Pasos Hacia La Salud - Physical Activity Intervention for Latinas: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pasos Hacia La Salud - Physical Activity Intervention for Latinas (NCT01834287), a randomized na study. The primary outcome is Total Weekly Minutes of Physical Activity as Measured by the 7-Day PAR (Physical Activity Recall), From Baseline to 6-months and 12-months..

2. Clinical Question

3. Trial Design

Pasos Hacia La Salud was a randomized, parallel-group behavioral trial sponsored by the University of California, San Diego. The record lists an enrollment of 207 and a completed status. The recorded start was 2011-12, and primary completion was 2015-03. The phase is listed as NA.

Participants were assigned to a physical activity intervention or a wellness control. The study was unmasked: masking is listed as none. In the intervention arm, participants received a motivationally tailored Spanish-language Internet program focused on physical activity. The control was also Internet-based and Spanish-language, but addressed health topics other than physical activity. This comparison therefore places the activity-focused program against a wellness contact condition, rather than against no intervention.

The registry describes the primary outcome as total weekly minutes of physical activity measured by the 7-Day PAR at baseline, 6 months, and 12 months. The stated comparison in the study summary concerns reported minutes of moderate-intensity physical activity at the end of treatment. Because the listed outcome covers multiple assessment times and is not reduced to one comparison, the registry record does not identify a single numerical contrast that can be interpreted as the primary result.

The record does not report the randomization procedure, allocation concealment, treatment adherence, participant flow, or the number analyzed for the primary outcome. It also does not report the intervention duration or explain how the end-of-treatment assessment relates to the listed 6-month and 12-month assessments. These details should not be inferred from the parallel design or the stated outcome schedule.

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.

Population: 205 eligible participants (13 ineligible post-randomization were removed from analysis)

6. Primary Endpoint

The registry lists the primary outcome as Total Weekly Minutes of Physical Activity as Measured by the 7-Day PAR (Physical Activity Recall), From Baseline to 6-months and 12-months., measured over Baseline, 6 months, and 12 months.

The primary outcome is total weekly minutes of physical activity, measured with the 7-Day PAR at baseline, 6 months, and 12 months. The registry describes the outcome as a mean of a continuous measure, with standard deviation as its dispersion measure. The instrument is interviewer-administered and uses multiple strategies to help participants recall activities, including time spent sleeping and activity at moderate, hard, and very hard intensity.

Weekly minutes give a measure of reported activity over a defined recall period. A continuous measure can preserve differences across participants rather than reducing activity to a category. The mean describes the group’s average reported amount, while the standard deviation describes the spread of individual values around that average. These are general interpretations of the statistics named in the registry.

The registry says the 7-Day PAR is used across studies of physical activity and has demonstrated acceptable reliability, internal consistency, and congruent validity with other objective activity measures. Those measurement properties support its use as a self-report instrument, but they do not make individual recall error impossible. The record does not provide the observed means, standard deviations, group contrasts, or uncertainty estimates at the listed assessments. It therefore does not establish the direction or precision of any group difference in weekly minutes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical concepts below explain how results for a continuous outcome are commonly read. The registry record does not report the detailed analysis methods used for this trial, so these concepts should not be mistaken for a description of the trial’s actual analysis.

What does a mean represent?

For a continuous measure such as weekly minutes, the mean is the arithmetic average of the observed values in a group. It provides a compact description of the group’s reported activity. The registry identifies the primary outcome parameter as a mean. It does not report the group means at baseline or follow-up, so no actual average can be interpreted from the record.

A mean alone does not describe how similar or different participants’ measurements are. The standard deviation is a measure of spread: a larger standard deviation indicates observations are more dispersed around the group mean. The registry identifies standard deviation as the dispersion measure, but reports no values. Neither the mean nor standard deviation conveys the full distribution; unusual values and skew can matter, particularly for activity minutes.

How is a group contrast interpreted?

A between-group contrast would compare the intervention group’s outcome with the wellness control group’s outcome. For a continuous outcome, an unadjusted mean difference would express that contrast in minutes per week. A positive or negative sign would depend on the order used for subtraction. The registry record does not report such a contrast, so its direction and size are unknown.

A confidence interval is a statistical range around an estimate. In general, it shows the precision of the estimated contrast under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, while an interval spanning values in opposing directions may leave the direction of the underlying difference uncertain. The confidence level and interval for this trial are not reported in the registry record.

A p-value is calculated relative to a null hypothesis and a statistical model. In general, it reflects how incompatible the observed data are with that null model; it is not the probability that the null hypothesis is true, nor a measure of the size or practical importance of an effect. The registry record does not report a p-value for the primary outcome. Thus, the stated hypothesis about greater reported moderate-intensity activity cannot be treated as a statistically supported result on the basis of the registry entry.

Why do repeated assessments matter?

The listed primary outcome includes baseline, 6-month, and 12-month assessments. Repeated measurements can describe change over time as well as differences between groups at particular follow-up times. The statistical interpretation depends on which contrast is targeted: a group comparison at a follow-up, a change from baseline, or a pattern across assessments are not interchangeable questions. The record does not specify which of these was the primary analysis or provide estimates for any of them.

When the same participants are measured repeatedly, their observations may be related. General statistical approaches can account for that within-participant relationship, but the appropriate approach depends on the outcome structure, missing measurements, and analysis objective. The registry record does not report a repeated-measures model, covariance assumptions, or another method for handling the assessment sequence.

What do the planning assumptions mean?

The record describes sample-size calculations as planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such illustrations describe hypothetical planning under stated assumptions. They are not observed trial results and are not observed power. The record does not report the trial’s own sample-size justification, so the illustration assumptions should not be taken as the original design rationale.

Planning estimates depend on the effect size assumed, outcome variability, significance criterion, allocation, and model. If an assumed effect differs from the effect ultimately seen, the planning illustration may not describe the ability to detect that realized effect. In this record, the observed primary-outcome estimates needed to assess such an illustration are not reported, and no new sample-size calculation can be inferred.

Why can variability and model choice matter?

General statistical methods rely on assumptions about how observations vary and how they relate to one another. For a continuous endpoint, the distribution and variability of weekly activity can affect the suitability and precision of a model. Over-dispersion is a general term for variation greater than a model expects; when present, standard errors may be too small if the extra variation is ignored. The registry does not report evidence of over-dispersion or a model that would allow this issue to be assessed for the trial.

Adjustment for baseline values or other participant characteristics can also affect an estimate and its precision. Whether adjustment is appropriate depends on the prespecified analysis plan and data. The record does not report covariate adjustment or the statistical analysis plan. No adjusted or recalculated estimate is available in the registry record, and no claim about the trial’s statistical significance can be made from its stated hypothesis alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure, but it spans baseline, 6 months, and 12 months and includes activity at different intensity levels in its instrument description. The record indicates that the primary outcome has several categories or time points and is not reduced to one comparison. Consequently, it does not specify a single primary contrast for interpreting an efficacy result.

In general, when several outcomes, time points, subgroups, or analyses are tested, the chance of at least one apparently unusual result can increase. Multiplicity procedures can address that issue, but their choice depends on which comparisons were prespecified and how they are related. The registry record does not report a multiplicity strategy, a hierarchy of comparisons, or which assessment time was designated as primary for statistical testing. It is therefore not possible to determine how multiple comparisons were handled.

The record also does not report how missing outcome measurements were handled, whether an intention-to-treat population was used, or how the analysis population was defined. These omissions matter because participants may not have measurements at every assessment, and methods for including incomplete records can affect the estimate and its uncertainty. The registry record does not provide participant flow or the number with outcome data at each time point. No assumptions about missingness, imputation, exclusions, or analysis populations should be inferred.

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.

The registry lists serious adverse events for the physical activity intervention among 104 participants at risk, with 0 affected, and for the wellness control among 101 participants at risk, also with 0 affected. Other adverse events are likewise listed as 0 affected in each group, using the same recorded group sizes at risk. Deaths are listed as 0 in both groups.

These are descriptive counts in the registry record. They do not provide information about event definitions, how events were solicited or monitored, the completeness of follow-up, or whether the listed risk populations represent all randomized participants. The record lists no top serious adverse-event terms. A zero count in the posted categories should not be interpreted as proof that the interventions carry no risk; it means that the registry reports no affected participants for those categories.

The registry does not report comparative statistical analyses of these safety counts or uncertainty estimates. Since the counts are zero in the listed groups, the record does not establish that the groups have identical safety profiles. It also does not support conclusions about events that were not included in the registry’s reporting categories.

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

The record’s main contribution is to describe a randomized behavioral comparison aimed at physical activity among Latina women. It identifies a Spanish-language, Internet-based activity intervention and a Spanish-language wellness contact control, and names weekly physical activity measured by the 7-Day PAR as the primary outcome. It also records assessments at baseline, 6 months, and 12 months.

That description does not answer whether the intervention group reported more activity than the control group. The registry record includes no primary-outcome means, standard deviations, group contrasts, confidence intervals, or p-values. The stated expectation of greater moderate-intensity activity is a hypothesis, not an outcome. Without the numerical results, the direction and magnitude of any difference and the precision of its estimate remain unknown.

The absence of a reported result should not be interpreted as evidence that the intervention had no effect, nor as evidence that it had an effect. It means the efficacy question cannot be resolved from the registry entry. In particular, no conclusion can be drawn about whether any difference was statistically distinguishable from chance or meaningful in size.

The safety entry reports zero serious and other adverse events in each listed group. This is a limited description of recorded events, not a complete assessment of safety or proof of no risk. Interpretation also remains constrained by the absence of reported analysis populations, outcome follow-up counts, missing-data methods, and the statistical plan.

In general, a clinical trial result is best understood by considering the outcome estimate, its uncertainty, the analysis population, and the prespecified comparison together. Those pieces are not reported for the primary outcome in this record. The available information therefore supports understanding what the study set out to compare, but not estimating the effect of the intervention.

13. Why This Trial Matters Statistically

This trial is statistically notable for its comparison of two active, Spanish-language Internet-based behavioral programs rather than a physical activity intervention against no contact. That design frames the question as whether an activity-focused program differs from a wellness contact condition. The distinction matters when interpreting any eventual group contrast: it would compare these assigned programs, not simply participation with no intervention.

The record also illustrates why an outcome definition and its timing are central to interpretation. The study summary emphasizes moderate-intensity activity at the end of treatment, while the listed primary outcome covers total weekly minutes at baseline, 6 months, and 12 months. Those descriptions point to related but not identical statistical questions. A clear primary contrast is needed to understand which estimate is intended to carry the principal inference.

The 7-Day PAR is described as an interviewer-administered recall instrument with established measurement properties across physical-activity studies. Self-report can capture participants’ reported activity across intensity categories, while still being subject to recall and reporting error. That general measurement consideration is relevant when interpreting reported minutes, but the registry does not give trial-specific validation or measurement-error results.

Finally, the entry illustrates a distinction between a study’s hypothesis and its results. The hypothesis describes the anticipated direction of a comparison; it does not substitute for an estimate and its uncertainty. Since those primary outcome results are not reported in the registry record, the trial’s statistical evidence about activity change cannot be evaluated from this entry alone.

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 statistical interpretation is that the registry record does not report numerical primary-outcome results. It supplies no group means, standard deviations, between-group estimates, confidence intervals, or p-values for the listed assessments. This prevents evaluation of effect size, direction, and precision.

The primary outcome is described across multiple assessment times, while the study summary frames a hypothesis about moderate-intensity activity at the end of treatment. The registry does not clarify how these formulations relate, identify a single primary contrast, or state how multiple comparisons were addressed. The meaning of a primary efficacy test is consequently unclear from the record.

The registry also does not report participant flow, outcome completion at each assessment, the analysis population, or methods for missing data. The absence of these details limits assessment of attrition and of how the analyzed participants may differ from those randomized. No inference about adherence or follow-up completeness is warranted.

Further, the record does not describe the randomization procedure, allocation concealment, intervention duration, statistical analysis plan, or adjustment strategy. Although the trial is listed as unmasked, the registry does not detail what participants or outcome assessors knew during outcome collection. These design and analysis details are not reported in the registry record and should not be assumed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pasos Hacia La Salud - Physical Activity Intervention for Latinas — NCT01834287.
• Registry record last updated 2025-11-25; status last verified 2025-11.
• Results first posted 2025-11-25.
• 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

Pasos Hacia La Salud was a completed, randomized, parallel-group behavioral trial sponsored by the University of California, San Diego. It enrolled 207 participants and compared a motivationally tailored Spanish-language Internet-based physical activity intervention with a Spanish-language Internet-based wellness control. The record lists no masking.

The primary outcome was total weekly minutes of physical activity measured with the interviewer-administered 7-Day PAR at baseline, 6 months, and 12 months. The study summary states a hypothesis about greater reported moderate-intensity activity in the intervention group. Numerical primary-outcome results and the detailed analysis plan are not reported in the registry record.

The safety record lists 0 serious adverse events, 0 other adverse events, and 0 deaths in each group. These are registry counts and do not establish absence of risk. The record identifies the research question and design, but does not provide enough outcome information to assess the intervention’s statistical effect.