Physical Therapy and Occupational Therapy After Transcatheter Aortic Valve Replacement: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Physical Therapy and Occupational Therapy After Transcatheter Aortic Valve Replacement (NCT03117296), a registered phase not stated study. The primary outcome is Post Procedure Hospital Length of Stay.

2. Clinical Question

3. Trial Design

This completed study evaluated a physical therapy and occupational therapy pathway after transcatheter aortic valve replacement at Henry Ford Hospital. The registry reports enrollment of 189. Its description says that retrospective data were collected from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Aortic Valve Replacement Procedures registry, covering March 2012 through July 31, 2015. It also says the pathway began on December 2, 2014, and that future analysis would extend the data through December 31, 2015.

The comparison was between a routine-care group and a group receiving the post-procedure pathway. The group descriptions identify the earlier control period as TAVR 3/1/12-11/1/14 and the pathway period as TAVR 11/2/14-12/31/15. The record does not explain how these date descriptions relate to the data-collection period or the stated future extension. It also does not describe individual allocation procedures. Allocation is not stated, and the groups are not a like-for-like randomized comparison.

The pathway description specifies nursing mobilization on post-procedure day zero and physical and occupational therapy assessment and intervention on post-procedure day one, followed by daily interventions. The control description is routine physical therapy or occupational therapy. The primary outcome was hospital length of stay at discharge. Secondary outcomes included discharge home and discharge to a rehabilitation facility. The registry marks the study completed, with primary completion on 2015-07-31, but the primary outcome results and the details of the analysis are not reported in the registry 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.

Before assignment: Patients excluded from database included those with an access sites other than femoral, the occurrence of major events including death, stroke, myocardial infarction (MI), additional cardiac or vascular surgery, electrophysiological monitoring, pacemaker placement, atrial fibrillation, other car-diovascular repair or surgery required, gastrointestinal bleeds, hematoma or access bleeds, or complications

Overall Study

Analysis population for the primary outcome, as defined in the registry: Adults admitted to Henry Ford Hospital and received a transcatheter aortic valve replacement via femoral access site and free from major events or complications.

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Post Procedure Hospital Length of Stay, measured over at discharge.

The primary endpoint, post-procedure hospital length of stay, measures the time from the procedure date until the date of hospital discharge. It is reported as a mean with standard deviation, in days, and assessed at discharge. The endpoint description says assessment was up to 50 days. The population is adults admitted to Henry Ford Hospital who received transcatheter aortic valve replacement through a femoral access site and were free from major events or complications.

Length of stay is a continuous outcome: it can take different values across patients, and a group mean describes the average duration in that group. The standard deviation describes how spread out individual stays are around the mean. In general, a length-of-stay endpoint can summarize the duration of a hospital admission, but it does not by itself explain why stays differ or whether a difference is attributable to a particular component of care.

The record does not report the group means, standard deviations, difference between groups, or uncertainty around a comparison. Consequently, the endpoint definition is clear, but the posted results do not show the observed length of stay in either group or the estimated contrast. The secondary discharge-destination outcomes are named, but their results are also not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure summarized by a mean and standard deviation. The mean describes the average length of stay for a group, while the standard deviation describes the variability of individual stays around that group average. These quantities answer different questions: the mean locates the group average, and the standard deviation characterizes dispersion among observations. The registry record specifies this summary format but does not report the numerical summaries.

What would a group comparison estimate?

For a comparison of two groups, the central quantity is usually a contrast between their outcome distributions, such as a difference between their means. That contrast would express how far apart the average stays were in the groups, in the endpoint's units. Its interpretation depends on the analysis population, the way missing observations are handled, and any adjustment or model used. The registry record does not report a comparative estimate, the model, or whether the analysis was adjusted. No contrast can be reconstructed from the available registry entries.

How should uncertainty be understood?

In general, a confidence interval conveys uncertainty around an estimate. It reflects the range of values that would be compatible with the data under the specified method and assumptions. Its width depends on factors such as the amount of information in the data and the variability of the outcome. A point estimate without an interval can conceal substantial uncertainty; an interval without an estimate would also be incomplete. Neither a primary effect estimate nor its confidence interval is reported in the registry record.

A p-value is a measure defined relative to a statistical model and a null hypothesis. It is not a measure of the probability that the null hypothesis is true, nor does it describe the size of an effect. A small p-value cannot substitute for the estimated difference and its uncertainty, and a result that does not meet a threshold does not establish equivalence. The registry record does not report a primary p-value or specify a threshold used for the outcome analysis.

What does the study design mean for inference?

The record describes a retrospective comparison of a routine-care period with a period after implementation of a pathway. Allocation is not stated, and the groups are not a like-for-like control comparison. In general, comparing groups formed in different calendar periods can mix the association of interest with other changes over time. Differences in patient mix, clinical practice, or other contextual factors could affect the outcome, but the record does not say whether any such differences occurred or how they were handled. Because the registry does not report covariate adjustment or an analysis plan, the degree to which the primary comparison accounts for group differences cannot be assessed.

Length of stay can be influenced by multiple events and processes between a procedure and discharge. A group average may summarize those stays but does not identify the reason for an observed difference. The standard deviation can help convey variability, but it does not resolve potential confounding or establish that the group distributions have a particular shape. The registry does not report distributional checks, transformations, or alternative analyses. In general, skewed continuous outcomes can make a mean and standard deviation less descriptive of a typical individual experience; whether that concern applies to these data cannot be determined from the record.

What do the planning assumptions mean?

The record describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. These are planning assumptions, not evidence about the observed outcome. Sample-size illustrations based on an observed effect show what sample sizes a specified calculation would imply under its assumptions; they are not observed power and do not supply the missing primary estimate. No numerical planning result is reported in the registry record, and the record does not state that these planning assumptions were the study's original design.

The record does not report the sample-size justification, the statistical model, the treatment of missing outcome values, or whether interim analyses were conducted. It also does not report an analysis population or a detailed statistical plan. These omissions matter because estimates and uncertainty are interpreted in relation to the methods that generated them. Without those details and the actual outcome summaries, the statistical findings cannot be independently interpreted or recalculated from the registry information.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Control Group (TAVR 3/1/12-11/1/14) Pre PT OT Path", "Intervention Group (TAVR 11/2/14-12/31/15) Post PT")
n   <- c(74, 115)
m   <- c(4.8, 3.5)
sp  <- c(2.9, 4)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Control Group (TAVR 3/1/12-11/1/14) Pre PT OT Path  74  4.800  2.900  4.128  5.472
CARM  Intervention Group (TAVR 11/2/14-12/31/15) Post PT  115  3.500  4.000  2.761  4.239

11. Multiplicity, Missing Data and Analysis Populations

The registry names a primary outcome of hospital length of stay and secondary outcomes of discharge home and discharge to a rehabilitation facility. It also reports four outcome measures and one listed analysis, but does not provide the results for these outcomes. The record does not state whether a multiplicity adjustment was planned or used, or how the primary and secondary outcomes were prioritized in the statistical analysis.

In general, testing several outcomes can increase the chance of observing at least one apparently notable result by chance if each is assessed separately. Methods for controlling multiplicity can address that issue, but they depend on the testing strategy and the claims being made. The absence of a reported multiplicity approach means that the interpretation of any unreported secondary findings cannot be evaluated. It does not establish that an adjustment was necessary or that one was omitted from the underlying analysis.

The registry record does not report the amount or pattern of missing primary or secondary outcome data, the handling of missing values, or the analysis population used. It is therefore not possible to assess whether all eligible patients contributed to the endpoint analysis, whether any observations were excluded, or how exclusions may have affected the estimates. The listed enrollment does not establish the number contributing data to a particular outcome.

The primary population description limits the endpoint to adults receiving femoral-access procedures who were free from major events or complications. The broader study description also specifies exclusions for major events and includes some patients with minor events. The record does not provide participant flow or further detail on which patients entered each outcome analysis. These missing analysis details limit reproducibility and the interpretation of results, independently of the absence of the outcome estimates themselves.

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

The registry record establishes that a retrospective study compared routine therapy with a post-procedure physical and occupational therapy pathway and defined hospital length of stay as its primary endpoint. It does not report the primary outcome values or comparative estimate. Accordingly, the posted results do not show the direction, size, or precision of a length-of-stay difference. They also do not support a conclusion that the pathway did or did not change length of stay.

This is not the same as evidence that there was no difference. A result can be estimated with substantial uncertainty, or the result may simply not be reported in the registry record. Without group summaries and a comparison estimate, those possibilities cannot be distinguished. The completed status and the enrollment count do not replace the outcome data necessary to assess the study question.

The retrospective design is relevant to what any comparison could mean. In general, groups observed during different periods may differ for reasons beyond the pathway under study. Because allocation is not stated and the record does not report adjustment methods, a group contrast, if available elsewhere, would need to be interpreted with attention to possible differences between periods. This general limitation does not identify a specific source of bias in this study.

The registry also does not report the secondary discharge-destination results. Its adverse-event entries do not provide interpretable counts for comparing event experience, and deaths are not reported. These absences mean that the record cannot support conclusions about the secondary outcomes or comparative safety. The study description can explain what was evaluated, but the available registry information is insufficient to quantify what the comparison found.

In general, statistical evidence should be considered alongside the estimated effect, its uncertainty, the study design, and the quality and completeness of outcome reporting. Here, the study design and endpoint are described, but the main numerical evidence is not reported. No clinical recommendation follows from this statistical summary.

13. Why This Trial Matters Statistically

This study raises a useful statistical question about evaluating a care pathway in a real clinical setting: how should a before-and-after comparison be interpreted when the groups arise in different periods rather than through randomized allocation? The record describes routine therapy before implementation and daily physical and occupational therapy under the pathway. That contrast is understandable, but the design alone cannot separate the pathway's association from other differences that may accompany a change in calendar period.

Length of stay is also an outcome for which averages and variability convey complementary information. A mean can summarize the overall duration of admission, while a standard deviation describes spread. Neither alone explains the causes of individual stays, and both need to be considered alongside a comparative estimate and its uncertainty. The registry specifies these descriptive measures but does not report their values, leaving the statistical question unanswered in the posted results.

The record illustrates why transparent reporting needs more than a study status and an endpoint definition. Group summaries, analysis methods, missing-data information, and an estimate with uncertainty are needed to assess the evidence. The named discharge-destination outcomes and adverse-event entries also show the importance of usable denominators and interpretable outcome reporting when evaluating outcomes beyond length of stay.

Statistically, the main contribution of the registry description is to identify the pathway, comparison, and target outcome. The absence of the outcome estimates makes it impossible to judge the magnitude or precision of an association. This distinction is important: a clearly stated study question is not itself evidence for or against an effect, and a planning calculation cannot stand in for an observed result.

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 central limitation is that the registry record does not report the primary outcome results. Group means, standard deviations, comparative estimates, confidence intervals, and p-values are not reported, so neither the magnitude nor the precision of the primary comparison can be evaluated. The secondary discharge-destination results are also not reported.

The comparison is retrospective, and allocation is not stated. The registry description identifies groups associated with different calendar periods, so the groups are not a like-for-like control comparison. The record does not report methods for addressing differences between groups or changes over time. It also does not provide enough information to assess whether potential confounding was considered in the analysis.

The study descriptions include different time windows: retrospective data collection is described as running from March 2012 through July 31, 2015, while the pathway group is described through 12/31/15 and the brief summary says future analysis would extend the data through December 31, 2015. The record does not explain how these time descriptions relate to the completed study or its reported enrollment. This makes the scope of the analyzed data unclear from the registry information alone.

Further limitations in interpretation arise because the record does not report the analysis population, participant flow, missing-data handling, statistical model, or multiplicity approach. Adverse-event fields list zero values for at-risk and affected counts, and deaths are not reported; these entries do not permit a meaningful comparative safety assessment. These reporting limitations do not establish what the underlying analysis found, but they restrict what can be concluded from the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Physical Therapy and Occupational Therapy After Transcatheter Aortic Valve Replacement — NCT03117296.
• Registry record last updated 2023-01-20; status last verified 2022-04.
• Results first posted 2023-01-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

This completed study evaluated a post-procedure physical therapy and occupational therapy pathway after transcatheter aortic valve replacement at Henry Ford Hospital. The registry reports enrollment of 189 and identifies hospital length of stay, measured in days from procedure to discharge, as the primary endpoint. The pathway description includes nursing mobilization on post-procedure day zero and therapy assessment and intervention on post-procedure day one, followed by daily therapy. The comparator is routine physical therapy or occupational therapy in an earlier period.

The study is described as a retrospective, nonrandomized comparison; allocation is not stated. Secondary outcomes were discharge home and discharge to a rehabilitation facility. Although the registry marks the study completed, it does not report the primary or secondary outcome estimates, their uncertainty, or enough analysis details to assess the results. The registry record therefore describes the study question and design but does not permit a quantitative interpretation of the comparison.