CAPABLE Transitions: A Home Health-Based Intervention for the Hospital or Post-Acute Care Facility-to-Home Transition: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for CAPABLE Transitions: A Home Health-Based Intervention for the Hospital or Post-Acute Care Facility-to-Home Transition (NCT04460742), a randomized na study. The primary outcome is Percentage of Enrolled Participants That Are Retained.

2. Clinical Question

3. Trial Design

NCT04460742 is a randomized, unblinded, parallel-group feasibility study sponsored by the University of Rochester. The registry lists an actual enrollment of 31. The study description says it planned to recruit 60 older adults with and without dementia who were admitted to a home health agency after discharge from a hospital or post-acute care facility. The trial is listed as completed; its recorded start was 2021-03-18 and its primary completion date was 2023-05-19.

Participants were assigned to CAPABLE Transitions or care as usual. The intervention group received usual home health care together with services from a CAPABLE-trained occupational therapist, registered nurse, and handyman. Those services were delivered in the home over 3-4 months. The comparison group received care as usual through University of Rochester Medicine Home Care. The registry lists no masking, so participants and study personnel were not described as blinded.

The stated purpose was to assess feasibility. The registry says the study was not designed or powered to test hypotheses. This distinction matters when reading its group comparisons: the outcome estimates describe the enrolled participants, but the record does not establish that the trial was planned to provide a definitive estimate of treatment effects. Phase is listed as not applicable. Details such as the method used to generate the random allocation sequence, allocation concealment, or stratification 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.

Overall Study

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 Percentage of Enrolled Participants That Are Retained, measured over 6 months.

The primary endpoint is the percentage of enrolled participants retained through the 6-month study period. The registry describes the measure as monitoring how many participants complete the study. It is therefore a measure of follow-up completion, rather than a direct measure of physical function, quality of life, or health-service use.

Retention is relevant to a feasibility study because it indicates whether participants can be followed through the planned study period. If follow-up is difficult, that can affect the practicality of a later, larger study and the completeness of its outcome data. Retention is also important to interpretation: when participants do not complete follow-up, information about their later outcomes may be unavailable. The registry record does not report a more detailed operational definition of completion or state how missing follow-up information was handled.

The posted results report 14 of 16 participants retained in the CAPABLE Transitions group and 14 of 15 in the care-as-usual group. The estimated risk difference is -0.058, with a confidence interval from -0.264 to 0.147. These results describe retention in this enrolled sample. They do not, by themselves, establish why any participant did not complete follow-up or what retention would be in another setting.

7. Results Posted in the Registry

• CAPABLE Transitions: 87.5% (14/16) versus 93.3% (14/15) on control; risk difference -5.8 percentage points (95% CI -26.4 to 14.7), risk ratio 0.94 (0.75–1.18); unadjusted two-proportion z-test p = 0.583.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Home Time in Days (From the Baseline to 3 Month Period)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • CAPABLE Transitions: mean 87.94 versus 88.67 on control; difference -0.73 (95% CI -4.82 to 3.36), standardized effect d = -0.12; z-test p = 0.726.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between CAPABLE Transitions and the control. The interval gives the range of effects that remain compatible with the data.

Home Time in Days (From the 3 to 6 Month Period)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • CAPABLE Transitions: mean 89.38 versus 89.86 on control; difference -0.48 (95% CI -1.48 to 0.52), standardized effect d = -0.32; z-test p = 0.346.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between CAPABLE Transitions and the control. The interval gives the range of effects that remain compatible with the data.

The detailed secondary comparisons reported in the registry concern home time over two consecutive follow-up periods. The estimated mean differences are negative in both periods, meaning the group averages were lower in the intervention group under the stated comparison direction. In both cases, however, the confidence interval includes no difference and also allows values in the opposite direction. The results do not provide a clear separation between the groups.

This broad pattern does not contradict the primary retention finding, because retention and home time measure different aspects of the study. Retention concerns completion of follow-up, whereas home time concerns days at home during specified periods. Similar retention proportions do not imply similar values for other outcomes, and home-time comparisons cannot explain why participants were or were not retained.

The registry also lists quality of life using EQ-5D-5L and health-services-use outcomes. Detailed numerical results for those outcomes are not reported in the registry record. It would therefore be inappropriate to infer their direction or magnitude from the home-time results, or to describe an overall pattern across all secondary outcomes as if each had been measured and analyzed in the same way.

Unadjusted secondary comparisons carry less weight than a prespecified, multiplicity-aware analysis because examining several outcomes creates more opportunities for apparently notable results to arise by chance. This is a general statistical concern, not a claim that any particular posted result is false. The registry does not report a multiplicity adjustment, a hierarchy of secondary outcomes, or detailed analysis methods for the listed secondary endpoints. The secondary findings are best regarded as exploratory context for the feasibility study rather than as independent confirmation of an effect.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Home Time in Days (From the Baseline to 3 Month Period)
• Home Time in Days (From the 3 to 6 Month Period)
• Mean Change in Quality of Life Using EQ-5D-5L (Unabbreviated Title)
• Mean Change in Quality of Life Using EQ-5D-5L (Unabbreviated Title)
• Health Services Use, Percentage
• Health Services Use, Percentage
• Health Services Use, Mean
• Health Services Use, Mean

9. Statistical Interpretation

10. Statistical Methods Explained

The registry describes randomized allocation to parallel groups and reports outcome summaries by assigned group. The primary outcome is binary: each participant either completed the study through the specified follow-up or did not. The comparison is expressed as a risk difference, with the intervention group's retention proportion compared with the care-as-usual group's proportion. A negative estimate means the observed retention proportion was lower in the intervention group under this subtraction order.

What does a risk difference express?

A risk difference expresses the difference between two proportions on the same absolute scale. It is distinct from a risk ratio, which compares proportions multiplicatively, and from an odds ratio, which compares odds. Those measures answer related but different questions, so their numerical values are not interchangeable. The posted primary comparison includes a risk ratio of 0.938 and an odds ratio of 0.5, each with its own interval. The risk difference is the direct absolute comparison used in the interpretation above.

How should the confidence interval and p-value be read?

A confidence interval conveys the uncertainty around an estimate under the assumptions of the method used to construct it. It is not a range that guarantees the true effect lies within its limits, and it does not identify the probability that a particular effect is correct. For the primary risk difference, the interval extends from -0.264 to 0.147. Because it includes no difference, the data do not distinguish clearly between the groups on this outcome. The unadjusted p-value is 0.583. A p-value measures how incompatible the observed data are with a specified no-difference model under the analysis assumptions; it is not a measure of clinical importance or a probability that the null hypothesis is true.

How are the continuous outcomes compared?

The posted home-time outcomes are reported as means with standard deviations. A mean describes the average in a group, while a standard deviation describes the spread of participant-level observations around that average. The comparison is a mean difference, calculated as the intervention group's mean relative to the care-as-usual mean. The registry also provides pooled standard deviations and standardized mean differences for these comparisons. A standardized mean difference expresses the difference in relation to the pooled spread; it can help describe scale-relative magnitude, but it does not replace the original unit of days.

The home-time estimates are unadjusted. Their confidence intervals indicate the range of differences compatible with the data and the calculation assumptions. A wide interval signals that the estimate is imprecise; an interval that includes no difference does not establish that the groups are equivalent. The registry does not list sponsor-reported analyses for these secondary outcomes, nor does it report details of covariate adjustment or the underlying statistical analysis plan.

Why does feasibility context matter?

Statistical tests and intervals can be calculated from a feasibility study, but their presence does not change the study's stated purpose. The registry says the trial was not designed or powered to test hypotheses. The posted comparisons should therefore be treated as descriptive, exploratory evidence about outcomes in the enrolled sample, not as confirmatory tests of effectiveness. The registry record does not report the original design assumptions or a sample-size justification for the trial.

The planning illustrations use the observed effects as a starting point and apply a two-sided significance level of 0.05, equal allocation, and a normal approximation. They show hypothetical participant requirements for detecting specified fractions of the observed effect. These are prospective planning calculations, not estimates of the probability that this completed study detected an effect. The planning illustration does not document the trial's original design process.

Some outcomes may be affected by variability or by the way data are distributed. In general, over-dispersion means that observed variation is greater than a model's assumptions allow; if present and unaccounted for, uncertainty can be understated. The registry does not report an over-dispersion assessment for these outcomes, so no such issue can be claimed for this trial. Similarly, the record does not report interim analyses, stopping rules, or detailed methods for missing data. Their use should not be assumed.

11. Confidence Intervals and Precision

The primary retention estimate is -0.058, with a confidence interval from -0.264 to 0.147. The interval is broad relative to the point estimate and crosses no difference. This means that the observed data leave substantial uncertainty about the direction and size of the group difference. The point estimate is not a precise statement that retention differs by a fixed amount.

In general, a confidence interval describes a range of estimates that are reasonably compatible with the observed data and the method's assumptions. It is not a guarantee about the true value, and it does not account for every possible source of bias. In this unblinded feasibility study, the interval characterizes statistical uncertainty in the comparison; it does not resolve questions about generalizability, missing outcome data, or the conduct of the trial.

The confidence intervals for both posted home-time comparisons also include no difference. The baseline-to-Month 3 comparison ranges from -4.816 to 3.356 days, while the Month 3-to-Month 6 comparison ranges from -1.478 to 0.518 days. Those intervals permit effects in either direction. They do not establish equivalence, and a smaller interval in one outcome would not necessarily mean that outcome is more important.

Precision is constrained by the scale of this feasibility study and by the available outcome information. The registry reports enrollment of 31, and the primary outcome denominators are 16 and 15. The estimates should therefore be read as uncertain descriptions of these participants, rather than precise estimates for a larger population. A confidence interval also reflects only the statistical method used; it cannot correct for limitations such as unreported missing-data procedures or the lack of blinding.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total event counts. The sample-size assumptions state that the calculations use a two-sided significance level of 0.05, equal allocation between the groups, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. The registry record does not report the original trial's own sample-size assumptions or justification.

The 80% power column gives the hypothetical number of participants per arm needed for an 80% chance of detecting the specified effect under the planning assumptions, if that effect and the calculation model were correct. The 90% power column expresses the corresponding planning target for a higher chance of detecting that effect. These percentages describe design targets for hypothetical studies; they do not describe the probability that the completed trial's result is correct.

Rows planning for 100%, 75%, and 50% of the observed effect explore different assumed effect sizes. A smaller effect is harder to distinguish from random variation, so it requires more participants under otherwise similar assumptions. The figures are planning illustrations based on the effects observed in this study, not a record of how the trial was originally designed. This is not observed power.

Equal allocation is an assumption of the planning calculation; it does not change the actual enrollment reported for this study. The planning outputs also depend on the normal approximation and the selected effect fractions, and should not be treated as guaranteed sample-size requirements for a future study without considering its own design and analysis plan.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.933; treatment proportion p₁ = 0.875; average p̄ = 0.904.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.4163 = 0.8159.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4142 = 0.3486.
4. n = (0.8159 + 0.3486)² / (-0.0583)² = 398.6, rounded up to 399 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.933333333333333                          # control proportion
p1 <- 0.875                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(4460742)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 399 (80% power), 534 (90% power)
 75% of observed effect: n per arm = 661 (80% power), 884 (90% power)
 50% of observed effect: n per arm = 1,377 (80% power), 1,842 (90% power)
power.prop.test: 398.6 
Simulated power at n = 399 per arm: 0.806 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple secondary outcomes, including home time over separate periods, quality-of-life change, and health-services use. When several outcomes or comparisons are examined, the chance of at least one apparently unusual result can increase. A prespecified multiplicity strategy can address that issue by controlling how evidence is interpreted across the family of tests. The registry record does not report whether such a strategy was planned or used, so the posted unadjusted secondary comparisons should be treated cautiously.

The record also does not report a detailed statistical analysis plan, analysis populations, or rules for excluding participants from analyses. It does not specify whether the primary comparison followed an intention-to-treat approach or another population definition. Those details affect how randomized assignments and participants with incomplete information are handled, and should not be inferred from the group summaries alone.

Retention is itself the primary endpoint, but the record does not report how missing follow-up data were handled for other outcomes. It also does not describe whether missingness was assessed, whether any imputation was used, or whether sensitivity analyses were conducted. Missing-data methods can influence estimates when outcomes are unavailable, particularly if the reasons for missingness relate to the outcomes themselves. Without the relevant details, the secondary comparisons cannot be evaluated for sensitivity to missing data.

The registry reports no sponsor-reported analyses for the posted secondary results. The comparisons and planning figures therefore should not be mistaken for a complete account of the trial's statistical plan. The record also does not report interim analyses or stopping rules. These omissions do not prove that procedures were absent; they mean that they are not reported in the registry record.

15. 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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: abdominal pain and discomfort (12.5%), muscle cramping or swelling (6.7%), fall with injury (6.2%), joint infection (6.2%), copd exacerbation (6.2%).

The registry reports serious adverse events in 5 of 16 participants in the CAPABLE Transitions group and 1 of 15 in the care-as-usual group. Other adverse events were reported for 3 of 16 participants and 1 of 15, respectively. Deaths were reported as 0 in each group. These are descriptive counts from a small feasibility study; they do not establish that group assignment caused an event or that the observed difference would persist in a larger study.

The registry lists serious-event terms and percentages, including abdominal pain and discomfort at 12.5%, muscle cramping or swelling at 6.7%, and fall with injury, joint infection, COPD exacerbation, and substance intoxication each at 6.2%. The record does not provide further detail in the listed information about the denominator or how these term percentages relate to individual participants. They should not be treated as comparative incidence estimates without that context.

Adverse-event counts are not a substitute for a formal safety comparison. The registry information does not establish relatedness to the intervention, severity beyond the serious-event designation, or the timing of events. The counts should be read as a record of reported events in each group, with substantial uncertainty given the study's feasibility purpose and enrollment.

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

The primary result describes study retention through 6 months among participants in a randomized, unblinded feasibility study. The posted group counts and risk-difference estimate indicate that retention was observed in both groups, while the confidence interval leaves uncertainty about the comparative difference. This is useful information about follow-up in this study, but it is not a definitive test of the intervention's clinical effect.

The registry specifically states that the trial was not designed or powered to test hypotheses. Accordingly, a non-significant unadjusted p-value does not demonstrate that the intervention and care as usual are the same. Nor does the point estimate demonstrate that the intervention causes lower retention. The estimate, interval, and study purpose need to be considered together.

The intervention is a bundle of services added to usual home health care: occupational therapy, nursing, and handyman services delivered in the home over 3-4 months. The design does not isolate the contribution of each component. The results also arise from older adults with and without dementia receiving care through a particular home health agency, so they should not automatically be generalized to all older adults, care settings, or transition programs.

The listed secondary outcomes broaden the study's scope, but detailed numerical comparisons are not reported for all listed outcomes. The home-time comparisons are imprecise and do not establish a clear group difference. The absence of detailed results for other listed outcomes is not evidence that those outcomes were unchanged.

In general, a feasibility result can help inform whether a larger study may be practical and what uncertainties deserve attention. The registry record does not report a full account of recruitment challenges, missing data, or the original design assumptions. The findings can therefore be used as limited descriptive evidence about this trial, not as medical advice or a basis for claims that CAPABLE Transitions does or does not work.

17. Why This Trial Matters Statistically

This trial is statistically notable because its stated aim is feasibility, while the registry also posts comparative outcome estimates and planning illustrations. Separating those purposes prevents a common interpretive error: treating a calculated p-value as proof that a feasibility study was designed to deliver a definitive answer about effectiveness. The registry explicitly says it was not designed or powered to test hypotheses.

Retention is a practical outcome for a study that follows people through a transition from a hospital or post-acute care facility to home. Follow-up completion bears on whether outcome data can be collected over the planned period. The primary comparison is informative as a description of retention in the two randomized groups, but the confidence interval is broad enough that the comparative estimate remains uncertain.

The planning illustrations also demonstrate how sample-size requirements depend on the effect a future study aims to detect. Planning for smaller effects requires more participants under the stated assumptions. These figures are based on the observed effects and do not establish what the original investigators intended or what a future trial should use. Their statistical value is to make assumptions visible, rather than to replace a prospective design decision.

Finally, the registry illustrates why a result should be read alongside what is not reported. Multiplicity procedures, missing-data handling, analysis populations, and detailed methods for the secondary endpoints are not reported in the registry record. Recognizing those limits makes the interpretation more proportionate: the posted estimates can inform statistical discussion of feasibility and uncertainty without being mistaken for confirmatory evidence.

18. 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 actual enrollment was 31, while the study description says planned recruitment was 60. The registry does not report why enrollment was lower than the planned target, how recruitment proceeded, or whether the difference affected the study's feasibility objectives. The relatively small enrolled sample is also reflected in the uncertainty around the primary comparison and limits how precisely group differences can be described.

The trial was unblinded. The intervention involved in-home services from several types of personnel in addition to usual care, so the comparison concerns a service package rather than an isolated component. The registry does not report procedures to reduce the influence of awareness of assignment on outcome assessment. Retention is less subjective than some outcomes, but the record does not provide enough detail to evaluate all possible effects of unblinded conduct.

The enrolled population included older adults with and without dementia, but the registry does not report subgroup results or describe the distribution of these characteristics across groups. It is therefore not possible to assess from the posted information whether estimates differ by dementia status. The study was conducted through University of Rochester Medicine Home Care, and the record does not establish how the results would apply in other home health systems or settings.

Additional limitations arise from missing detail in the registry record. The original sample-size justification, allocation procedures, analysis populations, missing-data methods, multiplicity strategy, and detailed analyses for most listed secondary outcomes are not reported. The record also does not report interim analyses or stopping rules. These are limits on what can be concluded from the record, not evidence that a particular procedure was or was not used.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: CAPABLE Transitions: A Home Health-Based Intervention for the Hospital or Post-Acute Care Facility-to-Home Transition — NCT04460742.
• Registry record last updated 2023-08-01; status last verified 2023-07.
• Results first posted 2023-08-01.
• 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.

22. Record Summary

NCT04460742, titled CAPABLE Transitions: A Home Health-Based Intervention for the Hospital or Post-Acute Care Facility-to-Home Transition, is a completed randomized, unblinded, parallel feasibility study sponsored by the University of Rochester. The registry records enrollment of 31 and describes planned recruitment of 60 older adults with and without dementia after hospital or post-acute care discharge.

The intervention combined usual home health care with occupational therapy, nursing, and handyman services delivered in the home over 3-4 months. The comparator was care as usual. The primary outcome was participant retention through 6 months. The posted retention comparison is uncertain, and the registry states that the study was not designed or powered to test hypotheses. Secondary outcomes include home time, quality of life, and health-services use; detailed results are not reported for all listed outcomes.