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 Enhancing Well-Being Through Exercise During Old Age (NCT04536727), a randomized na study. The primary outcome is Attendance of the Fit & Strong! Intervention Classes.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04536727 |
| Phase | NA |
| Condition | Depression, Osteoarthritis |
| Allocation | Randomized |
| Design model | Sequential |
| Masking | None (open label) |
| Enrollment | 28 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Illinois Chicago |
| Results posted | Yes |
2. Clinical Question
Population
Older adults with a range of depressive symptoms were the intended participants. The registry lists depression and osteoarthritis as conditions and describes classes offered at a residential senior housing development. The enrollment recorded for the trial was 28.
Intervention
The intervention was an adapted Fit & Strong! group physical activity and health education program. Its stated adaptation addressed exercise, positive and negative affect, and depressive symptoms. Classes were scheduled three times per week for 90 minutes per session over eight weeks.
Comparator
The comparator was a wait list. Participants in that group were scheduled to receive the eight-week intervention after the intervention group. The registry says the wait-list classes were planned for Winter 2020 but could not be delivered after the residential facility was locked down due to Covid.
Primary question
The primary endpoint was the number of Fit & Strong! classes attended, a feasibility measure of participation in the program. The registry reports attendance for the intervention group, with a median of 10 classes and a standard deviation of 6.94. It reports no wait-list attendance value, so the primary result does not provide an intervention-versus-wait-list comparison.
3. Trial Design
The registry describes a randomized, unmasked, sequential-model trial with phase listed as NA. It was sponsored by the University of Illinois Chicago. The trial began on 2019-02-01, had primary completion on 2020-02-28, and is recorded as completed. The stated enrollment was 28. The registry does not report details of the randomization sequence or allocation concealment; those details are not reported in the registry record.
The planned intervention was an eight-week adaptation of Fit & Strong!, a group physical activity and health education program. Classes were to meet three times per week for 90 minutes per session. The wait-list group was scheduled to receive the program after the intervention group. However, the registry explains that the wait-list classes, scheduled to begin in Winter 2020, could not be delivered because the facility was locked down due to Covid.
That interruption is consequential for interpretation. Although randomization created a planned comparison, the primary endpoint—class attendance—has a reported value only for the intervention arm. No wait-list attendance value is reported, and a two-arm primary comparison therefore cannot be made from the posted attendance results. The registry's primary outcome timeframe is Baseline, 8 weeks, and its description defines attendance as the total number of classes attended, from 0 to 24 classes.
The record lists 27 outcome measures and 25 posted secondary outcomes. It reports no analyses under the secondary outcome entries. Details such as the planned statistical analysis, sample-size justification, analysis populations, handling of missing data, and any interim analyses are not reported in the registry record. The label “sequential” should not be taken to imply a particular interim-monitoring procedure; such a procedure is 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.
Overall Study
| Stage | Intervention | Wait List |
|---|---|---|
| STARTED | 13 | 15 |
| COMPLETED | 12 | 13 |
| NOT COMPLETED | 1 | 2 |
Reasons for not completing this period:
| Reason | Intervention | Wait List |
|---|---|---|
| Lost to Follow-up | 1 | 1 |
| Death | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: The Fit \& Strong! classes were offered at a residential senior housing development. The wait list classes were scheduled to begin in Winter 2020, however due to Covid, the facility was locked down and classes could not be delivered to the wait list participants.
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 | Intervention | Wait List | Total |
|---|---|---|---|---|
| Participants analysed | 13 | 15 | 28 | |
| Age, Continuous | Years | 69.31 (SD 7.36) | 70.27 (SD 9.04) | 69.82 (SD 8.17) |
| Sex: Female, Male: Female | Participants | 12 | 13 | 25 |
| Sex: Female, Male: Male | Participants | 1 | 2 | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 13 | 15 | 28 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 13 | 15 | 28 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 13 | 15 | 28 |
6. Primary Endpoint
The registry lists the primary outcome as Attendance of the Fit & Strong! Intervention Classes, measured over Baseline, 8 weeks.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Standard Deviation |
| Unit | Classes attended |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint counts the Fit & Strong! classes attended by each participant. The registry defines the measure as total attendance over the program, with a possible range from 0 to 24 classes. Attendance is a direct indicator of whether participants took part in the scheduled intervention, making it relevant to the stated feasibility aim of adapting and delivering the program to older adults with a range of depressive symptoms.
For the intervention arm, the registry reports a median attendance of 10 classes and a standard deviation of 6.94. The median describes the middle of the observed attendance distribution and is less affected by unusually high or low attendance than the mean. The standard deviation describes variation around the mean, however, so it is not the most directly matched measure of spread for a median. The registry does not provide the individual attendance values or a confidence interval for this endpoint.
The wait-list arm has no reported attendance result. According to the registry, its classes were not delivered after the facility lockdown. Thus the reported attendance value describes participation among those assigned to the intervention, not a comparative estimate of attendance between randomized groups. Nor does attendance alone establish changes in mood, physical activity, or physical function; those are addressed by separate secondary measures.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary result is a feasibility observation: the intervention arm has a reported median of 10 classes attended, with a standard deviation of 6.94. Since the endpoint is class attendance, this describes participation in the delivered program. It is not an estimate of an effect on depressive symptoms or physical function.
The absence of a wait-list attendance value prevents a randomized comparison on this endpoint. The record explains why: wait-list classes could not be delivered after the facility was locked down due to Covid. A missing comparator result is not evidence that the groups would have had equal attendance, nor does it show what wait-list attendance would have been under normal delivery. It means the primary endpoint, as posted, cannot quantify a difference between intervention and wait-list groups.
The registry also posts secondary summaries for emotional well-being, physical activity, grip strength, and other outcomes. For the three secondary outcomes with posted arm summaries and recalculated comparisons, the unadjusted mean differences have intervals that include zero: emotional well-being, -0.03 with an interval from -3.105 to 3.045; physical activity, -28.97 with an interval from -87.21 to 29.27; and dominant-hand grip strength, -0.74 with an interval from -9.642 to 8.162. Their unadjusted p-values are 0.985, 0.33, and 0.871, respectively. These recalculations are not analyses reported by the investigators; the registry lists no reported analyses for these outcomes.
Such estimates should be read in light of their uncertainty and the small arm sizes reflected in the posted summaries: 13 for intervention and 15 for wait list. The intervals cover a range of possible differences, including values on either side of zero. The results therefore do not establish a precise difference in either direction. A p-value is not the probability that the null hypothesis is true, and a large p-value does not prove that two groups are equivalent.
The attendance result and secondary summaries answer different questions. Attendance reflects implementation and participation, while the secondary measures concern mood, activity, or function. The record describes the trial as a feasibility effort, and the missing wait-list delivery limits the randomized comparative evidence. The posted statistics are best understood as descriptive and exploratory rather than as definitive estimates of comparative effects.
9. Statistical Methods Explained
The registry identifies this as a randomized trial, but the outcome entries do not include reported investigator analyses. The numerical comparisons are simple, unadjusted recalculations from posted arm summaries. They do not replace a sponsor analysis; no sponsor analysis is listed for these secondary outcomes. The registry record does not report a statistical analysis plan, adjustment strategy, missing-data method, or analysis population.
What does a mean difference describe?
For a continuous outcome, a mean difference is the mean in one group minus the mean in the other, with the direction depending on the ordering used. A value near zero indicates similar group means in the posted summaries, but it does not by itself establish equivalence. The calculated emotional well-being mean difference is -0.03; the physical activity mean difference is -28.97; and the dominant-hand grip-strength mean difference is -0.74. These are unadjusted contrasts and do not account for baseline values or other covariates.
The registry reports outcomes at Baseline, 8 weeks. The posted arm values are means, but the record does not report whether the recalculated contrasts use change scores, endpoint scores, or an adjusted model. They should therefore be interpreted only as contrasts based on the posted summary statistics, not as a reconstruction of a fuller longitudinal analysis.
How should the intervals be read?
A confidence interval expresses the uncertainty around an estimate under the assumptions of the method used to calculate it. It gives a range of values compatible with the data and method; it is not a guarantee that the true effect lies within the particular interval. The recalculated intervals are -3.105 to 3.045 for emotional well-being, -87.21 to 29.27 for physical activity, and -9.642 to 8.162 for dominant-hand grip strength. Each interval includes zero, so each is compatible with no difference as well as with differences in either direction. The registry record does not identify a confidence level for these recalculated intervals.
The standard deviations show substantial dispersion relative to the group means for some outcomes, especially physical activity. In general, greater variability makes an estimate less precise when other factors are held constant. With the posted arm sizes of 13 and 15, the uncertainty around estimates is important; the intervals should not be reduced to a binary conclusion based only on whether a p-value crosses a threshold.
What do the p-values say?
The unadjusted p-values are 0.985 for emotional well-being, 0.33 for physical activity, and 0.871 for dominant-hand grip strength. In general, a p-value describes how unusual data at least as discrepant as the observed data would be under a specified null model. It is not the probability that a treatment effect exists, nor does it measure the size or practical importance of a difference. These p-values are unadjusted: they do not account for the number of outcomes examined or other possible comparisons.
The registry lists 27 outcome measures, 25 posted secondary outcomes, and no reported analyses for the secondary outcomes represented in the recalculations. Without a reported analysis plan, it is not possible to establish which comparisons were prespecified, whether any outcomes were selected for emphasis, or whether a multiplicity procedure was planned. This uncertainty gives the unadjusted results less evidential weight than confirmatory analyses conducted under a documented plan.
Why are the planning illustrations not trial findings?
The sample-size illustrations use the observed effect as a planning input and assume a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. They show participants per arm for 80% power and participants per arm for 90% power, for planning based on 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. For emotional well-being, the corresponding figures are 288,496 and 386,214 at 100% of the observed effect; 512,882 and 686,603 at 75%; and 1,153,983 and 1,544,855 at 50%. For physical activity, the figures are 105 and 141; 187 and 250; and 419 and 561. For dominant-hand grip strength, they are 4,362 and 5,840; 7,755 and 10,382; and 17,448 and 23,358.
These figures are planning illustrations, not observed power and not evidence that the trial was designed to detect those effects. Because they are based on observed effects from a small trial, they can be highly unstable, particularly when the observed estimate is close to zero. The registry does not report the trial's own sample-size justification. No such justification can be inferred from these illustrations.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 27 outcome measures and 25 posted secondary outcomes, while the secondary entries report no analyses. The record does not describe an adjustment for multiple comparisons, identify a primary secondary outcome, or explain whether the posted measures were prespecified. These details are not reported in the registry record. As a general statistical matter, examining multiple outcomes increases the chance that some unadjusted estimates may appear more unusual by chance alone. Unadjusted p-values should therefore be interpreted cautiously and in context, not as independent confirmation across outcomes.
Missingness is especially visible in the primary attendance result: intervention attendance is reported, but no wait-list attendance value is available because the wait-list program could not be delivered after the facility lockdown. The registry also does not report participant-level missingness for the secondary outcomes, reasons for missing measurements, or methods for handling missing values. It is therefore not possible to assess whether the posted arm summaries represent all randomized participants or a subset with available observations.
The record does not identify an intention-to-treat, per-protocol, or other analysis population. It does not report exclusions after randomization or explain how outcome availability was determined. Those elements are important because different analysis populations can answer different questions and can produce different estimates when outcomes are missing. They should not be inferred from the arm summaries alone.
The record also does not report interim analyses, stopping rules, or a prespecified statistical analysis plan. The trial's “sequential” model label does not establish that interim testing occurred. Without a documented plan, the posted results cannot be evaluated against a complete account of planned comparisons and decision rules. These reporting gaps do not establish that particular procedures were or were not used; they mean they are not reported in the registry record.
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 |
|---|---|---|---|
| Intervention | 0 | 13 | 0.0% |
| Wait List | 0 | 15 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Intervention | 0 of 13 |
| Wait List | 1 of 15 |
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 |
|---|---|
| Intervention | 0 of 13 |
| Wait List | 0 of 15 |
The registry reports zero serious adverse events and zero other adverse events among participants at risk in the intervention group, with 13 at risk. For the wait-list group, it likewise reports zero serious adverse events and zero other adverse events, with 15 at risk. The record separately lists one death in the wait-list group and zero in the intervention group.
These figures should be read as registry safety counts, not as evidence that the intervention caused or prevented an event. The record does not provide a serious adverse-event term, and it does not report a causal assessment linking the death to the intervention or to participation in the study. The wait-list classes were not delivered, which is relevant context for interpreting the group label but does not establish the circumstances of the death. The record does not provide further details about the event, its timing, or its relationship to study participation; those details are not reported in the registry record.
Zero recorded adverse events in a group does not prove that no harm occurred, particularly when the group is small and follow-up detail is limited. These counts describe what the registry reports and should not be generalized beyond the trial record.
12. What the Result Does, and Does Not, Mean
The registry supports a limited descriptive conclusion about program participation: the intervention arm's median attendance was 10 classes, with a standard deviation of 6.94. Attendance is relevant to whether participants took part in the scheduled classes, and the record states that the trial's purpose was to assess feasibility of adapting the program and employing it among older adults with a range of depressive symptoms.
It does not support a primary attendance comparison with the wait-list group, because no wait-list attendance value is reported. The registry attributes the absence of wait-list delivery to the facility lockdown due to Covid. Consequently, the primary result cannot show whether attendance differed between assigned groups. It also cannot quantify how the program changed depressive symptoms, physical activity, motor function, or other secondary outcomes.
The recalculated secondary contrasts are unadjusted and imprecise, and the registry does not report investigator analyses for them. Their intervals include zero, which means the available summaries are compatible with a range of possible differences. They do not establish equivalence or rule out meaningful effects. The planning illustrations are calculations for hypothetical future study planning based on observed effects, not evidence of power achieved in this trial and not the trial's own design justification.
More broadly, this record should not be read as proof that the intervention works or does not work. It describes a completed, randomized feasibility trial with a disrupted wait-list delivery and limited posted comparative analysis. The data can inform understanding of participation and the challenges of carrying out a comparison in this setting, while leaving the comparative efficacy questions unresolved. Details needed to assess the full analysis, including missing-data procedures and analysis populations, are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically informative in part because its feasibility question and its comparative question depend on different evidence. Attendance in the intervention group directly describes participation in delivered classes. A randomized comparison would additionally require usable outcome data from the wait-list group. Since those classes could not be delivered and no wait-list attendance value is posted, the primary endpoint is descriptive rather than comparative.
The disruption also illustrates why implementation context matters when interpreting randomized designs. Random assignment alone does not guarantee that the planned intervention and comparator are both delivered. When one arm's planned activities do not occur, the resulting missing endpoint can limit the question the trial can answer, even though the record remains classified as randomized.
The registry's secondary outcomes emphasize another important statistical point: many endpoints do not automatically create a stronger overall evidence base. Without a documented analysis plan, multiplicity handling, or investigator-reported analyses, individual unadjusted estimates are exploratory and can be difficult to distinguish from chance variation. Reporting uncertainty alongside point estimates is therefore essential, and the recalculated intervals show why near-zero estimates should not be treated as proof of no effect.
Finally, the planning illustrations demonstrate how estimates from a small feasibility study can translate into unstable sample-size projections, especially when the observed effect is very small. They may be useful as illustrations under stated assumptions, but they should not be mistaken for the trial's design rationale or for observed power. The registry record does not report its own sample-size justification. This distinction is important when using early-stage studies to plan later research.
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 trial-specific limitation is that the planned wait-list classes were not delivered after the residential facility was locked down due to Covid. This leaves the primary attendance result without a wait-list comparator and prevents a direct randomized comparison on that endpoint. The intervention group's attendance summary can describe participation in the delivered program, but it cannot show what attendance would have been in the comparison group.
The registry reports arm-level summaries rather than participant-level outcome data. The primary attendance result is a median accompanied by a standard deviation, but the record does not provide the full distribution or an interval estimate. For the secondary outcomes, the reported means and standard deviations do not reveal individual trajectories or explain how observations changed from baseline to eight weeks.
The secondary comparisons are recalculated from posted summaries and are not investigator analyses listed in the registry. No analysis plan, multiplicity procedure, analysis population, missing-data method, or sample-size justification is reported. These reporting gaps limit assessment of how the outcomes were selected and analyzed. The posted arm sizes are modest, so estimates are imprecise; the uncertainty intervals for the recalculated comparisons are broad and include zero.
The study is also tied to a particular delivery setting, a residential senior housing development, and the wait-list interruption affects what can be learned from the planned design. The record's stated aim concerns feasibility among older adults with a range of depressive symptoms; it does not provide enough detail to assess how broadly the results may apply to other settings or populations. Further characteristics of participants and the circumstances of missing measurements are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Enhancing Well-Being Through Exercise During Old Age — NCT04536727.
- Registry record last updated 2023-09-06; status last verified 2022-10.
- Results first posted 2023-09-06.
- 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.
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18. Record Summary
NCT04536727 is a completed, randomized, unmasked, sequential-model trial sponsored by the University of Illinois Chicago. The record lists enrollment of 28, a start date of 2019-02-01, and primary completion on 2020-02-28. Its stated aim was to assess the feasibility of adapting Fit & Strong! with affect and mood-related content for older adults with a range of depressive symptoms.
The primary endpoint was total class attendance over the eight-week program. The intervention arm's median was 10 classes, with a standard deviation of 6.94. No wait-list attendance value is reported because the classes could not be delivered after the facility lockdown due to Covid. Secondary measures cover emotional well-being, physical activity, motor function, gait speed, and cerebral functional connectivity. The registry lists no analyses for the secondary outcomes used in the recalculated comparisons. Statistical planning details, missing-data methods, and analysis populations are not reported in the registry record.