Like Father Like Son: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Like Father Like Son (NCT04119414), a na na study. The primary outcome is Number of Early Infant Male Circumcision.

2. Clinical Question

The study concerns offering the Spear and Shield (S&S) Program followed by the Like Father Like Son (LFLS) Program to expecting couples. Its stated focus is early infant male circumcision, measured by whether male infants received circumcision during the first 60 days of life. The brief summary describes the purpose as examining the best way to offer the combined programs.

This is therefore a question about an outcome observed within a program group, not a reported comparison of outcomes between intervention and control groups. Without a reported outcome count and a comparison group, the record cannot establish how the program sequence relates to circumcision uptake relative to another approach. It also does not report results that would show whether the program was the best way to offer these services.

3. Trial Design

The registry identifies NCT04119414 as “Like Father Like Son,” with the official title “Increasing Early Infant Male Circumcision Uptake in Zambia: Like Father Like Son.” The study is marked completed. Its listed start date is 2019-10-08, and its primary completion date is 2022-06-30. The phase is recorded as not applicable, and allocation is listed as NA.

The design is identified as single-group, with no masking. The described S&S + LFLS Group consists of 300 expecting couples totaling 600 participants, completing the S&S Program followed by the LFLS Program. Both named interventions are classified as behavioral. The registry record does not describe a concurrent control group or a randomized allocation scheme.

That design distinction matters for interpretation. A single-group record can describe the participants receiving a program and an outcome measured in that group. It cannot, by itself, provide a randomized comparison with an alternative program or usual care. The record explicitly cautions that its arms are not a like-for-like control comparison. As a result, a between-group treatment effect should not be inferred from these design details.

The record lists four outcome measures, but no analyses are listed. It does not report a statistical analysis plan, a sample-size justification for the trial, or details of any interim analyses. The planning assumptions associated with sample-size illustrations are not evidence of the design rationale or of analyses actually conducted.

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 pilot study randomized 8 clinics to Experimental and Observation conditions. Participants were recruited from the four Experimental clinics. All expecting parents received the S\&S + LFLS intervention. However, the circumcision outcomes were ultimately only measured in male infant and male adult participants. Observation clinics were not intended to recruit participants and as such, only clinic level data was intended to be obtained. These clinics ultimately did not provide their data.

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Early Infant Male Circumcision, measured over Up to 60 days of life.

The primary endpoint is titled “Number of Early Infant Male Circumcision.” It is defined as the number of male infants who received circumcision during the first 60 days of life, with the unit recorded as participants. In practical terms, this is a count of participants whose infants meet the stated event definition within the stated time window.

A count-based endpoint can describe how many participants experienced an event in the group being studied. It is useful for expressing the amount of the target outcome observed in that group, provided the result and the relevant analysis population are reported. The registry record gives the endpoint definition but does not report the observed count, its denominator for outcome assessment, or an estimate of uncertainty.

For this endpoint, the event is receipt of circumcision within the specified period; it is not a measure of the quality of the program, the reasons for uptake, or outcomes beyond that time window. Those interpretations would require information not reported in the registry record. The endpoint is also not, on its own, a comparative effect measure. A comparative conclusion would require a suitable comparator and an analysis, neither of which is reported as a like-for-like comparison in this single-group record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a single-group study with no masking and no reported like-for-like control comparison. It defines a binary event outcome in terms of whether a male infant received circumcision during the first 60 days of life, while expressing the primary measure as a number of participants. No analysis is listed for that endpoint. The explanations below describe general statistical concepts; they are not claims about methods used in this study.

What does a count-based event outcome describe?

In general, a count of participants with an event reports the observed frequency of that event in a defined group. To interpret such a count, readers need to know who was eligible for assessment, who had outcome information available, and how the event was determined. A count alone does not communicate uncertainty or distinguish an intervention effect from other influences. In this record, the endpoint definition is stated, but the observed primary outcome count and the number assessed for it are not reported in the registry record.

What would a confidence interval add?

In general, a confidence interval presents a range of effect values compatible with the observed data under a statistical procedure. A narrower interval indicates greater precision under that procedure; a wider interval indicates more uncertainty. The interval does not correct for selection bias, missing data, or an unsuitable comparison. No primary-outcome confidence interval is reported in the registry record. With no posted outcome estimate, readers cannot assess the precision of the primary result.

Why does the comparison design matter?

In general, an intervention effect is estimated by comparing outcomes between groups that represent different treatment conditions. A randomized comparison can support causal interpretation when allocation, conduct, outcome assessment, and analysis are appropriate. In a single-group study, the observed outcome has no reported concurrent control outcome against which to estimate a between-group contrast. Changes over time or differences from other settings cannot be attributed to the program solely from an outcome within one group. The record specifically notes that its arms are not a like-for-like control comparison.

What does the planning illustration represent?

The record describes sample-size illustrations as planning calculations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect targeted is a stated fraction of the observed effect. It also distinguishes total event planning for time-to-event outcomes from participants per arm for other outcomes. These are planning assumptions, not evidence of the trial’s own design justification and not observed power. The record does not report the trial’s sample-size justification. Since the study is recorded as single-group and no primary outcome result is reported, these assumptions should not be mistaken for an analysis of the study’s program group or a randomized trial comparison.

Why can over-dispersion matter?

In general, over-dispersion occurs when count outcomes vary more than a statistical model expects. If ignored, uncertainty estimates can be too small and tests can appear more conclusive than warranted. Methods that allow extra variation may be appropriate for some count data, depending on the data structure and model. The registry record does not report a count model, a dispersion assessment, or an analysis for the primary endpoint, so no claim can be made that over-dispersion was assessed or addressed in this study.

What is not documented?

The registry record lists no analyses. It does not report the model used for the primary endpoint, covariate adjustment, an analysis population, handling of missing outcomes, or any interim analysis. These omissions mean that readers cannot reproduce an inferential result or check whether the analysis matched a prespecified plan. General statistical principles can explain why these details matter, but they cannot fill in methods that are not reported in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("S&S + LFLS Group")
n      <- c(600)
events <- c(300)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  S&S + LFLS Group  600  300  50.0  45.9  54.1  46.0  54.0  46.0  54.0

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists four outcome measures and no analyses. It does not report whether a multiplicity strategy was specified, such as prioritizing outcomes, adjusting significance thresholds, or treating analyses as exploratory. When several outcomes or hypotheses are examined, the chance of at least one apparently unusual result can increase. General approaches to multiplicity address that issue, but the record does not indicate which, if any, approach was used.

Missing-data handling is also not reported. The registry does not state how many participants had primary-outcome information available, whether any outcome data were missing, why data might be missing, or how missing observations were treated. In general, missingness can affect estimates when the availability of data is related to participant characteristics or outcomes. An analysis that excludes participants with unavailable outcomes may differ from one using other assumptions; readers need the analysis description to evaluate that choice. No such description is listed.

The analysis population is not reported. The record therefore does not specify whether analysis was intended to include all enrolled participants, only those who completed a program, or another defined set. Those populations can answer different questions and may produce different estimates. The described enrollment and the safety at-risk count should not be treated as confirmation of the primary endpoint’s analysis denominator.

Without a reported analysis, outcome result, missing-data approach, or analysis population, the registry entry does not support an assessment of multiplicity control or robustness to missing data. These are reporting gaps, not evidence that a particular method was or was not used outside the registry record.

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 safety record lists the S&S + LFLS Group with 600 participants at risk for serious adverse events and 0 affected. It also lists 600 at risk for other adverse events and 0 affected, and records 0 deaths. These figures describe the safety fields as entered in the registry record; they do not provide further detail about how events were collected or classified.

A zero count in a registry entry means that no affected participants are recorded in that field. It does not establish that an event is impossible, nor does it reveal how completely events were monitored or reported. In general, safety counts are interpreted in light of the observation period, event definitions, reporting procedures, and completeness of follow-up. Those details are not reported in the registry record.

The safety at-risk counts should not be substituted for the denominator of the primary circumcision outcome. The registry does not report the primary outcome denominator or count. These safety figures also do not provide a comparative safety estimate, because no like-for-like control comparison is described.

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

The record documents a completed study of the S&S Program followed by the LFLS Program in a group of expecting couples. It identifies early infant male circumcision during the first 60 days of life as the primary endpoint and reports safety counts for the described group. These details establish what the study was intended to examine and how the primary event was defined.

They do not establish the primary outcome result. The observed number of male infants meeting the endpoint definition is not reported in the registry record. Nor are an uncertainty interval, statistical test, or model-based estimate reported. A reader therefore cannot determine the observed uptake level or how precise an estimate might be from this record.

The single-group design also limits causal interpretation. A result from a group receiving the combined program sequence could describe the outcome within that group, but without a comparable group it would not show what the outcome would have been under another way of offering services. The stated study purpose refers to identifying the best way to offer the programs, but a comparative conclusion is not supported by the design details and results reported in the registry.

The record does not report participant-level outcome data, the analysis population, missing-data handling, or statistical analysis. As a result, it is not possible to assess whether all enrolled participants contributed to the endpoint or how uncertainty and potential biases were handled. The completed status does not resolve these gaps.

In short, the registry record describes a program sequence and a relevant outcome, but not an interpretable primary-outcome estimate. It does not establish a beneficial or harmful effect, and it does not establish equivalence or lack of effect. Such conclusions would require reported results and, for comparative claims, an appropriate comparison with transparent methods.

14. Why This Trial Matters Statistically

This study addresses an outcome that is directly defined in behavioral terms: whether male infants received circumcision during the first 60 days of life. A clear event definition and time window help specify what a study is measuring. The record also describes the sequence of behavioral programs, allowing readers to identify the intervention approach under study.

Statistically, the distinction between describing uptake in a program group and estimating an intervention effect is central. A single-group design can document an outcome in the people studied, but it does not supply a control outcome for a like-for-like contrast. This distinction helps prevent descriptive counts from being interpreted as evidence that the program caused an outcome or was preferable to another approach.

The record also illustrates why results reporting matters. An endpoint definition and enrollment description are not enough to evaluate the observed outcome. Readers need the event count, the number assessed, an analysis description, and a measure of uncertainty to judge the result’s scale and precision. Without those elements, even a completed study cannot answer the primary statistical question from the registry entry alone.

Finally, the safety figures and the primary endpoint answer different questions. Safety counts describe adverse-event fields, while the primary endpoint concerns circumcision uptake. Keeping those outcomes and denominators distinct is important for accurate interpretation. The record’s limitations are therefore not merely technical: they determine which conclusions can responsibly be drawn from the posted information.

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 most important trial-specific limitation in the registry record is that the primary outcome result is not reported. The endpoint is defined, but its observed count, analysis denominator, and uncertainty are absent. This prevents assessment of the magnitude or precision of the recorded outcome.

The study is identified as single-group, and the record cautions that its arms are not a like-for-like control comparison. No concurrent comparator is described. The stated aim of examining the best way to offer the programs therefore cannot be evaluated as a comparative question from the design information reported. No causal effect relative to another approach can be inferred from a single-group outcome.

The record does not report the eligibility criteria in detail, participant characteristics, outcome ascertainment procedures, analysis population, missing-data handling, or statistical model. It also does not report whether any analyses were conducted beyond listing no analyses in the registry. These omissions limit assessment of representativeness, bias, and the reliability of any estimate that might be reported elsewhere.

Although sample-size planning assumptions are described, the trial’s own sample-size justification is not reported in the registry record. The planning illustrations should not be treated as evidence of observed power or as a substitute for a trial analysis. The registry also does not report details of interim analyses or a multiplicity strategy. These are limitations of the information recorded; they do not establish what may have occurred outside the registry entry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Like Father Like Son — NCT04119414.
• Registry record last updated 2023-08-02; status last verified 2023-07.
• Results first posted 2023-08-02.
• 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

NCT04119414, “Like Father Like Son,” is listed as completed. The official title is “Increasing Early Infant Male Circumcision Uptake in Zambia: Like Father Like Son.” The record lists a start date of 2019-10-08 and a primary completion date of 2022-06-30.

The study is identified as single-group, with no masking. The described group completes the behavioral Spear and Shield Program followed by the behavioral Like Father Like Son Program. The primary endpoint is the number of male infants who received circumcision during the first 60 days of life.

The registry record lists four outcome measures and no analyses. It does not report the primary endpoint result, an analysis population, or a like-for-like control comparison. Safety fields record 0 serious adverse events, 0 other adverse events, and 0 deaths in the described group. The recorded safety at-risk count is 600.