Treating Sleep Problems in VA Adult Day Health Care: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treating Sleep Problems in VA Adult Day Health Care (NCT01259401), a randomized na study. The primary outcome is Sleep Efficiency.

2. Clinical Question

The study addresses a care-setting question: whether a structured, non-medication behavioral program can be evaluated against basic sleep education among veterans receiving adult day health care. The registry’s background describes sleep disturbance as common in this setting and notes that it is not routinely addressed in clinical care. It also identifies concerns associated with insomnia and sleep medications in older people, while describing non-medication approaches as an area for study. Those statements explain the rationale recorded for the trial; they are not findings from this comparison.

The registry lists insomnia and sleep disorders as conditions and identifies the primary endpoint as sleep efficiency, expressed as the percentage of time in bed spent asleep. The endpoint was assessed at the end of the 4-week intervention. The posted group summaries are 86.6 for the Sleep Intervention Program group and 83.3 for the Control Group, each accompanied by a 95% confidence interval. The registry also reports an ANCOVA p-value of .04 for the group comparison, but does not post an adjusted effect estimate or its confidence interval.

3. Trial Design

This was a randomized, double-masked, parallel-group trial. The registry lists an enrollment of 72 and identifies the sponsor as the VA Office of Research and Development. The study was marked completed. Its recorded start was 2010-11 and its primary completion was 2013-06. The phase is listed as NA.

Participants were assigned to the Sleep Intervention Program or a control program of basic sleep education. Both programs consisted of 4 individual sessions within the Adult Day Health Care program. The intervention was described as behavioral and based on behavioral principles. The registry identifies the comparison as parallel-group, so the posted design describes separate groups rather than a crossover comparison.

“Double” masking is recorded, but the registry record does not identify which people were masked or explain how masking was maintained. The randomization sequence, allocation concealment procedures, and any stratification factors are not reported in the registry record. Details of eligibility criteria beyond the description of veterans with insomnia in a VA Adult Day Health Care program are not reported in the registry record.

The primary outcome was assessed at the end of the 4-week intervention. The posted primary-outcome summaries include 19 participants in the Sleep Intervention Program group and 21 in the Control Group. The registry notes that two Sleep Intervention Program subjects had missing data for this variable. The relationship between the enrollment figure and the outcome-specific analysis counts is not fully explained in the registry record.

The posted comparison method is ANCOVA. The registry does not identify its covariates, model specification, or analysis population. These omissions matter because the arm-level means and confidence intervals describe each group, while an ANCOVA comparison can account for model terms not reflected in those separate summaries. The available record therefore supports a description of the randomized design and the reported endpoint summaries, but not a full reconstruction of the analysis plan.

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: A total of 72 participants were enrolled into the study. After baseline assessment, 30 participants were not eligible for randomization: too cognitive impaired to participate (13); medical or behavioral issue (n=6); no longer met criteria for insomnia (n=3); discharged from ADHC (n=4); refused randomization (n=2); withdrew (n=2).

End of 4-week Intervention

4-month Follow-up

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Two SIP subjects had missing data for this variable.

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 Sleep Efficiency, measured over End of 4-week intervention.

The primary endpoint, sleep efficiency, is the percentage of time in bed spent asleep. In this trial it was estimated by actigraphy, and the registry specifies assessment at the end of the 4-week intervention. The outcome is continuous: it records a measured value on a scale rather than classifying each participant into an event or no-event category.

As a general statistical concept, a continuous sleep measure can describe variation in participants’ sleep without reducing the result to whether a particular threshold was crossed. Sleep efficiency is intended to capture the proportion of time in bed spent asleep. The registry’s stated unit makes the meaning of the outcome explicit, but does not specify a threshold that would classify a value as clinically important or unimportant.

For the Sleep Intervention Program group, the posted mean was 86.6, with a 95% confidence interval from 84.3 to 88.8, among 19 participants. For the Control Group, the posted mean was 83.3, with a 95% confidence interval from 81.2 to 85.4, among 21 participants. These are group-level summaries, not estimates of every participant’s result. The registry does not post the adjusted between-group estimate or its confidence interval.

Actigraphy is the measurement approach named in the record. Further details about the device, data-processing rules, measurement schedule within the intervention, and handling of measurements that could not be scored are not reported in the registry record. The endpoint indicates sleep efficiency as operationalized for this study; it does not by itself measure every aspect of sleep or establish whether a change is meaningful to participants.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the arm-level mean describe?

Sleep efficiency is a continuous measure, and the registry reports a mean for each arm. As a general statistical concept, a mean is a summary of the observed values in a group. It is useful for describing the group’s central level on the outcome scale, but it does not show the full distribution of individual measurements. The mean of 86.6 for the Sleep Intervention Program group and the mean of 83.3 for the Control Group are therefore summaries, not claims that every participant had that value.

The registry gives 95% confidence intervals for both means: 84.3 to 88.8 for the Sleep Intervention Program group and 81.2 to 85.4 for the Control Group. In general, a confidence interval expresses uncertainty about an estimate under the method used to construct it. It is not a range that contains a specified proportion of individual participants’ measurements. The registry does not provide the method used to calculate these arm-level intervals, so their construction cannot be independently assessed from the record.

What does the ANCOVA result add?

The reported comparison method is ANCOVA, or analysis of covariance. As a general statistical method, ANCOVA compares group outcomes while accounting for other variables included in the model. The registry does not identify those variables, so it is not possible to determine what adjustment was made or how the modeled contrast relates to the unadjusted arm summaries. The reported p-value is .04; an adjusted effect estimate and confidence interval are not posted.

A p-value does not measure the size of an effect. It also does not give the probability that the treatment effect is zero. Its interpretation depends on the model and assumptions, including the way the outcome and any adjustment variables are represented. The record does not describe model diagnostics, transformations, or checks of assumptions. Consequently, the posted p-value can be reported as the registry’s ANCOVA result, but its detailed statistical basis cannot be reconstructed.

Why does uncertainty matter?

Confidence intervals help distinguish an estimate from its precision. In general, a wider interval represents less precise information about the parameter it estimates, while a narrower interval represents greater precision under the chosen method. The intervals posted for the arms concern separate means; they are not a confidence interval for the between-arm effect. A direct comparison interval would be needed to assess the uncertainty around that contrast. It is not reported in the registry record.

Statistical uncertainty is only one kind of uncertainty. The missing outcome data, limited analysis details, and absence of a posted adjusted contrast also constrain interpretation. The group means and ANCOVA p-value should be read together, but one cannot be substituted for the other: the means communicate the observed arm-level outcome summaries, and the p-value communicates the reported model-based test result.

What does a planning illustration mean?

The record describes sample-size planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. As a general concept, such an illustration asks how many participants per arm might be needed to detect a specified fraction of an observed effect under stated assumptions. The illustrations are planning scenarios, not evidence about the actual design rationale or the trial’s achieved power.

Sample size and observed power should not be conflated. As a general statistical point, observed power calculated from an estimated effect does not provide a useful substitute for the effect estimate and its confidence interval. Any sample-size illustration based on the observed effect is particularly dependent on that effect estimate and the stated assumptions. The trial’s own sample-size justification is not reported in the registry record, and the planning assumptions do not establish that those assumptions governed the original design.

Why do missing data and over-dispersion matter?

The registry reports missing primary-outcome data for two Sleep Intervention Program subjects. In general, missingness can reduce the information available for estimating group means and can introduce bias if the probability of missingness is related to outcomes or participant characteristics. The consequences depend on why values are missing and on the method used to address them. The reasons for missingness, the handling method, and the analysis population are not reported in the registry record.

Over-dispersion is a general issue when outcome variation is greater than a model assumes; it can make uncertainty estimates too small if the model does not account for the extra variation. The registry does not report a count outcome model or any over-dispersion assessment for the continuous sleep-efficiency endpoint. It would therefore be inappropriate to infer that over-dispersion was present or that a particular correction was needed. More generally, statistical methods should match the outcome’s scale and the structure of the data, but the available record does not supply enough model detail to evaluate those choices fully.

10. Analyses Reported by the Sponsor

The registry reports the sponsor’s comparison as an ANCOVA analysis with p = .04. It does not post the ANCOVA effect estimate, confidence interval, covariates, or full model specification. The arm-level summaries are means with separate 95% confidence intervals; they are not a substitute for the adjusted comparison reported by ANCOVA.

No separate unadjusted recalculation of the two-arm continuous outcome is available in the posted record. The result cannot therefore be checked against a recalculated between-arm estimate using the posted summary statistics. There is no reported discrepancy between a sponsor analysis and a recalculation; rather, the record lacks the values needed for that comparison.

The sponsor’s reported ANCOVA result should be distinguished from the descriptive arm summaries. The p-value conveys the result of the reported model-based test, but without an adjusted effect estimate and its interval, it does not show the estimated size or precision of the comparison. The registry record also does not explain whether the reported analysis followed a prespecified statistical plan, which variables were included in ANCOVA, or how missing outcome data were handled.

Accordingly, the posted ANCOVA result is the available sponsor analysis, while the means and confidence intervals provide descriptive context. They should not be combined into a newly calculated effect or used to claim that the adjusted analysis has been independently reproduced.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures and 2 analyses, but identifies no secondary outcome results in the record. The primary endpoint described is sleep efficiency. The relationship between the listed outcome-measure and analysis counts, and the full set of outcomes or analyses considered, is not explained in the registry record.

When a study evaluates multiple outcomes or performs multiple tests, the chance of obtaining at least one small p-value can increase. As a general statistical concept, multiplicity procedures can control that risk, but the appropriate approach depends on the planned testing structure. A multiplicity adjustment, hierarchy of outcomes, or other strategy is not reported in the registry record. The ANCOVA p-value should therefore be understood as the posted result, without assuming that it was or was not adjusted for multiple comparisons.

The registry states that two Sleep Intervention Program subjects had missing data for the primary variable. It reports 19 participants in that arm and 21 in the Control Group for the outcome summaries. It does not state why the values were missing, whether any other outcomes were missing, or whether imputation or another missing-data method was used. The analysis population and the handling of missing outcomes in the ANCOVA are not reported in the registry record.

These omissions limit assessment of both bias and precision. If missingness is related to participant characteristics or outcomes, a complete-case analysis can differ from an analysis that accounts for missing values. This is a general possibility, not a claim about what occurred in this trial. The record does not report sensitivity analyses to assess how conclusions might change under different missing-data assumptions.

Interim analyses, stopping rules, and a prespecified statistical analysis plan are not reported in the registry record. Their absence from the record does not establish that none were conducted. It means that readers cannot assess these design and analysis features from the posted information.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The posted safety figures list 0 serious adverse events among 21 participants at risk in the Sleep Intervention Program group and 0 among 21 at risk in the Control Group. For other adverse events, the figures list 1 affected participant among 21 at risk in each group. These are participant counts, not event rates or proof that all possible harms were absent.

The registry does not list serious adverse-event terms. Death counts are not reported in the registry record. The figures do not describe event type, severity, timing, duration, or whether an event was considered related to the intervention. They also do not indicate whether participants could experience more than one event.

As a general statistical consideration, safety counts from groups of this size provide limited information about uncommon events. A count of zero in the posted figures does not establish that an event is impossible or that an intervention is free from risk. Conversely, one reported other adverse event in each group does not establish that the programs caused those events. The registry figures support only a descriptive reading of the counts and participants at risk recorded for each arm.

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

The record describes a randomized comparison of a behavioral Sleep Intervention Program with basic sleep education in a VA Adult Day Health Care program. At the end of the 4-week intervention, the posted mean sleep-efficiency values were 86.6 in the Sleep Intervention Program group and 83.3 in the Control Group. The registry reports an ANCOVA p-value of .04. These are the findings recorded for the primary endpoint; they do not by themselves establish the practical importance of the comparison.

The result does not show the adjusted difference between groups, because the adjusted estimate and its confidence interval are not reported. The separate confidence intervals describe each group’s mean rather than the uncertainty around the ANCOVA contrast. Without the adjusted effect and details of the model, the size and precision of the reported comparison remain unclear.

The result also does not establish that the intervention changes sleep for every participant, that any observed pattern persists beyond the assessment at the end of the 4-week intervention, or that it affects other health outcomes. Secondary outcome findings are not reported in the registry record. The posted data do not establish whether any difference is meaningful to participants, because a threshold for clinical importance is not reported.

The trial was conducted in a defined care setting with veterans described as having insomnia. Its findings cannot automatically be generalized to other populations, care settings, or sleep programs. The registry’s background discusses concerns about sleep disruption and medication use, but those statements are rationale rather than outcomes tested by the primary endpoint. The primary result should not be read as a direct comparison of behavioral care with medication.

In short, the registry reports two arm-level means and a model-based p-value for sleep efficiency, with missing primary-outcome data noted in the Sleep Intervention Program arm. It does not provide enough analysis detail to establish the exact adjusted effect, its precision, or the robustness of the comparison to missing data and other analytic choices.

14. Why This Trial Matters Statistically

This trial is statistically informative because it compares a structured behavioral program with an active educational control in the Adult Day Health Care setting described in the registry. Both groups received individual sessions, which makes the comparison different from one between a program and no contact. The registry’s design identifies randomization, double masking, and a parallel-group structure, while leaving important operational details unreported.

The primary endpoint is a continuous, objectively estimated measure of sleep efficiency, assessed at a defined point at the end of the 4-week intervention. Such an endpoint supports comparison of group-level measurements rather than only counting a selected event. The record’s arm-level means and confidence intervals provide descriptive information, and its ANCOVA p-value reports a model-based comparison.

The case also illustrates why a p-value alone is incomplete. Without the adjusted effect estimate and its confidence interval, readers cannot directly see the magnitude or precision of the comparative result. Separate intervals for group means do not fill that gap. Likewise, the registry’s note about missing outcomes signals a need to understand the analysis population and missing-data method before judging the stability of the result.

Finally, the safety figures show why descriptive counts need careful framing. Zero serious adverse events in the posted groups is a record of the observed counts, not a guarantee about all possible harms. The small number of participants with posted outcome data and the lack of event details constrain what can be inferred. The trial therefore offers a concrete example of interpreting observed summaries alongside incomplete reporting, rather than treating a single test result as a complete account of 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.

Several trial-specific limitations of interpretation arise from the information not reported in the registry record. The primary outcome is summarized by arm, but the adjusted ANCOVA effect estimate and its confidence interval are absent. The ANCOVA covariates and model specification are also not reported. As a result, the group-level means cannot be used to reconstruct the reported adjusted comparison.

The record notes that two Sleep Intervention Program subjects had missing data for sleep efficiency. It does not explain why those values were missing, how missingness was handled, or which participants were included in the ANCOVA. The outcome counts are 19 in the Sleep Intervention Program group and 21 in the Control Group, while the overall enrollment is listed as 72; the registry does not fully explain the relationship between enrollment and the outcome-specific counts.

The record does not report a sample-size justification for the original trial, a prespecified analysis plan, the intended multiplicity strategy, or interim-analysis procedures. The planning assumptions recorded for illustrations should not be mistaken for the original trial’s design rationale. The record also does not provide enough detail about eligibility, randomization procedures, masking roles, or the actigraphy measurement and scoring process to assess those aspects fully.

The primary endpoint is reported at the end of the 4-week intervention. Longer-term sleep-efficiency results are not reported in the registry record. Secondary outcome results, thresholds for clinical importance, and details of adverse events are also not reported. The safety figures list counts but not event descriptions or timing, and death counts are not reported in the registry record.

These limitations do not negate the posted observations, but they restrict assessment of effect size, precision, bias, reproducibility, and broader relevance. Interpretations should remain tied to the outcome, time point, population, and care setting recorded for this trial.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Treating Sleep Problems in VA Adult Day Health Care — NCT01259401.
• Registry record last updated 2025-02-25; status last verified 2025-02.
• Results first posted 2014-12-30.
• 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

NCT01259401, “Treating Sleep Problems in VA Adult Day Health Care,” is listed as a completed, randomized, double-masked, parallel-group trial sponsored by the VA Office of Research and Development. Enrollment was 72. The recorded start was 2010-11 and primary completion was 2013-06.

The comparison was a behavioral Sleep Intervention Program versus basic sleep education, with 4 individual sessions in each group. The primary endpoint was actigraphy-estimated sleep efficiency, measured at the end of the 4-week intervention. Posted group means were 86.6 among 19 Sleep Intervention Program participants and 83.3 among 21 Control Group participants. The registry reports 95% confidence intervals of 84.3 to 88.8 and 81.2 to 85.4, respectively, and an ANCOVA p-value of .04.

The registry notes missing primary-outcome data for two Sleep Intervention Program subjects. The adjusted comparative estimate, model details, missing-data method, and analysis population are not reported in the registry record. The safety figures list 0 serious adverse events in each group and 1 other adverse event in each group.