This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Testing Implementation Strategies to Improve Delivery of PrEP for Pregnant and Postpartum Women in Kenya (NCT05482360), a non-randomized na study. The primary outcome is Change in PrEP Penetration.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05482360 |
| Phase | NA |
| Condition | Pre-Exposure Prophylaxis, HIV Infections, Pregnancy Related |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 5173 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Washington |
| Results posted | Yes |
2. Clinical Question
Population
Women receiving antenatal or postnatal services in maternal and child health clinics in Kenya. The primary endpoint description concerns cross-sectional groups from two time periods.
Intervention
Three implementation packages intended to improve PrEP delivery. Each combines strategies such as changes in clinic workflow or staffing, training, educational activities, and dispensing PrEP in maternal and child health services.
Comparator
Facilities assigned to a comparator group that never received an implementation strategy. The registry describes comparator groups for each package.
Primary question
How did the proportion of women screened for PrEP among women receiving antenatal or postnatal services change following the implementation strategies, compared with the comparator condition?
The primary outcome is titled “Change in PrEP Penetration.” It is a service-delivery measure: it relates the number of women screened for PrEP to the total number receiving antenatal or postnatal services. The registry describes the study as using an interrupted time series and describes the primary population as cross-sectional groups from two time periods. Its description also identifies a difference-in-differences design.
Three packages are described. Package 1 combines fast tracking, provider re-training, and dispensing PrEP in maternal and child health services. Package 2 shifts PrEP counseling from clinicians or nurses to HIV testing services providers, trains different cadres, and dispenses PrEP in maternal and child health services. Package 3 uses educational materials and health talks in waiting bays, alongside dispensing PrEP in those services. The record does not report outcome estimates comparing the packages with their comparators, so the direction or size of any change cannot be established from the registry information.
3. Trial Design
This is a completed, nonrandomized, parallel implementation study, with no masking. Its registered title concerns strategies to improve PrEP delivery for pregnant and postpartum women in Kenya. The sponsor is the University of Washington. The registry lists phase as not applicable. It records enrollment of 5173 and describes the study as testing implementation strategies in maternal and child health clinics using an interrupted time series.
The intervention is named “PrEP Optimization Interventions.” Three distinct implementation packages are described, each with a corresponding comparator description. The record says that four facilities were assigned to the comparator group for Package 1, four for Package 2, and four for Package 3; these comparator facilities never received an implementation strategy. The record does not give the number of facilities assigned to each intervention package. It does not establish that the comparator groups are independent of one another, so they should not be treated as separate populations beyond what the registry states.
The primary outcome description refers to cross-sectional groups from two time periods and says the analyzed population is a summation of the participants analyzed in those periods. It identifies a difference-in-differences design with two time periods. This is not a randomized comparison: allocation is recorded as nonrandomized, and the registry explicitly warns that the arms are not a like-for-like control comparison. Differences between groups or changes over time therefore require interpretation in light of the nonrandomized assignment.
The study start date is 2022-01-01, primary completion is recorded as 2023-12-15, and status is completed. The registry record does not report the allocation process beyond its nonrandomized designation, the timing of implementation relative to outcome measurement, or details of how the interrupted time-series component was modeled.
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: The enrollment number in the protocol section (5,173) includes the sum of participants who started in the participant flow module below (4,972), as well as the 201 additional health care workers who provided cross-sectional data in the intervention group during the intervention period. There was no drop-off between consent and enrollment.
Baseline Period (3 Months)
| Stage | Package 1 | Comparator for Package 1 | Package 2 | Comparator for Package 2 | Package 3 | Comparator for Package 3 |
|---|---|---|---|---|---|---|
| STARTED | 392 | 420 | 402 | 415 | 419 | 406 |
| COMPLETED | 392 | 420 | 402 | 415 | 419 | 406 |
| NOT COMPLETED | 0 | 0 | 0 | 0 | 0 | 0 |
Intervention Period (3 Months)
| Stage | Package 1 | Comparator for Package 1 | Package 2 | Comparator for Package 2 | Package 3 | Comparator for Package 3 |
|---|---|---|---|---|---|---|
| STARTED | 408 | 416 | 439 | 426 | 420 | 409 |
| COMPLETED | 408 | 416 | 439 | 426 | 420 | 409 |
| NOT COMPLETED | 0 | 0 | 0 | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The total population includes cross sectional groups from 2 time periods. The population analyzed above is a summation of the participants analyzed in the 2 periods. This is a difference in differences design with 2 time periods.
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.
| Characteristic | Unit | Package 1 | Comparator for Package 1 | Package 2 | Comparator for Package 2 | Package 3 | Comparator for Package 3 |
|---|---|---|---|---|---|---|---|
| Participants analysed | 392 | 420 | 402 | 415 | 419 | 406 | |
| Age, Continuous | years | 24 (21 to 28) | 25 (22 to 29) | 23.5 (21 to 28) | 24 (22 to 29) | 24 (21 to 27) | 24 (21 to 29) |
| Sex: Female, Male: Female | Participants | 392 | 420 | 402 | 415 | 419 | 406 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 392 | 420 | 402 | 415 | 419 | 406 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Region of Enrollment: Kenya | participants | 392 | 420 | 402 | 415 | 419 | 406 |
6. Primary Endpoint
The registry lists the primary outcome as Change in PrEP Penetration, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint, “Change in PrEP Penetration,” measures the proportion of women screened for PrEP among all women receiving antenatal or postnatal services. The registry gives the unit as participants and a timeframe of 6 months. It defines the numerator as women screened for PrEP and the denominator as total women receiving antenatal or postnatal services.
This endpoint focuses on whether screening reaches women attending maternal and child health services. It is therefore a measure of implementation and service delivery, rather than a direct measure of PrEP uptake, continuation, adherence, or clinical outcome. Those topics appear among the listed secondary outcomes, but the registry does not report their results.
The record describes the primary population as cross-sectional groups from two time periods and specifies a difference-in-differences design. In general, that approach compares changes over time in an intervention group with changes over time in a comparator group. The endpoint’s meaning depends on consistent definitions of screening and of the service population across the periods and groups. The registry does not report operational details such as the screening criteria, the exact measurement windows, or how missing endpoint information was handled.
No primary endpoint estimate, comparison, confidence interval, or significance test is reported in the registry record. The endpoint definition alone therefore identifies what was intended to be measured, but not whether or how it changed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the study design, intervention descriptions, and outcome definitions, but does not report numerical results for the primary endpoint. It provides no estimate of change in PrEP penetration, no between-group contrast, and no confidence interval or p-value for the primary outcome. Consequently, the direction, magnitude, and statistical precision of the primary result cannot be assessed from the registry information.
This distinction matters because a definition of an outcome is not an outcome result. “Change in PrEP Penetration” specifies a proportion based on screening and service attendance. It does not tell readers what the proportion was in either period, how much it changed, or whether changes differed between packages and comparator groups. No conclusion about the observed implementation effect can be drawn from the endpoint description alone.
The design is nonrandomized. In general, nonrandomized comparisons can reflect differences between facilities or populations in addition to the implementation strategy. A difference-in-differences analysis is intended to compare changes across groups, rather than simply compare their values at one time. Its interpretation depends on assumptions about how outcomes would have changed over time without the intervention. The registry record does not report whether these assumptions were assessed, what adjustment variables were used, or how facility-level differences were addressed.
The registry identifies an interrupted time series, while the primary outcome description specifies two time periods and a difference-in-differences design. These descriptions indicate a time-based comparison, but do not provide enough information to reconstruct the analysis model or its estimates. The record does not report the number of observations at each time point, the model form, handling of clustering, or any sensitivity analyses.
Enrollment of 5173 is recorded, but the record does not say how that enrollment relates to the participants included in each endpoint analysis. The primary population description refers to participants analyzed across two periods, but does not provide analysis denominators. Enrollment should therefore not be read as the analyzed sample for the primary comparison.
Serious adverse event counts are recorded as zero in each listed group, with no serious adverse event terms listed. This is a report of the figures in the registry record, not evidence about unreported events or a complete safety assessment. The record does not give a safety analysis method or a detailed definition of the events captured.
9. Statistical Methods Explained
The registry describes an interrupted time series and a primary outcome population comprising cross-sectional groups from two time periods. It also identifies a difference-in-differences design. These terms describe ways of evaluating changes over time, but the record does not provide the statistical model, estimates, or analysis details needed to reproduce the study’s results.
What does difference-in-differences mean?
In general, a difference-in-differences analysis compares the change over time in a group receiving an intervention with the change over time in a comparator group. The comparison is about the difference between those changes, rather than only a comparison of the groups at a single time. This can account for shared changes affecting both groups, provided the relevant assumptions are reasonable.
A key general assumption is that, absent the intervention, the groups would have followed sufficiently similar trends. With only two periods specified in the primary outcome description, the registry record does not show whether this assumption was examined using additional pre-intervention observations or other evidence. It also does not report how baseline differences, facility characteristics, or other changing influences were handled. The nonrandomized allocation makes these considerations important: measured changes cannot automatically be attributed to the implementation package.
What does interrupted time series add?
In general, interrupted time-series methods assess outcome patterns over time around an intervention point. They can distinguish a change in level from a change in trend when the data and model support that distinction. The registry says the study uses an interrupted time series, but its primary outcome description specifies two time periods. It does not report the number or spacing of time observations, the intervention point used in the model, or whether level and trend changes were estimated. Those details are not reported in the registry record.
How should a proportion endpoint be understood?
The primary outcome is a proportion: women screened for PrEP divided by women receiving antenatal or postnatal services. In general, a proportion describes how common an event or characteristic is within a defined denominator. Its interpretation depends on measuring the numerator and denominator consistently across groups and periods. A change in the proportion could reflect a change in screening, a change in who attends services, or both. The registry does not provide the underlying counts or period-specific values, so the contribution of these elements cannot be assessed.
What do uncertainty measures tell readers?
In general, a confidence interval describes a range of estimates compatible with the observed data under the statistical model and its assumptions. A narrower interval indicates greater precision within that framework; it does not remove possible bias from nonrandomized allocation or model misspecification. A p-value addresses how compatible the data are with a specified null hypothesis under the analysis assumptions. Neither a confidence interval nor a p-value establishes that an observed change was caused by an intervention. The registry record reports no primary outcome confidence interval or p-value.
Why can clustering matter?
In general, when implementation is assigned or delivered at a facility level, participants within the same facility may have more similar outcomes than participants from different facilities. Treating all participant observations as independent in that setting can understate uncertainty. Analyses can account for facility clustering using appropriate methods, but the registry record does not report whether or how clustering was handled. It also does not report the number of facilities assigned to each intervention package.
What can be said about analysis planning?
The registry record does not report the trial’s sample-size justification, statistical analysis plan, interim analyses, model specification, or prespecified adjustment strategy. It records enrollment of 5173, but not the analyzed denominator for the primary endpoint. The record lists 12 outcome measures and no analyses. No statistical significance or precision claim can be reconstructed from those entries. General statistical concepts can clarify how such methods work, but they cannot replace unreported trial-specific analysis details.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists secondary outcomes of PrEP uptake, PrEP continuation, client PrEP knowledge, PrEP adherence, and PrEP efficiency. It records 12 outcome measures, but no analyses. The record does not identify which secondary outcomes were analyzed, give their estimates, or report a method for addressing multiplicity. When several outcomes or comparisons are tested, general statistical practice recognizes that the chance of at least one apparently notable result can increase. Whether any adjustment or hierarchy was planned for this study is not reported in the registry record.
The record also does not describe a missing-data approach. It does not report missingness by outcome or group, how incomplete observations were treated, or whether any imputation or sensitivity analysis was used. These details matter because missing outcome data can affect both the estimated change and its uncertainty, particularly if missingness differs across groups or periods. No missingness pattern should be inferred from the enrollment figure.
The primary population description refers to cross-sectional groups from two periods and says the population analyzed is a summation of participants analyzed in those periods. It does not provide the period-specific analysis populations or denominators, nor does it specify inclusion and exclusion criteria. Enrollment of 5173 is recorded, but the registry does not state that this is the primary endpoint analysis population.
The registry does not report whether analyses followed a prespecified protocol or statistical analysis plan, or how deviations were handled. It also does not report the population used for each secondary outcome. These omissions limit assessment of selective analysis and the comparability of results across outcomes. They are reporting gaps, not evidence that a particular method was or was not used.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Package 1 | 0 | 800 | 0.0% |
| Comparator for Package 1 | 0 | 836 | 0.0% |
| Package 2 | 0 | 841 | 0.0% |
| Comparator for Package 2 | 0 | 841 | 0.0% |
| Package 3 | 0 | 839 | 0.0% |
| Comparator for Package 3 | 0 | 815 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Package 1 | 0 of 800 |
| Comparator for Package 1 | 0 of 836 |
| Package 2 | 0 of 841 |
| Comparator for Package 2 | 0 of 841 |
| Package 3 | 0 of 839 |
| Comparator for Package 3 | 0 of 815 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Package 1 | 0 of 800 |
| Comparator for Package 1 | 0 of 836 |
| Package 2 | 0 of 841 |
| Comparator for Package 2 | 0 of 841 |
| Package 3 | 0 of 839 |
| Comparator for Package 3 | 0 of 815 |
The registry records serious adverse event counts of zero for Package 1, its comparator, Package 2, its comparator, Package 3, and its comparator. The corresponding numbers listed at risk are 800, 836, 841, 841, 839, and 815. The record lists zero deaths for each group and no serious adverse event terms. These are the safety figures recorded for the groups, not estimates of risk for other populations or settings.
A zero count means that no serious adverse events were recorded in the registry’s group figures. In general, an observed zero does not establish that an event is impossible or that all events were detected. Interpretation depends on the period and procedures used to collect adverse event information, as well as the event definition and completeness of reporting. The registry record does not provide those details or a formal safety analysis.
The figures do not establish a comparative safety effect. The study is nonrandomized, and the record does not report a statistical comparison of adverse events. The listed numbers at risk should not be treated as the denominators for the primary screening endpoint, which is defined using women receiving antenatal or postnatal services.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the study tested three implementation packages intended to improve PrEP delivery in maternal and child health clinics in Kenya. Its primary endpoint was a service-coverage measure: the proportion of women screened for PrEP among women receiving antenatal or postnatal services. The record describes a nonrandomized, parallel design and a time-based comparison, with the primary outcome description specifying two periods and a difference-in-differences design.
It does not establish the size or direction of any change in PrEP penetration. No primary outcome estimates, group-specific proportions, confidence intervals, or p-values are reported. It is therefore not possible to determine from the registry record whether screening increased, decreased, or changed differently across packages and comparators. The outcome definition and study design are not substitutes for the missing result estimates.
Even if a result estimate were available, a nonrandomized comparison would need to be interpreted with attention to differences between facilities and populations, changes over time, and the assumptions of the analysis. The registry does not report enough model or diagnostic detail to assess these matters. The record also does not explain how missing data, clustering, or multiple outcomes were handled.
The listed serious adverse event figures are zero across the recorded groups, and zero deaths are listed. These figures describe what is registered for safety; they do not by themselves demonstrate the absence of all harms or establish a comparative safety conclusion.
The study addresses an implementation question, not simply whether PrEP is efficacious. Its stated focus is how strategies may affect delivery in maternal and child health services. The registry information identifies that question and the planned outcome, but does not provide the analyzed findings needed to judge the observed implementation results.
13. Why This Trial Matters Statistically
Implementation studies examine whether and how services are delivered in real-world settings. In this study, the primary endpoint connects PrEP screening with the broader population receiving antenatal or postnatal services. That makes the outcome useful for asking a service-delivery question: whether screening reaches people attending maternal and child health services, rather than only whether a service is offered in principle.
The three packages use different combinations of workflow, staffing, training, and educational strategies. Comparing approaches to implementation can be statistically challenging because facilities are not randomly assigned in this study. Changes may reflect both the strategies and other differences between facilities or changes over time. The registry’s description of a difference-in-differences design makes the time comparison central, while the nonrandomized allocation makes assumptions and analysis details important to interpretation.
The record also illustrates why endpoint definitions and outcome results must be distinguished. It defines PrEP penetration clearly as a screening proportion, but does not report the estimates needed to assess whether that measure changed. Without those estimates and their uncertainty, readers cannot judge the magnitude or precision of the observed pattern.
Finally, the listed secondary outcomes extend beyond screening to uptake, continuation, knowledge, adherence, and efficiency. These are related but distinct dimensions of implementation and use. The registry records 12 outcome measures but no analyses, leaving the relationship among these outcomes and the primary question unreported. The study’s statistical importance lies in the design and measurement questions it raises, while the missing results prevent a conclusion about what the analyses found.
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 most immediate limitation for interpreting the registry record is that primary outcome estimates and statistical analyses are not reported. The record therefore does not show the observed PrEP penetration values, the change over time, or the contrast between intervention packages and comparator conditions. The absence of reported results prevents assessment of effect size and precision.
Allocation is nonrandomized, and the registry warns that the arms are not a like-for-like control comparison. Differences between facilities or populations could influence the outcome independently of the implementation strategies. The record does not report allocation procedures, adjustment variables, or methods for assessing comparability.
The study is described both as an interrupted time series and as a difference-in-differences design with two time periods. The record does not specify the timing and frequency of observations or the fitted model. It consequently does not allow assessment of trends, intervention timing, or the assumptions supporting the time-based comparison. Facility-level clustering is also not discussed in the registry record.
The primary endpoint depends on consistent measurement of screening and the population receiving services. The record does not describe the screening definition, period-specific denominators, or missing-data handling. Although enrollment of 5173 is recorded, the primary analysis population and its group-specific denominators are not reported.
Finally, the record lists secondary outcomes and 12 outcome measures but no analyses. It does not report a multiplicity strategy, analysis plan, or details of safety-event collection. These reporting gaps do not show that methods were absent; they limit what can be assessed from the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Testing Implementation Strategies to Improve Delivery of PrEP for Pregnant and Postpartum Women in Kenya — NCT05482360.
- Registry record last updated 2025-02-26; status last verified 2025-02.
- Results first posted 2025-02-26.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes a completed, nonrandomized, parallel implementation study sponsored by the University of Washington. It tests three packages intended to improve PrEP delivery in maternal and child health clinics in Kenya. The primary outcome is change in PrEP penetration, defined as the proportion of women screened for PrEP among women receiving antenatal or postnatal services, with a 6-month timeframe.
The primary outcome description refers to cross-sectional groups from two time periods and identifies a difference-in-differences design. The study summary also describes an interrupted time series. Enrollment is recorded as 5173. The record lists secondary outcomes of PrEP uptake, continuation, client knowledge, adherence, and efficiency, alongside 12 outcome measures and no analyses.
Serious adverse event counts and deaths are recorded as zero for each listed group. The record does not report primary endpoint estimates, statistical uncertainty, missing-data methods, or a detailed analysis plan. These omissions prevent interpretation of the study’s outcome results from the registry information alone.