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 Fast-track Rehabilitation After Elective Colorectal and Small Bowel Resection (NCT00606944), a randomized na study. The primary outcome is the Length of Hospital Stay.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00606944 |
| Phase | NA |
| Condition | Colorectal Tumor |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 200 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Seoul National University Hospital |
| Results posted | Yes |
2. Clinical Question
Population
Participants were patients undergoing elective colorectal resection. The registry lists colorectal tumor as the condition and describes the surgery as laparoscopic colorectal surgery in its summary. The primary outcome description notes that one mortality case was excluded from analysis in the ERP group. The registry does not report further eligibility details or participant characteristics in this record.
Intervention
The intervention was fast-track rehabilitation, described as early ambulation and diet after elective colorectal resection. The registry summary frames the underlying question as whether oral alimentation and ambulation exercise should begin early after surgery rather than waiting for the return of functional intestinal transit.
Comparator
The comparator was a traditional, conventional-care group. The summary contrasts this care with beginning diet and ambulation early, but further details of the conventional-care protocol are not reported in the registry record.
Primary question
The primary question was whether the length of hospital stay differed between fast-track rehabilitation and conventional care. The outcome was the median time to discharge, measured in days and assessed at discharge. Discharge criteria included tolerance of consecutive soft bland diet, unassisted ambulation, no need for analgesics, being afebrile without a major complication, and willingness to discharge. The registry reports group medians and inter-quartile ranges, but does not report a formal comparative estimate or test for this endpoint.
The registry also lists readmission rate, pain, quality of life, and postoperative complications as secondary outcomes. Their results are not reported in this record.
3. Trial Design
This was a randomized, parallel-group trial with no masking reported. The registry names Seoul National University Hospital as the sponsor and records the study as completed. Enrollment was 200. The listed phase is not applicable. The study title and registry summary describe elective colorectal and small bowel resection, while the condition is listed as colorectal tumor and the summary emphasizes laparoscopic colorectal surgery.
Participants were assigned to fast-track rehabilitation or conventional care. The ERP group received early ambulation and diet after elective colorectal resection. The control group received traditional, conventional care. More detailed descriptions of the allocation process, concealment, treatment schedules, permitted co-interventions, and the conventional-care protocol are not reported in the registry record. The registry records no masking, but does not explain whether outcome assessment was masked.
The primary endpoint was median length of hospital stay in days at discharge, with inter-quartile ranges. The registry reports 100 participants for the control-group endpoint and 97 for the ERP-group endpoint. It states that one mortality case was excluded from analysis in the ERP group. The adverse-event record uses different at-risk counts: 100 for control and 98 for ERP. The record does not explain this difference in analysis populations.
Four secondary outcomes are named: readmission rate, pain, quality of life, and postoperative complication. The record lists nine outcome measures overall, but results for the secondary outcomes are not reported in the registry record. It also does not report the planned sample-size justification, the randomization method, the intended analysis population, or a statistical analysis plan. No inferential analyses are posted in the record.
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 | Control Group | ERP Group |
|---|---|---|
| STARTED | 98 | 100 |
| COMPLETED | 98 | 100 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: 1 mortality case was excluded for analysis in the ERP group
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 | Control Group | ERP Group | Total |
|---|---|---|---|---|
| Participants analysed | 100 | 98 | 198 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 58 | 49 | 107 |
| Age, Categorical: >=65 years | Participants | 42 | 49 | 91 |
| Age Continuous | years | 61.1 (SD 11.0) | 61.5 (SD 10.9) | 61.3 (SD 10.9) |
| Sex: Female, Male: Female | Participants | 42 | 36 | 78 |
| Sex: Female, Male: Male | Participants | 58 | 62 | 120 |
| Region of Enrollment: Korea, Republic of | participants | 100 | 98 | 198 |
6. Primary Endpoint
The registry lists the primary outcome as the Length of Hospital Stay, measured over at discharge.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | day |
| Endpoint classification | Time-to-Event Analysis |
The primary endpoint is the length of hospital stay, recorded as a median number of days at discharge. It describes the typical time to discharge in each group, while the inter-quartile range describes the middle half of the observed values. The registry gives the control-group median as 8 days, with an inter-quartile range of 7 to 9 days. For the ERP group, it gives a median of 7 days and an inter-quartile range of 6.75 to 8.25 days.
Length of stay is relevant to this trial's question because the registry summary proposes that earlier diet and ambulation might facilitate earlier discharge. The stated discharge criteria help explain what discharge meant in the study: participants were expected to tolerate consecutive soft bland diet, ambulate without assistance, not need analgesics, be afebrile without a major complication, and be willing to leave hospital. The endpoint therefore reflects time until discharge under these criteria, not simply time until a single physiological event.
A median is useful for describing a time measure when the distribution may be uneven or contain unusually long stays. It does not, by itself, quantify uncertainty in a between-group contrast or establish that a difference is statistically distinguishable from chance. The registry does not report a confidence interval, hazard ratio, or formal test for the primary endpoint. The reported medians and ranges should therefore be read as descriptive group summaries, not as a complete estimate of the comparative effect.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome is a median hospital stay of 8 days in the control group, with an inter-quartile range of 7 to 9 days, and 7 days in the ERP group, with an inter-quartile range of 6.75 to 8.25 days. These summaries describe the observed distributions in the analyzed groups. They do not provide a formal estimate of the uncertainty around the between-group comparison.
The endpoint analysis includes 100 control participants and 97 ERP participants. The registry says one mortality case was excluded from ERP endpoint analysis. It does not explain the handling of other participants, whether all randomized participants were analyzed in their assigned groups, or why the adverse-event counts use 98 ERP participants rather than 97. These differences matter when interpreting which participants contributed to each posted result.
The registry record contains no reported p-value, confidence interval, hazard ratio, or other inferential comparison for hospital stay. Consequently, the record does not establish whether the observed group summaries are compatible with a wide range of underlying differences or are estimated precisely. A difference between two medians is not by itself evidence of a statistically reliable treatment effect. Nor can a formal result be reconstructed from the medians and inter-quartile ranges alone without making assumptions about the data and analysis.
The trial was randomized, which is a design feature intended to support a fair comparison, but the registry does not provide enough detail to assess the randomization procedure or the analysis plan. The record also does not report baseline characteristics, adherence, protocol deviations, or results for the listed secondary outcomes. Those omissions limit assessment of group comparability and of outcomes beyond hospital stay.
The safety record lists serious adverse events affecting 0 of 100 participants in control and 1 of 98 participants in ERP. The most frequent serious-event term is listed as Death, at 1.0%. These entries describe what the registry reports; they do not establish that the groups differ in safety. The record does not provide enough detail about event definitions, timing, causes, or attribution to interpret the event count further.
Overall, the registry presents descriptive endpoint summaries and a limited serious-event count, without a reported statistical comparison. The data support describing the observed group values and the record’s analysis counts. They do not support a conclusion about the precision or statistical significance of a comparative effect.
9. Statistical Methods Explained
The registry reports a median and inter-quartile range for hospital stay, rather than a mean and standard deviation. These summaries describe different features of a distribution. The median is its central value: half the observations lie at or below it and half at or above it, subject to ties. The inter-quartile range spans the central half of the observations. It gives a sense of spread without being pulled as strongly by extreme values as a range from minimum to maximum can be.
Why report a median for time to discharge?
General statistical explanation: time outcomes often have a lower bound and may have a long right tail, because a smaller number of participants can remain in hospital much longer than most. In such settings, the mean can be influenced by a few long stays. A median offers a measure of a typical observed time that is less sensitive to those extremes. The choice of a median does not, by itself, specify the statistical model or comparison method used.
The record labels this endpoint as a median-time outcome and gives the measurement unit as days. It does not report how the medians or inter-quartile ranges were calculated, whether any observations were censored, or what method would have been used for a formal comparison. Although the registry’s general endpoint description characterizes the endpoint as time-to-event, no sponsor-reported hazard ratio is present in this record. The posted primary result consists of the group medians and inter-quartile ranges.
What does a confidence interval add?
General statistical explanation: a confidence interval gives a range of values compatible with the observed data under a specified statistical procedure. For a comparison, it can communicate both the estimated direction and the precision of the result. A narrow interval indicates more precision than a wide interval, though precision is not the same as practical importance. The registry does not report a confidence interval for the primary comparison, so the precision of a comparative estimate cannot be read from the posted medians alone.
A p-value, when reported, addresses how unusual data at least as incompatible with a specified null hypothesis would be under the assumptions of the test. It is not the probability that the null hypothesis is true and does not measure the size or importance of an effect. No p-value or formal primary-outcome test is reported in this record. The absence of such a result should not be replaced by an informal judgment based on whether the medians look different.
Why can medians not be compared as if they were means?
General statistical explanation: subtracting group medians does not generally yield the median of individual treatment effects, nor does it provide the uncertainty of a treatment contrast. The distributions may differ in spread and shape, and a single summary can conceal those differences. A suitable comparison depends on the study design, endpoint definition, and analysis plan. The registry record does not report the planned test or model, so no particular analysis can be attributed to the study.
Time-to-event methods can account for participants whose event time is not observed during follow-up, provided the relevant censoring information and assumptions are available. General statistical explanation: a hazard ratio compares event rates over follow-up under a model and is not the same quantity as a difference between medians. The registry record does not report censoring details or a hazard ratio for this endpoint. It is therefore appropriate to describe the posted medians as descriptive summaries, rather than to imply a time-to-event model was used.
How should the sample-size material be read?
The record describes sample-size calculations as planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such illustrations are not the trial’s original design justification and are not observed power. A planning calculation asks what sample size would be associated with specified assumptions; it does not measure the probability that the completed trial found a real effect. The record does not report a sample-size justification for the original trial, and the registry entries do not include the illustration values to discuss.
General statistical explanation: planning calculations depend on assumptions about the effect to detect, variability or event behavior, significance threshold, allocation, and analysis method. Changing assumptions changes the resulting planning requirement. A calculation based on an observed effect also inherits uncertainty in that observed effect. It should not be treated as an independent confirmation of the result or as evidence that a trial was adequately powered.
Why does over-dispersion matter?
General statistical explanation: over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model understates variability, its standard errors can be too small and its intervals or tests can appear more certain than warranted. This concept is relevant when count outcomes are analyzed with models that make assumptions about the relationship between the mean and variance. The primary endpoint is reported as median time, and the registry does not report a count model or an over-dispersion assessment. It would be inappropriate to claim that over-dispersion was present or addressed in this trial.
The key methodological limit is that the registry offers descriptive results without the inferential analysis needed to quantify uncertainty in the primary comparison. General statistical concepts can explain what additional methods might accomplish, but they cannot fill in analyses that are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry names four secondary outcomes: readmission rate, pain, quality of life, and postoperative complication. It lists nine outcome measures overall, but does not report results for these secondary outcomes. The analysis plan, including whether any outcomes were designated as exploratory, is not reported in the registry record.
Multiplicity arises when several outcomes or comparisons are tested. General statistical explanation: the more tests conducted, the greater the chance that at least one result appears statistically significant by chance if each is interpreted independently. Approaches to addressing this include prespecifying a primary outcome, adjusting inference across a family of tests, or clearly labeling secondary analyses as exploratory. The registry does not report whether or how multiplicity was addressed. No claim about adjustment or its absence in the actual analysis can be made from this record.
For the primary endpoint, the record reports 100 control participants and 97 ERP participants, and states that one mortality case was excluded from ERP analysis. The adverse-event record lists 100 control and 98 ERP participants at risk. Reasons for the differing ERP counts, the handling of missing outcome data, and the intended analysis population are not reported. The registry also does not say whether participants were analyzed according to randomized assignment or whether any other exclusions occurred.
These details affect interpretation because an analysis population and missing-data strategy determine which observations contribute to an estimate. General statistical explanation: excluding participants can change the composition of a group, while assumptions used to handle missing values can influence estimates and uncertainty. Without the relevant details, the posted endpoint summaries should be interpreted as summaries of the recorded analysis groups, not as confirmed results for every randomized participant.
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 |
|---|---|---|---|
| Control Group | 0 | 100 | 0.0% |
| ERP Group | 1 | 98 | 1.0% |
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 |
|---|---|
| Control Group | 16 of 100 |
| ERP Group | 28 of 98 |
Most frequent serious adverse event terms
| Event term | Organ system | Control Group | ERP Group |
|---|---|---|---|
| Death | Gastrointestinal disorders | 0 of 100 | 1 of 98 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Control Group | ERP Group |
|---|---|---|---|
| Ileus | Gastrointestinal disorders | 7 of 100 | 17 of 98 |
| Urinary retention | Renal and urinary disorders | 5 of 100 | 9 of 98 |
| Chylous ascites | Gastrointestinal disorders | 5 of 100 | 6 of 98 |
Serious events with the highest arm-level rate: death (1.0%).
The serious-adverse-event record lists 0 affected participants among 100 at risk in the control group and 1 affected participant among 98 at risk in the ERP group. The registry’s listed top serious-event term is Death, at 1.0%. The record does not give further event-level details, such as timing, cause, or attribution, so the term should be read as the registry’s reported serious-event classification rather than an explanation of the event.
These counts have small denominators and describe the entries in the registry; they are not, by themselves, a precise comparison of safety between groups. The record does not provide a comparative statistical analysis or confidence interval for serious adverse events. It also does not explain the difference between the ERP at-risk count for adverse events and the ERP endpoint analysis count.
The primary outcome description separately notes that one mortality case was excluded from ERP endpoint analysis. The registry does not explicitly connect that case to the serious-event listing, so the two entries should not be assumed to refer to the same analysis record or to have the same handling. No causal attribution to the intervention is reported. The serious-event figures therefore warrant a cautious, descriptive reading and do not establish a safety difference.
12. What the Result Does, and Does Not, Mean
The record describes a randomized comparison of fast-track rehabilitation and conventional care after elective colorectal resection. Its primary posted result is median hospital stay: 8 days in the control group and 7 days in the ERP group, with the respective inter-quartile ranges of 7 to 9 days and 6.75 to 8.25 days. These figures characterize the analyzed groups and the observed spread of their values.
They do not, alone, establish the size or precision of a comparative effect. The registry does not report an inferential test, confidence interval, or hazard ratio for the primary endpoint. It also does not provide the statistical analysis plan or enough detail to determine how all randomized participants contributed to the outcome. A descriptive contrast should not be treated as proof of a difference or of no difference.
The record’s stated discharge criteria make clear that length of stay was tied to a set of clinical and participant criteria, including diet tolerance, unassisted ambulation, analgesic need, fever or major complications, and willingness to discharge. The endpoint therefore reflects the discharge process defined by the study, not a measure of recovery in every possible sense. The registry does not report results for the named secondary outcomes, so this record cannot characterize readmission, pain, quality of life, or postoperative complications beyond the limited adverse-event entries.
The serious-adverse-event counts are also descriptive. The record lists 0 affected control participants and 1 affected ERP participant, with different at-risk counts, and gives Death as the top serious-event term. It does not report a statistical comparison, event attribution, or further clinical details.
In short, the posted information supports a careful account of the recorded group summaries and the limits of their interpretation. It does not establish the certainty, statistical significance, or broader implications of a comparative treatment effect.
13. Why This Trial Matters Statistically
This trial illustrates why a randomized design and a posted numerical difference are not the whole statistical story. Randomization can support a comparison by reducing systematic differences between groups, but interpretation still depends on the allocation process, analysis population, outcome definition, and analysis plan. Several of those details are not reported in the registry record.
The endpoint is a time measure summarized by medians and inter-quartile ranges. This highlights the distinction between describing each group and estimating a comparative effect with quantified uncertainty. The medians and ranges provide useful information about the recorded length-of-stay distributions, but they do not supply a confidence interval or a formal test. A reader should not infer statistical significance from the appearance of the summaries.
The registry also notes an exclusion of one mortality case from ERP endpoint analysis, while adverse-event counts use a separate ERP at-risk total. This is a reminder that analysis populations can differ across outcomes and that count denominators need to be understood alongside the results. The record does not explain the difference, so it cannot be resolved from the posted information.
Finally, the listing of several secondary outcomes raises the general issue of multiplicity. When multiple outcomes are considered, a prespecified analysis strategy helps clarify which findings are confirmatory and how uncertainty should be interpreted. The registry does not report such a strategy or the secondary-outcome results. The case therefore demonstrates the value of complete reporting: group summaries are informative, but estimates, uncertainty, analysis populations, and planned methods are needed for a fuller statistical interpretation.
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 registry record provides limited detail about the trial’s methods. It identifies a randomized, parallel-group design without masking, but does not report how the random sequence was generated, whether allocation was concealed, or whether outcome assessment was masked. Further eligibility criteria, baseline characteristics, and details of the care protocols are not reported. The summary refers to laparoscopic colorectal surgery, while the title describes colorectal and small bowel resection; the record does not clarify the scope of procedures represented in the analyzed groups.
The primary result is descriptive. The record gives medians and inter-quartile ranges but no comparative estimate, confidence interval, p-value, or sponsor-reported hazard ratio. The statistical analysis plan, handling of censoring, and method used to compare the groups are not reported. The sample-size justification for the original trial is also not reported in the registry record.
There is an analysis-population ambiguity: the primary endpoint includes 97 ERP participants and notes one excluded mortality case, while the adverse-event record lists 98 ERP participants at risk. The registry does not explain the difference or describe missing-data handling, protocol deviations, adherence, or the analysis population intended by the protocol.
Although four secondary outcomes are listed, their results are not reported. The record does not describe how multiplicity was handled, whether there were interim analyses, or how adverse events were defined and attributed. These omissions limit assessment of the completeness, precision, and scope of the posted findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Fast-track Rehabilitation After Elective Colorectal and Small Bowel Resection — NCT00606944.
- Registry record last updated 2012-08-21; status last verified 2012-07.
- Results first posted 2012-08-21.
- 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 record describes a completed, randomized, parallel-group trial of fast-track rehabilitation after elective colorectal resection, with enrollment of 200 and no masking reported. The control group received conventional care; the ERP group received early diet and ambulation.
The primary outcome was median length of hospital stay at discharge. The control group had a median of 8 days, with an inter-quartile range of 7 to 9 days; the ERP group had a median of 7 days, with an inter-quartile range of 6.75 to 8.25 days. The endpoint analysis included 100 control participants and 97 ERP participants; one mortality case was excluded from ERP endpoint analysis.
The record lists readmission, pain, quality of life, and postoperative complications as secondary outcomes, but does not report their results. Serious adverse events were recorded for 0 of 100 control participants and 1 of 98 ERP participants; Death is listed as the top serious-event term at 1.0%. No formal comparative analysis or confidence interval for the primary outcome is reported.