The Stony Brook University Calm-Mom Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Stony Brook University Calm-Mom Study (NCT04018625), a randomized na study. The primary outcome is Change in Perceived Stress as Indexed by Perceived Stress Scale (PSS-10) Score.

2. Clinical Question

The clinical question concerns whether an online program for prenatal stress is associated with change in participants’ perceived stress over time. The registry record identifies the primary outcome as change in Perceived Stress Scale (PSS-10) score, with higher scores indicating greater stress or a worse outcome. It describes a comparison involving pregnant participants assigned to an online SMART Mom program or a comparison condition.

The study description also names depression, anxiety, mindfulness, and current status measures. It says potential infant health outcomes were to be assessed through post-delivery electronic medical record review. These aims describe planned assessments, not findings. No conclusion about whether either program changed stress or other outcomes can be drawn from the registry information available.

3. Trial Design

The Stony Brook University Calm-Mom Study is listed as a randomized, double-masked, parallel-group behavioral study. Its phase is recorded as NA. The registry lists an enrollment of 63 and a completed status. The record gives a start date of 2021-04-01 and a primary completion date of 2023-06-01.

The brief summary describes a feasibility, acceptability, and preliminary efficacy evaluation of two internet-delivered prenatal programs. It says sixty pregnant women with estimated gestational age under 20 weeks would be screened and either enrolled in SMART Mom or Mama Support. The intervention descriptions, however, identify the two arms as SMART Mom and treatment as usual. Treatment as usual is described as referrals to community-based support groups and individual mental health providers. This inconsistency means the registry record does not give one unambiguous account of the intended comparison.

The arm descriptions state that 30 participants would be randomized to the SMART Pregnancy stress management program and 30 to treatment as usual. Those are arm-description counts; they do not establish how many participants were ultimately randomized, treated, or included in outcome analyses. Although total enrollment is listed as 63, the record does not explain how that figure relates to the arm descriptions or the brief summary’s screening description.

Assessments were scheduled at T1, described as treatment session 1 or enrollment and occurring within <2 weeks of baseline T0; T2 at mid-treatment, 4 weeks after enrollment; T3 after treatment, 8 weeks after enrollment; and T4 at delayed follow-up, 20 weeks after enrollment. The brief summary also refers to assessments at post-treatment, three, and six months after program completion. The relationship between these schedules is not explained in the registry record.

Randomization indicates that assignment was intended to occur by chance, but the method for generating or concealing assignments is not reported in the registry record. Double masking is recorded, but the people masked and how masking was implemented are not reported in the registry record. The record also does not explain deviations from the planned schedule, participant flow, or delivery and uptake of the programs.

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: Eligibility Criteria: (1) \< 25 weeks pregnant with medically confirmed viability, (2) speak, read and write in English, and (3) endorse elevated levels of PNMS (at least 1 SD higher than the population on NuPDQ). Exclusion Criteria: (1) current enrollment in psychotherapy, (2) current un-managed serious mental illness; (3) history of previous suicide attempt, (4) planning to move from Long Island in the next six months.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants with complete data at specified timepoints.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Baseline data reflects all women who presented for at least one session of the intervention or control group.

6. Primary Endpoint

The registry lists the primary outcome as Change in Perceived Stress as Indexed by Perceived Stress Scale (PSS-10) Score, measured over T1 (treatment session 1/enrollment date, occurred within <2 weeks of baseline T0), T2 mid-treatment (4 weeks post enrollment), T3 post treatment (8 weeks post enrollment), T4 delayed follow up (20 weeks post enrollment)..

The primary endpoint is change in perceived stress measured by the Perceived Stress Scale, identified as the PSS-10. The measure is described as assessing subjective stress experiences. Its total score ranges from 0 to 40, and higher scores indicate greater stress or a worse outcome. A score is a quantitative outcome: its magnitude can be described using a mean, while its spread among participants can be described using a standard deviation.

Repeated assessment is relevant because the study planned to follow perceived stress during and after the program rather than relying only on a single endpoint assessment. The registry lists T1 at treatment session 1 or enrollment, T2 at mid-treatment, T3 after treatment, and T4 at delayed follow-up. Comparing measurements across those times can describe whether scores changed within the observed participants and whether patterns differed between assigned groups, if an appropriate analysis is reported.

General context: a self-reported stress scale provides a standardized way to capture participants’ reported experiences, but a score is not itself a diagnosis or a direct measure of every aspect of stress. Change in a group mean also does not describe every participant’s experience. The size and precision of any estimated change, the completeness of follow-up, and the analysis population would all matter when interpreting findings.

The registry record does not report PSS-10 means, standard deviations, changes, between-group estimates, confidence intervals, or significance tests. It therefore documents the endpoint and its planned timing, but not the observed result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The following is general statistical context for reading a randomized study with a continuous outcome measured repeatedly. It does not describe methods confirmed for this trial unless they are explicitly identified in the registry record.

What does a mean and standard deviation describe?

The primary outcome is identified as a mean, with standard deviation as the measure of dispersion. A mean summarizes the central value of a set of scores. A standard deviation describes how spread out individual scores are around that mean. Together, they provide a basic description of a continuous measure, but they do not reveal the full distribution, identify outliers, or show how scores changed for each participant.

For a change outcome, the interpretation depends on what is being compared: a change within an assigned group, a difference in change between groups, or a model-based estimate across multiple assessment times. These quantities answer different questions. The registry record identifies change in PSS-10 as the primary outcome but does not report the specific contrast, estimate, or model used.

How should repeated assessments be understood?

Repeated measurements on one participant are related because they come from the same person. General methods for repeated data account for that correlation rather than treating every measurement as if it came from a different participant. A longitudinal analysis may estimate change over time, differences between assigned groups, or whether the time pattern differs by group. The choice depends on the research question and the analysis plan. The registry record gives scheduled assessment times but does not report the statistical model or planned contrast.

General methods may also need to consider whether assessment intervals are aligned across participants and whether the outcome is available at every scheduled time. In this study, the outcome population is described as participants with complete data at specified timepoints. The record does not say how partial measurement histories were handled or whether the timing differences described in the summary and primary outcome schedule were reconciled in analysis.

What does a confidence interval add?

In general, a confidence interval conveys the precision of an estimate under a specified statistical procedure and its assumptions. A narrow interval indicates greater precision than a wide interval for the same quantity and method. It should be interpreted alongside the estimate and the outcome scale. A confidence interval does not establish that a finding is important to participants, and it does not remove concerns about bias, missing data, or the validity of the comparison. No confidence interval for the primary outcome is reported in the registry record.

What does a significance test address?

In general, a significance test compares data with a null hypothesis under a model. A p-value is not the probability that the null hypothesis is true, nor is it a measure of the size or practical importance of an effect. Interpretation should focus on the estimated contrast and its uncertainty, with the analysis question and assumptions made clear. No primary outcome test or p-value is reported in the registry record.

Why can over-dispersion matter?

General context: over-dispersion means that observed variability is greater than a statistical model expects. If a model assumes less variability than the data contain, standard errors can be too small and confidence intervals can be too narrow. This issue is especially relevant to some count outcomes. The primary measure in this trial is continuous, and the registry record does not report an outcome model or evidence of over-dispersion. It would not be appropriate to claim that over-dispersion was assessed or affected the analysis.

What role does randomization play?

General context: random assignment aims to make assigned groups comparable, on average, with respect to both measured and unmeasured baseline characteristics. It does not guarantee identical groups in a particular trial, especially when enrollment is limited. Analysis according to randomized assignment can preserve the benefits of randomization, while excluding participants or analyzing only those who completed treatment may change the comparison. The registry labels allocation as randomized, but the analysis population and treatment of post-randomization exclusions are not reported in the registry record.

How should planning illustrations be read?

The record describes sample-size assumptions as a planning illustration computed from an observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. It also distinguishes participant counts per arm from total event counts for time-to-event settings. These are general planning conventions, not a description of the trial’s own design justification. The sample-size justification for the trial is not reported in the registry record, and no numerical planning outputs are reported in the registry record. A planning illustration is not an observed result and does not establish observed power.

The registry record does not describe the specific inferential methods used for the primary outcome. It does not report a model specification, adjustment variables, assumptions checks, a significance threshold for the trial analysis, interim analyses, or a prespecified statistical analysis plan. Those omissions prevent a detailed assessment of whether the analysis matched the randomized design and repeated-measure schedule.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is scheduled at multiple assessment times, and the study also lists secondary outcomes. When several outcomes, timepoints, or comparisons are examined, the chance of finding at least one apparently notable result can increase if each is tested separately without a plan for interpreting multiple tests. General approaches include defining one primary comparison in advance, using a hierarchical testing strategy, or adjusting inference across a family of tests. These approaches answer different questions and can affect precision. The registry record does not report a multiplicity strategy or identify one primary timepoint comparison.

The record states that the primary outcome has several categories or timepoints and was not reduced to one comparison. It lists eight outcome measures and names four secondary measures: PHQ-9, GAD-7, CAMS-R, and MOCS-A. It does not provide a complete account of the other outcome measures or report analyses. The analysis count is zero. The intended handling of multiple outcomes and repeated assessments is therefore not reported in the registry record.

The stated primary outcome population consists of participants with complete data at the specified timepoints. General context: complete-case analysis can be straightforward, but it may be biased if the availability of measurements is related to participants’ outcomes or other relevant characteristics. Other methods can use incomplete records under assumptions, but those assumptions and methods must be described and assessed. The number of participants with missing measurements, reasons for missingness, and any imputation or sensitivity analyses are not reported in the registry record.

The record also does not report whether the primary analysis followed randomized assignment, whether participants were analyzed according to treatment received, or how deviations from the assigned program were handled. The analysis populations and missing-data procedures are not reported in the registry record. These are material uncertainties for interpreting any future or separately posted estimates.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event record lists two groups: Intervention and Treatment as Usual. For each group, 30 participants are listed as at risk for serious adverse events and 30 as at risk for other adverse events. The reported counts of participants affected are zero for serious events and zero for other events in each group. Deaths are also listed as zero in each group. No top serious-event terms are listed.

These are reported counts, not proof that no adverse events occurred outside the recorded categories or observation period. A zero count means that the registry record lists no affected participants in that category for the group; it does not establish that the underlying event risk is zero. Counts also do not convey how long participants were observed, whether event ascertainment was complete, or whether all events were judged related to the intervention. Those details are not reported in the registry record.

The at-risk counts should not be treated as the total enrollment or as proof that every enrolled participant contributed safety information. The registry lists enrollment of 63, while each adverse-event group lists 30 at risk. The record does not explain the relationship between those figures. The safety entries are descriptive and do not support a comparative estimate of risk. No medical conclusion should be drawn from these counts alone.

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

The registry record establishes that a randomized, parallel-group behavioral study was completed and that change in perceived stress measured by PSS-10 was identified as the primary outcome. It also records scheduled assessments during treatment and follow-up, names several secondary measures, and lists adverse-event counts. This information can clarify what the study was intended to examine.

It does not establish the observed effect of either program. No primary outcome scores, changes, group comparisons, uncertainty intervals, or analysis results are reported in the registry record. The record lists zero analyses. Therefore, it is not possible to determine the direction or size of any change, how precisely it was estimated, or whether any difference between assigned groups was compatible with no difference.

Nor does the record establish feasibility or acceptability findings, despite describing these as study aims. It does not report the uptake or completion of the programs, participant feedback, or the results of secondary measures. Potential infant health outcomes are described as being assessed through post-delivery record review, but no such findings are reported.

General statistical context: even when an effect estimate is available, statistical evidence and practical importance are distinct. Precision depends on the amount and variability of observed data, while interpretation also depends on the quality of measurement, the comparison, missingness, and the relevance of the population. A randomized design can help support a causal comparison when implemented and analyzed appropriately, but the design label alone cannot establish that the intended procedures were followed.

The difference between the brief summary’s Mama Support comparator and the arm description’s treatment-as-usual comparator further limits interpretation of what the two groups were meant to receive. The registry record does not reconcile these descriptions. Thus, the record supports describing the planned research question and the limits of the posted information, not a conclusion that either program did or did not change stress.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between a study’s design and its results. The registry describes randomization, masking, a parallel-group structure, a continuous primary outcome, and repeated follow-up. Those details identify the broad framework in which an effect could be estimated. They do not substitute for outcome data or an analysis.

The planned repeated PSS-10 assessments raise a substantive analysis question: whether the focus is change over time within groups, a comparison between groups at a chosen time, or a difference in trajectories. These are related but not identical estimands. Clear reporting of the target comparison would make the result interpretable, particularly when the endpoint has several scheduled timepoints. That comparison is not reported in the registry record.

The record also illustrates why comparator descriptions matter. The brief summary identifies Mama Support, while the arm descriptions identify treatment as usual. A treatment contrast is meaningful only when the assigned conditions are described consistently enough to understand what participants received. The registry record does not explain the discrepancy.

Missing-data information is important for longitudinal studies because the set of participants observed can change across assessment times. The stated complete-data population makes the handling of incomplete follow-up particularly relevant. Without participant flow, missingness details, and the analysis approach, readers cannot assess how well an estimate would represent the randomized participants.

Finally, planning assumptions and observed findings serve different purposes. The record describes an illustrative sample-size approach but does not report its numerical outputs or the trial’s own sample-size justification. Such planning information cannot replace reported estimates and uncertainty. The most important statistical limitation of the registry record is that it documents an outcome plan without reporting the analysis needed to answer the study question.

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 registry record has several trial-specific limitations for interpretation. It gives conflicting descriptions of the comparison: the brief summary names Mama Support as an 8-session social support group, while the arm description names treatment as usual with referrals to community support groups and individual mental health providers. The record does not clarify whether these refer to the same comparator or to different planned conditions.

The enrollment count is 63, while the arm descriptions specify 30 participants in each group and the brief summary describes screening sixty women. The registry record does not explain the difference among these figures or report the number randomized, treated, followed, or included in each outcome analysis. The safety entries list 30 at risk in each group, but the relation of those counts to enrollment is not explained.

The assessment schedules are also not fully aligned in the descriptions. The primary outcome schedule specifies T1 through T4, including a delayed follow-up at 20 weeks after enrollment; the brief summary refers to post-treatment and three- and six-month assessments after program completion. How these schedules relate is not reported in the registry record.

Although the record identifies a primary continuous outcome and a complete-data population, it reports no outcome values or analyses. It does not report missing-data counts, participant flow, an analysis plan, the statistical model, multiplicity handling, or the sample-size justification. It records double masking but does not identify who was masked or how that was implemented. The record also does not provide feasibility, acceptability, secondary outcome, or infant outcome findings. These omissions limit assessment of the study’s execution and of any treatment comparison.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: The Stony Brook University Calm-Mom Study — NCT04018625.
• Registry record last updated 2026-08-20; status last verified 2026-06.
• Results first posted 2026-08-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The Stony Brook University Calm-Mom Study is listed as a completed randomized, double-masked, parallel-group behavioral study with enrollment of 63. Its primary outcome is change in PSS-10 score, assessed at scheduled points from enrollment through follow-up. The registry describes online SMART Mom and a comparator, but the comparator is described inconsistently as Mama Support and treatment as usual.

The record lists the primary outcome population as participants with complete data at specified timepoints. It identifies secondary measures including PHQ-9, GAD-7, CAMS-R, and MOCS-A, and records zero analyses. Serious and other adverse-event counts, and deaths, are listed as zero in both groups. No primary or secondary outcome results, sample-size justification, detailed statistical plan, or missing-data analysis are reported in the registry record. The available information therefore describes the study’s design and planned measures, but does not establish an observed effect.