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 Increasing Activity in Liver Transplant Patients (NCT02058498), a na na study. The primary outcome is Physical Activity Measured by the International Physical Activity Questionnaire (IPAQ).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02058498 |
| Phase | NA |
| Condition | Liver Transplant |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
Adult liver transplant patients. The registry record lists liver transplant as the condition and records an enrollment of 12.
Intervention
Participants received physical activity walking instructions and were asked to record their daily activity on an activity log.
Comparator
There was no separate comparator group. The study is recorded as a single-group study, with no allocation to different groups.
Primary question
Did physical activity, measured by the International Physical Activity Questionnaire, change between baseline and 6 weeks after participants received walking instructions?
The registry's broader question also asks whether participants would perceive improved quality of life. Quality of life was listed as a secondary outcome at baseline, 6 weeks, and 4 months. Another secondary outcome was the number of patients who documented their physical activity.
These questions describe what the study set out to examine, not what it found. The registry record does not report physical activity values at either primary-outcome time point, a change estimate, or a statistical test. It also does not report quality-of-life results or the count of participants documenting activity. Therefore, the record does not establish whether activity or perceived quality of life changed after the instructions. With no concurrent control group, any change observed within participants would also need cautious interpretation: the design cannot separate an intervention-associated change from other explanations for change over time.
3. Trial Design
NCT02058498, titled Increasing Activity in Liver Transplant Patients, is recorded as a completed, single-group study sponsored by Mayo Clinic. The registry lists enrollment of 12 and a liver transplant population. The study dates recorded are 2014-02 for start and 2014-12 for primary completion. Its phase is listed as not applicable, and allocation is listed as not applicable. Masking is listed as none.
The intervention was behavioral: participants received physical activity walking instructions and were asked to keep a daily activity log. There was no separate control arm. Thus, this is not a randomized comparison, and the record does not support a like-for-like contrast between people assigned different treatments. The primary outcome was physical activity measured with the International Physical Activity Questionnaire (IPAQ) at baseline and 6 weeks.
The registry lists quality of life at baseline, 6 weeks, and 4 months, and the number of patients documenting physical activity, as secondary outcomes. It lists three outcome measures and one analysis, but does not describe the analysis method or provide analysis results. The record does not state how participants were recruited, how many completed each assessment, or whether activity logs were used to supplement or verify questionnaire responses.
Completion status indicates the study is recorded as completed; it does not itself supply evidence about the outcome. The record does not report a protocol rationale for the enrollment target, a sample-size justification, interim analyses, or detailed statistical methods. The design should therefore be read from the recorded structure: a small, single-group behavioral study with activity assessed at baseline and 6 weeks, not as a controlled efficacy 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 | Liver Transplant Patients |
|---|---|
| STARTED | 12 |
| 6 Weeks | 8 |
| COMPLETED | 8 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Liver Transplant Patients |
|---|---|
| Withdrawal by Subject | 4 |
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 | Liver Transplant Patients |
|---|---|---|
| Participants analysed | 12 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 12 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 10 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| 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 | 10 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: United States | participants | 12 |
6. Primary Endpoint
The registry lists the primary outcome as Physical Activity Measured by the International Physical Activity Questionnaire (IPAQ), measured over Baseline, 6 weeks.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Full Range |
| Unit | MET |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is physical activity measured with the International Physical Activity Questionnaire (IPAQ), reported in metabolic equivalent (MET) units. The registry specifies a median with the full range as the descriptive summary and gives baseline and 6-week assessment times. The questionnaire asks participants about the days and minutes they exercised during the previous one week in vigorous activity, moderate activity, and walking.
The recorded calculation combines activity categories using the formula MET=8(vigorous activity) (minutes) + 4 (moderate activity)(minutes) +3.3 (walking activity) (minutes). This gives weighted scores for the reported activity, rather than a direct measure from an external activity monitor. Asking about a recent week makes the measure relevant to activity patterns near each assessment, while the questionnaire allows different intensities of activity to contribute to the score.
Reporting a median and full range describes the middle observation and the spread from the lowest to highest observed values. As a general statistical point, a median can be informative when values are asymmetric or include unusually high observations, while the full range makes the extremes visible. Neither summary, by itself, shows how each participant changed between assessments. The registry record does not provide the observed MET values, the participant-level changes, or a numerical comparison of baseline with 6 weeks, so the magnitude and distribution of activity in this study cannot be assessed from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clear measurement plan for the primary outcome: IPAQ-based physical activity at baseline and 6 weeks, summarized by the median and full range. It does not report the corresponding values. There is no posted baseline median, 6-week median, range, estimate of within-participant change, confidence interval, or test result in the record. As a result, no direction or size of change can be described, and there is no basis for judging the precision of an estimated change.
The missing outcome results matter for interpretation. A study's completion status is not an outcome finding. Likewise, the stated question about whether participants increase activity is not evidence that activity increased. The registry record also does not report results for the secondary outcomes: quality of life at baseline, 6 weeks, and 4 months, or the number of patients who documented physical activity. Those outcomes cannot be interpreted from their titles alone.
The single-group design limits what any within-study change could establish, even if numerical results were available. Without a concurrent comparator group, a difference from baseline could not be attributed uniquely to walking instructions. Other changes over time, participants' expectations, or differences in who completed follow-up could potentially contribute. These are general interpretive concerns for uncontrolled before-and-after studies, not claims about what occurred among these participants.
Precision is also impossible to evaluate from the registry entry because it does not provide outcome variability or an interval estimate. The enrollment was 12, but the record does not state the number with usable observations at each time point. The enrollment figure alone does not establish the analysis sample for the primary outcome. Nor does the record give enough information to assess whether missing observations affected the results.
The registry describes an investigation of walking instructions and activity recording in liver transplant patients. It does not report evidence that the intervention changed activity or quality of life, and it does not report a controlled comparison. The appropriate reading is therefore descriptive: the record identifies the question, population, intervention, timing, and measurement approach, while leaving the actual outcome findings unavailable in the registry record.
9. Statistical Methods Explained
The statistical information in the registry record is limited. It names the primary measure, its summary form, and its assessment times, but does not describe the statistical analysis used to compare measurements or report an estimate. The following explains the recorded measurement choices and general concepts relevant to interpreting them; these concepts do not imply that a particular unreported method was used.
What the IPAQ score represents
The IPAQ asks about days and minutes spent in vigorous activity, moderate activity, and walking during the previous one week. The registry gives a weighted calculation: MET=8(vigorous activity) (minutes) + 4 (moderate activity)(minutes) +3.3 (walking activity) (minutes). The resulting MET score is intended to combine reported activity across categories. It depends on participants' reports of their activity, rather than a direct sensor measurement. As a general measurement point, questionnaire-based measures can reflect recall and reporting, so their interpretation is tied to how accurately participants remember and describe activity.
The stated assessment times are baseline and 6 weeks. This arrangement can describe activity at two points in time. In a repeated-measures setting, an analysis may account for the fact that observations from the same participant are related; such observations are not equivalent to measurements from unrelated people. The registry record does not say whether participant-level changes were calculated, which method was used, or how the relationship between repeated measurements was handled. It is not appropriate to infer an analysis method from the measurement schedule alone.
Why the median and full range are reported
The registry specifies the median and full range. The median is the central value when observations are ordered. The full range records the smallest and largest observed values. As a general statistical explanation, the median is less affected than the mean by extreme observations, which can make it useful for skewed measurements. The range conveys the span of observations but can be strongly influenced by the most extreme values and does not describe the distribution between them. These summaries can characterize each assessment, but separate medians and ranges do not reveal whether the same individuals increased or decreased.
A comparison of the baseline and 6-week values would require results that are not included in the registry record. A confidence interval, if reported, would describe uncertainty around an estimated quantity under the assumptions of the chosen method. A test result would address compatibility with a specified null hypothesis, but would not by itself convey the size or practical meaning of a change. Neither confidence intervals nor test results are reported for the primary outcome.
Why over-dispersion can matter
General statistical context: when outcome variability is greater than a model assumes, standard errors and intervals based on that model may not reflect the uncertainty adequately. This is often described as over-dispersion in settings where a model assumes a particular degree of variability. The registry does not identify a model for the primary outcome, report a dispersion assessment, or provide values with which to evaluate this issue. It would therefore be speculative to say that over-dispersion occurred or that a particular adjustment was needed.
Planning calculations and the analysis actually used
The planning assumptions associated with the study describe an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustration is not the study's own design: this study is recorded as single-group, with no allocation to two arms. The assumptions also describe detecting stated fractions of an observed effect. No planning estimates or observed effect values are reported in the registry record, so the numerical implications cannot be assessed. Such planning calculations are not observed power. Sample-size planning illustrates what a hypothetical design might require under stated assumptions; it does not demonstrate the probability that a completed study detected an effect.
The registry does not report a prespecified statistical analysis plan, a sample-size justification for the single-group design, details of any interim analyses, or a method for estimating change. These omissions prevent a detailed appraisal of whether the analysis followed a prespecified plan, how uncertainty was quantified, and how the primary outcome was handled analytically. The record's outcome definition alone is not enough to reconstruct those methods.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary physical activity outcome and secondary outcomes covering quality of life at baseline, 6 weeks, and 4 months, and the number of patients who documented physical activity. It also records three outcome measures and one analysis. The record does not explain how the three measures relate to the listed outcome descriptions, identify a hierarchy among secondary outcomes, or state whether adjustments for multiple comparisons were planned.
Multiplicity is a general statistical concern when several outcomes or comparisons are examined: the chance of at least one apparently notable result can rise as the number of tests increases. Whether an adjustment is needed depends on the analysis plan and the purpose of the comparisons. Since the registry does not report test results or a multiplicity strategy, it is not possible to assess whether multiplicity affected interpretation. No particular adjustment should be assumed.
Handling of missing data is also not reported in the registry record. The entry does not state how many participants contributed data at baseline, 6 weeks, or 4 months, whether all enrolled participants were included in analyses, or what was done if a questionnaire or activity log was incomplete. It does not identify an analysis population or describe imputation, exclusion, or sensitivity procedures. Enrollment of 12 does not establish that all 12 contributed to every outcome assessment.
These reporting gaps limit appraisal of both the completeness and robustness of the findings. Without outcome-specific participant counts and missing-data methods, readers cannot determine whether the analyzed observations represent all enrolled participants or whether incomplete follow-up could influence estimates. The registry record also does not report a prespecified plan that would clarify which comparisons were confirmatory and which were exploratory.
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 |
|---|---|---|---|
| Liver Transplant Patients | 0 | 12 | 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 |
|---|---|
| Liver Transplant Patients | 0 of 12 |
The registry records 12 participants at risk for serious adverse events and 0 affected participants. It also records 12 at risk for other adverse events and 0 affected participants. These are the event figures recorded for the Liver Transplant Patients group.
These entries mean that the registry lists no affected participants in either recorded adverse-event category. They should not be interpreted as proof that no adverse experiences occurred. The record does not provide additional detail about adverse-event collection, definitions, observation periods, or how events were solicited and assessed. It lists no top serious adverse-event terms. Deaths are not reported in the registry record.
As a general statistical point, a zero count in a small group does not establish that the underlying risk is zero. It is also important to distinguish a recorded count of affected participants from a complete description of event types, severity, timing, or attribution. The registry entry does not describe whether events were considered related to the intervention. These figures therefore convey only the recorded counts and denominators, not a comprehensive safety assessment.
The behavioral intervention consisted of walking instructions and activity logging. No conclusion about safety beyond the registry's reported adverse-event counts can be drawn from the entry.
12. What the Result Does, and Does Not, Mean
This record documents a study of walking instructions for adult liver transplant patients, with physical activity measured by the IPAQ at baseline and 6 weeks. It also identifies quality of life and activity documentation as secondary outcomes. The study is recorded as completed, with enrollment of 12.
What the record does not establish is whether the primary outcome changed, whether any change was large or small, or how uncertain an estimate might be. The registry does not report the primary outcome values, a change estimate, or an inferential result. It also does not provide results for the listed secondary outcomes. Consequently, neither improvement nor lack of improvement can be concluded from the posted registry information.
Even if a numerical before-and-after change were available, the absence of a concurrent control group would constrain causal interpretation. A change over time in a single group would not isolate the effect of the walking instructions from other possible influences. This is a general limitation of uncontrolled studies, not a statement that a particular alternative explanation occurred in this study.
The study's measurement approach is also relevant to what its endpoint can represent. IPAQ activity scores are based on participants' reports about the previous one week. They summarize reported activity across vigorous, moderate, and walking categories; they are not described in the registry as an objective monitor-based measure. The record does not report adherence to the instructions or completeness of activity logs, so the degree to which participants followed or documented the requested activity cannot be determined.
The defensible conclusion is narrow: the registry describes the question and design, but it does not publish outcome findings adequate to answer that question. The absence of reported results is not evidence that the intervention had no effect, just as the study's stated aims are not evidence that it had an effect. Any broader claim would go beyond what the registry record reports.
13. Why This Trial Matters Statistically
Statistically, the study is informative as an example of the distinction between a research question, a measurement plan, and reportable results. The registry specifies a population, a behavioral intervention, a primary measure, and assessment times. Those details make the intended inquiry understandable. Yet without the actual outcome values and analysis results, readers cannot estimate the direction, magnitude, or precision of any change.
The single-group structure is central to interpretation. It can describe what happened among participants over time if results are reported, but it does not offer a concurrent comparison that would help distinguish intervention-associated changes from other changes over the same period. This matters particularly when the question is framed as whether instructions lead to increased activity: the design and results must be considered together, rather than treating the question itself as a finding.
The registry also highlights the importance of outcome reporting beyond the primary measure. Quality of life and activity documentation were listed as secondary outcomes, but their results are not reported. Participant counts at each assessment, missing-data handling, and the analysis plan are also absent. These details help readers judge how complete the evidence is and how much confidence to place in estimates.
Finally, the record's planning assumptions illustrate why hypothetical sample-size calculations should not be confused with the actual design or with observed power. The assumptions describe an equal-allocation, two-arm illustration, whereas the study is recorded as single-group. Statistical planning only has meaning in relation to a specified design and outcome analysis. With no observed effect or numerical planning estimates reported, the illustration cannot fill the gap left by missing findings.
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 specific to this study follow directly from the registry description. First, the study is single-group, with no separate comparator and no allocation to different groups. Any reported change from baseline would therefore be a within-group observation rather than a controlled estimate of the effect of walking instructions.
Second, enrollment was 12. The registry does not provide outcome-specific sample counts, so it is not possible to establish how many participants contributed usable data at baseline, 6 weeks, or 4 months. It also does not report a sample-size justification for the study's actual single-group design.
Third, the primary measure is questionnaire-based. The IPAQ asks participants to report days and minutes of activity during the previous one week. This makes recall and reporting relevant considerations. Participants were also asked to maintain an activity log, but the registry does not report how many completed logs or whether log information was incorporated into the primary outcome analysis.
Fourth, the primary outcome is assessed at baseline and 6 weeks, while the listed quality-of-life outcome extends to 4 months. The record does not explain the rationale for these timing choices or report completion and follow-up results. It also does not provide a detailed statistical analysis plan, missing-data methods, or multiplicity procedures.
Most importantly, the registry record does not report outcome values or analysis results. This prevents evaluation of the observed activity distribution, change over time, uncertainty, and secondary outcomes. The completed status does not resolve these limitations or substitute for outcome reporting.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Increasing Activity in Liver Transplant Patients — NCT02058498.
- Registry record last updated 2016-06-06; status last verified 2016-04.
- Results first posted 2016-06-06.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT02058498, Increasing Activity in Liver Transplant Patients, is recorded as a completed, single-group behavioral study sponsored by Mayo Clinic. Enrollment was 12, and the listed condition was liver transplant. Participants received walking instructions and were asked to record daily activity.
The primary outcome was IPAQ-measured physical activity in MET units at baseline and 6 weeks, summarized by median and full range. Secondary outcomes were quality of life at baseline, 6 weeks, and 4 months, and the number of patients documenting physical activity. The registry reports no outcome values or analysis findings, and does not report details of missing-data handling or the statistical analysis plan. The record therefore describes the study question and measurement approach but does not establish what the study found.