Evaluation of S-adenosyl Methionine (SAM-e) for Recurrent Abdominal Pain in Children: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of S-adenosyl Methionine (SAM-e) for Recurrent Abdominal Pain in Children (NCT00694564), a na na study. The primary outcome is Wong-Baker FACES Pain Rating Scale.

2. Clinical Question

The study’s stated aim was to investigate SAM-e for recurrent abdominal pain in children, with the hypothesis that pain symptoms would be reduced. That aim is a research question, not a finding. Because the design has no control group, any observed change over time would not by itself distinguish a treatment effect from other explanations, such as natural fluctuation in symptoms, changes in reporting, or concurrent influences. The registry record does not report enough outcome data to describe even the direction or size of change.

The primary question can therefore be framed as whether pain ratings changed during follow-up among children receiving SAM-e. It cannot be framed as a comparative question about whether SAM-e performed better than another treatment or than no treatment: no such comparison group is described. The registry lists safety as a secondary outcome, but detailed safety results beyond the posted adverse-event counts are not reported in the registry record.

3. Trial Design

This was a completed pilot study of SAM-e in children with recurrent abdominal pain. The registry lists enrollment of 8 and identifies the design as single-group. All participants were in the treatment group and received SAM-e; allocation is recorded as not applicable, and masking is recorded as none. The title describes the study as open-labeled, consistent with the absence of masking.

The intervention was S-adenosyl methionine in 200 mg tablets, with daily doses ranging from 200 to 1400 mg. The registry record does not describe how a particular dose was selected, how dose changes were made, or how long participants remained at each dose. Details of adherence, concomitant care, and treatment discontinuation are not reported in the registry record.

The primary endpoint was the mean Wong-Baker FACES Pain Rating Scale score. The stated assessment times were 0, 2 weeks, 1 month, and 2 months. The scale was numerically scored from 0, indicating no pain, to 4, indicating worst pain. Although the measurement schedule is listed, the registry does not provide the number of observations at each time, the mean scores, their standard deviations, or a change estimate.

The registry lists safety as a secondary outcome and identifies two outcome measures and one analysis. It does not report the details needed to determine how each outcome was analyzed, whether all scheduled measurements were used, or which participants were included in each analysis. The phase is listed as NA. A protocol, sample-size justification, interim-analysis plan, and detailed statistical-analysis plan are not reported in the registry record.

The lack of a comparator is central to interpreting this design. Repeated measurements can describe how recorded pain scores vary during follow-up, but they do not create a randomized control group. The open-label design also means that knowledge of treatment could influence symptom reporting or assessment. These features make the study useful as a pilot description, while limiting the strength of causal conclusions that could be drawn even if the outcome values were available.

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

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Wong-Baker FACES Pain Rating Scale, measured over 0, 2 weeks, 1 month, 2 months.

The primary endpoint is the mean score on the Wong-Baker FACES Pain Rating Scale. The registry describes numerical scoring from 0 for no pain to 4 for worst pain, with assessments at 0, 2 weeks, 1 month, and 2 months. This is a continuous outcome in the registry’s analysis classification, and its dispersion is specified as the standard deviation.

In general, a pain rating scale gives participants a structured way to report symptom intensity. Repeated scores can be used to describe how pain ratings vary over time, while a mean summarizes the average score in the assessed group at a given time. A standard deviation describes how spread out individual scores are around that mean. It is not a measure of the uncertainty in the mean; that uncertainty would require an appropriate estimate such as a confidence interval.

The registry record does not report any mean scores, standard deviations, change from the initial assessment, confidence intervals, or test results. It is therefore not possible to determine the direction, size, or precision of the primary outcome result from the record. The assessment schedule and scale description alone do not establish that pain ratings improved, worsened, or remained stable.

In general, a participant-reported symptom measure may be relevant when the research question concerns pain as experienced by participants. In this open-label study, however, reported ratings could also be influenced by expectations or the circumstances of assessment. The scale’s bounded range also matters for interpretation: the registry’s mean-and-standard-deviation summary can describe the recorded scores, but the record does not provide the underlying distribution or participant-level values needed to examine that distribution directly.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the design. This is a single-group study, not a randomized comparison. In a randomized trial with a control group, an analysis can compare outcomes between groups while using the assignment process to support a causal interpretation. Here, every participant was in the treatment group. Repeated assessments can describe scores over time within that group, but cannot show what would have happened over the same period without SAM-e.

What does a mean score describe?

The primary endpoint is classified as continuous and summarized using a mean and standard deviation. In general, the mean is the arithmetic average of the observed scores. It provides a compact description of the group’s average rating, but it does not show how individual participants’ scores were distributed. The standard deviation describes the spread of observations around the mean. It is not interchangeable with a standard error or a confidence interval, which concern uncertainty in an estimated quantity.

The scale is bounded: the registry describes scores from 0, no pain, to 4, worst pain. In general, bounded scales can have distributions that are uneven, clustered at one end, or constrained from taking values outside their limits. A mean can still be useful as a group summary, but its interpretation depends on the observed distribution and on how the score is treated in the analysis. The registry record does not report participant-level values or the distribution of scores, so the appropriateness of any particular model cannot be evaluated from the posted details.

How should repeated assessments be understood?

The planned time points are 0, 2 weeks, 1 month, and 2 months. In general, repeated measurements on the same participant are related: a person’s score at one visit may be more similar to their own scores at other visits than to another participant’s scores. An analysis that accounts for this dependence can differ from an analysis that treats every measurement as unrelated. The registry record does not describe the model or test used for the repeated scores, whether the primary contrast was a change from the initial assessment, or whether an overall time effect was analyzed.

A mean at each time point and a mean change from the initial assessment answer different descriptive questions. The first describes the average observed score at a time; the second describes within-participant change, if calculated using the appropriate paired observations. Neither quantity is reported for the primary endpoint. The registry also does not report the number of participants contributing observations at each time point, so the completeness of follow-up cannot be assessed.

What does a confidence interval add?

In general, a confidence interval conveys the uncertainty associated with an estimate under a specified statistical procedure and its assumptions. A narrow interval indicates greater precision than a wide interval, but it does not remove bias from an uncontrolled design or establish that an association is causal. The registry record does not report a confidence interval for the primary outcome, so precision cannot be judged from the endpoint description alone.

A p-value, when reported, addresses how compatible the observed data are with a specified null model under the test’s assumptions. It does not measure the size or practical importance of an effect, and it does not resolve limitations in design. No primary-outcome p-value is reported in the registry record. It would therefore be inappropriate to infer statistical significance from the study aim, the enrollment, or the adverse-event counts.

What can the planning assumptions tell a reader?

The record’s sample-size assumptions describe a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. These are planning assumptions, not evidence that the study itself was designed with those conditions, and not a measure of observed power. The illustration is also not a substitute for reporting the primary outcome estimate and its uncertainty.

In general, a planning calculation asks how many participants per arm might be needed to detect a chosen effect under specified assumptions. It depends on the assumed effect, variability, test, and design. If the assumed effect comes from a small pilot estimate, that estimate can be uncertain. The registry record does not report a sample-size justification for the trial itself or the detailed assumptions that informed its enrollment. No numerical planning result should be treated as an observed result of this study.

Why does over-dispersion matter?

In general, over-dispersion refers to observed variability that is greater than a statistical model assumes. When a model underestimates variability, standard errors may be too small and confidence intervals too narrow, which can make evidence appear more precise than it is. This concept is relevant when selecting and checking a model, but the registry does not report a model or evidence about over-dispersion for this endpoint. It is therefore a general methodological consideration, not a reported feature of this study.

Overall, the registry gives the endpoint’s scale, summary type, dispersion measure, and planned assessment times, but not the statistical procedures or results needed to reconstruct an analysis. Interpretation should remain descriptive and limited to those recorded details.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and one analysis. It identifies the Wong-Baker FACES Pain Rating Scale as the primary outcome and lists safety as a secondary outcome. The record does not describe the full outcome set, the analysis corresponding to each outcome, or a prespecified approach to controlling the risk of false-positive findings when multiple outcomes or time points are examined. A multiplicity plan is not reported in the registry record.

In general, examining several outcomes, time points, or statistical contrasts creates multiple opportunities to find an apparently unusual result by chance. This does not mean that every analysis must use the same adjustment; the appropriate approach depends on the questions and analysis plan. Without a reported plan, readers cannot determine how the investigators handled multiple assessments of the primary outcome or how secondary findings should be interpreted. The absence of those details is not evidence that an adjustment was or was not performed.

The registry specifies assessment at 0, 2 weeks, 1 month, and 2 months, but does not report the number of completed observations at each time. It does not describe missing-data reasons, participant withdrawals, the method used to handle missing measurements, or any sensitivity analysis. The analysis population is also not defined in enough detail to determine whether the analysis included everyone enrolled, only participants with follow-up measurements, or another group.

In general, missing outcome data can affect both the estimate and its precision, particularly when the reasons for missingness are related to symptoms or treatment. Methods for handling missing data rely on assumptions, and those assumptions should be stated and examined where possible. Since the record does not describe missingness or analysis populations, the effect of incomplete follow-up cannot be assessed. The posted enrollment alone does not establish that all planned measurements were available or included in the primary analysis.

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 reports safety counts for the SAM-e treatment group. For serious adverse events, 0 of 8 at risk are listed as affected. For other adverse events, 7 of 8 at risk are listed as affected. The serious adverse event terms are not listed, and deaths are not reported in the registry record.

These are counts of participants recorded as affected, not measures of event severity beyond the serious-versus-other classification. The record does not provide event descriptions for the other adverse events, timing, duration, outcome, or an assessment of whether an event was related to treatment. It also does not provide a comparison group, so these figures cannot establish how the event counts compare with what would have occurred without SAM-e.

In general, adverse-event counts are descriptive safety information. They should be interpreted in light of how events were defined, collected, and followed, as well as the number of participants and duration of observation. The registry does not report those details sufficiently to assess event ascertainment or exposure time. The serious-event count should not be read as proof that serious harms are absent, and the other-event count should not be read as proof that treatment caused those events.

The safety figures therefore document what the registry lists for this group, while leaving important context unreported. They do not provide a comparative risk estimate.

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

This study addresses a clinically relevant research question: whether pain ratings change during a course of SAM-e among children with recurrent abdominal pain. It has a clearly named primary measure, a defined score range, and planned assessments at 0, 2 weeks, 1 month, and 2 months. It also records safety as a secondary outcome. These details clarify what the investigators intended to observe.

However, the registry record does not report the primary outcome values or a statistical result for pain. Readers cannot tell whether the average scores changed, how large any change was, or how precisely it was estimated. The stated hypothesis is not a result, and the trial’s completed status does not fill that gap. In the absence of the endpoint data, the primary research question remains unanswered by the posted results.

The single-group, open-label design places a further limit on what could be concluded even if a change were reported. A within-group change would describe what happened among participants receiving SAM-e, but it would not isolate the effect of the treatment from other possible causes of change. Without a control group, there is no concurrent comparison to help distinguish treatment effects from natural symptom variation, expectations, or other influences. Open-label reporting is particularly relevant for a participant-reported pain scale because awareness of treatment can shape responses.

The adverse-event counts provide a limited descriptive account: the registry lists no participants affected by a serious adverse event and lists other adverse events for 7 of 8 at risk. The record does not identify the other event types or report deaths, and does not provide a comparative safety analysis. These counts should not be used to conclude that SAM-e is safe or unsafe.

The results therefore do not establish that SAM-e reduces pain, that it has no effect, or that it is superior to another approach. Nor do they quantify the uncertainty around a treatment effect. The record supports a description of the study’s design, intended outcome, schedule, and posted safety counts. It does not support a treatment-effect conclusion.

13. Why This Trial Matters Statistically

Pilot studies can be statistically informative by clarifying how a research question is operationalized, what outcomes are planned, and what practical issues may need attention in later research. This registry describes a pain measure, its score range, follow-up times, a dosing range, and a single-group open-label design. Those features help readers understand the scope of the investigation even though the primary results are not reported.

The study also illustrates why outcome reporting is essential. A named endpoint and assessment schedule do not convey the observed result. Without means, variability, change estimates, and uncertainty measures, readers cannot judge whether participants’ pain ratings changed or how consistently they changed. A complete report would also explain the analysis population, missing follow-up, and statistical methods.

Statistically, the design highlights the difference between observing change and estimating a causal treatment effect. Repeated measurements can describe a trajectory within a group, but a single-group design cannot provide the same comparative evidence as a randomized control group. This matters especially for symptoms that can fluctuate and outcomes reported by participants in an unmasked study.

The registry’s planning assumptions also underline a general distinction: sample-size calculations are conditional planning exercises, while study results are estimates based on observed data. Planning illustrations based on an observed effect are not observed power and do not substitute for an adequately described analysis. The record does not report the trial’s own sample-size justification.

These points make the record useful for statistical education. It shows why design, outcome definition, result reporting, and uncertainty all matter, and why a small pilot’s descriptive information should not be expanded into a causal or comparative claim. The limits are not unique to this topic: they are central considerations whenever a clinical question is studied without a control group and the main outcome values are unavailable.

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 record is that the primary outcome results are not reported in the registry record. The mean scores, standard deviations, changes over time, confidence intervals, and primary-outcome test results are absent. The record therefore does not permit assessment of either the observed pain pattern or its statistical precision.

The single-group design does not include a like-for-like control comparison, and the study was open-label. Any observed change, if reported, could not be attributed to SAM-e on the basis of this design alone. The registry also does not report further information about eligibility criteria, participant characteristics, adherence, dose changes, concomitant care, or the extent of follow-up. These omissions limit assessment of who was studied and how treatment was delivered.

Methodological details are also sparse. The statistical analysis plan, missing-data methods, analysis population, handling of repeated measurements, and multiplicity approach are not reported in the registry record. The number of participants contributing data at each assessment time is not reported. Without this information, readers cannot assess whether the analysis matched the planned outcome schedule or how incomplete observations may have affected the results.

Safety interpretation is limited by the lack of event descriptions, timing, treatment-relatedness assessments, and a comparison group. The registry lists other adverse events but does not describe their terms; deaths are not reported in the registry record. The serious adverse-event count alone cannot establish the absence of risk.

Finally, the registry record does not report a sample-size justification for the trial. The separate planning assumptions do not resolve that omission and are not a measure of observed power. Taken together, these limitations make the posted record descriptive rather than sufficient for estimating a treatment effect or making a comparative safety assessment.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of S-adenosyl Methionine (SAM-e) for Recurrent Abdominal Pain in Children — NCT00694564.
• Registry record last updated 2018-03-16; status last verified 2016-01.
• Results first posted 2013-09-13.
• 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, open-label, single-group pilot study of SAM-e for recurrent abdominal pain in children. Enrollment is listed as 8. All participants were assigned to the treatment group and received SAM-e in 200 mg tablets, with daily doses ranging from 200 to 1400 mg.

The primary outcome was the mean Wong-Baker FACES Pain Rating Scale score, numerically scored from 0 for no pain to 4 for worst pain. Assessments were planned at 0, 2 weeks, 1 month, and 2 months. Safety was listed as a secondary outcome. The record reports 0 of 8 at risk affected by a serious adverse event and 7 of 8 at risk affected by other adverse events.

Primary pain outcome values, analysis details, missing-data information, and deaths are not reported in the registry record. With no control group and no primary results, the record does not establish whether pain ratings changed or support a comparative treatment-effect conclusion.