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 Screen to Save: A Colorectal Cancer Educational Intervention (NCT03907579), a na na study. The primary outcome is Change in Knowledge Related to Colorectal Cancer Risk, Prevention, and Screening.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03907579 |
| Phase | NA |
| Condition | Colorectal Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 100 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Dartmouth-Hitchcock Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The record concerns participants in an educational intervention about colorectal cancer prevention and screening. Enrollment is listed as 100, but participant characteristics and eligibility details are not reported in the registry record.
Intervention
Participants attend a brief educational presentation in an inflatable colon. The description says they also receive a study information sheet and may receive written educational materials to take home.
Comparator
There is no separate comparator group. The study is listed as single-group, with allocation recorded as NA and masking recorded as none. The knowledge assessment is conducted before and immediately following the intervention.
Primary question
The primary question is whether participants’ knowledge related to colorectal cancer risk, prevention, and screening changes between baseline and immediately after the educational intervention. The registry record does not report the scores or the estimated change.
This is a within-participant educational question, not a randomized comparison of the module against another program or against no intervention. The pre-test and post-test assess knowledge using 14 questions related to expected learning outcomes. A before-and-after pattern could describe the knowledge scores observed around the intervention, but without a separate comparison group it cannot isolate the intervention from other explanations for change. For example, general statistical interpretation recognizes that repeated testing itself can affect responses; whether that occurred in this study is not reported in the registry record.
The study description also mentions interest in participants’ intention to get screened. However, the listed primary outcome is change in knowledge, and the registry record does not report an intention-to-screen result among the outcomes described in the available information. The central question that can be assessed from this record is therefore narrower: what knowledge outcome was intended to be measured, and are its results reported? The outcome is described, but its baseline and post-intervention values are not reported in the registry record.
3. Trial Design
The study is titled Screen to Save: A Colorectal Cancer Educational Intervention and is sponsored by Dartmouth-Hitchcock Medical Center. It is listed as completed, with a start date of 2017-03-11 and a primary completion date of 2017-06-17. The record lists enrollment as 100. The phase is NA, the allocation is NA, masking is none, and the model is single-group.
Participants receive an educational presentation in an inflatable colon focused on colorectal cancer prevention and screening. The description says participants also receive a copy of the study information sheet and may receive written educational materials to take home. A pre-test and post-test are used to assess knowledge before and immediately following the intervention. The intervention is categorized as behavioral.
Because this is a single-group study, the pre-intervention measurement is not a concurrent control group. It gives a baseline measure for the same intervention setting, but it cannot account for changes that might have occurred without the presentation. The record explicitly notes that the study is not a randomized comparison and that its arms are not a like-for-like control comparison. There is one intervention group described, rather than a randomized allocation between intervention and control conditions.
The record lists two outcome measures and one analysis, but the available information does not identify the analysis method or provide its results. The primary outcome is described as a median score with full range, measured at baseline and immediately following the intervention. Further design details—including recruitment procedures, eligibility criteria, participant characteristics, test administration procedures, and handling of incomplete tests—are not reported in the registry record. The single-group structure is important when interpreting any before-and-after change: an observed difference could be associated with the intervention, but the design alone cannot establish that the intervention caused it.
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 | Inflatable Colon Educational Module |
|---|---|
| STARTED | 100 |
| COMPLETED | 100 |
| NOT COMPLETED | 0 |
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 | Inflatable Colon Educational Module |
|---|---|---|
| Participants analysed | 100 | |
| Age, Customized: Mean age | years | 59.5 (SD 5.75) |
| Sex: Female, Male: Female | Participants | 92 |
| Sex: Female, Male: Male | Participants | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 100 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 96 |
| Race (NIH/OMB): More than one race | Participants | 3 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 100 |
| Correct Answers on Knowledge Questions | correct answers | 10.78 (SD 2.20) |
6. Primary Endpoint
The registry lists the primary outcome as Change in Knowledge Related to Colorectal Cancer Risk, Prevention, and Screening, measured over Baseline and immediately following intervention.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Full Range |
| Unit | score on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is change in knowledge related to colorectal cancer risk, prevention, and screening. The record describes a pre-test and post-test using 14 questions that assess key learning outcomes expected from the educational intervention. Measurements are scheduled at baseline and immediately following the intervention. The outcome is expressed as a score on a scale, with the summary parameter specified as the median and the dispersion specified as the full range.
A knowledge assessment is relevant to an educational intervention because it measures whether participants’ responses to content-related questions differ after the presentation. The median describes the middle of the observed scores when they are ordered; the full range describes the lowest and highest observed scores. These summaries can help convey the distribution’s center and extent, though they do not show each participant’s paired change or, by themselves, quantify uncertainty around an estimated change.
The registry record does not report the baseline median, post-intervention median, full ranges, or a numerical estimate of change. It also does not report the scoring rules, the possible score values, or whether the same questions were used at both assessments beyond the description of a pre-test and post-test. As a result, the endpoint’s intended content and timing are clear, but its observed magnitude and precision cannot be evaluated from the registry record. The record’s brief summary also refers to intention to get screened, but the primary endpoint listed is knowledge; an intention outcome is not described in the available primary-outcome information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a completed single-group educational study and describes a baseline and immediate post-intervention knowledge assessment. It does not report the observed knowledge scores, a change estimate, an uncertainty interval, or a significance test. Therefore, the registry record does not establish whether the scores increased, decreased, or remained similar. It also does not establish how large or precise any change might have been.
The primary outcome is specified as a median score with full range. Those summaries would describe the center and spread of scores at the measured time points, but the available information does not include their values. Even if the two medians were reported, a difference between medians would not automatically provide the distribution of individual participants’ changes. For paired pre-test and post-test data, the distribution of within-participant changes can be informative because each person contributes measurements at both time points. Whether the analysis used paired observations is not reported in the registry record.
General statistical interpretation distinguishes a measured change from evidence that the intervention caused that change. This study has no concurrent control group, so a before-and-after difference, if reported, would not by itself separate the intervention’s possible contribution from other influences. Repeated exposure to a test, changes in who completed each assessment, or events during the study period can complicate interpretation in a single-group design. The record does not state whether these issues were assessed or how they were handled.
The enrollment listed in the record is 100, but the number contributing data to the primary outcome and the number with paired assessments are not reported in the registry record. Enrollment therefore should not be treated as the analysis denominator. The record lists one analysis, but its statistical method, population, and results are not described in the information available.
There are no basis in the reported information for a claim about the direction or magnitude of knowledge change, its statistical uncertainty, or participants’ screening intentions. The sound interpretation is limited to the stated study question and measurement plan: knowledge was intended to be assessed before and immediately after an educational presentation, while the resulting scores and analysis are not reported in the registry record. This is an absence of reported results, not evidence that no change occurred.
9. Statistical Methods Explained
The primary outcome is described using a score summarized by its median and full range. These terms describe a way to report observations; they do not supply the actual outcome values. The registry record does not report either time point’s median or range, nor does it specify a numerical estimate of the change.
What does a median describe?
In general, the median is the middle value after observations are ordered. It is less affected by very high or low observations than the arithmetic mean. That feature can be useful when score distributions are uneven or include unusually extreme values. A median is still only a summary: it does not show the complete distribution, and a median at each time point does not reveal exactly how individual participants changed between assessments.
What does the full range add?
In general, the full range gives the smallest and largest observed values. It communicates the span of the data, but it is sensitive to extreme observations and does not describe how densely values cluster between the endpoints. A range is not a confidence interval. A confidence interval, in general, expresses uncertainty around an estimated quantity under a statistical model and analysis; it is not simply the observed spread of individual scores. No confidence interval is reported for this outcome in the registry record.
Why does the paired structure matter?
The outcome is measured at baseline and immediately following the intervention. When the same participants contribute both measurements, the observations are paired. A paired analysis uses the relationship between each participant’s two scores and can target the within-participant change. Comparing the two sets of scores as if they came from unrelated groups would discard that pairing. The registry record does not report the analysis method, whether the analysis used paired data, or how participants with only one assessment were handled.
General statistical practice is to define the target quantity before choosing a test. Possible targets include a typical within-person change or a difference between summaries at the two time points. These are not interchangeable quantities. The registry record specifies a median and full range for the score, but it does not state the exact contrast or test used to evaluate change. The single analysis listed in the record does not by itself identify those choices.
What can a test of change establish?
In general, a statistical test evaluates how compatible the observed data are with a specified null hypothesis under the assumptions of the test. A p-value does not measure the size or importance of a change, and it does not establish that an intervention caused an observed pattern. Effect estimates and uncertainty intervals are needed to describe magnitude and precision; a study design with an appropriate comparison is needed to strengthen causal interpretation. No p-value, effect estimate, or uncertainty interval for the primary outcome is reported in the registry record.
The record lists a behavioral intervention and a single-group model, with no masking. Masking is not the same as randomization or control: it concerns whether people involved in a study are unaware of assigned treatment or other study information. With no randomized comparator listed, this design is not a randomized treatment comparison. The record does not explain whether assessors were masked or whether scoring could be influenced by knowledge of assessment timing.
How should planning calculations be read?
General sample-size illustrations based on an observed effect are planning exercises. They describe how a future study might be planned under stated assumptions; they are not observed power and do not replace the actual analysis of the trial. The stated assumptions for such illustrations include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those assumptions do not describe the design of this single-group study, which has no randomized two-arm comparison. The registry record does not report the observed effect value or the numerical planning results. Such calculations should not be read as evidence about the effect in this study.
The record does not report a statistical analysis plan, model diagnostics, treatment of missing data, or adjustments for other variables. In general, those details help readers understand which data contributed to an estimate, what assumptions support it, and how robust the conclusions might be. Without the analysis details and outcome results, the intended measurement can be described, but the statistical findings cannot be independently interpreted from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists two outcome measures and one analysis. The available information identifies the primary knowledge outcome but does not describe the other outcome measure or provide the analysis details. It does not state whether the analysis involved multiple tests, whether outcomes or time points were tested separately, or whether any adjustment for multiple comparisons was planned or performed. A multiplicity strategy is therefore not reported in the registry record.
In general, when many hypotheses are tested, the chance of obtaining at least one apparently unusual result can increase. Adjustment methods or a prespecified hierarchy can help control how results are interpreted, but the appropriate approach depends on the questions and analysis plan. It would not be appropriate to infer a multiplicity problem or assume that an adjustment was used from the count of outcome measures alone.
The record lists enrollment as 100, but it does not report how many participants completed both tests or contributed to the primary analysis. The number of missing baseline or post-intervention scores, reasons for missing assessments, and any imputation or other missing-data procedure are not reported in the registry record. In general, missingness can affect an estimate if the participants with observed data differ systematically from those without observed data. A complete-case analysis and an analysis that models or imputes missing values can answer different questions under different assumptions.
The analysis population is also not described. The record does not specify whether all enrolled participants, all participants who attended the presentation, or only those with both assessments were included in the primary analysis. It does not report exclusions or deviations from the intended assessment procedure. These omissions mean that the relationship between enrollment and the analyzed outcome cannot be evaluated. They also limit assessment of whether the reported analysis, if later available, represents the participants originally enrolled.
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 |
|---|---|---|---|
| Inflatable Colon Educational Module | 0 | 100 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Inflatable Colon Educational Module | 0 of 100 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Inflatable Colon Educational Module | 0 of 100 |
The registry record lists the inflatable colon educational module group with 100 participants at risk for serious adverse events and zero serious adverse events reported. It also lists 100 participants at risk for other adverse events and zero other adverse events reported. Deaths are listed as zero. No top serious adverse event terms are listed.
These figures describe what is recorded for this intervention group. They do not establish that no adverse experiences of any kind occurred, because the registry record reports zero in the specified serious and other adverse event categories but does not provide further detail about collection methods, event definitions, follow-up duration, or completeness of reporting. Those details are not reported in the registry record.
General statistical interpretation cautions against treating an observed zero as proof that an event is impossible or that risk is absent. The meaning of a zero count depends on the number observed, the period of observation, how events were sought and defined, and the completeness of follow-up. The record lists the at-risk group size and event counts, but does not provide uncertainty estimates for safety outcomes. These counts should be read as registry-reported event figures, not as a guarantee about safety or as a comparison with another group.
12. What the Result Does, and Does Not, Mean
The record’s primary purpose is to describe an educational intervention and the knowledge outcome it was intended to assess. It documents a presentation focused on colorectal cancer prevention and screening, delivered in an inflatable colon, with a pre-test and post-test at baseline and immediately after the intervention. The primary knowledge assessment covers 14 questions and is specified as a score summarized by its median and full range.
What the record does not provide is the result needed to answer whether knowledge changed. There are no reported baseline or post-intervention scores, no estimate of change, and no uncertainty measure. The record also does not report a result for intention to get screened in the available outcome information. Consequently, the posted information cannot establish the direction, size, or precision of a knowledge change or a change in screening intention.
Even if a before-and-after difference were available, the design would remain a single-group study. General statistical interpretation treats such a difference as an observed pattern over time, not as a definitive causal effect. Without a concurrent comparison group, other explanations for a change cannot be separated confidently from the intervention. The design is useful for describing an educational activity and its assessment, but it does not offer the same causal contrast as a randomized comparison.
The record’s listed enrollment is not the same as a reported analysis population. It does not say how many participants completed both assessments or contributed to the primary outcome. Thus, readers cannot determine whether the outcome analysis represents all enrolled participants or a subset. The details needed to evaluate missing assessments and the statistical method are also not reported in the registry record.
These limits do not mean that the intervention had no effect. They mean that the registry record, as described, does not provide results that allow the effect to be estimated. The appropriate conclusion is that the study was completed and its intended knowledge measure is described, while the primary outcome findings and key analysis details are not reported in the registry record.
13. Why This Trial Matters Statistically
This study illustrates a common statistical distinction in education research: defining an outcome is not the same as reporting an outcome result. The registry record clearly identifies a knowledge construct, the assessment timing, and a summary approach using a median and full range. Yet without the observed scores or an estimate of change, readers cannot assess the size or precision of the result. Statistical interpretation depends on both a well-described measure and accessible results.
The single-group pre-test and post-test structure also makes the comparison target important. Measurements taken from the same participants can describe change over time, but they do not supply a concurrent estimate of what would have happened without the intervention. A control group can help address alternative explanations, while randomization can help make groups comparable in expectation. Neither a control group nor randomized allocation is listed for this study.
The record also highlights why analysis-population and missing-data information matters. Enrollment is reported, but the number contributing paired scores is not. If the people with complete assessments differ from those who do not complete them, the analyzed data may not reflect the full enrolled group. Clear reporting of completion, exclusions, analysis methods, and uncertainty would help readers judge the strength and scope of any result.
Finally, a primary endpoint based on question scores measures a particular aspect of an educational program: responses to knowledge questions. It is not automatically equivalent to later screening behavior or health outcomes. The brief summary mentions intention to get screened, but the primary outcome information available is about knowledge. Keeping these constructs distinct helps prevent an educational score from being interpreted as evidence about behavior or clinical outcomes that are not reported.
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.
Several limitations follow from the design and the information reported in the registry record. The study is single-group, with no randomized comparator listed. A pre-test and post-test can describe scores before and after the presentation, but the design cannot isolate the intervention from other possible influences on score changes. The record does not describe procedures intended to address this limitation.
The primary outcome is defined, but its results are not reported in the registry record. There are no baseline or post-intervention medians, full ranges, change estimates, or uncertainty measures available in the information described. This prevents assessment of the direction, magnitude, and precision of the outcome. The record lists one analysis, but does not report its method, assumptions, or result.
Enrollment is listed as 100, but the number of participants with complete pre-test and post-test data is not reported. Participant characteristics, eligibility criteria, recruitment procedures, and the score scale’s possible values are also not reported in the registry record. Without these details, it is difficult to assess who the results would represent or how the assessment was implemented.
The record does not describe missing-data handling, the analysis population, or whether other outcomes were analyzed. Although the brief summary mentions intention to get screened, an intention result is not included in the available outcome description. Follow-up beyond the immediate post-intervention assessment is not reported, so the record does not establish whether any knowledge changes were sustained.
These are limits on interpretation of the registry record, not proof that the study lacked additional procedures or analyses. Details not present in the record cannot be assumed. The findings that can be evaluated are therefore restricted to the stated design, intervention, outcome definition, enrollment, and reported adverse event counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Screen to Save: A Colorectal Cancer Educational Intervention — NCT03907579.
- Registry record last updated 2020-09-04; status last verified 2020-08.
- Results first posted 2020-09-04.
- 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
NCT03907579 is a completed single-group study of an inflatable colon educational module focused on colorectal cancer prevention and screening. The study is sponsored by Dartmouth-Hitchcock Medical Center and lists enrollment as 100. Its primary outcome is change in knowledge related to colorectal cancer risk, prevention, and screening, measured at baseline and immediately after the intervention with a 14-question pre-test and post-test. The score is specified as a median with full range. The registry record does not report the observed scores, an estimate of change, or the statistical analysis method. It lists zero serious adverse events, zero other adverse events, and zero deaths in the intervention group. There is no randomized control group, and the number contributing data to the primary analysis is not reported in the registry record.