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 MK0462 5 mg, Sumatriptan 50 mg, and Placebo Comparison Study (0462-029) (NCT00897104), a randomized phase 3 study. The primary outcome is Pain Relief at 2 Hours After Treatment.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00897104 |
| Phase | Phase 3 |
| Condition | Migraine Headache |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 933 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Organon and Co |
| Results posted | Yes |
2. Clinical Question
Population
Participants in a study of acute migraine treatment. The primary analysis included participants who had at least one pain-severity assessment within 2 hours after dosing.
Intervention
Oral rizatriptan benzoate, identified as MK0462, at 5 mg.
Comparator
Oral sumatriptan at 50 mg and placebo. The adverse-event group label for sumatriptan is recorded as “Sumatriptan 5 mg,” which differs from the trial title and intervention description.
Primary question
How many participants reported pain relief 2 hours after treatment, defined as a reduction from moderate or severe headache at baseline to no headache or mild headache?
The study concerns treatment of an acute migraine attack rather than prevention of future attacks. Its primary outcome focuses on change in reported headache severity over a short period after a dose. The registry also lists measures concerning pain freedom, functional disability, associated symptoms, use of escape medication, and duration of relief.
The stated comparison includes rizatriptan, sumatriptan, and placebo. The record identifies a randomized, double-masked, parallel-groups design. It does not report the numerical primary outcome results or an estimated difference between groups. Consequently, the registry description establishes what the study set out to measure, but does not by itself answer how the groups compared on pain relief.
3. Trial Design
The registry describes a Phase 3, randomized, double-masked, parallel-groups outpatient study of acute migraine treatment. The official title identifies oral MK0462 at 5 mg and oral sumatriptan at 50 mg as active treatments, with placebo as a comparator. The intervention list identifies MK0462 as rizatriptan benzoate. The registry records an enrollment of 933 and lists the study status as completed.
The study dates recorded are 1995-08 for the start and 1996-05 for primary completion. These dates provide context for when the trial was conducted; they do not establish when results were analyzed or reported. The record identifies Organon and Co as sponsor and Migraine Headache as the condition.
Randomization is intended, in general, to assign participants to study groups by chance, helping reduce systematic differences at assignment. Double masking generally means that treatment assignment is concealed from participants and specified study personnel, although the registry record does not identify exactly who was masked or describe how masking was maintained. A parallel-groups design means participants are assigned to a group and assessed under that assigned treatment rather than crossing through multiple treatments.
The primary analysis population is described as an “all-participants-treated” approach. It included participants with at least one pain-severity assessment within 2 hours after dosing, and missing values were handled by carrying forward the preceding value. The record does not provide detailed eligibility criteria, allocation procedures, masking procedures, or the number assigned to each treatment for the primary analysis. Those details are not reported in the registry record.
Although the overall enrollment is recorded, it should not be treated as the analysis denominator for every outcome. The primary population has its own assessment-based criterion, and group-specific denominators for that analysis are not reported in the registry record. The adverse-event record gives separate group counts at risk, but those are safety denominators and should not be substituted for primary efficacy denominators.
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: Participants screened at a pretreatment visit were given allocated drug supply with instructions. If participants had not treated an attack within 2 months of being enrolled, they were required to return for a rescreen visit. If by 4 months after being enrolled participants still had not treated an attack, they were discontinued from the study.
Overall Study
| Stage | Rizatriptan 5 mg | Sumatriptan 5 mg | Placebo |
|---|---|---|---|
| STARTED | 418 | 428 | 87 |
| Participants Treated | 355 | 357 | 80 |
| Participants Not Treated | 63 | 71 | 7 |
| COMPLETED | 354 | 357 | 79 |
| NOT COMPLETED | 64 | 71 | 8 |
Reasons for not completing this period:
| Reason | Rizatriptan 5 mg | Sumatriptan 5 mg | Placebo |
|---|---|---|---|
| Lost to Follow-up | 12 | 17 | 2 |
| Pregnancy | 0 | 1 | 0 |
| Protocol Violation | 0 | 1 | 0 |
| Withdrawal by Subject | 23 | 27 | 3 |
| Abnormal Prestudy Labs | 2 | 0 | 0 |
| Abnormal Baseline ECG | 2 | 2 | 0 |
| Need for Concom. Med. | 0 | 1 | 1 |
| Lack of Migraine Attack | 20 | 22 | 1 |
| No Longer Met Inc/Exc Criteria | 1 | 0 | 0 |
| Other | 3 | 0 | 0 |
| Protocol Violation | 1 | 0 | 0 |
| Withdrawal by Subject | 0 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: An "all-participants-treated" approach was used in the primary analysis, including all participants who had at least one assessment of pain severity within 2 hours after dose. Missing data were replaced by carrying forward the preceding value.
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 | Rizatriptan 5 mg | Sumatriptan 5 mg | Placebo | Total |
|---|---|---|---|---|---|
| Participants analysed | 355 | 357 | 80 | 792 | |
| Age, Continuous | years | 39.9 (SD 10.3) | 41.8 (SD 10.1) | 44.3 (SD 10.5) | 41.2 (SD 10.3) |
| Sex: Female, Male: Female | Participants | 291 | 291 | 70 | 652 |
| Sex: Female, Male: Male | Participants | 64 | 66 | 10 | 140 |
| Race/Ethnicity, Customized: Caucasian | participants | 352 | 356 | 80 | 788 |
| Race/Ethnicity, Customized: Asian | participants | 3 | 1 | 0 | 4 |
| Baseline Headache Severity: Grades 0,1: no pain, Mild, or missing | Participants | 6 | 8 | 0 | 14 |
| Baseline Headache Severity: Grade 2: Moderate | Participants | 216 | 221 | 51 | 488 |
| Baseline Headache Severity: Grade 3: Severe | Participants | 133 | 128 | 29 | 290 |
6. Primary Endpoint
The registry lists the primary outcome as Pain Relief at 2 Hours After Treatment, measured over 2 hours after treatment.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is pain relief 2 hours after treatment. It counts participants whose headache severity decreased from grade 2 or 3 at baseline, described as moderate or severe pain, to grade 0 or 1 at 2 hours, described as no headache or mild pain. The outcome is therefore a binary classification of whether the stated threshold for relief was met at the assessment time.
This kind of endpoint is used to capture a participant-reported change in headache severity within a clinically relevant treatment window. It is distinct from complete pain freedom: mild pain still qualifies as relief under this definition. It is also distinct from sustained relief, because the primary measure concerns status at the stated assessment rather than how long relief continued afterward.
In general, a clearly defined threshold makes an outcome easier to interpret than an unspecified change in symptom severity. However, a threshold outcome does not show the full range of individual changes: participants just inside and just outside the cutoff are classified differently, even if their experiences are similar. The registry also lists pain freedom at 2 hours as a secondary outcome, emphasizing that the two concepts are not interchangeable.
The record describes the endpoint and the assessment-based analysis population, but does not report the number meeting the endpoint in each group or a treatment-effect estimate. The size and precision of any group contrast therefore cannot be assessed from the primary outcome information recorded in the registry.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the trial question and the primary endpoint definition, but it does not provide the numerical primary outcome results. It therefore supports a description of what was measured, not a conclusion about the comparative pain-relief results. In particular, no group-specific primary counts, effect estimate, confidence interval, or significance test is reported in the record.
For the primary outcome, a useful comparison would ordinarily describe the proportion or count of participants meeting the pain-relief definition in each randomized group, followed by a contrast between groups and an uncertainty interval. An interval would show how precisely the estimated contrast is determined by the data and analysis. Without those results, neither the direction nor magnitude of the primary comparison can be characterized from this registry record.
The record lists seven outcome measures and names several secondary outcomes, including pain freedom at 2 hours, functional disability, associated symptoms, escape-medication use, and duration of relief. Those measures cover related but different aspects of an acute migraine episode. Their presence in the registry does not establish that numerical results were reported for each measure, or that a particular result was statistically significant.
The safety information records zero serious adverse events in each listed group. It also records participants at risk for serious events as 355 for rizatriptan 5 mg, 357 for the group labeled Sumatriptan 5 mg, and 80 for placebo. These are counts in the safety record, not efficacy results. The record does not report deaths. The non-serious event counts are recorded separately, but they do not replace the missing primary efficacy results or establish a comparative safety conclusion.
General statistical interpretation depends on both the estimated effect and its uncertainty. A small p-value, if reported, would not by itself indicate the size or practical importance of a difference. A confidence interval, if available, would help distinguish a precise estimate from one compatible with a wider range of effects. Neither type of primary comparison result is reported in the registry record.
The study is marked completed, but completion does not mean that every outcome result is available in this record. Nor does the enrollment entry establish the analysis population for each outcome. The primary analysis required at least one assessment within 2 hours and used a carry-forward rule for missing data. The number of participants contributing to each group’s endpoint is not reported in the registry record.
The central interpretive boundary is therefore straightforward: the record describes a randomized comparison and a defined pain-relief endpoint, while leaving the comparative primary result unreported. Any statement that one treatment had more or less pain relief than another would go beyond the results documented.
9. Statistical Methods Explained
Randomization and masking address different sources of bias. In general, randomization assigns participants to treatment groups using a chance process, aiming to balance both measured and unmeasured characteristics across groups. Masking is intended to limit the influence of knowledge about treatment assignment on participant reports, care, or outcome assessment. The registry identifies the trial as randomized and double-masked, but details of the randomization procedure and masking implementation are not reported in the registry record.
What does a parallel-groups design mean?
In a parallel-groups study, participants remain in the treatment group to which they were assigned for the relevant comparison. This contrasts with a crossover design, where participants receive multiple treatments in sequence. The registry identifies a parallel-groups design and outpatient setting. It does not describe visit schedules beyond the outcome timeframes listed, nor does it provide further operational detail about treatment administration.
How is the primary endpoint classified?
The primary measure classifies each participant according to whether pain severity meets a defined change threshold at 2 hours after treatment. Baseline grades 2 or 3 represent moderate or severe pain; grades 0 or 1 at the later assessment represent no headache or mild pain. In general, a binary endpoint turns a graded measure into a yes-or-no outcome. This can make a group comparison easier to communicate, while discarding information about the exact severity grade and any changes that do not cross the chosen threshold.
The endpoint is not the same as pain freedom. A participant with mild pain at the assessment meets the registry definition of relief but not the description of complete absence of headache. Pain freedom at 2 hours is listed separately as a secondary outcome. Other secondary outcomes address functional impairment, photophobia, phonophobia, nausea, vomiting, escape-medication use, and duration of relief. Each speaks to a different dimension of the episode, so results for one should not be treated as a substitute for another.
What does a confidence interval communicate?
General explanation: a confidence interval expresses uncertainty around an estimated effect under the statistical method used. A narrower interval indicates greater precision than a wider interval, while the interval’s location indicates which effect values remain compatible with the data and method. An interval is not a guarantee that the true effect lies within its endpoints. The registry record does not report a primary effect estimate or confidence interval, so no such precision assessment is possible for the primary comparison.
Why can over-dispersion matter?
General explanation: over-dispersion occurs when observed variation is greater than a statistical model expects. If a model assumes less variation than the data contain, uncertainty can be understated and tests can appear more decisive than warranted. The primary endpoint is described as a binary participant count, but the registry record does not report a model, dispersion estimate, or analysis method that would establish whether over-dispersion was assessed. No particular modeling approach should be inferred from the endpoint description alone.
What does carrying forward a preceding value do?
The registry states that missing data were replaced by carrying forward the preceding value. This means that an earlier observed pain-severity assessment could stand in for a missing later assessment under the stated rule. In general, this method keeps participants with an earlier measurement in the analysis, but it relies on an assumption that the carried-forward value is a reasonable stand-in at the later time. Symptoms can change over time, so that assumption may not hold for every participant. The record does not report how many values were carried forward or how results would differ under another missing-data approach.
The primary population is described as all participants treated who had at least one pain-severity assessment within 2 hours after dose. This definition is based on treatment and assessment availability. It is not enough to establish whether every randomized participant was analyzed in the originally assigned group, or to characterize exclusions and protocol deviations. Those details are not reported in the registry record.
How should planning illustrations be read?
General explanation: sample-size planning asks how many participants per arm might be needed under specified assumptions to detect a chosen effect with a chosen level of power and significance. Such calculations depend on the assumed effect, allocation, statistical test, and outcome variability. The registry’s planning description says its illustrations use the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effect fractions. These are described as planning illustrations, not as the trial’s own design calculations. Numerical planning results are not reported in the registry record, and they are not observed power.
The record does not report the statistical analysis plan, a primary hypothesis-testing procedure, confidence-interval method, or multiplicity adjustment. A registry entry’s description of an endpoint is not a substitute for those methods. The registry lists 0 analyses, which means comparative analysis details are not represented in the results record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists seven outcome measures, with the primary measure focused on pain relief at 2 hours and secondary measures covering pain freedom, function, associated symptoms, escape-medication use, and duration of relief. When a study examines multiple outcomes or comparisons, the chance of at least one apparently unusual result can increase. General approaches to this issue include identifying a primary hypothesis in advance, setting an order for testing outcomes, or adjusting inference across a family of comparisons.
The registry record does not report a multiplicity strategy, a hierarchy for secondary outcomes, or details about which comparisons were tested. It also lists 0 analyses. The absence of reported analysis details should not be interpreted as evidence that no adjustments were made; the approach is not reported in the registry record.
For missing primary endpoint data, the record says the analysis included treated participants with at least one pain-severity assessment within 2 hours after dose and replaced missing data by carrying forward the preceding value. It does not report how many assessments were missing, how many values were carried forward, or the results of sensitivity analyses using alternative assumptions.
The record’s population description also does not fully establish the handling of all randomized participants. The exact group-specific primary analysis denominators, exclusions, and analysis by assigned group are not reported in the registry record. These gaps limit assessment of how missingness and analysis-population choices may affect the primary comparison.
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 |
|---|---|---|---|
| Rizatriptan 5 mg | 0 | 355 | 0.0% |
| Sumatriptan 5 mg | 0 | 357 | 0.0% |
| Placebo | 0 | 80 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Rizatriptan 5 mg | 92 of 355 |
| Sumatriptan 5 mg | 108 of 357 |
| Placebo | 16 of 80 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Rizatriptan 5 mg | Sumatriptan 5 mg | Placebo |
|---|---|---|---|---|
| Asthenia/Fatigue | General disorders | 25 of 355 | 18 of 357 | 1 of 80 |
| Nausea | Gastrointestinal disorders | 13 of 355 | 21 of 357 | 2 of 80 |
| Dizziness | Nervous system disorders | 13 of 355 | 17 of 357 | 4 of 80 |
| Somnolence | Psychiatric disorders | 13 of 355 | 17 of 357 | 0 of 80 |
| Paresthesia | Nervous system disorders | 11 of 355 | 12 of 357 | 2 of 80 |
| Pain, Chest | General disorders | 8 of 355 | 16 of 357 | 0 of 80 |
| Dry Mouth | Gastrointestinal disorders | 10 of 355 | 9 of 357 | 0 of 80 |
| Headache | Nervous system disorders | 7 of 355 | 6 of 357 | 0 of 80 |
| Hypesthesia | Nervous system disorders | 4 of 355 | 6 of 357 | 3 of 80 |
| Pain, Neck | Musculoskeletal and connective tissue disorders | 2 of 355 | 7 of 357 | 2 of 80 |
The safety record lists serious adverse events as 0 for Rizatriptan 5 mg, 0 for the group labeled Sumatriptan 5 mg, and 0 for Placebo. The corresponding numbers at risk are 355, 357, and 80. These figures are counts recorded for the safety outcome. They do not establish that no adverse events of any kind occurred: the record separately lists other adverse-event counts of 92, 108, and 16 for the same groups.
Deaths are not reported in the registry record. The sumatriptan safety-group label says “Sumatriptan 5 mg,” while the trial title and intervention description identify sumatriptan 50 mg. This internal labeling difference should be kept in view when interpreting the safety entry.
In general, a zero serious-event count means no serious events are recorded for that group in the posted safety data; it does not prove that the underlying risk is zero. Interpretation also depends on the observation period, event definitions, completeness of reporting, and group denominators. The registry does not provide enough detail on those points to characterize them further. These counts alone should not be treated as a complete comparison of safety between treatments.
12. What the Result Does, and Does Not, Mean
The record documents a randomized, double-masked comparison of rizatriptan, sumatriptan, and placebo for acute migraine treatment. It defines the primary endpoint as pain relief 2 hours after treatment and describes the primary analysis population and missing-data rule. Those details establish the question and measurement approach, but they do not reveal the primary outcome results.
There are no reported group-specific primary pain-relief counts, effect estimates, uncertainty intervals, or significance tests in the registry record. Therefore, the record does not establish which group had a higher pain-relief result, how large any contrast was, or how precisely a contrast was estimated. It also does not support a conclusion about whether the treatments were equivalent or different on the primary endpoint.
The serious adverse-event counts are recorded as zero for each listed group, with non-serious event counts recorded separately. These safety entries are limited to the information in the registry and do not establish that a treatment has no risk. The discrepancy between the sumatriptan dose in the safety group label and the dose named in the trial description further calls for caution when connecting that safety entry to the stated intervention.
General explanation: statistical evidence is best interpreted by considering the estimated effect, its uncertainty, the outcome definition, and the analysis assumptions together. A result’s statistical significance, if reported, would not by itself describe clinical importance. Here, the primary estimate and its uncertainty are not reported, so that combined interpretation cannot be made.
The record’s status of completed indicates that the study is marked completed in the registry; it does not fill the gaps in the posted comparative results. The appropriate conclusion is limited to what is documented: a trial design and endpoint are described, but the numerical primary comparison is not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how a well-defined endpoint and an interpretable result are separate requirements. The registry specifies a threshold-based pain-relief outcome at 2 hours, including the baseline and follow-up severity grades. That definition makes clear what counts as meeting the primary endpoint. But without group-specific outcome results and an estimate of the between-group contrast, the endpoint definition cannot answer the comparative question.
The entry also illustrates why analysis-population details matter. The primary analysis is described as including treated participants with at least one assessment within the outcome window, with preceding values carried forward for missing data. Those choices affect which observations contribute and how missing measurements are represented. The record does not quantify the missing data or report alternative analyses, so their influence cannot be assessed.
Multiplicity is another relevant statistical issue because several related outcomes are listed. Pain relief, pain freedom, functional disability, associated symptoms, escape medication, and duration of relief are not interchangeable measures. Without a reported testing strategy, readers cannot determine how the study handled the inferential consequences of examining multiple outcomes.
Finally, the safety entry demonstrates that zero recorded serious events should be read as a count, not as proof of zero risk. Denominators, follow-up, event definitions, and reporting completeness matter to interpretation. The sumatriptan dose-label discrepancy is a further reminder to check consistency across registry fields rather than treating every entry as interchangeable.
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 most consequential limitation for interpretation is that the registry record does not report the numerical primary outcome results. Group-specific pain-relief counts, an effect estimate, and its uncertainty are not available. The comparative primary question therefore cannot be answered from the recorded results.
The primary analysis population and missing-data rule are described, but the record does not report the number of participants contributing to the primary endpoint by group, the amount of missingness, or sensitivity analyses. Carrying forward a preceding value can affect the endpoint classification if symptoms change between the observed measurement and the assessment time. The impact of that rule cannot be judged without the missing-data details and comparative results.
The record lists secondary outcomes but does not report their numerical results or a multiplicity strategy. It also lists 0 analyses, so statistical methods for estimation and testing are not available. The sample-size description refers to planning illustrations based on an observed effect, but the numerical illustrations are not reported in the registry record, and they are not evidence of observed power.
Safety interpretation is limited by the absence of reported deaths and further context on event definitions, follow-up, and completeness. There is also a label inconsistency: the safety group is called “Sumatriptan 5 mg,” while the trial title and intervention description identify sumatriptan 50 mg. The record does not explain this difference.
Other details, including eligibility criteria, allocation procedures, masking implementation, and the statistical analysis plan, are not reported in the registry record. These omissions constrain assessment of trial conduct and analysis beyond the design features explicitly listed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: MK0462 5 mg, Sumatriptan 50 mg, and Placebo Comparison Study (0462-029) — NCT00897104.
- Registry record last updated 2022-02-03; status last verified 2022-02.
- Results first posted 2010-07-23.
- 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
NCT00897104 is a completed Phase 3 randomized, double-masked, parallel-groups outpatient study of acute migraine treatment. The registry identifies oral rizatriptan (MK0462) at 5 mg, oral sumatriptan at 50 mg, and placebo. Enrollment is recorded as 933; the study dates are 1995-08 and 1996-05 for start and primary completion.
The primary endpoint is pain relief 2 hours after treatment, defined by a reduction from moderate or severe baseline headache to no headache or mild headache. The primary analysis included treated participants with at least one pain-severity assessment within 2 hours and carried forward preceding values for missing data.
Numerical primary results and comparative statistical analyses are not reported in the registry record. Serious adverse-event counts are recorded as 0 in each listed group; deaths are not reported. The sumatriptan safety-group label differs from the dose stated in the trial description.