Maintenance Intravenous Fluids in Children: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Maintenance Intravenous Fluids in Children (NCT00621348), a randomized phase 3 study. The primary outcome is Incidence of Hyponatremia (Defined as Serum Sodium Less Than 130 mmol/L).

2. Clinical Question

The three-group design makes the clinical question a comparison of different fluid compositions and volumes in hospitalized children receiving maintenance fluids. The registry describes the trial as phase 3 and completed. It does not report participant characteristics, eligibility details beyond the flow figures, or the clinical setting beyond hospitalization. Those omissions limit how specifically the findings can be related to particular groups of children or care contexts.

3. Trial Design

The registry describes a phase 3, randomized, parallel-group trial with no masking. The three assigned strategies were normal saline in 5% dextrose at standard maintenance rate; N/5 saline in 5% dextrose at 2/3 maintenance rate; and N/5 saline in 5% dextrose at standard maintenance rate. The registry records enrollment as 167 and status as completed. The start is recorded as 2006-09 and primary completion as 2008-04.

The primary outcome was the number of participants with serum sodium less than 130 mmol/L at 72 hrs. The registry says intention-to-treat analysis was used. It reports that 58 patients were randomized to Arm 1, 53 to arm 2 and 56 to arm 3. The primary outcome counts are 1, 2 and 8, respectively, in the posted group order of Dextrose Normal Saline, Fluid Restriction Group and Hypotonic Saline. These are event counts, not continuous sodium measurements.

The record lists three secondary outcomes: hypernatremia defined as serum sodium >150 mmol/L, symptomatic hyponatremia and symptomatic hypernatremia. It reports results for hypernatremia and symptomatic hyponatremia; a separate result for symptomatic hypernatremia is not reported in the registry record. The registry lists the All India Institute of Medical Sciences as sponsor.

Details of how the random sequence was generated, how allocation was concealed, whether outcome assessors were masked, and the trial’s original sample-size assumptions are not reported in the registry record. Nor are the reasons for choosing the study duration, any interim analyses, or protocol deviations described. The absence of masking is relevant because participants and care providers could know which fluid strategy was assigned; the record does not state whether that knowledge could influence outcome measurement or other care.

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: Patients were stratified based on their age in to three groups (age 3 months to 1 year, 1-5 years, 6-12 years) and stratified randomization was used.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 432 patients were eligible. 203 patients were excluded and 62 patients declined consent . Out of 167 patients, 58 patients were randomized to Arm 1, 53 to arm 2 and 56 to arm 3.Intention to treat analysis was used.

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 Incidence of Hyponatremia (Defined as Serum Sodium Less Than 130 mmol/L), measured over 72 hrs.

The primary endpoint is the number of participants whose serum sodium was less than 130 mmol/L at 72 hrs. It is a binary outcome: each participant either met the stated threshold or did not. The registry reports event counts by assigned group rather than individual sodium values, changes in sodium, or the timing of any event within the assessment period.

A threshold outcome turns a laboratory measurement into a clinically interpretable event definition. It allows the frequency of hyponatremia to be compared across fluid strategies, while retaining the same cutoff and assessment timeframe for the groups. The registry’s description links this endpoint to the trial’s stated concern about hyponatremia during maintenance fluid therapy. It also lists symptomatic hyponatremia separately as a secondary outcome, so the primary endpoint should not be treated as a measure of symptoms or severity.

As a general statistical point, a binary endpoint can be summarized by event counts and by the proportion of participants with an event. Comparisons between groups can then be expressed as an absolute risk difference or a relative measure. The posted counts do not show the full distribution of sodium values, how close measurements were to the threshold, or whether a participant’s sodium changed over time. Those details are not reported in the registry record.

The assessment timeframe is 72 hrs. The record does not provide further detail about the precise measurement schedule, the handling of measurements made outside that interval, or the laboratory procedures used. The endpoint therefore supports interpretation of events meeting the registry definition within the stated timeframe, not broader claims about longer-term electrolyte outcomes.

7. Results Posted in the Registry

• Fluid Restriction Group: 3.8% (2/53) versus 1.7% (1/58) on control; risk difference 2.0 percentage points (95% CI -4.1 to 8.2), risk ratio 2.19 (0.20–23.45); unadjusted two-proportion z-test p = 0.506.
• Hypotonic Saline: 14.3% (8/56) versus 1.7% (1/58) on control; risk difference 12.6 percentage points (95% CI 2.8 to 22.3), risk ratio 8.29 (1.07–64.12); unadjusted two-proportion z-test p = 0.013.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Incidence of Hypernatremia (Serum Sodium >150 mmol/L)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Fluid Restriction Group: 7.5% (4/53) versus 3.4% (2/58) on control; risk difference 4.1 percentage points (95% CI -4.4 to 12.6), risk ratio 2.19 (0.42–11.47); unadjusted two-proportion z-test p = 0.340.
  • Hypotonic Saline: 3.6% (2/56) versus 3.4% (2/58) on control; risk difference 0.1 percentage points (95% CI -6.6 to 6.9), risk ratio 1.04 (0.15–7.10); unadjusted two-proportion z-test p = 0.972.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Fluid Restriction Group and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Hypotonic Saline and the control. The interval gives the range of effects that remain compatible with the data.

Incidence of Symptomatic Hyponatremia

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Fluid Restriction Group: 1.9% (1/53) versus 0.0% (0/58) on control; risk difference 1.9 percentage points (95% CI -1.8 to 5.5); unadjusted two-proportion z-test p = 0.293.
  • Hypotonic Saline: 0.0% (0/56) versus 0.0% (0/58) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0); unadjusted two-proportion z-test p = n/a.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Fluid Restriction Group and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Hypotonic Saline and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes extend the trial’s focus beyond the primary hyponatremia threshold. The posted results include hypernatremia, defined as serum sodium >150 mmol/L, and symptomatic hyponatremia. Symptomatic hypernatremia is listed as a secondary outcome, but its result is not reported in the registry record. The overall pattern across the posted secondary outcomes is sparse event data, with few events in each group and no broad set of reported analyses.

These outcomes add context to the primary result because they concern other electrolyte events or the symptomatic form of hyponatremia. They do not duplicate the primary endpoint: symptomatic hyponatremia is distinct from the laboratory-threshold outcome, and hypernatremia uses a different threshold and direction of sodium abnormality. The secondary results therefore cannot be treated as a confirmation or disproof of the primary result. They are separate outcomes with their own event counts and uncertainty.

The registry does not report a multiplicity adjustment for secondary outcomes or comparisons. General statistical explanation: when many outcomes or comparisons are examined, the chance of finding at least one result that looks unusual by chance increases. An unadjusted secondary p-value does not account for that family of tests. Secondary outcomes can be informative, especially when prespecified and clinically relevant, but without the analysis plan and multiplicity approach their p-values carry less weight than a clearly specified primary analysis.

The record lists four outcome measures and one analysis, while only three secondary outcomes are identified in the outcome list. These registry counts do not explain which outcomes entered the reported sponsor analysis or whether all intended secondary results were posted. The protocol’s outcome hierarchy, timing of outcome selection, and planned multiplicity strategy are not reported. Accordingly, the secondary information is best read as descriptive context rather than as a separate basis for a definitive conclusion.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Incidence of Hypernatremia (Serum Sodium >150 mmol/L)
• Incidence of Symptomatic Hyponatremia
• Incidence of Symptomatic Hypernatremia

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary, and the registry posts the number of participants with the event in each group. A useful way to compare two groups is the risk difference: the event proportion in one group minus the event proportion in the reference group. This is an absolute contrast, expressed on the proportion scale. The recalculated risk differences for the primary endpoint compare each active strategy with Dextrose Normal Saline. They are simple, unadjusted recalculations from the posted counts, not a claim about the sponsor’s selected analysis.

What does an unadjusted comparison mean?

General statistical explanation: an unadjusted comparison uses the observed group summaries without accounting for other participant characteristics or covariates. It can be useful for describing the raw group contrast, especially when only summary counts are available. It cannot show whether the result changes after adjustment for prognostic factors, and it does not correct for differences that might arise by chance. The registry does not report an adjusted primary analysis in the posted analysis information.

The listed p-values for the recalculated contrasts are unadjusted. A p-value is calculated under a null hypothesis and a specified statistical model. In general, it indicates how unusual the observed data, or more extreme data, would be if that null model were true. It is not a measure of clinical importance, does not give the probability that the null hypothesis is true, and should not be read apart from the effect estimate and its interval. The primary recalculated p-values are 0.506 for the fluid-restriction comparison and 0.013 for the hypotonic-saline comparison.

Why use confidence intervals?

General statistical explanation: a confidence interval expresses uncertainty around an estimate under the method used to construct it. A narrower interval indicates greater precision in the estimate; a wider interval indicates that a broader range of values is compatible with the data and method. The primary pairwise intervals are especially important because event counts are sparse. Sparse binary outcomes often lead to imprecise estimates, and small changes in observed counts can materially change a comparison. An interval is not a guarantee that the true effect lies within its limits.

The registry also lists relative measures for the pairwise recalculations, including risk ratios and odds ratios. A risk ratio compares event proportions as a ratio; an odds ratio compares event odds. These relative measures can look large when the reference event proportion is low, and they can be unstable when counts are small. The risk difference keeps the comparison on an absolute scale. Neither scale is sufficient by itself for judging clinical relevance, and the registry’s reported sponsor analysis should not be conflated with these recalculated measures.

What is Fisher’s exact test?

General statistical explanation: Fisher’s exact test is a method for evaluating association in categorical count data. It is often used when event counts are small, because it does not rely on the same large-sample approximation used by some other tests. The registry identifies Fisher Exact as the sponsor’s method for the reported analysis. It does not provide additional detail about the test’s implementation, the exact contrast, or how the three groups entered the reported risk ratio.

The sponsor result is reported as a risk ratio of 0.12 with a 95% confidence interval from 0.016 to 0.93 and p <0.05. Because the registry record flags a discrepancy between the posted analysis and the simple recalculations, the sponsor’s own analysis takes precedence. The record’s label of non-inferiority or equivalence does not supply the margin or test details needed to interpret a formal non-inferiority or equivalence conclusion. Those details are not reported in the registry record.

Why can event counts matter for the method?

General statistical explanation: sparse data can make estimates sensitive to individual events and can produce wide intervals. Methods designed for small counts can be preferable to methods that depend heavily on large-sample approximations, but the choice of method does not remove uncertainty in the underlying data. For binary outcomes, the number of events and the number of participants at risk both shape precision. The posted primary counts are low, so the reported contrasts should be read with their uncertainty rather than as precise estimates.

The trial is described as randomized and parallel-group. Randomization is intended, in general, to create comparable groups on average, while a parallel design assigns each participant to one strategy for the trial comparison. The registry does not describe the random-sequence method, allocation concealment, or any stratification. No masking is reported. The registry states that intention-to-treat analysis was used, but does not explain how missing outcome measurements or departures from assigned treatment were handled.

All pairwise recalculations are unadjusted and use the Dextrose Normal Saline group as the reference. The record does not report adjustment for multiple comparisons. As a general matter, making several comparisons or testing several outcomes increases the opportunity for at least one apparently notable result by chance. This is why unadjusted p-values across outcomes should be treated as exploratory unless the analysis plan specifies otherwise. The original statistical plan, multiplicity strategy, and interim-analysis procedures are not reported in the registry record.

11. Confidence Intervals and Precision

The primary outcome estimates have different degrees of precision. For the recalculated comparison of Fluid Restriction Group with Dextrose Normal Saline, the risk difference is 0.021 and its confidence interval ranges from -0.041 to 0.082. The interval spans zero and includes both a negative and a positive risk difference. This means the posted summary data do not pin down the direction of that pairwise contrast with high precision.

For Hypotonic Saline compared with Dextrose Normal Saline, the recalculated risk difference is 0.126, with a confidence interval from 0.028 to 0.223. This interval is also broad, so the size of the difference remains uncertain even though the interval is entirely positive. The interval should be interpreted as uncertainty under the recalculation method, not as a range guaranteed to contain the true effect.

General statistical explanation: a confidence interval combines the estimate with information about sampling uncertainty. Wider intervals are common when event counts are limited, and small samples can leave substantial uncertainty even if the point estimate appears notable. Here, the primary event counts are 1, 2 and 8. The results therefore warrant attention to the interval limits and not only to the point estimates or p-values.

The sponsor’s 95% confidence interval for its reported risk ratio extends from 0.016 to 0.93. That interval is the one attached to the sponsor analysis in the registry. Because the registry does not specify the exact contrast or coding used for the risk ratio, it cannot be directly reconciled with the recalculated pairwise risk differences from the posted counts. The discrepancy makes the sponsor analysis the primary reported analysis for interpretation.

Precision is not the same as validity. A narrow interval would not address possible bias from outcome measurement or missing data; a wide interval does not prove there is no effect. The registry’s lack of detail on missing measurements, allocation concealment and the original analysis plan limits further assessment of how the reported precision should be understood.

12. 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 sample-size figures are planning illustrations based on the observed effect, not the trial’s original design calculations. The figures are participants per arm for 80% power and participants per arm for 90% power. The assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. The original design assumptions are not reported in the registry record.

The 80% power column gives the illustrative number of participants per arm for a future two-arm study to have an 80% chance of detecting the specified effect, if the planning assumptions hold and the effect is real. The 90% power column makes the corresponding illustration for a 90% chance. Higher target power generally requires more participants for the same assumed effect. These are planning quantities, not descriptions of the number enrolled in this trial.

Rows for planning for 100%, 75% and 50% of the observed effect show how the illustrative sample size changes when the effect to detect is made smaller. A smaller effect is harder to distinguish from random variation and therefore needs more participants under the stated assumptions. The figures are calculated separately for the listed pairwise comparisons and should not be read as a design for the three-group trial as a whole.

These calculations are not observed power. Observed power is not a useful substitute for the confidence interval or the uncertainty evident in the data; the planning figures instead illustrate the sample sizes that would be needed under specified assumptions. They also do not establish that the observed effect is a reliable estimate of the effect a future study would encounter. The posted effect is itself uncertain, particularly where event counts are sparse.

13. 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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.017; treatment proportion p₁ = 0.038; average p̄ = 0.027.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.2312 = 0.4532.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.2308 = 0.1942.
4. n = (0.4532 + 0.1942)² / (0.0205)² = 997.9, rounded up to 998 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
p0 <- 0.0172413793103448                          # control proportion
p1 <- 0.0377358490566038                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(621348)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 998 (80% power), 1,336 (90% power)
 75% of observed effect: n per arm = 1,614 (80% power), 2,160 (90% power)
 50% of observed effect: n per arm = 3,268 (80% power), 4,374 (90% power)
power.prop.test: 997.9 
Simulated power at n = 998 per arm: 0.815 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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.

14. Analyses Reported by the Sponsor

The registry reports a sponsor analysis using Fisher Exact, with a risk ratio of 0.12, a 95% confidence interval from 0.016 to 0.93, and p <0.05. The analysis is labeled non-inferiority or equivalence, and the groups listed are Dextrose Normal Saline, Fluid Restriction Group and Hypotonic Saline. The record does not state the exact contrast represented by the risk ratio, its coding direction, or the non-inferiority or equivalence margin.

The simple recalculations compare each non-reference group with Dextrose Normal Saline using unadjusted risk differences. Their estimates and p-values do not reproduce the sponsor’s reported result. The registry explicitly flags a discrepancy. Accordingly, the sponsor’s own analysis takes precedence over the recalculations when describing the trial’s reported analysis. The recalculations remain useful as transparent descriptions of pairwise contrasts from the posted summary counts, but they should not be framed as corrections to or replacements for the sponsor’s method.

The reported sponsor result cannot be interpreted fully without knowing which comparison it represents and how the non-inferiority or equivalence analysis was specified. The margin, direction of the test, handling of the three groups, and details of the analysis population are not reported in the registry record. A confidence interval and p-value alone cannot supply those missing design details. The registry says intention-to-treat analysis was used for the primary outcome, but does not give further information about how that statement relates to the sponsor-reported test.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary outcome and three secondary outcomes, but does not report how multiplicity was handled. It also does not describe whether the primary outcome was the only confirmatory test, whether secondary outcomes were prespecified in a hierarchy, or whether any adjustment was planned for multiple comparisons. The record lists one reported analysis, but this does not establish the full statistical plan or the number of analyses conducted. Details of interim analyses are not reported in the registry record.

General statistical explanation: multiplicity arises when researchers perform multiple tests or examine multiple outcomes. Even if each test uses the same significance threshold, the probability of at least one nominally significant result can increase across a collection of tests. Adjustment procedures, hierarchical testing, or a clearly defined primary outcome can help manage this issue. Without the trial’s plan, the unadjusted p-values for pairwise recalculations and secondary outcomes should not be treated as if they were adjusted for all possible comparisons.

The registry states that intention-to-treat analysis was used for the primary outcome. This identifies the stated analysis population in broad terms, but the record does not explain the handling of missing outcome measurements, participants who did not follow their assigned strategy, or any post-randomization exclusions. The amount and pattern of missing primary outcome data are not reported in the registry record. It is therefore not possible to assess whether the analysis retained every randomized participant for whom an outcome could not be observed.

The eligibility flow says 432 patients were eligible, 203 were excluded and 62 declined consent, followed by 167 randomized patients. Reasons for exclusion and consent refusal are not reported. The record does not state whether the randomized groups differed from eligible patients who did not enter the trial. Such information would help readers assess the population to which the findings may apply, but it cannot be inferred from the flow figures alone.

Other details relevant to interpreting the analysis are also absent: the random-sequence method, allocation concealment, protocol deviations, and the original sample-size justification. The registry’s non-inferiority or equivalence label is not accompanied by a margin or sufficient contrast details. These gaps do not erase the posted counts, but they limit the ability to evaluate the full analysis strategy and its robustness.

16. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death or symptomatic hyponatremia (1.9%).

The adverse-event record lists serious events for each group, with 1 serious event among 58 at risk in Dextrose Normal Saline, 1 among 53 at risk in the Fluid Restriction Group, and 0 among 56 at risk in Hypotonic Saline. The registry also lists Death or symptomatic hyponatremia as a serious adverse-event term at 1.9%. The record does not clarify how that term relates to the group-level serious-event counts.

Other adverse events are listed as 2 among 58 at risk in Dextrose Normal Saline, 4 among 53 at risk in the Fluid Restriction Group, and 2 among 56 at risk in Hypotonic Saline. These are descriptive registry figures, not adjusted comparisons. The numbers alone do not establish whether an event was caused by an assigned fluid strategy or whether groups differ reliably in safety.

Deaths are not reported in the registry record. Definitions, event descriptions beyond the listed serious term, follow-up procedures, and the method for attributing events to treatment are not reported. Sparse adverse-event counts provide limited precision, so the absence of a listed event in a group should not be read as proof that the event cannot occur. Safety findings should be interpreted alongside the registry’s limited detail and not as medical advice.

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

The posted primary counts show that hyponatremia, as defined by serum sodium less than 130 mmol/L at 72 hrs, was recorded in all three groups, with counts of 1, 2 and 8 in the posted group order. The unadjusted recalculations show a positive risk-difference estimate for each comparison with Dextrose Normal Saline, but the degree of precision differs. The fluid-restriction comparison has an interval that includes zero; the hypotonic-saline comparison has an interval entirely above zero. Those estimates describe the posted summaries and do not replace the sponsor’s reported analysis.

The sponsor’s reported risk ratio and its 95% confidence interval are the registry’s own analysis, and the record flags a discrepancy with the recalculations. The sponsor result takes precedence, but its contrast and non-inferiority or equivalence details are not sufficiently described to draw a complete interpretation from the registry entry alone. The record does not report a margin or explain how the three groups were incorporated into that analysis.

The findings do not establish what would happen in other populations, settings, or treatment protocols. Participant characteristics and important aspects of trial conduct are not reported. The primary endpoint is a laboratory threshold measured within 72 hrs, not a complete assessment of clinical course, longer-term electrolyte status, or symptom burden. Symptomatic hyponatremia appears as a separate secondary outcome, and its observed event count is limited.

General statistical explanation: randomization can support causal comparisons when the trial is conducted and analyzed as planned, but interpretation also depends on outcome ascertainment, missing data, adherence, and analysis choices. The registry record does not provide enough detail to assess all of these features. A statistically notable estimate is not the same as proof of a clinically important effect, while an imprecise or non-significant comparison does not establish equivalence.

The results should therefore be read as a report of observed events and analyses in this trial, with meaningful uncertainty and incomplete reporting. They do not constitute medical advice and do not establish that one fluid strategy works or does not work. Broader conclusions require the full analysis context, including the sponsor’s intended contrast and the details not reported in the registry record.

18. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation needs more than a comparison of event counts. The primary endpoint is binary and the posted event counts are sparse. A few events can have a substantial influence on the estimated difference, while confidence intervals convey that the size of the contrast may remain uncertain. Reading estimates together with their intervals is more informative than relying on a single p-value.

It also illustrates the importance of distinguishing the sponsor’s analysis from a simple recalculation. The registry reports a Fisher Exact analysis and labels it non-inferiority or equivalence, while the recalculations are unadjusted pairwise risk differences. Those are not interchangeable analyses. Because the record flags a discrepancy, the sponsor’s own analysis takes precedence; because its contrast and margin are not stated, the analysis also illustrates why transparent reporting of estimands and methods matters.

The three-group design raises interpretive questions about comparisons and multiplicity. The registry provides pairwise summaries for the recalculations but does not report a multiplicity strategy or the full statistical plan. Likewise, the secondary outcomes add clinically related information without resolving the uncertainty of the primary comparison. Separating primary and secondary evidence helps avoid treating every reported result as equally confirmatory.

Finally, the planning illustrations show how assumed effect size and target power affect future sample-size requirements. They are not evidence that the trial had adequate or inadequate power, and they are not observed power. The trial’s original sample-size assumptions are not reported. Overall, this record is a useful example of how endpoint definition, sparse events, analysis discrepancies, and incomplete methods reporting shape the strength and scope of statistical conclusions.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several trial-specific limitations affect interpretation. The registry reports no masking, and it does not say whether outcome assessors were masked. The primary outcome is based on a serum sodium threshold, but the measurement schedule and laboratory procedures are not described. These omissions leave uncertainty about how consistently the outcome was assessed across groups.

The sponsor analysis is not fully specified. Although the registry gives a Fisher Exact method, a risk ratio, a confidence interval and a p-value, it does not identify the exact contrast or provide the non-inferiority or equivalence margin. The discrepancy flag means the recalculated comparisons cannot be treated as a substitute for the sponsor result. The record also does not report the original sample-size justification or analysis plan.

The event counts for the primary and secondary outcomes are sparse, making estimates potentially sensitive to individual events. The confidence intervals for the recalculated primary comparisons show differing degrees of uncertainty. The registry does not report adjustment for multiple comparisons, and the handling of missing outcome data is not described. Although intention-to-treat analysis is stated, operational details are absent.

Participant characteristics, reasons for exclusion, and reasons for declining consent are not reported. The record therefore provides limited information about the enrolled population and how it compares with the eligible patients who did not participate. It also does not describe allocation concealment, adherence, protocol deviations, or interim analyses. These limits should be kept in view when considering whether the observed results apply beyond the trial population and period.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Maintenance Intravenous Fluids in Children — NCT00621348.
• Registry record last updated 2011-08-10; status last verified 2011-08.
• Results first posted 2011-08-05.
• 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.

23. Record Summary

The registry describes a completed phase 3 randomized, unmasked, parallel-group trial of three intravenous maintenance-fluid strategies in hospitalized children. The primary endpoint was the number of participants with serum sodium less than 130 mmol/L at 72 hrs. The posted counts were 1 in Dextrose Normal Saline, 2 in Fluid Restriction Group and 8 in Hypotonic Saline.

The sponsor reported a Fisher Exact analysis with a risk ratio of 0.12, a 95% confidence interval from 0.016 to 0.93, and p <0.05. The registry flags a discrepancy with unadjusted recalculations, so the sponsor’s analysis takes precedence. The exact contrast and non-inferiority or equivalence margin are not reported in the registry record. Sparse events, uncertain precision, and missing methodological details limit the conclusions that can be drawn from the posted results.