Buoy Electrolyte Study on Hydration Status of Active Men and Women: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Buoy Electrolyte Study on Hydration Status of Active Men and Women (NCT05768789), a na na study. The primary outcome is Net Fluid Balance.

2. Clinical Question

3. Trial Design

The registry record describes a completed study sponsored by the University of Pittsburgh, with enrollment of 30. The listed study dates are 2023-09-13 for the start and 2024-04-27 for primary completion. The phase is listed as not applicable, allocation is recorded as NA, masking is none, and the model is single group. These labels describe the record; they do not provide a full protocol or establish how every participant experienced the interventions.

Three interventions are listed: Buoy Electrolyte, Water only, and Nuun Electrolyte. One arm description gives the sequence “Buoy Electrolyte then Water only then Nuun Electrolyte.” It also describes a Buoy intervention amount of 4% of total body weight given in 16 divided doses over 4 hours, with a goal of 600mg of Na+ over 4 hours and urine output measured over 6 hours. The remainder of that arm description is incomplete, so its truncated text should not be used to infer additional dosing details. A full description of the other intervention schedules, visit spacing, and any washout periods is not reported in the registry record.

Allocation is not specified, and the record explicitly identifies this as not a randomized comparison. The sequence in the arm description is not evidence that treatment order was randomized or counterbalanced. The study should therefore not be read as a randomized trial comparing three arms. How participants were assigned to intervention periods, if assignment occurred, is not reported in the registry record. The study status is completed, but completion alone does not establish that all planned measurements were collected or analyzed.

The primary outcome is net fluid balance at 360 minutes after ingestion. Bio Impedance is listed as a secondary outcome. The record lists four outcome measures in total, but does not give a complete description of each measure or the analysis methods used for them. No inferential analyses are recorded 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.

Visit 1 : Buoy Electrolyte

Visit 2: Water Only

Visit 3: Nuun Electrolyte

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 Net Fluid Balance, measured over 360 minutes after ingestion.

Net fluid balance is the primary endpoint. The registry defines it as total fluid consumed minus cumulative urine output and gives the unit as liters. It is assessed at 360 minutes after ingestion. In general, this type of measure represents the balance between an identified fluid input and an identified fluid output over a stated observation period. It can summarize the amount retained relative to the amount consumed and excreted during that period.

The measure is useful for describing a short-term hydration-related response because it combines intake and urine output rather than considering either alone. Its interpretation depends on how intake and urine output were measured, whether all relevant fluid inputs and outputs were captured, and whether the timing was consistent. Those operational details are not reported in the registry record beyond the endpoint definition and timeframe. The record does not report the observed mean, standard deviation, number of participants with endpoint data, or a comparison among interventions. As a result, the endpoint’s observed magnitude and precision cannot be described from the registry record.

The use of liters specifies the scale of the outcome, while the stated time point defines when the balance is evaluated. A mean would describe the average net balance in the analyzed observations; a standard deviation would describe how dispersed individual values are around that mean. These are general interpretations of the stated summary measure, not findings about the study. The registry record does not report whether additional time points were analyzed or how repeated observations, if present, were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record supplies a small amount of design and outcome information but does not report a statistical analysis plan. The primary endpoint is a continuous measure summarized as a mean with standard deviation, and its stated assessment time is 360 minutes after ingestion. The explanations below describe general statistical concepts; they are not claims about analyses performed in this study.

What does a mean and standard deviation describe?

For a continuous outcome, the mean is the arithmetic average of the observed values in an analysis group or period. The standard deviation describes how spread out those observed values are around the mean. A mean alone can conceal substantial variation: two sets of observations can have the same average but different degrees of dispersion. Reporting both can therefore provide a basic description of location and variability. The registry record names these summary statistics for net fluid balance but does not report their values or the number of observations used to calculate them.

The standard deviation is not the same as the uncertainty in a mean estimate. In general, uncertainty in an estimated mean depends on both the variability of the measurements and how many measurements contribute. A confidence interval is one way to express uncertainty around an estimate, subject to the model and assumptions used. No confidence interval is reported for the primary endpoint, and the registry record does not identify a method for calculating one.

What makes a comparison interpretable?

A comparative analysis requires clarity about which observations are being compared and how the comparison was formed. In a randomized comparison, random assignment is intended to make groups comparable on average with respect to factors other than the intervention. Here, allocation is recorded as NA, and the registry record states that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The single-group model and the listed intervention sequence do not establish a randomized between-group design. The record does not describe a complete analysis that accounts for the study’s design.

In general, if the same participants contribute measurements under more than one condition, those measurements are related rather than independent. A suitable analysis would need to reflect that dependence and the intervention order. If different participants contribute to different conditions, the analysis would instead need to account for the structure of those groups. The registry record does not explain which observations were analyzed together, whether participants contributed measurements under each intervention, or what statistical model was used. It would therefore be inappropriate to infer a paired, crossover, or independent-group analysis from the available design labels.

Why does measurement variability matter?

Net fluid balance is defined from total fluid consumed and cumulative urine output. In general, variation in either component contributes to variation in the resulting measure. Accurate and consistently timed measurement is important because differences in observation procedures can appear as differences in the endpoint. The registry record provides the endpoint definition and the 360-minute timeframe, but does not report measurement procedures, adherence information, or how incomplete intake or urine-output records were handled.

For continuous outcomes, statistical methods also depend on the distribution and variance of the observations. General methods based on a normal approximation may be less reliable when data are strongly skewed, contain influential outliers, or have unequal variability across groups. Over-dispersion refers generally to variability greater than a model expects; when present, a model that ignores it can understate uncertainty. These are general considerations only. The registry record does not report distributional checks, over-dispersion assessments, transformations, or alternative models for net fluid balance.

What do the planning assumptions mean?

The registry record’s planning assumptions describe an illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The target effect is stated as a fraction of the observed effect. These are planning assumptions, not evidence that the study used that design or analysis. The illustration is not observed power, and a planning sample size should not be read as a result from participants. The actual planning counts are not reported in the registry record described for this analysis, and the observed primary endpoint effect needed to interpret such an illustration is also not reported there.

In general, a planning calculation estimates how many participants may be needed under specified assumptions about an effect, variability, allocation, and error rates. If those assumptions differ from the actual study or the true effect, the calculation may not describe the study’s achieved precision. A calculation framed around a fraction of an observed effect also depends on a value for that effect. Without the endpoint results and the calculation outputs, no particular participant requirement can be interpreted.

What is not documented?

The registry record does not report a statistical analysis plan, primary endpoint estimate, confidence interval, p-value, or detailed model. It records zero analyses and lists four outcome measures, while identifying Bio Impedance as a secondary outcome. Whether analyses were conducted elsewhere, which outcome populations were used, how missing measurements were treated, and whether any adjustments were made are not reported in the registry record. The general methods clarify what such information would help readers evaluate; they do not fill in the missing analysis details.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Buoy Hydration Drops", "Water Alone - Control", "Nuun Sport Hydration Tabs")
n   <- c(30, 30, 30)
m   <- c(0.28, 0.05, 0.03)
sp  <- c(0.28, 0.32, 0.2)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Buoy Hydration Drops  30  0.280  0.280  0.175  0.385
CARM  Water Alone - Control  30  0.050  0.320  -0.069  0.169
CARM  Nuun Sport Hydration Tabs  30  0.030  0.200  -0.045  0.105

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists four outcome measures and names Net Fluid Balance as the primary outcome. Bio Impedance is listed as a secondary outcome. It does not describe the other measures in sufficient detail here, specify which comparisons were planned for each outcome, or report a multiplicity adjustment. When several outcomes, time points, or treatment contrasts are tested, the chance of at least one apparently notable result can increase. In general, a prespecified testing strategy or suitable adjustment can help readers interpret a collection of tests. No such strategy is reported in the registry record.

The number of analyses recorded is zero, and no primary or secondary outcome results are reported. This does not show that no analysis was performed outside the registry record; it means there is no recorded analysis to evaluate. The record also does not describe whether analyses were prespecified, whether any analyses were exploratory, or how the primary outcome was prioritized if multiple contrasts were considered.

Missing-data methods and analysis populations are not reported in the registry record. Although enrollment is listed as 30, the number of participants with usable data for each outcome is not stated. The record does not say whether participants were excluded, whether incomplete measurements occurred, or how any missing values were handled. In general, complete-case analysis uses only observations with the required data, while other approaches make assumptions about missing values and their relationship to observed information. The appropriate interpretation depends on the missingness pattern and the method used; neither is documented.

The registry record does not identify an intention-to-treat population, a per-protocol population, or another analysis population. It also does not explain whether all participants were expected to experience every listed intervention. These omissions prevent assessment of how closely the analyzed data, if any, correspond to the enrolled group and the stated study question.

12. 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 3% reporting threshold.

The registry record gives adverse-event group entries for Buoy Hydration Drops, Water Alone - Control, and Nuun Sport Hydration Tabs. For each listed group, 30 participants are recorded as at risk for serious events and 0 as affected; the entries for other adverse events also record 30 at risk and 0 affected. Deaths are recorded as 0 in each group. No serious-event terms are listed.

These entries should be read as registry counts, not as proof that an event was impossible or that the interventions have no safety concerns. The record does not explain how events were solicited, defined, assessed, or attributed, nor does it give detail about the duration or completeness of safety monitoring. It also does not clarify how the listed groups relate to the single-group model or whether the same participants appear in more than one group. The repeated at-risk counts should not be added to infer a total number of unique participants.

A count of zero affected indicates that no affected participants are recorded in that entry; it does not establish that no events occurred outside the record or that the chance of an event is zero. The registry record does not report further safety analyses, event timing, severity details beyond the serious-event category, or exposure-specific follow-up. These limitations restrict interpretation of the safety counts.

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

The registry record identifies a study of electrolyte supplementation and hydration status in active men and women, with net fluid balance as its primary endpoint. It reports a completed status, enrollment of 30, and a 360-minute assessment timeframe. Those details establish the question and broad scope of the study, but they do not provide the endpoint findings.

Because the mean, standard deviation, and any comparison results are not reported in the registry record, the size and direction of the observed net fluid balance cannot be described. Its precision cannot be assessed either. No reported estimate supports a conclusion about whether one listed intervention produced a larger or smaller balance than another. A missing result should not be interpreted as a finding of no difference.

The design labels also matter. Allocation is NA, masking is none, and the model is single group. The record notes that this is not a randomized comparison and that the arms are not a like-for-like control comparison. Even if numerical differences were available, the design information would require careful consideration of comparability, treatment order, and measurement conditions. The registry record does not report enough detail to determine how those issues were handled.

In general, statistical significance and clinical importance are distinct. A small estimate can be statistically distinguishable from a reference value yet be of limited practical importance, while an imprecise estimate can remain compatible with a range of effects. Interpreting either requires the estimate, uncertainty, study context, and a relevant threshold or benchmark. The registry record does not report those elements for net fluid balance. No medical conclusion about the supplement’s effects follows from the design description alone.

The record does list zero affected participants for serious and other adverse events in each named group, with zero deaths recorded. These are limited registry counts, not a complete characterization of safety. The information available supports a description of what was registered, while leaving both outcome effectiveness and broader safety interpretation unresolved.

14. Why This Trial Matters Statistically

This study is statistically interesting because it combines a continuous hydration-related endpoint with multiple listed interventions and a design that the registry does not characterize as randomized. Net fluid balance is defined using fluid consumed and cumulative urine output, so its interpretation depends on the measurement process as well as on the analysis. The stated endpoint and timeframe make the study question identifiable, while the absence of outcome estimates means readers cannot evaluate magnitude or precision.

For biostatisticians and clinical researchers, the design labels illustrate why study structure must be clear before interpreting contrasts. The record identifies a single-group model, allocation NA, no masking, and a sequence of Buoy Electrolyte, Water only, and Nuun Electrolyte in one arm description. It also explicitly cautions that this is not a randomized comparison and not a like-for-like control comparison. Without a complete description of participant flow, intervention order, and analysis, a comparison cannot be treated as if it arose from randomized parallel groups.

The record also highlights the distinction between descriptive results and inferential evidence. A mean and standard deviation are identified as the primary outcome summary, but their values are not reported. No analysis is recorded, and no uncertainty estimate is available. Statistical methods can only answer a meaningful question when the outcome data, analysis population, and model are sufficiently documented. Here, those omissions prevent assessment of the observed response and its uncertainty.

Finally, the planning assumptions demonstrate a general issue: sample-size illustrations depend on assumptions about the effect and design, and are not measures of what the study actually achieved. They should not be confused with observed power. The registry record’s planning assumptions can be described, but the absent endpoint results and planning counts do not support a numerical interpretation of the illustration. The case therefore underscores the value of complete outcome reporting alongside concise design labels.

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.

The most important limitation for interpretation is that the primary endpoint results are not reported in the registry record. There is no reported mean, standard deviation, estimate of a contrast, confidence interval, or p-value for net fluid balance. Consequently, neither the observed response nor its uncertainty can be assessed.

Design information is incomplete. Allocation is recorded as NA, masking is none, and the model is single group. The registry record says the comparisons are not randomized or like-for-like. One arm description gives an intervention sequence, but a full schedule for all interventions, visit spacing, and washout information are not reported in the registry record. The record therefore does not establish how the listed interventions were compared or how order-related effects were handled.

Participant details are limited. Enrollment is listed as 30, but characteristics beyond the description of active men and women are not reported in the registry record. The numbers in each sex or other relevant subgroups, the definition of active, and the number contributing data to each outcome are not stated. Enrollment should not be mistaken for an endpoint analysis count.

Methods for measurement and analysis are also not described in detail. The endpoint definition and timeframe are given, but procedures for measuring intake and urine output, handling incomplete observations, and calculating uncertainty are not reported. The record lists four outcome measures and Bio Impedance as secondary, but does not report results or a multiplicity strategy. It records zero analyses, without clarifying whether analyses were conducted elsewhere. These limitations restrict conclusions about both the outcome and the reliability of any comparisons.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Buoy Electrolyte Study on Hydration Status of Active Men and Women — NCT05768789.
• Registry record last updated 2025-05-14; status last verified 2025-05.
• Results first posted 2025-05-14.
• 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

The registry record describes a completed study sponsored by the University of Pittsburgh, with enrollment of 30 and a study population described as active men and women. The listed start date is 2023-09-13, and the primary completion date is 2024-04-27. The interventions are Buoy Electrolyte, Water only, and Nuun Electrolyte; the design labels are single group, allocation NA, and no masking.

Net Fluid Balance, measured 360 minutes after ingestion, is the primary endpoint. It is defined as total fluid consumed minus cumulative urine output and is summarized as a mean with standard deviation. Bio Impedance is listed as a secondary outcome. The registry record does not report the primary outcome results, a statistical analysis, or detailed missing-data and analysis-population methods. Adverse-event entries record zero affected participants and zero deaths in each named group, with the limitations described in interpreting those counts.