This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Side Effect Profiles of Brand Name Versus Generic Oral Contraceptives (NCT00775190), a randomized na study. The primary outcome is Amount of Bleeding.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00775190 |
| Phase | NA |
| Condition | Contraception |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Corewell Health East |
| Results posted | Yes |
2. Clinical Question
Population
Women enrolled in a study of oral contraceptives for contraception. The registry record reports enrollment of 12 participants, but does not report the participants’ baseline characteristics or the number assigned to each group.
Intervention
Ortho tricyclen, described in the arm record as one tablet by mouth daily. The study objective was to assess its side-effect profile.
Comparator
Trinessa, described as the generic equivalent and as one tablet by mouth daily. Participants were to be randomized to one of the two oral contraceptive groups.
Primary question
How does menstrual bleeding, rated on a light-to-heavy scale, compare between the two groups over the six-month timeframe? The broader objective also concerned bleeding patterns, mood changes, nausea and vomiting, menstrual cramps, breast tenderness, blood pressure elevation, stroke, blood clots, and patient compliance.
This is the question the study was designed to address, not a conclusion about the two products. The registry describes daily recording of symptoms or bleeding and monthly surveys. It does not report an analysis of those records or survey responses. The primary outcome is named as amount of bleeding, but no group-level scores, comparison estimate, or uncertainty interval is reported. The record therefore does not establish whether the groups differed, or how precisely any difference could be estimated. The reported enrollment alone does not indicate how many participants contributed primary-outcome data or how many were assigned to each group. Those details are not reported in the registry record.
3. Trial Design
The registry describes a randomized, parallel-group trial comparing Ortho tricyclen with Trinessa. Randomization means assignment was intended to occur by chance; a parallel-group design means the intervention groups are compared rather than each participant serving as their own crossover control. The record describes quadruple masking, but does not identify which roles or people were masked. It lists the phase as not applicable.
Enrollment is reported as 12. The registry does not report the number assigned to each group, the number who began treatment, or the number who completed follow-up. The listed arm instructions specify one tablet by mouth daily for each product. Participants were to keep a daily diary of symptoms or bleeding and complete a survey once a month. The primary outcome timeframe is six months.
The study started in 2008-10, and primary completion is recorded as 2013-10. Its status is terminated. The reason for termination and the timing of the termination relative to planned follow-up are not reported in the registry record. These design details give context for the intended comparison, but they do not show that the planned follow-up was completed or that all intended measurements were obtained.
The registry lists nine outcome measures and zero analyses. The primary outcome is amount of bleeding; the listed secondary outcomes include nausea, vomiting, breast tenderness, mood changes, menstrual cramps, and incidence of thromboembolic events. The record does not report a statistical analysis plan, a sample-size justification, or a description of the analysis populations. With no analysis reported, the design information cannot be used to infer comparative effects.
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
| Stage | Ortho Tricyclen™ | Trinessa™ |
|---|---|---|
| STARTED | 7 | 5 |
| COMPLETED | 3 | 0 |
| NOT COMPLETED | 4 | 5 |
Reasons for not completing this period:
| Reason | Ortho Tricyclen™ | Trinessa™ |
|---|---|---|
| Lost to Follow-up | 2 | 3 |
| Withdrawal by Subject | 1 | 2 |
| Protocol Violation | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Study Terminated with no data analysis.
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.
| Characteristic | Unit | Ortho Tricyclen™ | Trinessa™ | Total |
|---|---|---|---|---|
| Participants analysed | 7 | 5 | 12 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 7 | 5 | 12 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | years | 24 (21 to 31) | 24 (21 to 31) | 24 (21 to 31) |
| Sex: Female, Male: Female | Participants | 7 | 5 | 12 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 7 | 5 | 12 |
6. Primary Endpoint
The registry lists the primary outcome as Amount of Bleeding, measured over 6 Months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is amount of menstrual bleeding, assessed over a six-month timeframe. The registry describes a 1 to 3 Likert scale with categories of light, medium, and heavy. This is an ordinal rating: the categories have a stated order, but the record does not describe numerical distances between adjacent categories. It does not report a unit of measurement, a summary parameter, or a measure of dispersion.
Bleeding is relevant to the stated study objective because the comparison concerns side-effect profiles and specifically includes bleeding patterns. A structured rating can make reports of flow more consistent than an unrestricted description, while daily recording was intended to capture symptoms or bleeding as they occurred. The registry also describes monthly surveys, but does not explain how diary entries and survey responses were combined or which source determined the primary endpoint.
The endpoint description tells readers what was intended to be measured, not what was observed. The population field states that the study was terminated with no data analysis. No category counts, group summaries, between-group estimate, or uncertainty measure for bleeding are reported in the registry record. The record also does not explain how missing diary entries, multiple ratings over time, or ratings changing within a participant would be handled. Without those details and an analysis, the endpoint cannot support a quantitative comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the registry record reports a terminated study with no data analysis. The primary outcome is defined, but no analyzed bleeding results are reported. There is therefore no posted estimate of the difference between Ortho tricyclen and Trinessa, and no confidence interval or test result to interpret. The record does not establish that the products had similar or different side-effect profiles.
Enrollment is reported as 12, but enrollment is not the same as the number with usable primary-outcome data. Group-specific enrollment and analyzed sample sizes are not reported. The record gives no baseline summaries, follow-up completion counts, or outcome distributions. Consequently, it is not possible to judge how representative the analyzed participants might have been, whether the groups were balanced in the observed data, or how much information would have contributed to an estimate.
The primary outcome is an ordered three-category rating of bleeding. A statistical comparison would need to respect that outcome’s structure and account for the repeated daily or monthly observations if those were used. The registry does not say whether the planned analysis would compare categories, summarize ratings, use repeated observations, or follow another approach. Those analytic choices can affect the question answered and the precision of the estimate, so no particular method should be attributed to the trial.
The record lists zero analyses among nine outcome measures. Its secondary-outcome list includes several symptoms and incidence of thromboembolic events, while the study objective also mentions other concerns such as blood pressure elevation, stroke, blood clots, and compliance. The absence of reported analyses means that the record does not supply comparative results for these outcomes either. It does not say whether each outcome was collected, whether events occurred but were not analyzed, or why analyses were not available.
The adverse-event record lists zero serious adverse events and zero other adverse events in each group, with zero deaths. These entries are counts as recorded, not estimates showing that the underlying risks are zero. The registry provides no further detail about event ascertainment, follow-up completeness, or how the at-risk counts were defined. In a small study, zero recorded events would not by itself establish absence of risk; more importantly, the record does not report enough information to characterize the sensitivity of event detection.
Overall, the posted information describes an intended randomized comparison and some registry-recorded safety counts, but not an efficacy or side-effect analysis. The most defensible interpretation is descriptive: the study was terminated, enrollment was 12, and no outcome analysis is reported. The record cannot quantify similarity, difference, or precision for the primary bleeding outcome or the other intended comparisons.
9. Statistical Methods Explained
The record identifies random allocation, a parallel-group model, and quadruple masking. It does not report the sequence-generation procedure, allocation concealment details, or which parties were masked. Those missing details limit what can be said about implementation, even though the design fields indicate the intended framework. No statistical analysis plan is reported in the registry record.
What does randomization contribute?
General explanation: Random allocation is intended to make treatment assignment independent of participants’ measured and unmeasured characteristics, on average. It supports a causal comparison when assignment is implemented as planned and the analysis preserves the randomized groups. Randomization does not guarantee that small groups will have the same characteristics, and it does not correct bias from missing outcomes or departures from assigned treatment. Here, the registry says the study was randomized, but does not provide group sizes, baseline data, adherence information, or an analysis population. The practical success of randomization therefore cannot be assessed from the record.
How should the bleeding scale be understood?
General explanation: An ordinal outcome has categories that can be ordered, without an established equal distance between each adjacent category. A method that assumes equal spacing makes a different modeling assumption from a method that analyzes category ordering or category probabilities. The registry describes light, medium, and heavy ratings on a 1 to 3 scale, but does not report a summary parameter or analysis method. It is not possible to determine which assumptions the investigators intended to use. A single rating per participant would also answer a different question from an analysis that uses repeated ratings across the follow-up period.
What would a confidence interval convey?
General explanation: A confidence interval expresses uncertainty around an estimated effect under a specified statistical model and procedure. A narrow interval indicates greater precision for that estimate than a wide interval, while neither width nor location alone resolves concerns about design, measurement, or missing data. No primary-outcome estimate or confidence interval is reported in this registry record. There is therefore no precision estimate to interpret for bleeding or for the listed secondary outcomes.
What is the role of a significance level?
General explanation: A significance level is a threshold used in some hypothesis-testing procedures to define how often a specified test would reject a null hypothesis under its assumptions. It does not measure the probability that a conclusion is true, and a threshold cannot substitute for an effect estimate and its uncertainty. The sample-size planning assumptions in the record mention a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are described as planning-illustration assumptions, not as a reported analysis plan or evidence that a test was conducted. No test statistic or p-value is reported.
What can planning illustrations tell readers?
General explanation: A sample-size calculation is conditional on assumptions about the target effect, variability, design, and analysis. A planning illustration is not an observed result, and a calculation based on an observed effect would not establish that the original study had adequate power. The registry characterizes its sample-size assumptions as an illustration based on a fraction of the observed effect, but no observed primary effect is available because no analysis is reported. The record does not provide a formal sample-size justification or a numerical sample-size result. These illustrations should not be read as a reason the study was terminated or as evidence about the precision of its unreported outcome data.
Why can over-dispersion matter?
General explanation: Over-dispersion occurs when outcome variation is greater than a statistical model assumes. If it is not accounted for, estimated uncertainty can be too small, making results appear more precise than they are. Whether over-dispersion is relevant depends on the outcome and model. The registry does not report a model, outcome distribution, or analysis for which this issue could be evaluated. It would be inappropriate to say that over-dispersion was present or that a particular correction was used.
In short, the registry provides design labels and an outcome definition, but not the inferential methods needed to reproduce or evaluate a comparative result. The general concepts above explain what such methods can address; they do not describe analyses performed in this trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists nine outcome measures and zero analyses. The named secondary outcomes cover nausea, vomiting, breast tenderness, mood changes, menstrual cramps, and incidence of thromboembolic events. The primary outcome is amount of bleeding. The broader objective also refers to bleeding patterns, blood pressure elevation, stroke, blood clots, and patient compliance. The registry does not report which outcomes were analyzed, how many comparisons were planned, or whether any adjustment for multiple comparisons was specified.
General explanation: When multiple outcomes or comparisons are examined, the chance of at least one apparently unusual result can increase if each is tested separately. Statistical approaches can address multiplicity in different ways, depending on whether outcomes are primary, secondary, exploratory, or arranged in a prespecified testing sequence. Without an analysis plan or reported tests, readers cannot determine how multiplicity would have been handled in this trial. Since no analyses are reported, there are no p-values whose multiplicity adjustment can be assessed.
The record does not report missing-data counts, reasons for missingness, or methods for handling missing observations. Although the description mentions daily diaries and monthly surveys, it does not state whether those records were complete. It also does not report an intention-to-treat, per-protocol, or other analysis population. These omissions prevent assessment of how participants with incomplete follow-up or unavailable outcome measurements would have been treated analytically.
General explanation: Missing outcomes can affect both the estimated effect and its uncertainty, especially when missingness is related to treatment assignment or participants’ experiences. The direction and size of any resulting bias cannot be inferred without information about the missingness and analysis. For this trial, the registry’s statement that there was no data analysis means no missing-data strategy or analysis population is available to evaluate.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Ortho Tricyclen™ | 0 | 7 | 0.0% |
| Trinessa™ | 0 | 5 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ortho Tricyclen™ | 0 of 7 |
| Trinessa™ | 0 of 5 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ortho Tricyclen™ | 0 of 7 |
| Trinessa™ | 0 of 5 |
The registry’s adverse-event record lists Ortho Tricyclen with 7 participants at risk, 0 with serious adverse events, 0 with other adverse events, and 0 deaths. For Trinessa, it lists 5 participants at risk, 0 with serious adverse events, 0 with other adverse events, and 0 deaths. These are the posted counts; they are not comparative risk estimates.
A count of zero means that no events in that category are recorded in the registry for the listed group. It does not, by itself, demonstrate that no event occurred outside the recorded information or that the underlying risk is absent. The registry does not report how the at-risk groups were defined, the completeness of event collection, or whether the counts cover the full intended follow-up. It also does not provide event descriptions beyond the listed categories or a statistical comparison of safety outcomes.
General explanation: Safety counts are more informative when interpreted alongside the number observed, follow-up duration, event definitions, and completeness of reporting. Sparse or absent recorded events can leave substantial uncertainty about uncommon outcomes. The record’s counts should therefore be read narrowly as registry entries, not as proof of equivalent safety or as evidence that a treatment caused or prevented an event.
12. What the Result Does, and Does Not, Mean
The registry record supports a limited description of the study: it was designed as a randomized comparison of Ortho tricyclen and Trinessa, enrolled 12 participants, and was terminated. Its primary outcome was intended to rate menstrual flow on a light-to-heavy scale over six months. The record also lists several intended side-effect outcomes. It reports no data analysis.
That combination does not yield a comparative estimate. There is no reported amount of bleeding by group, no estimate of a difference, and no confidence interval to show precision. The record therefore cannot answer whether the groups were similar or different on the primary outcome. It also cannot answer those questions for the secondary outcomes. The absence of an analysis is not evidence that the groups had identical outcomes, nor is it evidence of a difference.
The listed adverse-event counts are descriptive registry entries. They do not establish that the products have the same safety profile, and they do not establish that either product caused or prevented an event. The at-risk counts and event counts do not supply a full account of outcome collection or follow-up. The reasons for termination and the availability of underlying participant-level data are not reported in the registry record.
General explanation: A randomized study can help compare groups, but conclusions depend on how assignment, follow-up, outcome measurement, and analysis were carried out. Even a well-defined outcome cannot answer a comparative question until data are summarized and uncertainty is assessed. In this case, the registry record documents the intended comparison and its outcome definitions, not an analyzed treatment effect. The appropriate conclusion is about the limits of the available record, rather than about the relative performance of the products.
13. Why This Trial Matters Statistically
This trial illustrates the distinction between a registered research question and a statistical result. The record gives a recognizable comparative design, identifies a primary endpoint, and lists additional outcomes. Yet it also states that the study was terminated with no data analysis. A clearly stated question is not itself evidence for an answer, and an endpoint definition is not an outcome estimate.
The enrollment of 12 makes it especially important not to treat the absence of reported analyses as reassuring evidence of similarity. The registry does not report how many participants were assigned to each arm or contributed usable measurements, so the amount of information available for any comparison cannot be established. The record also does not provide an estimated effect or its precision. Without those elements, the magnitude of any potential difference remains unknown.
The study further highlights the statistical choices raised by repeated, ordered symptom measurements. A light, medium, or heavy bleeding rating has an order, while the spacing between categories is not described. Daily diaries and monthly surveys could produce different forms of data, but the registry does not say how they were to be analyzed together. These are general design and analysis considerations, not claims about methods used in this trial.
Finally, the safety entries demonstrate why zero recorded events should be interpreted as counts rather than proof of no risk. Event definitions, follow-up completeness, and the at-risk population are not sufficiently described to support a broader conclusion. Statistically, the most important contribution of this record is transparency about the gap between the intended comparison and the unavailable analysis.
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 principal limitation is explicit: the study was terminated with no data analysis. Accordingly, no comparative result is available for the primary bleeding endpoint or the listed secondary outcomes. The reason for termination is not reported in the registry record, so it cannot be attributed to recruitment, safety, logistics, or any other cause.
Enrollment is reported as 12, but the record does not report group-specific assignment numbers, follow-up completion, or the number with evaluable outcomes. It does not provide participant characteristics, baseline comparisons, adherence information, or details of withdrawals. The daily diary and monthly survey procedures are described, but completeness of those measurements is not reported.
The primary endpoint has an ordered three-category scale and a six-month timeframe, but the registry does not report a summary method, analysis population, or approach to repeated observations. It also does not describe how missing measurements would be handled. No statistical analysis plan, formal sample-size justification, or analysis results are reported. The record’s planning assumptions do not fill these gaps or establish that the trial could answer its question.
The safety information is limited to group-level counts. Definitions, ascertainment procedures, timing, and completeness of the adverse-event records are not reported. The record does not explain the relationship between the listed at-risk counts and study enrollment. It therefore cannot support a detailed safety comparison.
These limitations concern what the registry record documents. They do not establish that unreported procedures or data did not exist; those details are simply not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Side Effect Profiles of Brand Name Versus Generic Oral Contraceptives — NCT00775190.
- Registry record last updated 2017-04-17; status last verified 2017-03.
- Results first posted 2017-04-17.
- 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.
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18. Record Summary
The registry describes a randomized, parallel-group, quadruple-masked comparison of Ortho tricyclen and Trinessa for contraception. Enrollment is 12, the study status is terminated, and the registry lists no data analysis. The primary outcome is amount of bleeding, rated as light, medium, or heavy over six months.
Daily symptom or bleeding diaries and monthly surveys are described. The registry lists nine outcome measures, including secondary outcomes concerning nausea, vomiting, breast tenderness, mood changes, menstrual cramps, and thromboembolic events. It does not report comparative outcome estimates or a statistical analysis plan.
The adverse-event record lists zero serious adverse events, zero other adverse events, and zero deaths for each group, with 7 at risk for Ortho Tricyclen and 5 at risk for Trinessa. These counts do not provide an analyzed comparison. The reason for termination, group assignment totals, missing-data information, and formal sample-size justification are not reported in the registry record.