysis approach needed to assess whether any such issue arose for CD4 count.

The registry’s listed planning assumptions include a normal approximation. That assumption belongs to the described planning illustration; it does not establish that the primary endpoint analysis used a normal model. The analysis distribution, model checks, and any strategy for over-dispersion are not reported in the registry record. Over-dispersion is a general concern when observed variability exceeds what a model expects, because model-based uncertainty may then be understated if the extra variability is ignored. There is no basis in this record to say whether it occurred.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures and 14 analyses. Multiple outcomes and analyses create a multiplicity question: when many statistical tests are conducted, the chance of at least one apparently notable result can increase if each is interpreted independently. General approaches may prespecify a primary analysis, adjust inference for multiple testing, or treat secondary analyses as exploratory. The registry record does not report whether any multiplicity adjustment, hierarchical testing strategy, or distinction between confirmatory and exploratory analyses was used.

The mean CD4 count is identified as the primary endpoint, while the listed secondary measures cover knowledge, satisfaction with care, self-efficacy, adherence, health status, and health literacy. The record does not provide a detailed analysis plan establishing the role or priority of each of the 14 analyses. Nor does it report their results. The number of listed analyses alone does not show whether they were statistically independent or whether any adjustment was appropriate.

For the primary endpoint, the registry says that two participants were withdrawn by the principal investigator and were not included in analyses. It does not report the reasons, timing, or whether the withdrawal was related to outcome data. It also does not state the number with observed measurements at each visit, how missed assessments were handled, whether any imputation was used, or whether analyses were limited to participants with complete follow-up.

These omissions leave the analysis population and the extent of missing data unclear. In general, missing-data methods rely on assumptions about why values are unavailable; different assumptions can yield different estimates. No such assumptions or sensitivity analyses are described in the registry record. The stated exclusion of the two withdrawn participants is the only explicit information about exclusion from analyses; the record does not explain whether other exclusions occurred.

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 reports 30 participants at risk for serious adverse events and 0 participants with serious adverse events in the intervention group. It lists no serious adverse event terms. For other adverse events, it reports 30 participants at risk and 0 participants affected. The record reports 0 deaths.

These are the adverse-event figures recorded for the study. A count of zero means that no affected participants or events are recorded in those categories in this entry; it should not be read as proof that an intervention has no risk. The record does not provide event-level details, definitions, severity grading, follow-up duration for safety monitoring, or an explanation of how adverse events were solicited and classified. It also does not report a comparison group, so the figures cannot be interpreted as a comparative safety estimate.

The safety population counts are distinct from a complete account of the primary endpoint analysis population. The endpoint description says two participants were withdrawn by the principal investigator and excluded from analyses, while the adverse-event entry gives 30 at risk. The registry does not explain the relationship between these counts or provide participant-level disposition across follow-up.

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

The record documents a completed pilot of infographic-based health education in a single group, with planned baseline and follow-up assessments and interview components. It identifies mean CD4 count as the primary endpoint and names a range of secondary outcomes. It also records adverse-event counts for the intervention group. These details describe what the study set out to examine and how the intervention was delivered.

The record does not report the numerical results for the primary endpoint or the listed secondary outcomes. It therefore does not show whether mean CD4 count changed between visits, how variable the measurements were, or how precisely any change was estimated. Interview findings are also not reported. The absence of reported endpoint values is not evidence that the values were unchanged; the registry information simply does not allow a result to be characterized.

Even if within-group outcome values were available, the design would remain a single-group pretest-posttest study rather than a randomized comparison. General causal interpretation requires considering whether observed changes can be distinguished from other influences occurring over time. With no control group, a before-and-after pattern alone cannot establish that the infographics caused a change.

The record reports 0 serious adverse events among 30 participants at risk, 0 other adverse events among 30 at risk, and 0 deaths. These are registry counts, not a comparative estimate of safety, and they do not establish absence of risk. Details about event definitions and monitoring are not reported.

The appropriate interpretation is therefore limited: the registry describes a pilot intervention and its planned evaluation, but does not provide outcome estimates from which to assess the observed results. It does not establish an intervention effect, the precision of an effect, participant perceptions, or clinical team views.

13. Why This Trial Matters Statistically

Statistically, this trial is useful as an example of the distinction between a study’s design and the evidence needed to quantify an outcome. The registry identifies a single-group pretest-posttest pilot, names measurement times, specifies a mean and standard deviation for the primary endpoint, and lists secondary outcomes. Those elements clarify what was intended to be measured. Yet without the outcome values and an analysis description, readers cannot assess the size or precision of any observed pattern.

The design also illustrates why a baseline measurement is not equivalent to a control group. Baseline data permit description of the group before the intervention, while follow-up data describe the group later. General statistical reasoning separates that temporal comparison from a causal comparison, which requires a credible account of what would have happened without the intervention. The registry describes no like-for-like control group.

The study combines quantitative assessments with planned interviews. These methods address different kinds of questions: numerical outcomes can summarize measurements, while interviews can elicit participant and clinical team perspectives. The registry outlines both approaches but does not report their findings. The distinction matters because an endpoint cannot stand in for perceptions, and interview descriptions cannot supply an unreported quantitative estimate.

Finally, the record lists multiple outcomes and analyses, while leaving multiplicity procedures, missing-data methods, and the detailed analysis plan unspecified. These are central parts of statistical interpretation, not merely technical details. The study’s record thus highlights the value of clear reporting of estimates, uncertainty, analysis populations, and analytic decisions alongside a design description.

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 registry record does not report the primary endpoint values, standard deviations, changes over time, confidence intervals, or statistical tests. This prevents evaluation of the magnitude and precision of any outcome pattern. Results for the listed secondary measures and the described interview components are also not reported in the registry record.

The single-group pretest-posttest design has no randomized control group, so it cannot by itself distinguish intervention-associated change from other changes over time. The record does not describe a comparison with usual care or another intervention. The study is identified as a pilot, but the registry does not report the rationale for its enrollment target or a sample-size justification for this design.

The record says two participants were withdrawn by the principal investigator and excluded from analyses, but does not state why or when. It does not report participant counts at each follow-up assessment, the extent of missing data, or how incomplete measurements were handled. Detailed eligibility criteria, participant characteristics, and the analysis population are also not reported in the registry record.

The registry lists 12 outcome measures and 14 analyses but does not describe multiplicity procedures or a detailed statistical analysis plan. It does not identify the method used to account for repeated measurements, specify model assumptions, or report sensitivity analyses. Consequently, the analysis cannot be reconstructed from the registry description.

The adverse-event entry records no affected participants, but does not provide event definitions, monitoring procedures, or further safety detail. These are limitations of what is reported in the registry record; they do not establish that such procedures were absent from the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Information Visualizations to Facilitate HIV-related Patient-provider Communication in New York City (Info Viz: HIV-NYC) — NCT04102540.
• Registry record last updated 2021-09-17; status last verified 2021-08.
• Results first posted 2021-09-17.
• 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 registry describes NCT04102540, “Information Visualizations to Facilitate HIV-related Patient-provider Communication in New York City (Info Viz: HIV-NYC),” sponsored by Columbia University. The study is listed as completed, with enrollment of 32, no masking, and no randomized allocation. It is a mixed-methods, single-group pilot of health education using infographics during a study visit after a regularly scheduled clinic visit.

Assessments were described at baseline and at 3- and 6-month follow-up. Mean CD4 count was the primary endpoint, with standard deviation identified as the dispersion measure. The record also lists secondary outcomes concerning knowledge, satisfaction, self-efficacy, adherence, health status, and health literacy. Two participants were withdrawn by the principal investigator and were not included in analyses.

The record reports 0 serious adverse events among 30 participants at risk, 0 other adverse events among 30 at risk, and 0 deaths. It does not report the numerical outcome results, interview findings, detailed analysis methods, or missing-data procedures.