Texting to Promote Breastfeeding (TOPS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Texting to Promote Breastfeeding (TOPS) (NCT06375655), a randomized na study. The primary outcome is Number of Participants Who do Not Opt Out of Receipt of Text Messages.

2. Clinical Question

3. Trial Design

Texting to Promote Breastfeeding (TOPS), registered as NCT06375655, is a randomized, parallel-group behavioral trial sponsored by Case Western Reserve University. The registry lists the study as completed. Its recorded start date is 2024-07-15, and its primary completion date is 2025-08-08. The phase is listed as NA. The registry describes masking as none, so the study is recorded as open-label rather than masked.

Participants were assigned to Team2BF or Bright By Text. Team2BF focuses on breastfeeding-supportive messages and uses a schedule that changes from pregnancy through the postpartum period. Bright By Text sends messages about a broader range of maternal and child health subjects, with some messages specifically about breastfeeding. The comparison is therefore between two active texting programs, not between texting and no texting. The registry record does not report further details about the randomization procedure, allocation concealment, or whether any outcome assessors were masked.

The registry reports enrollment of 83, while the brief summary describes a plan to enroll up to 80 mothers and infants. The primary results list 40 participants in each arm. These figures describe different registry entries, and the record does not explain their relationship. For the secondary exclusive-breastfeeding result, the posted arm counts are 39 in Team2BF and 40 in Bright By Text. The record does not report why the analyzed counts differ across endpoints.

The primary outcome is the count of participants who do not opt out of receiving messages, with a timeframe of up to 6 months postpartum. Breastfeeding outcomes are listed among the secondary outcomes, including exclusive breastfeeding at 2 months postpartum and changes in exclusive or partial breastfeeding. A detailed statistical analysis plan, the intended analysis population, and the handling of missing outcome data are not reported in the registry record.

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: Enrolled participants were not removed from the study prior to assignment. Three participants delivered prematurely and 3 new participants were recruited in their places to achieve 80 total participants.

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 Participants Who do Not Opt Out of Receipt of Text Messages, measured over Up to 6 months postpartum.

The primary endpoint counts participants who do not opt out of receiving text messages, over a timeframe of up to 6 months postpartum. In these posted results, the count is 40 in the Team2BF arm and 40 in the Bright By Text arm. This outcome reflects continued receipt of messages, rather than whether participants breastfeed or whether the messages change breastfeeding behavior.

As a measure of program engagement, an opt-out endpoint can describe whether participants remain subscribed to a texting program. That may be relevant to interpreting whether a program is acceptable or usable over time. This is a general explanation of the endpoint type; the registry record does not report why this endpoint was selected as primary or how investigators intended to interpret it relative to breastfeeding outcomes.

The distinction between engagement and breastfeeding is important. The primary result cannot, by itself, answer whether one program leads to more exclusive breastfeeding. The registry lists exclusive breastfeeding at 2 months postpartum as a secondary outcome measured by participant report or chart review. That outcome is more directly related to the stated breastfeeding question, but its status as secondary means it does not replace the primary endpoint in the registered outcome hierarchy. The registry record does not provide further definitions of opting out, the confirmation process for subscription status, or the rules used to classify breastfeeding status.

7. Results Posted in the Registry

• Bright By Text: 100.0% (40/40) versus 100.0% (40/40) 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. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Number of Participants Who Are Exclusively Breastfeeding at 2 Months Postpartum as Measured by Participant Report/Chart Review

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Bright By Text: 45.0% (18/40) versus 41.0% (16/39) on control; risk difference 4.0 percentage points (95% CI -17.8 to 25.8), risk ratio 1.10 (0.66–1.82); unadjusted two-proportion z-test p = 0.721.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Bright By Text and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists three secondary breastfeeding outcomes: exclusive breastfeeding at 2 months postpartum, changes in exclusive breastfeeding, and changes in partial breastfeeding. Numerical results are posted for the exclusive-breastfeeding outcome at 2 months. Numerical estimates for the two change outcomes are not reported in the registry record. The available secondary evidence is therefore incomplete as a picture of all the listed breastfeeding outcomes.

The posted exclusive-breastfeeding comparison addresses a different outcome from the primary endpoint. The primary result counts participants who did not opt out of messages; it does not measure breastfeeding. The secondary result is more directly relevant to breastfeeding status, but its estimate is uncertain, with a confidence interval that includes zero and values in both directions. The primary result should not be treated as confirmation of the secondary result, nor should the secondary result be interpreted as explaining the primary engagement count.

Secondary outcomes generally carry less confirmatory weight than a prespecified primary outcome because multiple outcomes create more opportunities to find an apparently noteworthy result by chance. This is a general statistical concern, not a claim about what occurred in this trial. A multiplicity strategy can account for testing several outcomes, but such a strategy is not reported in the registry record. The available secondary p-value is unadjusted, and the record does not say whether any adjustment or hierarchy was planned.

The secondary outcome results should therefore be read as supportive or exploratory evidence, with attention to their uncertainty and their relationship to the registered outcome hierarchy. They do not establish an overall effect across all breastfeeding measures. No combined estimate across the listed secondary outcomes is reported in the registry record, and the unreported numerical results should not be inferred from the one available comparison.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Number of Participants Who Are Exclusively Breastfeeding at 2 Months Postpartum as Measured by Participant Report/Chart Review
• Change in the Number of Participants Who Are Exclusively Breastfeeding as Measured by Participant Report/Chart Review
• Change in the Number of Participants Who Are Partially Breastfeeding as Measured by Participant Report/Chart Review

9. Statistical Interpretation

10. Statistical Methods Explained

The primary result is a comparison of counts between two randomized arms. For a binary outcome, each participant can be classified according to whether the event of interest occurred. Here, the endpoint is not opting out of messages, and the posted result reports the number of participants meeting that condition in each arm. A risk difference expresses the difference between the two arms’ event proportions. A risk ratio compares those proportions as a ratio. An odds ratio compares the event odds across arms. These are different ways to describe a binary comparison; they do not change what outcome was measured.

The primary comparison reports equal counts of 40 in both arms. Its risk difference is 0.0 and its risk ratio is 1.0. The reported Fisher Exact analysis has an odds ratio value of 0 and p = 1. The registry does not provide confidence limits for that sponsor-reported odds ratio. A p-value measures how compatible the observed data are with a specified null model under the test’s assumptions; it is not the probability that the null hypothesis is true, nor a measure of the size or importance of an effect. A value of p = 1 does not prove equivalence. In this case, the identical posted counts indicate no observed difference for this endpoint, but the registry record does not report an equivalence margin or an equivalence analysis.

The secondary exclusive-breastfeeding outcome is also binary: participants are counted as exclusively breastfeeding or not at 2 months postpartum. Its posted comparison includes a risk difference of 0.040 and a confidence interval from -0.178 to 0.258. The interval describes a range of values compatible with the observed data under the method used, subject to its assumptions. Because it includes zero, the data do not rule out no difference. Because it extends in both directions, it also reflects uncertainty about which arm might have the higher rate and about the size of any difference.

The reported sponsor analysis for the secondary outcome is a chi-squared test, with p = 0.7. The recalculated unadjusted p-value is 0.721. A chi-squared test assesses evidence against the null hypothesis of no association between arm and outcome. The recalculation uses the posted summary counts and is an unadjusted comparison. The sponsor’s stated analysis is the registry’s reported inferential result; the recalculation is a supplementary way to describe the posted data, not a replacement for a prespecified analysis.

What does unadjusted mean?

An unadjusted comparison evaluates the arm difference without accounting for other participant characteristics or covariates. This can be an appropriate simple description of randomized groups, but it does not show whether an adjusted analysis would give the same result. The registry record does not report a covariate-adjusted analysis or specify covariates for such an analysis. It also does not report whether the sponsor’s chi-squared test was prespecified in a detailed analysis plan.

What can the planning illustration tell us?

The planning illustration uses the observed secondary effect as its starting point and gives participant counts per arm for specified power targets and effect fractions. It assumes a two-sided significance level of 0.05, equal allocation, and a normal approximation. For 100% of the observed effect, it gives 2,435 participants per arm for 80% power and 3,260 participants per arm for 90% power. For 75% of the observed effect, it gives 4,317 participants per arm for 80% power and 5,779 participants per arm for 90% power. For 50% of the observed effect, it gives 9,684 participants per arm for 80% power and 12,964 participants per arm for 90% power.

These are planning illustrations, not observed power and not the trial’s documented sample-size justification. The registry record does not report the trial’s sample-size calculation or the assumptions used to design the study. Such illustrations are sensitive to the effect estimate used: an effect smaller than the observed estimate requires more participants to detect under the stated assumptions. The observed effect itself is uncertain, as reflected by its confidence interval, so these counts should not be read as definitive requirements for a future trial.

Why does outcome definition matter?

The primary endpoint is an engagement count, whereas exclusive breastfeeding is a separate secondary outcome. Statistical methods can quantify uncertainty for the chosen outcome, but they cannot make one outcome stand in for another. A result about remaining subscribed to messages does not directly establish a result about feeding practice. Likewise, the secondary breastfeeding estimate should be interpreted according to its measurement definition and data source. The registry identifies participant report or chart review, but does not report further details about assessment procedures, adjudication, or agreement between sources.

11. Confidence Intervals and Precision

Precision concerns how narrowly the data estimate a comparative effect. The secondary exclusive-breastfeeding comparison has a risk-difference estimate of 0.040 and a confidence interval from -0.178 to 0.258. The point estimate is the single value calculated from the posted counts, while the interval conveys uncertainty around that estimate under the method’s assumptions. The interval includes zero, so the posted results are compatible with no difference. It also includes values in either direction, so they do not precisely identify which program has the higher rate or the magnitude of any difference.

The associated risk-ratio estimate is 1.097, with a confidence interval from 0.659 to 1.825. The odds-ratio estimate is 1.176, with a confidence interval from 0.482 to 2.869. These measures use different scales, but their intervals likewise include their respective null values. Taken together, they indicate uncertainty rather than a tightly estimated comparative effect.

Confidence intervals are not guarantees that the true effect lies within the interval, and they do not express the probability that a particular effect is true. They are constructed by a statistical procedure with stated coverage properties under its assumptions. The registry record does not report additional interval-method details beyond the posted estimates. The relatively wide range of plausible differences should caution against treating the point estimate as a precise estimate of the programs’ comparative effect.

For the primary opt-out endpoint, the posted risk difference and its limits are all 0.0, and the risk ratio is 1.0. These values reflect the identical counts reported in the two arms. The registry does not report confidence limits for the sponsor’s primary odds-ratio result. Equal observed counts are not by themselves evidence that all plausible population effects are exactly zero; interpretation of precision depends on the analysis and its uncertainty estimates.

12. Analyses Reported by the Sponsor

For the primary endpoint, the registry reports a Fisher Exact analysis with an odds ratio value of 0 and p = 1. The posted counts are 40 participants who did not opt out in each arm, and the accompanying unadjusted comparison reports a risk difference of 0.0. The registry does not provide confidence limits for the sponsor-reported odds ratio. These results describe identical observed counts; they do not demonstrate equivalence or establish that the programs have identical effects in the wider population.

For exclusive breastfeeding at 2 months postpartum, the sponsor’s reported analysis is a chi-squared test with p = 0.7. The simple unadjusted recalculation from the posted summary counts gives p = 0.721, alongside a risk difference of 0.040 and a confidence interval from -0.178 to 0.258. The sponsor’s rounded p-value and the recalculated p-value are close, and both indicate that the posted comparison does not provide strong evidence against a null difference. The registry does not report enough detail to establish whether the sponsor used exactly the same computational conventions as the recalculation.

The recalculated result is a supplementary summary of posted counts, not an alternative sponsor analysis. If a discrepancy between a sponsor result and a simple recalculation were present, the sponsor’s own analysis would take precedence. For this secondary outcome, the values do not suggest a material conflict, although the exact analysis plan and the rationale for test selection are not reported in the registry record.

13. Multiplicity, Missing Data and Analysis Populations

The registry lists several outcomes, including a primary measure of not opting out of messages and secondary measures of breastfeeding status and change. When multiple outcomes or analyses are tested, the chance of at least one apparently positive result can increase. Statistical plans often address this issue by specifying a hierarchy, adjusting significance thresholds, or identifying some analyses as exploratory. These are general approaches. A multiplicity procedure, a hierarchy among secondary outcomes, and any designation of exploratory analyses are not reported in the registry record.

The available secondary comparison is accompanied by an unadjusted p-value of 0.721. The record does not report an adjustment for the number of secondary outcomes or analyses. An unadjusted p-value should not be treated as if it accounts for all opportunities to test outcomes. This does not invalidate the estimate, but it affects the strength of claims based on nominal statistical evidence.

Missing-data handling is another important part of interpretation. The exclusive-breastfeeding result uses 39 participants in Team2BF and 40 in Bright By Text, while the primary endpoint reports 40 in each arm. The reason for the differing endpoint counts and the handling of participants without outcome data are not reported in the registry record. The record does not describe imputation, complete-case rules, sensitivity analyses, or how participant report and chart review were combined.

The analysis population is also not specified in detail. The registry does not report whether results were analyzed according to randomized assignment, whether any participants were excluded after randomization, or how protocol deviations were handled. Randomization can support fair comparisons, but exclusions or missing outcomes can affect the comparability of analyzed groups. The registry record does not provide enough information to assess these matters fully.

Finally, the registry does not report a detailed statistical analysis plan, interim analyses, or a sample-size justification. Their absence from the record should not be taken as evidence that a particular procedure was or was not used; it means those details cannot be assessed from the registered information. The planning illustration based on the observed secondary effect is not evidence about the original design assumptions.

14. 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 posted safety figures list 40 participants at risk in each arm, with zero serious adverse events, zero other adverse events, and zero deaths in each arm. These are the registry’s reported counts for the displayed safety categories. They indicate that no events were recorded in those categories among the participants represented by these figures.

Zero recorded events does not establish that the programs have no risks. Rare events may not appear in a study of this size, and the registry record does not report additional details about event definitions, collection procedures, follow-up completeness, or attribution. The record also does not identify serious adverse event terms, because none are listed. These figures should be read as a description of what was reported, not as proof of absence of harm.

The intervention is described as behavioral text messaging. The safety counts do not assess breastfeeding outcomes or message engagement; those are separate endpoints. Interpretation of safety also depends on the timeframe and completeness of surveillance, and details beyond the reported counts are not reported in the registry record.

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

The posted results describe two different kinds of outcomes. The primary endpoint is whether participants did not opt out of messages, and the observed counts are equal in the two arms. That finding describes engagement with the texting programs over the stated timeframe; it does not answer whether either program increases breastfeeding. The available secondary comparison concerns exclusive breastfeeding at 2 months postpartum. Its estimate has substantial uncertainty, and the registry does not report numerical results for the other listed secondary breastfeeding outcomes.

The results do not establish that the programs are equivalent. A failure to show a clear difference is not the same as demonstrating that any true difference is small enough to be unimportant. Equivalence or non-inferiority requires a defined margin and an analysis designed to assess that question; such details are not reported in the registry record. Similarly, the posted estimates do not prove that the programs have no effect, or that any observed difference is caused by the message content.

The comparison is between Team2BF and Bright By Text, both active texting programs with different content and schedules. It does not compare texting with no messaging. The trial’s randomized design is relevant to the comparative question, but the available registry information does not provide all details needed to evaluate the randomization process, missing data, or analysis populations.

Results apply most directly to the participants and procedures represented in the trial record. The registry describes the intended population as African-American/Black expectant women, but does not provide enough participant characteristics to assess how well the enrolled group represents that broader population. The results should not be generalized to other settings, populations, or texting programs without evidence that the relevant circumstances are comparable. Overall, the record supports a cautious description of the posted counts and estimates, not a broad claim about breastfeeding outcomes or program effectiveness.

16. Why This Trial Matters Statistically

This trial illustrates why endpoint choice matters in clinical research. A study can have a primary outcome that captures engagement with an intervention while its underlying scientific interest concerns a health behavior. Those endpoints may be related, but they are not interchangeable. Here, not opting out of text messages measures continued receipt, whereas exclusive breastfeeding is a separate outcome. Clear interpretation requires keeping the outcome actually measured distinct from the broader question motivating the study.

It also illustrates the role of uncertainty. The secondary estimate is accompanied by a confidence interval spanning the null and effects in both directions. The point estimate alone would give an incomplete account; the interval conveys how imprecisely the comparative effect is estimated. A non-significant comparison is not proof of no difference, and identical observed primary counts do not establish equivalence.

For biostatisticians and clinical researchers, the record highlights the importance of transparent reporting of the analysis population, missing-data procedures, multiplicity strategy, and design assumptions. These details help readers determine what inferences the results support. Their absence from the registry record limits independent assessment, even when counts and a sponsor analysis are posted.

Finally, planning calculations based on an observed effect should be interpreted as illustrations rather than as retrospective evidence of power or as a record of the trial’s original sample-size rationale. The observed effect is itself uncertain. Separating planning assumptions from observed findings is essential to avoid overstating what a small set of posted results can establish.

17. 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 leaves several trial-specific details unclear. It reports enrollment of 83 and a brief-summary plan to enroll up to 80, while the primary outcome lists 40 participants in each arm. It does not explain the relationship among these figures. The secondary exclusive-breastfeeding outcome uses 39 participants in Team2BF and 40 in Bright By Text, and the reason for that difference is not reported in the registry record.

The primary endpoint measures not opting out of text messages rather than breastfeeding. This distinction limits how directly the primary result answers the trial’s stated breastfeeding question. The registry lists breastfeeding outcomes as secondary, but numerical results are not reported for the two listed change outcomes. As a result, the available posted findings do not describe the full set of breastfeeding measures identified in the record.

The record does not report a detailed analysis plan, randomization procedure, allocation concealment, analysis population, missing-data handling, or multiplicity adjustment. It also does not give detailed definitions or assessment procedures for the breastfeeding outcomes beyond participant report or chart review. These omissions constrain assessment of bias, robustness, and whether analyses followed prespecified procedures.

The study is recorded as open-label, with no masking. The registry does not describe safeguards against awareness affecting reporting or assessment. The posted planning illustration is based on the observed effect and is not the trial’s documented sample-size justification. Finally, the study’s counts and estimates should be interpreted in the context of the enrolled sample and the two specific messaging programs; the record does not establish how results would translate to other populations or programs.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Texting to Promote Breastfeeding (TOPS) — NCT06375655.
• Registry record last updated 2025-11-18; status last verified 2025-11.
• Results first posted 2025-11-18.
• 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.

21. Record Summary

Texting to Promote Breastfeeding (TOPS), NCT06375655, is a completed randomized, parallel-group behavioral trial sponsored by Case Western Reserve University. The registry records no masking and lists the study phase as NA. The recorded start date is 2024-07-15, and the primary completion date is 2025-08-08.

The comparison is Team2BF, a breastfeeding-focused texting program, versus Bright By Text, a broader maternal and child health texting program that includes breastfeeding messages. The primary outcome counts participants who did not opt out of messages, up to 6 months postpartum. The posted count is 40 in each arm, with a risk difference of 0.0 and reported Fisher Exact p = 1.

The available secondary result for exclusive breastfeeding at 2 months postpartum is 16 of 39 in Team2BF and 18 of 40 in Bright By Text. Its unadjusted risk difference is 0.040, with a confidence interval from -0.178 to 0.258 and p = 0.721. Other listed secondary results and further analysis details are not reported in the registry record.