A Study Promoting Critical Illness Recovery in the Elderly: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study Promoting Critical Illness Recovery in the Elderly (NCT02963558), a randomized na study. The primary outcome is Number of Patients in the Intervention Arm Who Are Able to Undergo a Cycling Session.

2. Clinical Question

ASPIRE was designed to examine early rehabilitation during critical illness. Its brief description states a hypothesis that early rehabilitation could affect functional outcomes and the functional trajectory of this population. The primary outcome posted in the registry, however, is a feasibility measure: it counts participants able to receive the specified cycling session. It does not directly measure change in function or compare functional outcomes between the intervention and usual-care arms.

The record describes a pilot study of early mobilization using a cycle ergometer and notes that a second phase was added in September 2019 to focus on clinical outcomes. The posted primary result should therefore be read according to its stated scope, not as an answer to every functional or clinical question associated with the broader study.

3. Trial Design

ASPIRE (NCT02963558), titled A Study Promoting Critical Illness Recovery in the Elderly, is recorded as a randomized, parallel-arm study with no masking. The listed phase is NA. The recorded enrollment is 24. The study status is completed; the recorded start date is 2017-05-30 and the primary completion date is 2020-09-11.

The intervention was cycle ergometry. The intervention description specifies in-bed cycling within 48 hours after randomization if safety criteria were met, alongside early physical therapy. That physical therapy was described as following a protocol of additional ICU and hospital-administered rehabilitation strategies. The comparator was usual-care physical therapy ordered by the treating team in the ICU and on the hospital floor through hospital discharge. Outpatient therapy in the usual-care arm was described as being given only when ordered by participants’ regular physicians.

The primary outcome is restricted to the intervention arm. Its posted result gives a group size of 13 and a count of 13. The usual-care row has a group size of 0 and a value of 0, but the record explicitly says the primary outcome pertains only to the intervention arm. That row therefore does not provide a usual-care result for the feasibility question. The adverse-event display separately gives at-risk counts of 13 for the intervention group and 9 for usual care; those figures describe the adverse-event record and should not be used to reinterpret the primary outcome.

The study description says the initial pilot concerned early mobilization and pre-clinical mechanisms that might mediate early mobility effects. A second phase was added in September 2019 with a focus on clinical outcomes. The registry record does not report how the phases were operationally separated, whether the primary endpoint changed, or whether the analysis plan changed.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: This outcome only pertains to the interventional arm.

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 Number of Patients in the Intervention Arm Who Are Able to Undergo a Cycling Session, measured over up to 48 hours after randomization.

The primary endpoint counts intervention-arm participants able to undergo a cycling session. The registry defines feasibility as applying the MOTOmed device for at least a 15-minute session within 48 hours after randomization while meeting safety criteria. The stated timeframe is up to 48 hours after randomization, and the outcome unit is participants.

A feasibility count is useful for describing whether a planned procedure could be delivered under the study’s stated conditions. It is distinct from a measure of function, recovery, or clinical benefit. A count can answer how many participants met the operational criterion in the intervention arm, but, by itself, it does not establish whether the intervention changed later outcomes or how those outcomes compare with usual care.

The posted intervention result is 13 participants, with a reported group size of 13. The registry marks the outcome as applicable only to the intervention arm. As a result, the zero shown for usual care is not a comparable control-arm measure of feasibility; the posted usual-care group size for this endpoint is 0. No comparative effect estimate, confidence interval, or hypothesis test for this primary outcome is reported in the registry record.

The criterion also combines delivery, duration, timing, and safety eligibility: failure to meet any part would mean the session did not satisfy the stated feasibility definition. The registry record does not report a breakdown of those reasons, so the count cannot show which specific condition limited or enabled a session.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the allocation as randomized and the model as parallel, with no masking. Random allocation is intended, in general, to make comparison groups similar on average with respect to measured and unmeasured factors. A parallel design assigns participants to a group that receives its assigned care rather than crossing each participant between interventions. Lack of masking means that treatment assignment was not masked, but the record does not specify which study personnel or participants knew the assignment.

What does the primary outcome estimate?

The primary outcome is a count of intervention-arm participants meeting a feasibility criterion. It is not specified as a risk difference, odds ratio, or other comparative effect. The registry describes the outcome as applying only to the intervention arm; the usual-care group-size entry for that outcome is 0. A two-arm binary comparison is therefore not estimable from this endpoint as posted. The registry record does not report a comparative model or an inferential analysis for this outcome.

For a binary endpoint, each participant would ordinarily be classified according to whether the defined event occurred. Here, the event is not a clinical event in the sense of illness or harm; it is successful delivery of a qualifying cycling session under the stated conditions. The result is recorded as a count of participants. Since no comparison result is reported, there is no basis for interpreting the count as a treatment effect.

How should uncertainty be understood?

General statistical explanation: an estimate from a sample is subject to sampling variability. A confidence interval communicates uncertainty around an estimate under the assumptions of a chosen method. A hypothesis test can assess compatibility of data with a specified null hypothesis, but its meaning depends on the design, endpoint, model, and analysis plan. The registry record does not report a confidence interval, p-value, or test for the primary result. The descriptive count should not be treated as more precise than those details support.

The record’s sample-size assumptions describe planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such illustrations are planning tools, not observed power and not a retrospective demonstration that a study had a particular probability of finding an effect. For this binary endpoint, the record states that values are missing or not estimable for a two-arm comparison. Consequently, no participants-per-arm planning figure for a comparative analysis of this primary outcome can be interpreted from the available result.

What analysis details are unavailable?

The registry record does not report a statistical analysis plan, a sample-size justification for the trial, an interim analysis plan, an adjustment strategy, or the specific model used for any clinical outcome. It also does not report an analysis population definition, such as whether analyses were based on assignment regardless of treatment received or restricted to participants meeting particular criteria. These details matter because choices about population, exclusions, outcome handling, and model can affect estimates and their uncertainty.

The record indicates zero posted analyses. This should be read as the registry’s analysis-record status, not as evidence that no investigators performed analyses outside the registry. The information available does not identify how missing outcomes were handled, whether all randomized participants were included in each outcome analysis, or how deviations from the intervention were treated. Those methods are not reported in the registry record.

Why does feasibility differ from efficacy?

General statistical explanation: feasibility outcomes often establish whether an intervention can be delivered as intended, while efficacy or effectiveness outcomes assess effects on health or function. A favorable feasibility count does not by itself establish a clinical benefit. Conversely, a feasibility count may be important for deciding whether a procedure can be implemented and what practical barriers require measurement in later research. The interpretation depends on the outcome’s definition and does not replace analysis of clinical endpoints.

The listed secondary outcome names include the Short Physical Performance Battery, handgrip strength, mobility assessment, cognitive assessment, quadriceps strength, health status, and tibialis anterior muscle ultrasound. The record also indicates 21 outcome measures and 12 posted secondary outcomes. The Short Physical Performance Battery appears twice in the listed secondary outcome names; the record does not explain that repetition. Results, time-specific estimates, and analysis methods for those secondary measures are not reported in this record’s outcome details.

Multiplicity arises when multiple outcomes or tests are considered: the chance of at least one apparently notable result can increase as the number of comparisons grows. General approaches include prespecifying a primary outcome, adjusting inference, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy. It is therefore not possible to determine how any analyses across the recorded outcomes were prioritized or whether their inferential uncertainty was adjusted.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Intervention")
n      <- c(13)
events <- c(13)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Intervention  13  13  100.0  75.3  100.0  77.2  100.0  76.8  99.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 21 outcome measures and 12 posted secondary outcomes. The secondary outcome names cover measures of physical performance, strength, mobility, cognition, health status, and muscle ultrasound. The Short Physical Performance Battery is listed twice. The record does not explain whether this repetition represents different time points, distinct analyses, or a duplicated entry, so it should not be resolved by assumption.

When a study examines multiple outcomes, time points, or statistical tests, chance findings can arise even when there is no underlying effect. General statistical practice may address this through prespecification, adjustment for multiple comparisons, or clear labeling of secondary analyses as exploratory. The registry record does not report a multiplicity adjustment or a hierarchy among secondary outcomes. It also does not provide results for those outcomes in the registry entries.

Missing-data methods are not reported in the registry record. There is no description of how missing measurements, missed sessions, withdrawals, or unavailable follow-up were handled. The record also does not state the analysis populations or whether participants were analyzed according to randomized assignment, treatment received, or another rule. These omissions limit assessment of potential bias and of how the posted results relate to all enrolled or randomized participants.

The primary feasibility measure is intervention-only, and a two-arm binary comparison is marked as missing or not estimable. No conclusion about relative performance versus usual care can be drawn from that endpoint. The registry record does not report an analysis plan, inferential results for this endpoint, or a sample-size justification. Those statistical details should be regarded as unreported rather than inferred from the study’s design or outcome list.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: exacerbation of underlying condition resulting in death (30.8%).

The adverse-event record reports serious-event counts and deaths separately by group. For the intervention group, 13 participants are listed at risk for serious adverse events and 4 as affected; 13 are listed at risk for other adverse events and 0 as affected; deaths are recorded as 4. For usual care, the corresponding at-risk and affected counts for serious events are 9 and 2, the other-adverse-event counts are 9 and 0, and deaths are recorded as 2.

These are counts in the registry record, not adjusted comparisons. The record does not report a risk estimate, confidence interval, or statistical test for these figures. The serious-event counts and death counts should not be added together: the record does not describe them as mutually exclusive categories, and deaths may be represented among serious events. It also does not report event timing, duration, severity grading beyond the serious classification, or a causal assessment for each event.

The most frequent serious-event term listed is “exacerbation of underlying condition resulting in death,” at 30.8%. The record does not identify the group-specific distribution of this term in the registry entries. These descriptive safety figures alone do not establish whether events were caused by the intervention or whether rates differ between groups.

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

The posted primary result answers a narrow operational question: how many intervention-arm participants met the stated cycling-session feasibility criterion. The registry reports a count of 13, with a group size of 13 for that outcome. That finding describes delivery under the study’s recorded conditions; it is not an estimate of improvement in physical function, recovery, or other clinical outcomes.

The result does not show a comparative effect against usual care. The primary endpoint applies only to the intervention arm, and the usual-care row has a group size of 0. A zero value in that row is not a usual-care outcome count that can be compared with the intervention count. No comparative estimate or uncertainty interval is reported for the primary endpoint.

The study’s broader rationale concerns early rehabilitation and functional outcomes in critically ill older adults. The registry’s list of secondary outcomes includes measures relevant to function and other domains, but results for those measures are not reported in the record details analyzed. The primary count therefore cannot be used as evidence that function changed, that the functional trajectory changed, or that any particular clinical outcome improved.

The adverse-event counts provide descriptive safety information, including serious events and deaths, but they are not adjusted comparisons and do not specify causal attribution. The record does not report an analysis that would establish whether group differences, if any, are statistically distinguishable from chance. The figures must be interpreted with their group-specific at-risk counts and the registry’s limited reporting in mind.

In short, the result documents a feasibility count, while comparative clinical effectiveness, precision, missing-data handling, and several analysis details remain unreported in the registry record. Neither the feasibility count nor the adverse-event counts alone settle broader questions about intervention effects.

14. Why This Trial Matters Statistically

This study is statistically notable because its primary endpoint is a feasibility count rather than a comparative clinical outcome. That distinction determines what the posted number can answer. A count can document whether the study’s specified procedure was delivered to participants in the intervention arm, but it cannot serve as a treatment-effect estimate when the endpoint has no comparable usual-care result.

The registry identifies a randomized, parallel design, which commonly supports comparisons between assigned groups. Yet the primary outcome is explicitly intervention-only. The design label does not turn an intervention-only measure into a two-arm comparison. Statistical interpretation must follow the outcome definition and available data, rather than assume that every endpoint is comparative merely because the study is randomized.

Feasibility measurement is important in early intervention research. It can reveal whether an intervention can be carried out within a stated time window and subject to safety criteria. Such information can inform the design of later research, while remaining distinct from evidence about clinical effects. The record’s broader interest in functional outcomes and its list of secondary measures make that separation especially relevant: the primary feasibility count is not a substitute for results on those outcomes.

The registry also highlights the value of complete reporting. Comparative estimates, uncertainty measures, analysis populations, missing-data methods, and multiplicity plans help readers understand how strongly results support a conclusion. Those details are not reported in the record details available for this analysis. Clear recognition of what is and is not reported prevents descriptive counts from being mistaken for confirmatory evidence.

15. 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 primary endpoint is restricted to the intervention arm, so it does not support a direct intervention-versus-usual-care comparison. The usual-care entry for this endpoint has a group size of 0. The result is therefore a descriptive feasibility count, not an estimate of a comparative effect. The registry does not report a confidence interval, p-value, or other measure of uncertainty for it.

The outcome definition combines a minimum session duration, a time window after randomization, and safety criteria. The record does not break down whether a participant failed to meet the definition because of device delivery, session duration, timing, or safety eligibility. It also does not provide additional detail about how adherence to the session criterion was assessed.

The record’s broader description mentions functional outcomes and a second phase focused on clinical outcomes, but outcome-specific results and phase-specific analysis details are not reported in the registry record. The registry record does not explain the relationship between the phases, whether the outcome schedule changed, or how the listed secondary measures were analyzed. It also does not report missing-data methods, analysis populations, multiplicity handling, or a statistical analysis plan.

The adverse-event counts are descriptive. The record does not provide event-level timing, causal assessments, uncertainty estimates, or a statistical comparison. The listed serious-event term is not broken down by group in the available information. Finally, the study’s recorded enrollment and group-specific entries refer to different record components; they should not be combined to manufacture an endpoint denominator or reconcile unreported details.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study Promoting Critical Illness Recovery in the Elderly — NCT02963558.
• Registry record last updated 2024-10-18; status last verified 2024-05.
• Results first posted 2024-10-18.
• 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.

19. Record Summary

ASPIRE (NCT02963558) is recorded as a completed randomized, parallel study with no masking, sponsored by Wake Forest University Health Sciences. The listed enrollment is 24. The intervention involved early in-bed cycle ergometry and physical therapy; the comparator was usual-care physical therapy.

The primary outcome counts intervention-arm participants able to complete a cycling session lasting at least 15 minutes within 48 hours after randomization while meeting safety criteria. The registry reports 13 for the intervention group, with a group size of 13. The endpoint is stated to apply only to the intervention arm, and a two-arm binary comparison is not estimable from the posted outcome entry.

Serious adverse-event counts and deaths are reported by group, but no comparative safety analysis is reported. The registry record does not report inferential results for the primary endpoint, results for the listed secondary outcomes, or key statistical details such as missing-data handling, analysis populations, and multiplicity strategy. The findings should therefore be read as descriptive feasibility and safety reporting, not as a comparative estimate of clinical benefit.