Uncontrolled Hypertension Among the Homeless: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Uncontrolled Hypertension Among the Homeless (NCT05187013), a randomized na study. The primary outcome is Blood Pressure.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group trial with no masking. Participants were assigned to either hypertension-specific education by text message or general health education by text message. Both groups were followed for 6 months. The record lists an enrollment of 123. The study summary also describes a randomized clinical trial involving homeless participants, with a stated trial count of 120; it does not explain how that description relates to the enrollment figure. Participant flow, including numbers screened, assigned, followed, and included in each analysis, is not reported in the registry record.

The study was designed for homeless adults age 21 or older with hypertension and uncontrolled blood pressure in shelter-clinics in New York City. The hypertension-specific arm was intended to add blood-pressure-focused support, medication reminders, appointment reminders, education, and support for lifestyle changes. The general-health arm received text messages about basic healthcare and general health promotion. The registry describes blood-pressure measurements and adherence assessments at shelter visits for the general-health group.

The study summary also describes semi-structured interviews with homeless patients and providers who serve homeless people in shelter settings. It gives planned interview counts of 30 homeless participants and 20 providers. These qualitative interviews were intended to explore barriers and opportunities related to blood-pressure control. The registry lists the number of participants completing interviews as a secondary outcome, but does not report the interview findings or completion results.

The study status is completed. The listed start date is 2022-09-12, and the listed primary completion date is 2025-09-15. The statistical analysis plan, allocation procedures, concealment methods, and details of follow-up are not reported in the registry record. Randomization can reduce systematic differences between groups on average, but it does not by itself establish that the groups were similar in the realized study or that all assigned participants contributed outcome 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.

Before assignment: No significant study events occurred after participant enrollment and before study assignment.

Overall Study

Reasons for not completing this period:

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: Providers only participated in semi-structured interviews. No baseline or demographic data were collected for this group.

6. Primary Endpoint

The registry lists the primary outcome as Blood Pressure, measured over 6 months.

The primary outcome is blood pressure at 6 months, described as systolic and diastolic blood pressure readings, with the unit listed as mmHG. The outcome type is continuous, and the registry describes the measure as a mean with standard deviation. Systolic and diastolic pressure represent different components of a blood-pressure reading, so the registered endpoint includes more than one outcome measure rather than a single combined value.

Blood pressure is used to assess whether the groups differ in measured pressure at the specified follow-up. A comparison can describe the average readings in each group and, when reported, the estimated difference between groups with its uncertainty. The registry record does not report the outcome values, group means, standard deviations, between-group estimates, confidence intervals, or p-values. It also does not specify in the primary outcome description whether the main comparison is based on change from baseline, follow-up values alone, or an adjusted analysis. Those details are not reported in the registry record, so the registered measure should not be mistaken for a fully specified statistical contrast.

The study summary states a hypothesis of a reduction in blood pressure of 8mmHg systolic BP or diastolic BP in the intervention group and better adherence to medication and appointments. This is a stated hypothesis, not a reported trial result. The blood-pressure results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized, unmasked, and parallel-group. In a randomized study, assignment is intended to make treatment groups comparable in expectation, including on characteristics that may not be measured. Randomization does not ensure that every group characteristic is balanced in the participants who enroll, and it does not eliminate the possibility of missing outcome data, departures from assigned treatment, or measurement issues. The registry record does not report the randomization procedure or the analysis population used for the posted outcomes.

What does a continuous outcome mean?

Blood pressure is treated as a continuous measure rather than a binary event. A continuous outcome can be summarized by a mean, which describes the average observed value, and a standard deviation, which describes the spread of individual measurements around that average. The registry lists the primary outcome as a mean with standard deviation. These summaries are not reported for the study results in the registry record.

A comparison might be expressed as a difference in average blood pressure between assigned groups, or as a comparison of follow-up values that accounts for baseline readings. These approaches answer related but not identical statistical questions. The registry outcome description does not state which contrast was used, whether baseline blood pressure was included in an adjusted model, or which covariates were considered. The analysis method is not reported in the registry record.

Why does the estimate need an uncertainty measure?

An observed group difference is an estimate based on the participants with usable data. It can vary from sample to sample even when the underlying study process is unchanged. A confidence interval communicates the precision of an estimate by showing a range of values compatible with the data and the chosen method. A narrower interval generally indicates greater precision than a wider interval, while the interval's location indicates which effect sizes remain compatible with the data. The registry record does not report confidence intervals for the blood-pressure outcomes.

A p-value is a measure defined relative to a null hypothesis and statistical model. It does not tell readers the probability that the null hypothesis is true, and it does not measure the clinical importance of a result. Interpretation requires the effect estimate, its uncertainty, the analysis context, and the outcome definition. No p-value for the primary outcome is reported in the registry record.

What does the planning illustration represent?

The record describes sample-size planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. Such illustrations ask how many participants per arm would be needed under the stated assumptions for a chosen power target and effect size. They are planning calculations, not counts of participants who were observed, and not evidence that the completed study had a particular probability of detecting an effect.

The record does not report the numerical planning outputs in the registry record for this analysis, and it does not report the observed primary outcome effect needed to interpret an effect-based planning illustration. Accordingly, no sample-size figure or achieved power can be inferred. Sample-size calculations are not a substitute for the observed effect estimate and its uncertainty.

Why might over-dispersion matter?

In general, over-dispersion means that the observed variability is greater than a statistical model assumes. It can make standard errors too small and confidence intervals too narrow if the model does not accommodate the extra variability. This concern is most directly relevant to some count or event outcomes, rather than to the mean blood-pressure endpoint as described. The registry record does not report a model for any count outcome or indicate whether over-dispersion was assessed.

What can be inferred from the analysis count?

The registry lists 6 analyses. An analysis count alone does not identify the outcome, comparison, model, adjustment set, or population used in each analysis. It also does not show whether analyses were planned in advance or conducted after examining the data. The statistical analysis plan and analysis-specific results are not reported in the registry record. The sponsor's analysis cannot be compared with a recalculated estimate because no outcome summary statistics or recalculated results are reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 4 outcome measures and 6 analyses, while the primary outcome description includes both systolic and diastolic blood pressure. The study summary also identifies medication adherence and appointment adherence as outcomes to be assessed, and the registry lists interview completion as a secondary outcome. The record does not describe how these outcomes were prioritized for statistical testing, whether any adjustment for multiple comparisons was planned, or how the six analyses were allocated across endpoints, time points, or groups. The statistical plan for multiplicity is not reported in the registry record.

In general, testing multiple outcomes or conducting multiple analyses increases the chance that at least one result will appear unusual by chance when each is considered separately. A multiplicity strategy may control the overall error rate, prioritize a primary comparison, or present estimates descriptively with appropriate caution. Without a reported plan and analysis-specific results, it is not possible to determine how multiplicity was handled. This uncertainty does not mean that any reported result is invalid; it limits how confidently a collection of findings can be interpreted as confirmatory.

Missing data also affect interpretation. The registry record does not report how many participants had blood-pressure measurements at 6 months, reasons for missing measurements, or the method used to handle missing outcomes. It does not report whether adherence outcomes or interview data were missing, or how missingness was addressed. In general, complete-case analyses can be biased if participants with observed outcomes differ systematically from those without them. Methods such as imputation or sensitivity analyses can address some assumptions about missingness, but the record does not state whether these methods were used.

The analysis population is not reported in the registry record. It is therefore unclear whether the outcome analysis included all randomized participants, only those who completed follow-up, or another defined group. That distinction matters because the analysis population affects what comparison is being estimated.

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 serious adverse events as zero affected participants in the hypertension-specific education group and zero in the general health education group. It also lists zero serious adverse events among providers. The corresponding at-risk counts are 57, 56, and 10, respectively. These are registry counts, not estimates of comparative risk. The record lists one death in the general health education group and none in the other listed groups.

For other adverse events, the registry lists zero affected participants in each of the three groups, with at-risk counts of 57, 56, and 10, respectively. No top serious adverse-event terms are listed. The provider group is not one of the two randomized education arms, so its figures should not be read as a randomized treatment comparison.

These entries describe what the registry record reports; they do not establish that no unrecorded events occurred or explain how events were collected, classified, or followed. The record does not provide event narratives, causes of death, timing, relatedness to the intervention, or a comparative safety analysis. The single death listed for the general health education group should not be attributed to the intervention or interpreted as evidence of a treatment effect based on this information alone.

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

The record describes a completed randomized trial designed to compare hypertension-specific text-message support with general health education by text message. It identifies blood pressure at 6 months as the primary outcome and gives a rationale for studying medication and appointment adherence as well. These details explain the intended comparison and the types of outcomes the investigators planned to assess.

The record does not report the primary outcome results. As a result, it does not establish whether average systolic or diastolic pressure differed between groups, what the size of any difference was, or how precisely it was estimated. It also does not report numerical findings for adherence or interview completion. The stated hypothesis about an 8mmHg reduction is a proposed expectation, not a result.

In general, a trial result applies most directly to the population, intervention, comparator, setting, and follow-up actually studied. This study focused on homeless adults age 21 or older with uncontrolled hypertension in New York City shelter-clinics and used text messages over 6 months. The registry does not provide enough information about recruitment, participation, follow-up, or outcome availability to assess how closely the observed study population represents the broader population described.

Even when results are available, a statistical difference is not automatically a measure of clinical importance, and absence of a statistically clear difference does not by itself demonstrate equivalence. Those judgments require the estimated effect, its uncertainty, the outcome context, and suitable prespecified criteria. None of the primary blood-pressure estimates or uncertainty measures is reported in the registry record.

Accordingly, the appropriate reading is limited: the registry documents the design and planned outcomes, but the posted information does not support a conclusion about the comparative blood-pressure result. Neither the study's completion status nor the intervention description can substitute for outcome data.

13. Why This Trial Matters Statistically

This trial addresses a measurement and design question in a population that the registry describes as homeless adults receiving care in shelter-clinics. The comparison is between two forms of text-message support, not between text messaging and no messaging: one group received hypertension-specific content, while the other received general health education. That distinction is important when defining the effect the study was designed to estimate.

Random assignment is useful for a comparative question because it can reduce systematic differences between assigned groups at baseline. The study's parallel structure also allows outcomes to be compared between the groups over the same follow-up period. However, interpretation depends on the actual outcome data and analysis details. The registry record does not report the blood-pressure estimates, follow-up completeness, or the analysis population, so the extent to which the intended comparison was realized cannot be assessed from this entry.

The endpoint combines systolic and diastolic readings, and those measures should be interpreted as separate aspects of blood pressure rather than merged into one result without a defined method. Reporting each estimate with an uncertainty measure would allow readers to distinguish the size of a difference from its precision. The registry record does not report those estimates.

The study also includes a qualitative component involving patients and providers. Such interviews can describe experiences and perceived barriers, but their role differs from estimating a randomized treatment effect. The record describes the interview aims and planned counts, while interview completion results and qualitative findings are not reported in the registry record.

Statistically, the record illustrates why design information and outcome evidence must be kept distinct. A clear trial question and a completed study are not enough to establish what the observed data show. Estimates, uncertainty, missing-data information, and analysis details are needed for a defensible interpretation.

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 interpreting this registry entry is that numerical primary outcome results are not reported. Group means, standard deviations, between-group estimates, confidence intervals, and p-values for systolic and diastolic blood pressure are absent from the record. Without these, the magnitude, direction, and precision of the primary comparison cannot be evaluated.

The record lists an enrollment of 123, while the study summary describes a randomized clinical trial with 120 homeless participants. It does not explain the relationship between these figures. The adverse-event entries list at-risk counts by group, but those counts do not provide a complete participant-flow account. Numbers screened, assigned, followed, and analyzed, as well as reasons for withdrawal or missing measurements, are not reported in the registry record.

The registry does not report detailed eligibility criteria, the definition of uncontrolled blood pressure, the randomization procedure, allocation concealment, or the statistical analysis plan. It also does not state whether the primary comparison used change from baseline, adjusted follow-up measurements, or another approach. The handling of missing data, multiplicity, protocol deviations, and analysis populations is not reported in the registry record.

Intervention descriptions are available, but the record does not report text-message delivery, participant engagement, treatment adherence, or fidelity to the intended content. The interview results are not reported, so the qualitative component cannot add explanatory context to the quantitative outcomes from this entry. These limitations restrict interpretation of the registry record; they do not establish that the study itself lacked these data or analyses.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Uncontrolled Hypertension Among the Homeless — NCT05187013.
• Registry record last updated 2025-10-27; status last verified 2025-10.
• Results first posted 2025-09-09.
• 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, unmasked, parallel-group study of text-message support for homeless adults age 21 or older with uncontrolled hypertension in New York City shelter-clinics. The intervention was hypertension-specific education and support by SMS, compared with general health education by SMS, over 6 months. The primary outcome was systolic and diastolic blood pressure at 6 months, described as a mean with standard deviation.

The record also describes planned qualitative interviews with homeless participants and providers, and lists interview completion as a secondary outcome. It reports serious adverse-event counts, other adverse-event counts, and one death in the general health education group. It does not report the primary blood-pressure results, adherence results, interview findings, analysis methods, missing-data handling, or analysis populations. The design and hypotheses are documented, but comparative efficacy conclusions cannot be drawn from the outcome information reported in the registry record.