Physical Activity Choices Everyday: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Physical Activity Choices Everyday (NCT03824769), a randomized na study. The primary outcome is Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry.

2. Clinical Question

This is a question about physical activity during a behavioral maintenance program, not a direct test of whether either approach preserves weight loss. Weight is listed as a secondary outcome, while the stated primary outcome concerns activity. The comparison concerns the maintenance phase among participants who met the Phase I weight-loss criterion and were then randomly assigned. It should not be interpreted as a comparison of the initial weight-loss program with no program, or as a comparison involving everyone enrolled in Phase I.

3. Trial Design

Physical Activity Choices Everyday (NCT03824769) was a completed, randomized, single-masked, parallel trial sponsored by the University of Connecticut. The registry lists the study condition as obesity, an enrollment of 160, and Phase as NA. The study began on 2019-03-11, with primary completion on 2021-05-03. The record does not explain who was masked.

The study had a weight-loss phase followed by a maintenance phase. In Phase I, participants received a 16-week Web-based behavioral weight-loss program with weekly information and personalized feedback about diet, activity, and weight-loss goals. People losing at least 5% of their initial body weight were invited to Phase II. The registry does not report how many met this criterion or accepted the invitation.

At the start of Phase II, participants were randomly assigned to one of two maintenance programs. Both included in-person group meetings and daily exercises. The healthy-thinking program reviewed healthy-lifestyle information; the future-thinking program reviewed descriptions of positive future events. Each maintenance treatment was described as lasting 4 months, with 7 sessions focused on evidence-based strategies related to diet, exercise, and behavior. The registry does not provide further detail about the content of those strategies.

The primary outcome was assessed from Phase II baseline to 1 month, 2 months, and 4 months, the end of treatment. The registry describes additional assessments of delay discounting, physical activity, weight, and other health and psychosocial outcomes. Weight is listed as a secondary outcome. The statistical analysis plan, including the planned approach to repeated assessments and the identity of the masked party, 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.

Before assignment: Following enrollment, participants began Phase I, a 16-week weight loss program aiming to induce clinically significant weight loss (5% of starting body weight). After Phase I, eligibility to continue to Phase II (weight maintenance) was evaluated. Those who lost at least 5% of their body weight remained eligible. Given that Phase II was the primary focus of the study, primary outcome data were analyzed only from randomized, Phase II participants (eligible subset of Phase I participants).

Phase I (Weight Loss): 16 Weeks

Phase II (Weight Maintenance): 4 Months

Analysis population for the primary outcome, as defined in the registry: The number of participants analyzed in this outcome measure generally reflects the number that completed accelerometry assessment procedures at each timepoint. At the 2 month assessment, one Healthy Thinking participant's data was excluded due to insufficient device wear time. All other missing participant data indicates that the participant did not complete this assessment procedure.

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 Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry, measured over Phase II baseline to 1 month, 2 months and 4 months (end of treatment).

The primary endpoint is change in weekly minutes of moderate-to-vigorous physical activity, measured by accelerometry during the Phase II maintenance program. The assessment schedule runs from Phase II baseline through 1 month, 2 months, and 4 months, at the end of treatment. The measure is expressed in minutes and is reported as a mean with standard deviation.

Participants were instructed to wear an accelerometer on the right waist during waking hours for 7 days at each assessment. A participant’s data were eligible for the reported outcome when the device recorded at least 600 minutes of valid daily wear time for at least 4 days. This rule aims to ensure that activity summaries reflect a sufficient amount of recorded wear. It also means the reported measure depends on both activity and usable device data.

Accelerometry offers an objective measure of movement during the monitoring period, rather than relying only on participants’ recollection or estimates of activity. Weekly moderate-to-vigorous activity is relevant to a trial focused on physical activity adherence during weight-loss maintenance. However, this endpoint measures activity, not weight change, overall health, or whether the intervention changes long-term behavior beyond the reported follow-up.

The registry record does not report mean changes, standard deviations, confidence intervals, or a comparison between treatment groups. Therefore, the direction and size of any difference in the primary endpoint cannot be described from the registry results available in this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized parallel-group design. In a parallel design, participants are assigned to a treatment group and followed in that group rather than crossing between treatments. Randomization is used to reduce systematic differences in baseline characteristics between groups. It does not ensure that every prognostic factor is balanced, particularly in a study with a limited number of participants in the randomized phase. The record does not report the randomization sequence method, allocation concealment, or which person or group was masked.

What does a mean describe?

The primary outcome is a continuous measure reported as a mean: weekly minutes of moderate-to-vigorous physical activity. A mean combines participants’ measured values into a group summary. It can provide a useful description of the typical level or change, but it does not show how values are distributed among participants. Participants may differ substantially even when group means are close, and a mean can be influenced by unusually high or low values.

The registry identifies standard deviation as the measure of dispersion. Standard deviation describes the spread of individual observations around a mean. It is not the same as the standard error, which describes uncertainty in an estimated mean, and it is not a confidence interval. Since the posted primary outcome results do not include the group means or standard deviations, the observed activity levels and their variability cannot be assessed from the record.

Why does repeated measurement matter?

Activity was assessed at baseline and at follow-up during the maintenance phase. Repeated observations from the same participant are generally related: a participant’s later activity can be associated with their earlier activity. General statistical practice accounts for this within-participant relationship when estimating change or comparing groups over time. Treating every assessment as independent can misstate uncertainty because it ignores that related observations come from the same person.

Different analysis strategies can target a change from baseline, compare groups at a particular follow-up, or assess whether the pattern over time differs between groups. These are not interchangeable questions. A repeated-measures model may use information from multiple assessments, while a separate comparison at a given visit focuses on that visit. The registry does not report which strategy was planned or used, which follow-up was the main contrast, or how any model handled incomplete repeated measures.

How should uncertainty be read?

In general, a confidence interval gives a range of estimates compatible with the observed data and the assumptions of the analysis. It helps readers assess precision and the range of effects that remain plausible. A p-value, when reported, measures how incompatible the data are with a specified null model under the test assumptions; it is not the probability that the null hypothesis is true, nor does it measure the size or importance of an effect. No primary-outcome confidence interval or p-value is reported in the registry record.

Effect size and precision should be considered together. A small estimated difference with a narrow interval suggests a different evidential picture from the same estimate with a wide interval. A result that does not meet a statistical significance threshold would not by itself show that the treatments are equivalent. Equivalence requires a prespecified margin and a suitable analysis. Neither an equivalence margin nor an equivalence analysis is reported in the registry record.

What does the sample-size illustration mean?

Any sample-size illustration associated with the posted material is planning information, not an observed trial result and not observed power. The stated illustration assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; it considers effects expressed as a fraction of the observed effect. Such an illustration asks what sample size might be required under those assumptions to detect a specified effect. It does not establish that the study had that power, and it is not a substitute for the trial’s own design justification. The registry record does not report the trial’s sample-size justification.

The illustration depends on its assumptions and on the estimated effect used as a reference. An effect estimated in a study can be uncertain, so planning from it does not guarantee the same effect in a future study. The record does not report interim analyses or the statistical plan used for the primary endpoint. Those details are not reported in the registry record, and should not be inferred from a planning illustration.

What can be concluded from the analysis record?

The registry lists 0 analyses and does not post a numerical primary outcome comparison. Thus there is no reported treatment-effect estimate to explain or independently recalculate. A simple unadjusted recalculation would require posted summary statistics, and none are reported for the primary outcome. The appropriate interpretation is that the registry provides the outcome definition and measurement rules, but not the statistical result needed to quantify the comparison.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome was measured at Phase II baseline and at 1 month, 2 months, and 4 months. The registry lists four outcome measures and identifies weight as a secondary outcome. It also describes assessments of delay discounting, physical activity, weight, and other health and psychosocial outcomes. Considering multiple outcomes and assessment times can create multiple opportunities to identify an apparently notable result. Statistical plans may address this through prespecified outcome hierarchies, adjusted testing, or a clear distinction between confirmatory and exploratory analyses.

The registry record does not report whether multiplicity adjustments were planned, which time point was designated as the principal comparison, or how secondary outcomes were to be handled. It lists 0 analyses, so there is no posted analysis output from which to determine how multiple outcomes or time points were treated. The direction, size, and precision of any primary or secondary outcome findings are not reported in the registry record.

For the accelerometry outcome, participants needed at least 600 minutes of valid daily wear time for at least 4 days to be included in reported outcomes. The record says one Healthy Thinking participant’s data were excluded at the 2-month assessment because of insufficient device wear time. It states that other missing data were handled in a manner whose description is truncated; the complete approach is not reported in the registry record.

The record says that the number analyzed generally reflects the number completing accelerometry procedures at each time point. It does not provide the analysis population definition, group counts at each visit, a method for handling missing outcomes, or sensitivity analyses. These omissions limit assessment of whether missingness could have affected the comparison. The number who entered Phase II after meeting the Phase I weight-loss criterion is also not reported.

11. 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: other (0.9%), motor vehicle accident (0.9%).

The registry reports serious and other adverse event counts separately for the Phase II randomized groups and the Phase I-only group. For the healthy-thinking maintenance group, serious adverse events affected 0 of 24 participants listed at risk; other adverse events affected 9 of 24. For the future-thinking maintenance group, serious adverse events affected 0 of 28 participants listed at risk; other adverse events affected 7 of 28. In the Phase I-only group, serious adverse events affected 2 of 108 participants listed at risk; other adverse events affected 4 of 108. Deaths were reported as 0 in each group.

These are descriptive counts, not a causal comparison. The Phase I-only group was not one of the randomized maintenance treatments, so its figures should not be treated as a randomized comparator. The groups also reflect different parts of the study. The record does not provide a statistical comparison of adverse events, event timing, exposure-adjusted rates, or further details about the other adverse events.

The registry’s listed top serious-event terms are “Other” and “Motor vehicle accident,” each reported as 0.9%. These terms and percentages do not establish a treatment relationship. The counts should be read as events recorded during the study, not as evidence that an intervention caused or prevented an event. The registry does not report an assessment of causality for these figures.

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

The central statistical meaning of the record is that it describes a randomized maintenance comparison and an objectively measured activity outcome, while leaving the primary comparison unreported. The study asked whether physical activity changed differently between participants assigned to future-thinking and healthy-thinking maintenance programs. Without group estimates and uncertainty measures, the result cannot be characterized as favoring either program, showing no difference, or being too imprecise to distinguish between effects.

The outcome is weekly moderate-to-vigorous activity measured by accelerometry over a defined monitoring period. It is relevant to the study’s focus on activity adherence, but it is not identical to weight maintenance or to a broad measure of health. Weight is listed as a secondary outcome, and no result for weight is reported in the registry information. A conclusion about activity would not automatically answer questions about weight or other outcomes.

The eligibility process also matters. The randomized treatment comparison followed a Phase I weight-loss program and was restricted to people invited to Phase II after losing at least 5% of initial body weight. Thus, even with complete outcome reporting, results would pertain most directly to the population entering this maintenance comparison. They would not directly describe the effect of the maintenance treatments among people who did not meet the Phase I criterion.

The study is marked completed, but completion status does not itself provide evidence about the primary outcome. The registry reports enrollment and the outcome measurement plan, as well as adverse-event counts, but does not provide a primary statistical analysis. A completed study can therefore have an incomplete public account of its results. The record does not report the sponsor’s analysis for the primary endpoint, and no analysis is listed.

Readers should distinguish the observed-data question from the broader policy or clinical question. Even a precise difference in this activity measure would not, by itself, establish lasting behavior change, generalizability to people outside the Phase II eligibility group, or a difference in weight outcomes. Those questions require the relevant measures, follow-up, and analyses. The registry record does not report enough primary outcome information to answer the comparative activity question.

13. Why This Trial Matters Statistically

This trial is statistically informative as a design example because it separates an initial weight-loss phase from a randomized maintenance comparison. The eligibility criterion makes clear that the maintenance question applies to participants who first achieved the specified weight loss. That distinction is important when interpreting the target population and when considering whether results would generalize to people who did not enter the maintenance phase.

The primary outcome also combines a repeated-measures design with an objective measurement process. Accelerometry can reduce reliance on recalled activity, but usable data depend on adherence to device wear requirements. The stated minimum wear rule and the exclusion of one participant’s 2-month data illustrate how outcome definitions and data completeness affect which observations contribute to a reported measure. The rest of the missing-data approach is not reported in the registry record.

The comparison concerns two active behavioral programs that share in-person meetings and daily exercises but differ in the focus of the exercises. This makes the statistical question a comparison between program approaches, not a test of either program against no treatment. The registry’s design description identifies that contrast, but its missing outcome estimates prevent readers from judging the magnitude or precision of the result.

Finally, the record illustrates why completion, enrollment, and outcome reporting are distinct. A completed status and an enrollment figure do not substitute for group-specific estimates, analysis methods, or uncertainty intervals. Transparent reporting of those elements would allow readers to assess the comparative result and its limitations. In their absence, the design can be described, but the primary statistical finding cannot be interpreted.

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 principal limitation for interpretation is that the primary outcome results are not reported in the registry record. There are no group means, changes, standard deviations, confidence intervals, or primary comparison estimates. The record lists 0 analyses. The comparative effect and its precision therefore cannot be evaluated.

The registry describes outcome measurement and wear-time eligibility, but the full missing-data explanation is not available. It reports the exclusion of one Healthy Thinking participant’s 2-month accelerometry data for insufficient wear, while the description of other missing data is incomplete. Group-specific assessment counts, reasons for missingness, and sensitivity analyses are not reported. These omissions prevent evaluation of how incomplete device data may have affected the results.

Important statistical details are also absent. The record does not report the analysis model, the principal time-point contrast, adjustment for baseline activity, handling of repeated measurements, multiplicity procedures, or whether analyses followed assignment regardless of adherence. It does not report the randomization sequence or allocation concealment method. These details are not reported in the registry record and should not be inferred from the design label.

Interpretation is additionally limited by the Phase II eligibility process. Entry depended on losing at least 5% of initial body weight in Phase I, but the number reaching Phase II and the number analyzed at each assessment are not reported. The registry’s enrollment figure does not establish how many people contributed to each randomized outcome comparison. The results, if reported, would apply most directly to the maintenance-phase population meeting the entry criterion.

Finally, the follow-up described for the primary outcome ends at the 4-month end-of-treatment assessment. Longer-term activity results are not reported in this record. The registry also does not report the full findings for the other health and psychosocial outcomes.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Physical Activity Choices Everyday — NCT03824769.
• Registry record last updated 2023-12-11; status last verified 2023-12.
• Results first posted 2023-12-11.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT03824769, Physical Activity Choices Everyday, is listed as a completed, randomized, single-masked, parallel study sponsored by the University of Connecticut. Enrollment is listed as 160. The study included a 16-week Web-based weight-loss phase, followed by a 4-month maintenance comparison for participants who lost at least 5% of their initial body weight.

The Phase II comparison assigned participants to maintenance programs centered on healthy-lifestyle information or positive future-event descriptions. The primary outcome was change in weekly minutes of accelerometer-measured moderate-to-vigorous physical activity, assessed from Phase II baseline through 1 month, 2 months, and 4 months. Weight was listed as a secondary outcome.

The registry reports accelerometer wear-time criteria and adverse-event counts, but does not report the primary outcome estimates or statistical analysis. It lists 0 analyses. Consequently, the comparative activity result and its precision cannot be determined from the registry record.