Evaluating the Effectiveness of Sertraline in Treating Women With Premenstrual Dysphoric Disorder: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating the Effectiveness of Sertraline in Treating Women With Premenstrual Dysphoric Disorder (NCT00536198), a randomized phase 4 study. The primary outcome is Premenstrual Tension Scale (PMTS).

2. Clinical Question

This question concerns a symptom measure over the stated assessment period, not every possible outcome associated with premenstrual dysphoric disorder. The record also lists secondary measures covering clinical global severity, depression, physical symptoms, anger or irritability, and clinical global improvement. Those additional measures broaden the range of outcomes considered, but their presence does not resolve the missing primary comparison. Without reported group estimates and measures of uncertainty, the direction, size, and precision of the primary contrast cannot be determined from the registry record.

3. Trial Design

The registry describes a Phase 4 study with randomized allocation, triple masking, and a parallel-group model. In a randomized parallel-group trial, participants are assigned to one of the treatment groups and remain in that assigned group for comparison; randomization is intended to support a fair comparison by limiting systematic differences in assignment. The record does not describe the sequence-generation method, allocation concealment, or the people included in the triple masking.

The study enrolled 252 participants and compared sertraline with placebo. Sertraline was taken during the symptomatic period, with a planned dose between 50 and 100 mg. The arm description allows a reduction to 25 mg for women reporting moderate to severe side effects, with an increase in the next cycle unless rate-limiting side effects continued. The placebo arm took a similar-looking placebo during the symptomatic period. The record does not state how adherence, dose changes, or treatment discontinuation were handled in the analysis.

The primary outcome was PMTS, measured from baseline to Cycle 6. The registry describes the primary population as all randomized participants. It also lists five secondary outcomes: Clinical Global Severity (CGI-S), DRSP Depression Subscale, DRSP Physical Subscale, DRSP Anger/Irritability Subscale, and Clinical Global Impressions-Improvement (CGI-I). It records 12 outcome measures and 43 analyses, but does not provide a detailed analysis plan that explains how these measures and analyses relate to one another.

The study is marked completed. Its start date is 2007-11-06, and its primary completion is recorded as 2012-02. The registry record does not report the protocol details needed to establish how many assessments occurred, how participants were followed, or how the reported analyses were selected. Although the record notes that the primary outcome has several categories or time points and was not reduced to one comparison, it does not supply a numerical primary-outcome estimate for interpretation.

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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: all randomized participants

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: Analysis included all women enrolled.

6. Primary Endpoint

The registry lists the primary outcome as Premenstrual Tension Scale (PMTS), measured over Measured from baseline to Cycle 6.

The primary endpoint is the Premenstrual Tension Scale (PMTS), a measure described as a 10-item scale constructed to study premenstrual syndromes and sensitive to change with treatment. Its listed content includes irritability-hostility, tension, efficiency, dysphoria, motor coordination, mental-cognitive functioning, eating habits, social impairment, sex drive, and physical symptoms. The record gives a range from 0, described as asymptomatic, to 40, described as highly symptomatic; higher scores indicate more severe problems.

The stated timeframe is measured from baseline to Cycle 6. Measuring a symptom scale over time can make it possible to describe change during the study period and compare the patterns between randomized groups. The registry identifies the outcome as a mean with standard deviation, which describes the average score and the spread of scores around that average. Those summary statistics alone would not establish the size or precision of a between-group difference; an estimate of the contrast and its uncertainty would be needed for that interpretation.

The record includes the wording “PMTS-O or PMTS-SR?” but does not clarify which form was used. It also does not give the numerical scores, a primary contrast, or a confidence interval. The record notes that the primary outcome has several categories or time points and was not reduced to one comparison. As a result, the outcome’s scale and intended assessment period are identifiable, but the primary result is not interpretable as a single reported estimate.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The design features and statistical concepts below help explain how a trial of this type is generally interpreted. They do not establish which specific analysis procedures were used in this study. The registry record does not report a detailed statistical analysis plan, the test used for the primary endpoint, or the model used to handle repeated measurements.

What does randomization contribute?

In general, random assignment aims to make treatment groups comparable at the start of a study, including with respect to factors that may be measured and factors that may not be measured. It supports interpreting a between-group contrast as a comparison of assigned groups rather than a comparison created by participants choosing their treatment. Randomization does not guarantee that every baseline feature will be identical between groups, and it does not resolve problems caused by missing outcome data or incomplete reporting. The registry identifies the allocation as randomized but does not describe the randomization sequence or concealment procedures.

What does masking mean?

The registry labels the study triple-masked and describes the placebo as similar-looking. Masking is generally intended to limit the influence of knowing treatment assignment on participant experience, clinical care, outcome assessment, or analysis. The record does not identify the three masked roles or state how masking was maintained or assessed. Therefore, the label can be reported, but the exact protections it represents cannot be determined from this record.

How should a mean and standard deviation be understood?

The primary outcome is identified as a mean of a continuous measure, with standard deviation as its dispersion. In general, a mean gives the average score in a group, while a standard deviation describes how spread out individual scores are around that average. A standard deviation is not the uncertainty around a treatment comparison. To assess the comparison, readers need an effect estimate, such as a difference between groups or a difference in change, and a measure of its uncertainty. The registry does not report a single such primary estimate.

What does a confidence interval convey?

In general, a confidence interval presents a range of values compatible with an estimated effect under the assumptions of the analysis. A narrower interval indicates greater precision than a wider interval, while the interval’s position relative to a null value helps readers judge which effect sizes remain compatible with the data. A confidence interval does not guarantee that the true effect lies within its bounds, and it cannot correct for bias in design, measurement, or analysis. No primary-outcome confidence interval is reported in the registry record.

Why does the outcome structure matter?

The registry says the primary outcome has several categories or time points and was not reduced to one comparison. In general, repeated measurements can be analyzed in different ways: each time point might be compared separately, change might be summarized across time, or a model might use the measurements jointly. These approaches answer different questions and can produce different estimates. The analysis plan, including the selected time point or overall contrast, is needed to interpret a primary result. The registry record does not specify that plan.

The record gives baseline to Cycle 6 as the primary outcome timeframe. That definition identifies the intended window, but does not tell readers which measurements were available for each participant or how incomplete follow-up was addressed. It also does not report whether the primary analysis used all randomized participants as intended, a subset with observed outcomes, or another analysis population. The outcome description names all randomized participants, but this alone does not document the analysis actually performed.

Why can over-dispersion matter?

In general, over-dispersion describes variability greater than a statistical model expects. It is particularly relevant when outcomes are counts or categories and the model’s assumptions do not capture the observed spread. If over-dispersion is ignored, standard errors can be too small and uncertainty can be understated. The primary PMTS measure is described as continuous, and the registry does not report an over-dispersion assessment or a model for the primary analysis. This general concept should not be mistaken for evidence that over-dispersion occurred in this trial.

What do the planning assumptions mean?

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It also says the effect to detect is a stated fraction of the observed effect. Such calculations are generally conditional on the assumed effect and analysis framework; they are not a measure of how likely the completed study was to find a result, and they are not observed power. The registry record does not provide the numerical illustration outputs or the observed effect in the registry record for interpretation. The record also does not report the trial’s original sample-size justification, so the planning illustration should not be treated as that justification.

For a continuous outcome, planning calculations generally depend on the expected difference, variability, allocation, significance level, and desired power. If the assumed effect is smaller, more participants may be needed to distinguish it from random variation under a chosen framework. That is a general statistical relationship, not a reconstruction of this trial’s design. No numerical sample-size result should be inferred from the listed assumptions alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry records 12 outcome measures and 43 analyses. It lists PMTS as the primary outcome and names secondary measures for clinical global severity, depression, physical symptoms, anger or irritability, and clinical global improvement. Multiple outcomes, time points, categories, and analyses can create multiplicity: when many statistical comparisons are made, the chance of at least one apparently notable result can increase. General methods for addressing multiplicity include prespecifying a primary comparison, adjusting inferential thresholds, or treating some analyses as exploratory. The registry record does not report whether any such approach was planned or used.

The record specifically notes that the primary outcome has several categories or time points and was not reduced to one comparison. It does not identify a single primary contrast or explain how the multiple time points or categories were treated. Without that information, a reader cannot determine which comparison was intended to support the principal conclusion or how the collection of analyses affects interpretation.

Missing-data methods are also not reported in the registry record. The primary outcome population is described as all randomized participants, but the record does not say how many had outcome measurements at each time point, how missing measurements were handled, or whether sensitivity analyses were performed. In general, missing-data methods matter because conclusions can depend on why observations are missing and on the assumptions used to account for them.

The analysis population actually used is not reported in the registry record. The description “all randomized participants” identifies the stated population for the primary outcome, but it does not establish whether the analysis followed that population definition. The record also does not describe adherence-based, per-protocol, or other analysis populations. These omissions limit assessment of whether the reported analyses, if any, retained the protection intended by randomization.

11. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry’s adverse-event figures list 125 participants at risk in the sertraline group and 127 in the placebo group. The serious adverse-event count is 0 for each group. The counts recorded for other adverse events are 48 for sertraline and 40 for placebo. These are the counts as recorded; the registry entry does not provide additional detail in the registry record about event types, timing, severity, recurrence, or whether individual participants experienced more than one event.

The death count is not reported in the registry record. The figures do not describe the statistical comparison used for safety, and no confidence interval or test is reported for the group counts. Counts alone cannot establish whether a difference is meaningful or attributable to treatment. They also do not show how adverse events were defined, collected, or coded. The registry lists no top serious-event terms, so the specific serious events are not described. These safety entries should be read as registry counts, not as a complete account of all safety information from the trial.

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

The registry record supports a limited description of the study: it was a randomized, triple-masked, parallel-group comparison of sertraline and placebo for women with premenstrual dysphoric disorder, and it identified PMTS measured from baseline to Cycle 6 as the primary outcome. It also gives the PMTS scale’s direction and general content. These details clarify what the investigators set out to assess.

They do not establish the observed effect. The record does not report a single numerical PMTS comparison, a confidence interval, or a p value. Therefore, it is not possible from this record to describe whether the groups’ outcomes differed, how large any difference was, or how precisely it was estimated. The absence of a reported result is not evidence that the groups were the same, and it is not evidence that one treatment was better.

The listed secondary outcomes and analysis count indicate a broader set of measurements and analyses, but their titles and counts do not reveal the findings or their statistical strength. The safety counts are also limited: the registry reports serious adverse-event counts and other adverse-event counts, but does not give event-level descriptions or uncertainty around comparisons. Death counts are not reported in the registry record.

More generally, a trial result needs to be interpreted in light of its prespecified question, analysis population, missing-data handling, multiplicity approach, and uncertainty. Those details are not reported. The trial’s enrollment and completed status do not fill those gaps. The appropriate conclusion is that the registry describes the comparison and outcome but does not supply enough primary-outcome results to judge the magnitude or precision of the effect. No treatment recommendation follows from these registry entries alone.

13. Why This Trial Matters Statistically

This trial raises several useful statistical issues for clinical researchers. First, it illustrates why an endpoint description and an endpoint result are different things. The registry defines PMTS, its score direction, and the baseline-to-Cycle-6 timeframe, but does not give a single numerical comparison. Without an estimate and uncertainty, the outcome definition alone cannot answer the comparative question.

Second, the record explicitly notes that the primary outcome spans several categories or time points and was not reduced to one comparison. This highlights the value of specifying a primary contrast in advance. A clear estimand and analysis plan help readers distinguish a central test of the study question from other possible analyses. The registry record does not identify that single contrast or explain the handling of the outcome’s multiple time points or categories.

Third, the 12 outcome measures and 43 analyses make multiplicity relevant to interpretation. In general, a larger collection of comparisons needs transparent planning and reporting so readers can understand which results were confirmatory and how uncertainty should be viewed. The record does not report a multiplicity strategy, so none can be assumed.

Finally, the record shows why participant counts and completion status cannot replace outcome reporting. Enrollment is recorded as 252, but the numerical primary results, missing-data handling, and analysis population are not reported. The registry therefore offers useful design and measurement information while leaving central questions about the trial’s estimates and their precision unanswered.

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 main limitation for interpreting this specific trial from the registry record is that the primary outcome is not reported as a single numerical comparison. The record identifies PMTS and its timeframe, but it does not provide group means, a between-group estimate, a confidence interval, or a p value. It also states that the outcome includes several categories or time points and was not reduced to one comparison.

Several details needed to evaluate the analysis are not reported in the registry record. These include the statistical model and test, the prespecified primary contrast, the handling of multiple time points, the multiplicity approach, the actual analysis population, and the method for dealing with missing measurements. Although all randomized participants are named as the primary outcome population, the record does not establish how many contributed data or whether the analysis followed that definition.

The PMTS description includes the unresolved wording “PMTS-O or PMTS-SR?” and does not clarify which version was used. The record gives the scale range and interpretation but not the observed scores. The roles included in triple masking and the procedures for allocation concealment are also not described.

The safety information is limited to counts. Serious adverse-event counts are 0 in both groups, other adverse-event counts are 48 for sertraline and 40 for placebo, and death counts are not reported in the registry record. Event descriptions, timing, and comparative uncertainty are not given. Together, these reporting gaps limit assessment of the trial’s estimates and the precision and robustness of any conclusions.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluating the Effectiveness of Sertraline in Treating Women With Premenstrual Dysphoric Disorder — NCT00536198.
• Registry record last updated 2017-04-14; status last verified 2017-03.
• Results first posted 2016-10-19.
• 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 registry describes a completed Phase 4, randomized, triple-masked, parallel-group study of sertraline versus placebo in women with premenstrual dysphoric disorder. Enrollment was 252. Sertraline was taken during the symptomatic period at a planned dose between 50 and 100 mg, with a dose-reduction allowance described for moderate to severe side effects. The placebo was similar-looking and also taken during the symptomatic period.

The primary outcome was mean PMTS from baseline to Cycle 6, with higher scores indicating more severe problems. The record identifies five secondary outcomes and lists 12 outcome measures and 43 analyses. It reports serious adverse-event counts of 0 in each group and other adverse-event counts of 48 for sertraline and 40 for placebo. Death counts are not reported in the registry record.

The record does not give a single numerical primary-outcome comparison or the analysis details needed to assess its precision. It notes that the primary outcome spans several categories or time points and was not reduced to one comparison.