Nutricity: An mHealth Nutrition Intervention to Improve Diet Quality Among Latino Children: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Nutricity: An mHealth Nutrition Intervention to Improve Diet Quality Among Latino Children (NCT06266468), a randomized na study. The primary outcome is Child: Change in Diet Quality (Healthy Eating Index) From Baseline to 3 Months.

2. Clinical Question

3. Trial Design

The registry describes Nutricity as a randomized, parallel-group behavioral intervention study with no masking. Its status is completed. The recorded study start date is 2024-02-21, and the primary completion date is 2025-06-16. The registry lists enrollment as 162. The primary-outcome description separately states that 81 child participants were enrolled and that follow-up missing data are reflected in the reported counts. These are different registry entries, and the record does not explain their relationship.

The intervention arm received 12 weeks of mobile intervention through a website and text messaging. The waitlist arm received no intervention for 12 weeks, or until completion of the second study visit. The registry’s stated pilot aim was to compare Nutricity with waitlist control in primary-care clinics and estimate differences in child diet quality at 3 months after Nutricity exposure. The brief summary describes an intended pilot of 40 Latino families in each group, while the posted primary-outcome group counts are 36 for intervention and 39 for waitlist.

The study also set out to evaluate individual-level measures, including nutrition literacy, body mass index, skin carotenoid, feeding behaviors, media-use mediation, self-efficacy, and nutrition attitudes. Organizational aims concern adoption, implementation, maintenance, and the clinic context for possible future uptake. Mixed methods are mentioned as part of understanding context and scalability. The registry identifies the phase as NA and lists diet quality as the condition. The original design assumptions and detailed statistical analysis plan 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 81 child participants enrolled. Missing data at follow up reflected in counts.

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: A total of 81 parent-child dyads (162 participants) were enrolled and randomized. Baseline characteristics are reported separately for the 81 parent participants and the 81 child participants. Because each enrolled dyad consists of one parent and one child, baseline measures reflect up to 162 individual participants when parent and child characteristics are displayed separately.

6. Primary Endpoint

The registry lists the primary outcome as Child: Change in Diet Quality (Healthy Eating Index) From Baseline to 3 Months, measured over Baseline to 3 months.

The primary endpoint is change in child diet quality from baseline to 3 months, measured with the Healthy Eating Index (HEI). The registry says HEI is calculated from nutrient data derived from 2, 24-hour recalls. It describes the outcome as a mean change and gives standard deviation as the measure of spread. The HEI score ranges from 0 to 100; a score of 100 means a better outcome, reflecting alignment of foods with key dietary recommendations and dietary patterns published in the Dietary Guidelines. A positive change in score is also defined as a better outcome.

Using a change score focuses the comparison on how participants’ measured diet quality differs between baseline and follow-up, rather than only on a single measurement. The randomized comparison asks whether the average change differs between the intervention and waitlist groups. This is relevant to the pilot’s stated objective of estimating a group difference that could inform a future larger intervention study. The registry record does not describe the recall-processing details, the timing of individual recalls, or how missing recall data were handled. Accordingly, the posted endpoint describes the measure and direction of improvement, but not every operational detail behind its calculation.

7. Results Posted in the Registry

• Waitlist: mean -1.97 versus 0.81 on control; difference -2.78 (95% CI -7.87 to 2.32), standardized effect d = -0.25; z-test p = 0.285.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure: change in HEI score. A mean summarizes the group’s average observed change, while a standard deviation describes how dispersed individual changes are around that average. A standard deviation is not the uncertainty of the mean difference; it describes participant-level variation. The intervention mean change is 0.806, with standard deviation 10.8, and the waitlist mean change is -1.97, with standard deviation 11.7. The posted counts for this outcome are 36 and 39, respectively.

What does the mean difference represent?

A mean difference compares the group averages on the same outcome scale. The posted estimate is -2.776 for waitlist relative to intervention. This subtraction order matters when interpreting the sign: a negative estimate means the waitlist average is lower than the intervention average for the measured change. The scale is HEI change, for which positive change is defined as a better outcome. The estimate is not an individual participant’s change and does not imply that every participant changed in the same direction.

Random allocation is intended to support a fair comparison of groups, because assignment is not based on participants’ expected outcomes. In general, randomization helps reduce systematic differences between groups at the point of assignment. It does not guarantee that every characteristic will be balanced in a pilot, and it does not resolve missing follow-up data or other limitations in measurement. The registry identifies randomized allocation, but the allocation process and any concealment procedures are not reported in the registry record. Masking is listed as none.

How should the confidence interval be understood?

A confidence interval expresses uncertainty around an estimated quantity. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. The posted 95% confidence interval for the mean difference is -7.868 to 2.316. It includes zero, the value corresponding to no mean difference. Values on both sides of zero remain compatible with this interval, so the estimate does not establish a clear direction of the group difference. The interval is based on the posted comparison; the registry does not describe its calculation method in detail.

The unadjusted p-value is 0.285. In general, a p-value assesses how unusual data at least as incompatible with a specified null model would be if that model were true; it is not the probability that the null hypothesis is true, nor a measure of effect size. Here it should be read alongside the estimated difference and its confidence interval. The registry record does not report whether any adjusted p-value, covariate-adjusted model, or other primary analysis was used.

Why do variability and over-dispersion matter?

For a continuous endpoint, variability affects how precisely a group mean and a between-group difference can be estimated. Greater variation makes it harder to distinguish a group difference from the natural spread of participant outcomes. The reported standard deviations, 10.8 and 11.7, describe that spread. General statistical methods may need to account for over-dispersion when observed variability exceeds what a model assumes. The endpoint is continuous and the registry does not report an over-dispersion assessment or a model that would make that issue applicable. It would therefore be inappropriate to claim that such an adjustment was or was not needed in the sponsor’s analysis.

The comparison reports a pooled standard deviation of 11.28 and a standardized difference of -0.246. A standardized difference expresses a mean difference relative to a measure of spread, which can assist comparisons across scales. It does not replace interpretation in HEI points, and it does not establish clinical importance. These posted summaries do not show how individual outcomes were distributed or whether unusual observations affected the averages.

What can be said about analysis choices?

The registry lists the outcome parameter as a mean and dispersion as standard deviation. It does not report the analysis population, missing-data method, covariates, model form, assumptions checks, or multiplicity procedure. The posted comparison is unadjusted, and the p-value is identified as unadjusted. These details should not be filled in by assumption. General statistical interpretation can explain what the summaries mean, but the precise analysis choices behind the registry result are not reported in the registry record.

The pilot’s stated purpose included generating preliminary data to inform future power calculations. The separate planning illustrations use the observed effect under stated assumptions, and they should not be mistaken for the original design justification. The registry record does not report the original sample-size assumptions or whether interim analyses were planned. No claim about observed power follows from the posted p-value or the planning illustrations.

10. Confidence Intervals and Precision

The estimated mean difference is -2.776, with a 95% confidence interval from -7.868 to 2.316. This interval is wide enough to include zero and values on either side of it. The estimate therefore has limited precision: the posted data do not identify a narrow range of plausible differences. In HEI-change terms, the interval includes a possible lower mean change in the waitlist group, no difference, and a possible higher mean change in that group relative to intervention.

A confidence interval is not a guarantee that the true difference lies within its endpoints, nor does it assign a probability to each value in the interval. As a general interpretation, a 95% confidence procedure would capture the true parameter in the stated proportion of repeated samples under its assumptions. The registry record does not report the interval calculation details or assumption checks, so the statistical interpretation should remain tied to the posted interval rather than presume a particular model.

The standard deviations of 10.8 for intervention and 11.7 for waitlist describe substantial variation in observed change scores. Variation among participants contributes to uncertainty in the group comparison. The p-value of 0.285 is consistent with the interval’s inclusion of zero, but it does not make the interval unimportant or remove uncertainty about the size and direction of a difference. The registry does not report a threshold for a clinically or practically meaningful HEI change, so precision cannot be judged against such a threshold from this record.

Follow-up missing data are noted in the primary-outcome description, and the posted counts are 36 and 39. The record does not report the missingness pattern or the method used to address it. Those omissions limit assessment of how missing follow-up information may affect precision or interpretation.

11. 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 events. They are planning illustrations based on the observed effect, rather than a report of the trial’s original design calculation. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect to detect is a stated fraction of the observed effect.

For planning for 100% of the observed effect, the illustration gives 260 participants per arm for 80% power and 347 participants per arm for 90% power. For planning for 75% of the observed effect, it gives 461 participants per arm for 80% power and 617 participants per arm for 90% power. For planning for 50% of the observed effect, it gives 1,037 participants per arm for 80% power and 1,388 participants per arm for 90% power.

In plain terms, the 80% power column describes the planned number per arm under which the stated assumptions would give an 80% chance of detecting the assumed effect if it were present. The 90% power column uses a higher target chance of detection under those assumptions. Smaller effects need more participants to detect, which is why the planning figures increase when the assumed fraction of the observed effect is reduced. These are planning illustrations, not observed power. The registry record does not report the original design assumptions or a sample-size justification for the trial.

12. 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, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -2.776; pooled standard deviation σ = 11.277.
2. n = 2 × (1.96 + 0.842)² × 11.277² / -2.776² = 259.1, rounded up to 260 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
delta <- -2.776                      # observed difference in means
sigma <- 11.2774596381637                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^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 (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(6266468)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 260 (80% power), 347 (90% power)
 75% of observed effect: n per arm = 461 (80% power), 617 (90% power)
 50% of observed effect: n per arm = 1,037 (80% power), 1,388 (90% power)
power.t.test: 260 
Simulated power at n = 260 per arm: 0.800 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-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.

13. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures, including the primary HEI-change outcome, and identifies 7 secondary outcomes as posted. The secondary measures include parent nutrition literacy, child body mass index, child skin carotenoid, parent and child feeding behaviors, parent mediation of children’s media use, parent self-efficacy, and parent nutrition attitudes. The stated aims also describe exploratory relationships among nutrition literacy, psychosocial constructs, engagement, satisfaction, and diet quality.

When a study examines multiple outcomes or comparisons, the chance of at least one apparently notable result can increase. General approaches to multiplicity include prespecifying a primary comparison, adjusting inference across selected tests, or clearly treating other findings as exploratory. The registry record does not report a multiplicity procedure, a hierarchy of secondary outcomes, or which exploratory analyses were conducted. The posted primary comparison is identified as unadjusted, and the analysis count is listed as 0. That field does not explain the relationship between the posted result and any analyses that may have been conducted.

The record states that missing follow-up data are reflected in the primary-outcome counts. It does not describe how much data were missing by group, why measurements were unavailable, whether missingness was related to outcome, or how missing observations were handled. It also does not report an imputation method, sensitivity analysis, or complete-case definition. These details matter because estimates based on available measurements may be affected if missingness is related to participants’ outcomes or group assignment.

The analysis population is not reported in the registry record. Although the study is randomized, the record does not say whether the primary analysis included all randomized participants, only those with observed follow-up, or another defined population. The group counts attached to the posted endpoint are 36 and 39; no further population definition should be inferred from those counts alone.

14. 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 5% reporting threshold.

The registry reports 0 serious adverse events among 80 at risk in the intervention group and 0 among 82 at risk in the waitlist group. It also reports 0 other adverse events among 80 at risk in the intervention group and 0 among 82 at risk in the waitlist group. Deaths are reported as 0 in each group, and no serious-event terms are listed.

These are registry safety counts, not the primary efficacy outcome. The at-risk figures differ from the group counts posted for the HEI endpoint, and the record does not explain the relationship between those denominators. Zero recorded events means that none are listed in the registry’s results for these categories; it does not prove that an event was impossible or that every type of harm was assessed. The record does not provide further detail about event definitions, collection procedures, reporting windows, or the handling of missing safety information. The counts should therefore be interpreted as the posted safety summary, without extending them beyond the recorded categories and denominators.

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

The posted primary result is an estimated difference in mean change in child HEI score between Nutricity and waitlist. The estimate is -2.776 for waitlist relative to intervention, with a 95% confidence interval from -7.868 to 2.316 and an unadjusted p-value of 0.285. The intervention group’s mean change is 0.806, while the waitlist group’s mean change is -1.97. These summaries describe the observed pilot comparison and its uncertainty.

The confidence interval includes zero and extends in both directions. Accordingly, the posted result does not establish a precise difference between groups. It also does not establish that there is no difference: the interval remains compatible with a range of possible values. The p-value is not a measure of the probability that Nutricity is effective, and it should not be interpreted as such. The registry record does not report a threshold for a meaningful HEI change, so the result cannot be classified as clinically important or unimportant from these statistics alone.

The trial’s stated purpose was to pilot the intervention in pediatric clinics serving Latino families, examine implementation potential, and obtain preliminary information for future research. Its broader aims included individual and organizational outcomes. The primary result alone does not answer those implementation questions, and the registry record does not provide posted analysis results for the listed secondary outcomes. Nor does a pilot comparison determine whether findings would generalize to other populations, clinics, or settings.

The record notes missing follow-up data and provides the outcome counts, but it does not report missing-data methods or the primary analysis population. This limits assessment of how missing observations may influence the estimate. The most defensible reading is therefore descriptive and cautious: the posted group averages differ in the observed direction, while the uncertainty around the comparison is substantial and analysis details are limited.

16. Why This Trial Matters Statistically

This trial is statistically useful as a pilot because the stated aims include estimating child diet-quality differences and informing planning for a future larger study. Pilot estimates can help researchers understand the scale of observed variability and the uncertainty around a treatment-group comparison. Here, the posted group means and standard deviations describe both the average change and the spread of individual changes, while the confidence interval shows that the between-group estimate remains imprecise.

The study also goes beyond an individual-level outcome. Its aims include clinic adoption, implementation, organizational maintenance, and understanding context and scalability through mixed methods. Those questions matter statistically because an intervention’s practical reach and delivery can affect how outcome data are generated and how later studies should be designed. The registry record describes these aims, although it does not report results for them in the posted outcome summaries.

The primary comparison highlights why estimates, confidence intervals, and design assumptions should be considered together. The observed point estimate is not enough to establish a stable effect, especially when the interval spans zero and plausible differences in both directions. Planning illustrations based on the observed effect show how sample-size requirements depend on the effect a future study aims to detect. They are illustrations, not a substitute for a prespecified design based on justified assumptions.

Finally, the registry’s notes on missing follow-up data and the absence of reported analysis details identify information that would help readers assess the result more fully. Clear reporting of analysis populations, missing-data handling, and multiplicity plans would support a more complete appraisal of both the primary comparison and the broader pilot aims.

17. 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 registry record leaves important details unavailable for interpreting this pilot. It does not report the original sample-size justification, the detailed statistical analysis plan, the analysis population, or the method used to handle missing follow-up data. Although missing data are acknowledged and outcome counts are posted, the record does not explain the reasons or pattern of missingness. The difference between the registry enrollment entry of 162 and the primary-outcome description of 81 child participants is not explained in the record.

The primary outcome relies on HEI scores calculated from nutrient data derived from 2, 24-hour recalls. The record does not describe recall timing, data-processing procedures, or how incomplete recalls were treated. It also does not report a threshold for a meaningful score change, limiting interpretation of the practical importance of the estimated difference.

The study is listed as open-label, with no masking. The record does not describe safeguards against measurement or reporting effects. The primary endpoint is based on dietary recall data, but further information about collection procedures is not reported. This is a reporting limitation; the record does not establish whether any particular bias occurred.

The posted primary comparison has an interval that includes zero and a p-value of 0.285, while the registry supplies limited analysis detail. No multiplicity procedure or adjusted analysis is reported, and the analysis count is listed as 0. The record also does not provide posted results for the listed secondary outcomes or implementation aims. These gaps restrict interpretation to the primary summaries and safety counts that are recorded, rather than supporting conclusions across all study aims.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Nutricity: An mHealth Nutrition Intervention to Improve Diet Quality Among Latino Children — NCT06266468.
• Registry record last updated 2026-08-27; status last verified 2026-08.
• Results first posted 2026-08-27.
• 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.

21. Record Summary

NCT06266468 is a completed, randomized, open-label, parallel-group study of Nutricity, a 12-week mobile nutrition intervention using a website and text messaging. The comparator was a waitlist condition. The registry lists enrollment as 162 and gives a primary completion date of 2025-06-16.

The primary outcome is mean change in child HEI score from baseline to 3 months. Posted mean changes are 0.806 for intervention and -1.97 for waitlist; the waitlist-relative-to-intervention difference is -2.776, with a 95% confidence interval from -7.868 to 2.316 and unadjusted p-value 0.285. The registry notes missing follow-up data and does not report the missing-data method, analysis population, or detailed analysis plan.

The study’s aims also cover secondary individual outcomes and clinic implementation. The safety summary reports 0 serious adverse events and 0 other adverse events in each group, with the recorded at-risk counts of 80 and 82, respectively. No serious-event terms are listed.