Promoting Cervical Cancer Screening for Emergency Department Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Promoting Cervical Cancer Screening for Emergency Department Patients (NCT03483610), a randomized na study. The primary outcome is Number of Participants Who Scheduled or Completed Cervical Cancer Screening.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group study with no masking, registered as NCT03483610. The registry lists the study as completed, with a phase of NA. The study sponsor was the University of Rochester. The recorded start date is 2018-06-25, and the primary completion date is 2019-05-31. Enrollment is listed as 95.

The study was designed to pilot approaches intended to encourage adherence to cervical cancer screening recommendations among emergency department patients. The registry summary describes a screening-status assessment followed by random assignment for patients who were not up to date. One group received referral to a women's health care provider; the other received referral plus text-message encouragement. The text messages were described as three messages at 30-day intervals. The record does not report the precise method of randomization, whether allocation was concealed, or how assignment was implemented.

The primary endpoint was the number of participants who scheduled or completed cervical cancer screening within 150 days. The arm-level outcome entries list 28.0 for Screening and Referral and 21.0 for Behavioral Intervention, with corresponding arm sizes of 28.0 and 21.0. Enrollment is separately listed as 95, and the registry record does not explain the relationship between enrollment and these arm-level figures. It also does not report participant flow, exclusions after screening, or the number assessed for eligibility.

The unmasked design means participants and study personnel were not described as blinded to the assigned intervention. This is relevant for an endpoint involving scheduling or completion, which may depend on participants' actions and how those actions were recorded. The record does not state whether outcome assessment was independent of treatment assignment or whether outcome verification followed a prespecified procedure.

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: Women with past hysterectomy with cervical removal, known HIV infection, inability to consent, non-English speaking, or not having a text-capable phone were excluded. 502 eligible approached to achieve the target of 450. The primary reason for declining was lack of interest. Among consented potential-participants, 355 (79%) were adherent with screening recommendations and their participation ended. The remaining 95 participants that were determined to be eligible to be randomized.

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 Number of Participants Who Scheduled or Completed Cervical Cancer Screening, measured over 150 days.

The primary endpoint counts participants who scheduled or completed cervical cancer screening during the 150-day timeframe. It is a binary participant-level outcome represented as a count: each participant is counted as having or not having the event. The registry title combines scheduling and completion, and does not give separate results for these two stages. Thus, the result cannot establish how many participants completed screening rather than only scheduling it.

The endpoint is relevant to the study's stated purpose because the interventions were intended to encourage follow-up for recommended screening. In general, a behavioral intervention can be evaluated using a measurable action related to the intended behavior. A count of participants who reach a scheduling or completion milestone can describe whether follow-up occurred within the defined period, although it does not by itself describe the quality of care, the screening result, or longer-term adherence.

The registry reports the outcome timeframe as 150 days. It does not report additional endpoint definitions, such as how a scheduled appointment was verified, how cancellations or rescheduling were treated, or whether an appointment after the timeframe counted. Those details matter because combining scheduling with completion may classify different levels of follow-through together. Separate counts for scheduling and completed screening are not reported in the registry record.

7. Results Posted in the Registry

• Behavioral Intervention: 100.0% (21/21) versus 100.0% (28/28) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0), risk ratio 1.00 (1.00–1.00); unadjusted two-proportion z-test p = n/a.

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized parallel-group design. In a parallel trial, participants are assigned to one study group and remain in that group for the comparison; the intervention groups are not crossover periods. Random assignment is intended, in general, to make groups comparable on average with respect to factors that could affect an outcome. The registry record does not describe the randomization sequence, allocation concealment, stratification, or other implementation details, so those features cannot be assessed from the record.

What does the risk difference represent?

For a binary outcome, a risk is the proportion of participants with the event in a group. A risk difference compares those proportions by subtraction, with the direction depending on which group is defined as the reference. Here, the registry comparison names Behavioral Intervention and reports a risk difference of 0.0. The arm-level proportions are both reported as 1.0, so the posted difference indicates no separation in the observed proportions. A risk difference is expressed on the absolute probability scale; it can communicate how far apart the group proportions are without converting the result into a relative measure.

The registry also reports a relative risk entry of 1.0 with its interval endpoints at 1.0. A relative risk compares one group's risk with the other group's risk. When the reported risks are equal, the ratio is reported as 1.0, which corresponds to no relative difference in the posted proportions. In general, absolute and relative measures can provide complementary descriptions, but neither resolves concerns about unclear denominators, outcome ascertainment, or analysis methods.

How should the p-value be understood?

In general, a p-value describes how compatible the observed data are with a statistical model in which there is no group difference, assuming the model and analysis conditions hold. It is not the probability that the null hypothesis is true, and it does not measure the size or importance of an effect. The registry reports p = 1.0. That value accompanies the equal proportions and zero risk difference, but the record does not state the test used, its assumptions, or whether the value is from an unadjusted or adjusted analysis.

A p-value alone does not communicate precision. The confidence interval is ordinarily used to show a range of effect estimates compatible with the data and analysis assumptions. In this record, the reported risk-difference interval runs from 0.0 to 0.0, without width. Because the analysis procedure is not described, the reason for that presentation is not reported in the registry record. It should not be taken as evidence that uncertainty is absent.

What can the count outcome establish?

The endpoint is a count of participants who scheduled or completed screening, not a count of all screening appointments or a measure of time to screening. The binary outcome treats a participant who scheduled screening and one who completed it as having the event, according to the combined endpoint title. General interpretation of this type of endpoint depends on consistent event definitions and complete ascertainment in both groups. The record does not describe verification of appointments or completion, missing outcome handling, or separate results for the endpoint components.

The outcome entries and comparison are registry-posted summaries; the record reports no analyses in addition to the primary comparison. It does not report a model, covariate adjustment, test specification, or an analysis plan. Without these details, a reader cannot determine whether the posted comparison reflects an intention-to-treat analysis, another analysis population, or a particular treatment of participants with unobserved outcomes. The statistical method and population used for the reported effect are not reported in the registry record.

10. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimated effect. A confidence interval ordinarily gives a range of values compatible with the observed data and the statistical method, under its assumptions. A narrower interval indicates greater precision than a wider interval, but interpretation also depends on whether the method is appropriate and whether the interval covers effects that would matter for the research question.

The registry reports a risk difference of 0.0 with interval endpoints of 0.0 and 0.0. This interval has no displayed width. The arm-level proportions are both 1.0, with posted counts of 28.0 and 21.0 and arm sizes of 28.0 and 21.0. However, an interval with no width does not convey the ordinary sampling uncertainty that generally accompanies estimates based on finite groups. The registry record does not explain the calculation or report another interval that would clarify uncertainty.

The p-value of 1.0 is not a substitute for a precision measure. It indicates the value reported for the comparison under an analysis that is not described in the record. It does not show which nonzero effects are compatible with the data. The zero risk difference is a point estimate, while the reported interval would ordinarily help distinguish an estimate that is precise from one that is uncertain. In this case, the posted interval cannot support that distinction in a meaningful way without information about its construction.

The record does not report a sample-size justification, a statistical analysis plan, or an explanation of the relationship between overall enrollment and the arm-level endpoint counts. As a result, the precision of the treatment comparison cannot be fully evaluated from the registry record. The exact equality of the posted proportions should be understood as a feature of the reported summaries, not as proof that the underlying effects are identical.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and no secondary outcomes posted. It also lists zero analyses. A single posted primary comparison does not establish that the study conducted only one analysis; analysis details and any prespecified statistical plan are not reported in the registry record. The record does not describe whether there were additional exploratory analyses, repeated looks at the accumulating data, or any adjustment for multiple testing.

Multiplicity arises when several outcomes, groups, time points, or analyses are considered. In general, examining multiple comparisons can increase the chance of a statistically notable result arising by chance, so a prespecified plan can help readers understand which results are confirmatory. Here, the registry record does not report multiplicity procedures or enough analysis detail to determine whether they were relevant. No claim about interim analyses or their absence can be made from the posted information.

Missing data are also not addressed in the posted results. The record does not say whether every participant had an outcome assessed, how participants without observed screening status were handled, or whether any imputation or sensitivity analysis was used. Missingness can affect a binary outcome estimate if the probability of an unobserved outcome differs between groups or is related to whether screening occurred. General methods for missing data rely on assumptions, and the record does not identify any assumptions or methods used.

The analysis population is not reported in the registry record. It is therefore unclear whether the comparison includes everyone randomized, only those with observed outcomes, or another population. The record does not report exclusions, withdrawals, protocol deviations, or arm-specific participant flow. Those details are necessary to assess whether the reported comparison follows the randomized assignment and how much information contributed to the endpoint.

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.

The adverse-event record lists 47 participants at risk in Screening and Referral and 48 in Behavioral Intervention. It reports zero serious adverse events, zero other adverse events, and zero deaths in each group. These safety figures are separate from the arm sizes listed for the primary endpoint. The registry record does not explain the different participant counts or their relationship to the primary outcome analysis.

Zero recorded events means that no events were entered in these categories for the groups and at-risk counts as posted. It does not prove that no event occurred, that all participants were followed for safety in the same way, or that the groups have identical safety profiles. Interpretation depends on how events were defined, collected, and attributed, and on the duration and completeness of safety follow-up. Those details are not reported in the registry record.

The registry does not list serious adverse-event terms. No comparison estimate or uncertainty measure for safety outcomes is reported. The zero counts are therefore descriptive registry entries, not a precise estimate of the probability of harm and not a basis for comparing safety between groups.

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

The posted primary result describes equal proportions of participants with the combined outcome of scheduling or completing cervical cancer screening within 150 days. It reports a risk difference of 0.0, a relative risk of 1.0, and p = 1.0. These values indicate no observed separation between the groups in the registry's summary for this endpoint.

That result does not show that the interventions are equivalent or that their true effects are exactly the same. Equivalence or non-inferiority claims require a suitable design and prespecified criteria, neither of which is reported in the registry record. A non-significant or neutral-looking comparison does not prove the absence of a difference. The confidence interval posted has no width, and the statistical method behind it is not described, so it does not establish a useful range of plausible effects.

The endpoint combines scheduling with completion. It cannot show whether the groups differed in getting an appointment, attending it, or completing screening if those components were considered separately. The registry does not report separate component counts, screening results, later follow-up, or longer-term adherence. The outcome therefore addresses a limited, time-bounded measure of follow-up rather than all aspects of screening behavior or clinical outcomes.

The trial is described as a pilot of approaches to encourage screening among emergency department patients. The record does not report enough design or analysis detail to determine how broadly the result applies, how missing outcomes were handled, or how the observed estimate should be interpreted statistically. The safest reading is confined to the posted data: the registry records the same event proportion in both arms for the stated primary endpoint, while leaving important questions about precision and analysis unresolved.

14. Why This Trial Matters Statistically

This study raises a useful statistical question about evaluating behavioral interventions: the outcome is an action that can occur after a participant leaves the clinical setting, and its recording may depend on follow-up and verification. For a fair comparison, the event definition and assessment process need to be clear across groups. The registry identifies a combined scheduling-or-completion endpoint, but does not describe how those events were confirmed or distinguish the components.

The posted values also illustrate why a point estimate and a p-value are not enough to judge a result. Equal group proportions yield a zero risk difference, but interpretation also depends on uncertainty, sample definition, and analysis method. The reported interval has no width, and the registry does not explain its construction. Without a clear uncertainty estimate, readers cannot tell what range of differences remains compatible with the data.

Another statistical issue is accounting for participants. Overall enrollment is listed as 95, while the primary outcome entries list arm sizes of 28.0 and 21.0, and the safety record lists different at-risk counts. The registry record does not explain the relationship among these figures. Participant flow and analysis-population definitions would help clarify what each denominator represents and whether the outcome comparison includes all randomized participants.

These features make the registry useful as a record of the study question and posted outcome, while also illustrating why transparent reporting of outcome definitions, analysis populations, uncertainty methods, and missing data is essential. The result is informative as a description of the posted comparison, but its statistical meaning is limited by the unanswered questions in the record.

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 registry record gives limited detail about eligibility, participant characteristics, and the process used to identify patients who were not up to date with screening. It does not report the number assessed, reasons for exclusion, participant flow after randomization, or the relationship between the enrollment figure and the arm-level outcome entries. These omissions make it difficult to understand the analyzed population and the reach of the study.

The interventions are described at a broad level. The summary specifies referral and three text messages at 30-day intervals for the behavioral intervention, but the record does not report message content, delivery success, referral procedures, or whether participants used the services. It also does not state whether intervention exposure or adherence was measured. These details could affect interpretation of the contrast between the groups.

The primary endpoint combines scheduling and completion and has a 150-day timeframe. Separate component results and details on event verification are not reported. The record also does not describe missing outcome handling, the analysis population, statistical methods, or the construction of the confidence interval. The posted interval has no width, which limits assessment of precision.

The study is unmasked, and the registry does not describe independent outcome assessment. Because scheduling and completion involve actions that may need follow-up to observe, incomplete or different ascertainment could affect the recorded outcome. The adverse-event entries use at-risk counts that differ from the primary endpoint arm sizes; the reason is not reported in the registry record. No conclusion about the cause of that difference can be drawn from the posted information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Promoting Cervical Cancer Screening for Emergency Department Patients — NCT03483610.
• Registry record last updated 2025-01-24; status last verified 2025-01.
• Results first posted 2025-01-24.
• 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

NCT03483610 is a completed randomized, unmasked, parallel-group study sponsored by the University of Rochester. It evaluated referral to a women's health care provider alone versus referral with text-message encouragement for emergency department patients who were not up to date with cervical cancer screening recommendations. Enrollment is listed as 95.

The primary outcome was the number of participants who scheduled or completed screening within 150 days. The registry reports proportions of 1.0 in both groups, a risk difference of 0.0, a confidence interval from 0.0 to 0.0, and p = 1.0. The record does not explain the interval calculation, the relationship between enrollment and endpoint arm sizes, or the analysis population. No secondary outcomes or additional analyses are posted.