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 Laparoscopic Versus Open Appendectomy? Let the Patient Decide (NCT01738750), a randomized na study. The primary outcome is Choice Based on Cost.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01738750 |
| Phase | NA |
| Condition | Appendicitis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 100 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Utah |
| Results posted | Yes |
2. Clinical Question
Population
Children admitted with a diagnosis of uncomplicated appendicitis who agreed to review a consent form. The registry record does not give a more detailed description of eligibility, clinical characteristics, or the population included in the reported outcome.
Intervention
Consent materials that included cost information for laparoscopic and open appendectomy. The intervention description says patients received this information before choosing a procedure. The study summary also describes a computerized presentation about the procedures.
Comparator
Consent materials without cost information for the two procedures. The registry record describes both groups as viewing a group-specific computerized presentation about each procedure, but does not report the presentation content in detail.
Primary question
Did cost information affect the choice made between laparoscopic and open appendectomy? More specifically, the stated hypothesis was that participants receiving cost information would more often choose the less expensive procedure. The record does not identify which procedure was less expensive or report a statistical comparison of choices.
The study concerns the effect of information on a choice, rather than a comparison of surgical outcomes. Participants were to choose between two procedures, while randomization assigned them to consent information with or without costs. Thus, the randomized contrast is the presence of cost information in the consent materials; it is not random assignment to laparoscopic or open surgery.
The primary outcome was assessed before surgery. This timing is relevant because the choice is the outcome of interest, rather than a later measure of recovery or hospital use. The registry lists arm-level values of 63.0 for the cost-information group and 35.0 for the group without cost information, with a unit described as percentage of open appendectomy. The record does not specify enough detail to interpret those values as a particular count or proportion, and it gives no confidence interval or formal test for the between-group comparison.
3. Trial Design
This was a randomized, parallel-group study with no masking. The registry lists planned enrollment of 100 and records a completed study. The trial was sponsored by the University of Utah. The recorded start was 2012-07 and the primary completion was 2013-12. The phase is listed as not applicable.
The brief description concerns children admitted with uncomplicated appendicitis. After agreeing to review a consent form, participants were randomly assigned to one of two information groups. One group received cost information for the laparoscopic and open procedures; the other received consent information without those costs. Both groups were also described as viewing a group-specific computerized presentation about the procedures. The intervention is therefore an information strategy layered onto a choice between procedures, not assignment to a particular operation.
Random allocation can support a comparison of the groups as assigned, provided outcome collection and analysis preserve that assignment. The registry record does not describe the randomization sequence, allocation concealment, who generated or implemented allocation, or any procedures used to prevent foreknowledge of group assignment. Those details are not reported in the registry record. No masking was used, which is unsurprising for an information intervention participants can recognize, but the record does not say whether outcome assessors or analysts were masked.
The posted arm sizes are 49 for the cost-information group and 51 for the group without cost information. These are the arm denominators associated with the primary outcome values. The registry lists the outcome as assessed before the surgical procedure, with data presented within 1 year. It does not describe follow-up beyond the decision outcome, the timing of the computerized presentations, or whether all randomized participants contributed an outcome.
The protocol summary frames the study around whether information about costs influences patient choice. It does not report a sample-size justification, a detailed statistical analysis plan, or a prespecified method for handling participants who did not make a choice or whose outcome was unavailable. These details are not reported in the registry record, so the stated enrollment should not be mistaken for evidence about the precision or power of the final comparison.
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 | Cost Information Included | No Cost Information Included |
|---|---|---|
| STARTED | 49 | 51 |
| COMPLETED | 49 | 51 |
| NOT COMPLETED | 0 | 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.
Population: Age, Gender
| Characteristic | Unit | Cost Information Included | No Cost Information Included | Total |
|---|---|---|---|---|
| Participants analysed | 49 | 51 | 100 | |
| Age, Continuous | years | 10.8 (SD 3.3) | 10.6 (SD 3.2) | 10.7 (SD 3.2) |
| Age, Categorical: <=18 years | Participants | 49 | 51 | 100 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 22 | 20 | 42 |
| Sex: Female, Male: Male | Participants | 27 | 31 | 58 |
| Region of Enrollment: United States | participants | 49 | 51 | 100 |
6. Primary Endpoint
The registry lists the primary outcome as Choice Based on Cost, measured over Outcome assessed prior to surgical procedure with data presented within 1 year.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of open appendectomy |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is titled Choice Based on Cost. Its description asks whether the group receiving cost information more often chose the less expensive procedure than the group without that information. It was assessed before surgery, so it is intended to capture the decision made after the information intervention rather than a clinical result of the operation.
This endpoint is useful for the trial’s stated question because it focuses on whether the information changes behavior at the moment of choice. The registry labels its unit as percentage of open appendectomy and gives an outcome type of number. It lists a value of 63.0 for the cost-information group and 35.0 for the group without cost information. The record does not explain the coding or calculation behind those arm-level values, including whether they represent percentages, counts, or another summary. It also does not identify which operation was less expensive.
These details limit interpretation. The stated endpoint description concerns choosing the less expensive procedure, while the unit refers to open appendectomy. Without a definition linking the recorded values to individual choices, the values cannot safely be translated into numbers of participants who chose a particular operation. No confidence interval, standard error, or comparative test is reported. The outcome’s intended meaning is clear at a broad level, but the registry record does not fully document its operational definition or the precision of the observed results.
The record also lists Hospital/Operative Dollars as a secondary outcome. It does not provide a secondary-outcome result in the registry record described for this trial. As a result, the primary choice outcome should not be conflated with actual hospital or operative spending.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry lists 63.0 for the cost-information group and 35.0 for the group without cost information. These are the posted arm-level values for the primary outcome, whose registry unit is percentage of open appendectomy. The record does not provide a definition sufficient to translate those values into counts or to confirm exactly what choices they represent. The values therefore offer a descriptive contrast, but their magnitude and direction should not be given a more specific interpretation than the registry supports.
The stated hypothesis concerned whether patients given cost information would more often choose the less expensive procedure. However, the registry record does not say which procedure was less expensive, nor does it state explicitly how each recorded value maps to choosing the less expensive option. It is therefore not possible to determine from the record whether the listed values support the hypothesis. The title and brief summary cannot substitute for a clear outcome definition and a comparative analysis.
No effect estimate for the randomized contrast is posted. There is no reported confidence interval, standard error, p-value, or test result. The record also lists zero analyses, and the comparison is marked as not estimable for this count-type outcome. This means that the arm values should not be presented as evidence of a statistically established difference. Without uncertainty estimates, the precision of the observed contrast cannot be assessed. A difference between arm-level summaries can reflect a real intervention effect, random variation, or issues in outcome definition and recording; the registry record does not resolve those possibilities.
The random allocation and similar arm sizes are relevant design features, but they do not by themselves establish how reliable a result is. Interpretation also depends on what was measured, whether outcome data were complete, and whether analysis followed the randomized assignment. Those details are not reported in the registry record. Nor is there a reported adjustment for any other factors or a prespecified analysis method.
The numbers should be read as descriptive posted results, not as a complete analysis of the primary question. They do not quantify how precisely the intervention changed a participant’s probability of choosing either operation, and they do not establish that costs changed actual spending. The secondary outcome is hospital or operative dollars, but no result for it is included in the record details. The registry also reports no serious or other adverse events in either group; this is a separate safety summary and does not clarify the choice outcome.
Overall, the record documents a randomized comparison of cost information versus no cost information and gives arm-level primary-outcome values. It does not report a sufficiently specified outcome calculation or inferential analysis to support a firm conclusion about the effect of cost information. The appropriate statistical reading is descriptive and cautious: the posted values are available, but their meaning and precision remain unclear.
9. Statistical Methods Explained
The design is a randomized parallel-group comparison. In a randomized study, assignment is intended to make the groups comparable, on average, with respect to factors that could affect the outcome. The intervention being assigned in this trial was whether the consent materials included cost information. Participants were not randomized to receive laparoscopic or open appendectomy; they were allowed to choose between procedures. That distinction determines what the randomized comparison can estimate: the effect of assignment to cost information on the recorded choice outcome, not the effect of one operation versus the other.
What does an arm-level value tell the reader?
An arm-level summary describes the observed outcome within a group. By itself, it does not establish the size or precision of a difference between groups. To interpret a choice outcome, the reader needs to know how each participant’s choice was coded, how the group summary was calculated, and what denominator was used. The registry gives values of 63.0 and 35.0 and labels the unit as percentage of open appendectomy, but it does not explain the calculation or map each value to an explicit choice category. The arm sizes are recorded as 49 and 51. These figures should not be converted into participant counts without a stated calculation method.
Why does a confidence interval matter?
A confidence interval is a range of values that expresses statistical uncertainty about an estimated effect under a specified method. It helps distinguish the observed estimate from the range of effects reasonably compatible with the data and method. A point estimate alone does not show how precisely the effect has been estimated. No confidence interval is reported for the primary comparison, so the precision of the contrast cannot be evaluated from the registry record.
A hypothesis test addresses whether data are inconsistent with a specified null hypothesis, according to an analysis method and significance threshold. A p-value is not a measure of the size or importance of an effect, and it does not replace an interval estimate. The registry record reports no p-value or test for the primary comparison. It also does not report the statistical test or model that would have been used. Consequently, no inferential conclusion should be attributed to the posted arm values.
What does the non-estimable comparison indicate?
The record marks the two-arm comparison as not estimable for this count-type outcome. In this setting, that means a comparative estimate was not produced in the posted results. It does not mean that the two groups were proven identical, nor does it establish that the intervention had no effect. The record’s listed values remain descriptive, while the lack of a comparative estimate prevents assessment of the intervention contrast using an effect estimate and its uncertainty.
Why does outcome definition matter?
Statistical analysis can only answer a clear question if the outcome is defined in a way that connects the recorded data to the scientific target. Here, the target is a choice based on cost, but the unit label refers to percentage of open appendectomy. The record does not clarify whether the values refer to the share choosing open surgery, a percentage calculated in another way, or a coded outcome. It also does not identify which procedure was less expensive. These gaps affect not only clinical interpretation but also the statistical meaning of the outcome and the direction of any effect.
For a binary outcome, a comparative analysis might report a difference in proportions or another prespecified effect measure, together with uncertainty. The appropriate choice depends on the analysis plan and outcome definition. This is a general statistical explanation, not a claim about the method used in this trial. The registry does not report a chosen effect measure or model, so none should be inferred.
What can be said about sample-size planning?
Enrollment is listed as 100, and the posted arm sizes are 49 and 51. Those figures describe the study enrollment and arm denominators in the outcome record; they do not establish that the study had adequate precision for the primary question. A sample-size justification, target effect, and power calculation are not reported in the registry record. No planning conclusion can be drawn from enrollment alone.
Power is a design-stage probability of detecting a specified effect under assumed conditions. It is not a property that can be recovered as an observed measure after results are known. Any sample-size illustration based on an observed effect would be a planning exercise, not observed power. In this case, the outcome definition and comparative estimate are not sufficiently specified in the registry record to support a substantive sample-size interpretation. The study’s own design justification is not reported in the registry record.
Because the endpoint is described as a choice outcome, a model for event counts may not be relevant unless the data were actually recorded as counts. The record’s comparison limitation explicitly concerns a count-type endpoint, but does not clarify the underlying coding. General statistical methods such as logistic regression, exact tests, or differences in proportions could be considered for some binary outcomes, but naming them does not establish that they were used or would have been appropriate. The analysis plan is not reported in the registry record.
Dispersion describes how variable observations are around a model’s expected values. Over-dispersion occurs when the data vary more than a model assumes, which can make standard errors too small and confidence intervals too narrow if ignored. This is a general concept; the registry does not report a count model, dispersion estimate, or evidence of over-dispersion for this trial. It would be inappropriate to attribute such a problem to the posted results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome, Choice Based on Cost, and one secondary outcome, Hospital/Operative Dollars. It does not report a multiplicity plan describing how inference across outcomes or analyses would be handled. A multiplicity plan matters when several hypotheses are tested, because repeated testing can increase the chance of at least one apparently notable result by chance. This general concern does not show that the trial made multiple tests; the record lists zero analyses and does not provide test results.
Missing-data methods are not reported in the registry record. The arm sizes recorded with the primary outcome are 49 and 51, but the record does not state whether every randomized participant contributed an outcome, whether any choice data were missing, or how missing or ambiguous choices were handled. It also does not give a participant flow account that would clarify exclusions after randomization. A denominator alone cannot establish complete outcome ascertainment or explain how the analysis population was defined.
The registry does not specify whether the primary analysis followed an intention-to-treat approach, used participants as randomized, or relied on another analysis population. It does not describe any per-protocol or as-treated analysis. These distinctions matter because removing participants or reclassifying them after randomization can affect the comparability created by random assignment. The record also does not report how deviations from the assigned information group, if any, were handled.
The registry record does not state whether there were interim analyses, prespecified stopping rules, or adjustments associated with any such analyses. These details are not reported in the registry record. The lack of posted analyses and uncertainty estimates means there is no multiplicity-adjusted or unadjusted inferential result to interpret. Thus, the reported arm-level outcome values should be treated as descriptive rather than as the endpoint of a documented testing strategy.
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 |
|---|---|---|---|
| Cost Information Included | 0 | 49 | 0.0% |
| No Cost Information Included | 0 | 51 | 0.0% |
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 |
|---|---|
| Cost Information Included | 0 of 49 |
| No Cost Information Included | 0 of 51 |
The registry lists zero serious adverse events and zero other adverse events for the cost-information group, with 49 participants at risk in each category. For the group without cost information, it likewise lists zero serious adverse events and zero other adverse events, with 51 participants at risk in each category. These are the adverse-event figures recorded for the two groups.
A zero in an adverse-event field means that no events were recorded in that field for the listed group in the registry record. It does not establish that no event occurred outside the collection or reporting process, and it does not show that the groups have identical safety profiles. The record does not describe the adverse-event collection window, ascertainment method, or event definitions. The timing and completeness of safety follow-up are therefore not reported in the registry record.
Deaths are not given as a numeric result in the record. They should not be interpreted as zero. The serious adverse-event fields also do not provide event descriptions, because no serious-event terms are listed. These safety summaries are distinct from the primary choice outcome and do not provide evidence about the effect of cost information on choices. They also do not describe comparative surgical safety, since the randomized intervention was the information presented, not the operation performed.
12. What the Result Does, and Does Not, Mean
This trial addresses a focused behavioral question: whether including cost information in consent materials changes how children with uncomplicated appendicitis choose between laparoscopic and open appendectomy. Randomization was assigned to the information condition, and the outcome was intended to be assessed before surgery. The study therefore concerns the effect of cost information on a decision, rather than whether one procedure produces better clinical outcomes.
The registry lists a primary-outcome value of 63.0 for the cost-information group and 35.0 for the group without cost information. It labels the unit as percentage of open appendectomy, but does not specify how the values were calculated or exactly what choices they represent. The record also does not identify which procedure was less expensive. These limitations prevent a confident interpretation of whether the posted values show more frequent selection of the less expensive procedure in the cost-information group.
The registry does not report an effect estimate comparing the groups, an interval expressing uncertainty, or a test result. The values therefore do not establish that cost information caused a change in choice, and they do not establish that there was no change. The absence of a reported analysis is not evidence that the groups were equivalent. It leaves the size and precision of the randomized contrast unknown.
The record also cannot establish whether cost information changed actual hospital or operative spending. Hospital/Operative Dollars is listed as a secondary outcome, but a result for that outcome is not reported in the registry record. A stated hypothesis is not itself a result, and the intervention’s intended influence should not be confused with evidence that it occurred.
More broadly, this study does not compare the clinical effectiveness or safety of laparoscopic and open appendectomy. Participants chose between operations; the randomized contrast was consent information with versus without costs. The posted adverse-event figures concern the two information groups and do not provide a procedure-specific comparison. The best-supported conclusion is consequently limited: a randomized study of cost information was conducted, arm-level values were posted, and the registry record does not provide the outcome detail or statistical analysis needed to determine the effect of that information on choice.
13. Why This Trial Matters Statistically
The trial is statistically interesting because it separates the effect of information from the effect of the procedure selected. Patients were offered a choice, while randomization concerned whether costs appeared in the consent materials. This design makes the intended estimand—the effect of cost information on a recorded choice—different from a comparison of surgical methods. Keeping those questions separate is essential when interpreting the results.
It also illustrates why a registry outcome needs a clear operational definition. The trial’s stated question is about choosing the less expensive procedure, while the recorded unit is percentage of open appendectomy. Without an explanation of the coding and calculation, readers cannot confidently link the arm summaries to the hypothesis. Clear outcome definitions are not merely editorial details: they determine what an estimate means and whether it answers the study question.
The record illustrates the distinction between descriptive data and an inferential comparison. Arm-level values can be reported even when no comparative estimate, confidence interval, or test is available. Statistical interpretation requires both an understandable outcome and an analysis that quantifies the contrast and its uncertainty. Neither is fully documented for this primary outcome in the registry record.
Finally, the trial shows why planned enrollment does not by itself tell readers whether a study was precise enough to address its question. A sample-size justification and analysis plan are not reported in the registry record. Without those details, the enrollment and arm sizes cannot establish the intended sensitivity of the study. The registry’s record of the design and values is useful, but it leaves key steps between randomized assignment, recorded choice, and statistical conclusion undocumented.
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 interpretation is incomplete specification of the primary outcome. The record describes a choice based on cost, but labels the unit as percentage of open appendectomy and does not explain how the arm values were derived. It also does not identify which procedure was less expensive. This makes it difficult to connect the posted values to the stated hypothesis without making assumptions.
The registry provides no comparative effect estimate or uncertainty interval, and no statistical test is reported. The comparison is marked not estimable for this count-type outcome. As a result, it is not possible to assess the precision of the between-group contrast or to determine whether the observed arm-level values are compatible with a range of possible effects. The values should not be treated as a demonstrated intervention effect.
Further trial-conduct details are not reported in the registry record. These include the randomization procedure and concealment, the analysis plan, the sample-size justification, the definition of the analysis population, and methods for handling missing or ambiguous choices. The record does not describe participant flow or confirm whether all participants in each arm contributed an outcome. Masking was listed as none, while masking of outcome assessors or analysts is not described.
The protocol summary describes computerized presentations in both groups, but it does not give their content or explain how consistently they were delivered. The registry also does not report whether participants understood the cost information or whether the information reflected actual costs. The primary outcome was assessed before surgery, but the outcome collection process is not described in detail.
The secondary outcome Hospital/Operative Dollars is listed without a reported result in the record details. Safety follow-up details are also not described, and the death field is not reported as a numeric result. These limits mean the posted record cannot support conclusions about actual spending, longer-term outcomes, or the completeness of adverse-event capture. They are limitations of what the registry record documents, not evidence that any particular problem occurred.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Laparoscopic Versus Open Appendectomy? Let the Patient Decide — NCT01738750.
- Registry record last updated 2014-05-19; status last verified 2014-04.
- Results first posted 2014-05-19.
- 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 study with no masking, sponsored by the University of Utah. Enrollment is listed as 100; the recorded study start was 2012-07 and primary completion was 2013-12. The population described in the summary was children admitted with uncomplicated appendicitis.
Participants were assigned to consent materials with cost information for laparoscopic and open appendectomy or to materials without cost information. The primary outcome, Choice Based on Cost, was intended to capture the choice made before surgery. The record lists values of 63.0 and 35.0 for the respective groups, with a unit described as percentage of open appendectomy, but does not explain how those values were calculated.
No comparative effect estimate, confidence interval, or test result is reported, and the two-arm comparison is marked not estimable for the count-type outcome. A sample-size justification, detailed analysis plan, missing-data approach, and analysis population are not reported in the registry record. Hospital/Operative Dollars is listed as a secondary outcome without a result in the record details.