A Clinical Trial Using a New Medical Device to Evaluate Its Impact on IV Care and Clinical Complications: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Clinical Trial Using a New Medical Device to Evaluate Its Impact on IV Care and Clinical Complications (NCT04469218), a randomized na study. The primary outcome is Delay in Therapy.

2. Clinical Question

The trial’s stated aim was to assess the device’s impact on IV care and clinical complications. The primary endpoint focused on delay in therapy, while a secondary outcome was to estimate the impact on other peripheral IV complications. The primary comparison therefore describes a continuous measure of therapy delay rather than a count of restarts or a time-to-event outcome.

The registry describes random assignment to the two groups. In the device group, SafeBreak Vascular was placed in the peripheral IV line; the control group received the study hospital’s standard care for peripheral IVs. The group descriptions say treatment was intended to be as near to identical as possible apart from the device. The registry record does not report further detail about how the device might affect therapy delays or how delays were defined or recorded.

For the primary endpoint, the posted results give group means and standard deviations, along with an unadjusted comparison. These summaries address the difference in average delay between the assigned groups. They do not by themselves describe every patient’s experience, the distribution of delays, or the causes of individual delays.

3. Trial Design

This was a randomized, parallel-group device trial. Participants were assigned to standard peripheral IV care or to care with SafeBreak Vascular attached to the peripheral IV line. The registry lists masking as none, so the trial was not masked according to the record. The registry status is completed, and the listed enrollment is 148.

The control group received standard peripheral IV care at the study hospital. The SafeBreak Vascular group was intended to receive treatment as near to identical as possible, except that the device was placed in the peripheral IV line. The sponsor was Lineus Medical. The registry lists the study start date as 2020-07-14 and the primary completion date as 2020-12-31.

The primary endpoint was delay in therapy, expressed as a mean in minutes per 24 hours with standard deviation. The endpoint description says patients were evaluated at every IV check from enrollment until IV therapy discontinuation or up to 7 days, whichever came first. The endpoint population is described as all patients in the Per Protocol population. The registry record does not define the Per Protocol population or explain how patients were assigned to it.

The registry lists two outcome measures and one secondary outcome: estimating the impact on other peripheral IV complications. Results are posted for the primary endpoint, but no analysis records are listed. The registry record does not report the randomization procedure, allocation concealment, the original sample-size rationale, or additional operational details. The study’s phase is listed as NA.

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

Analysis population for the primary outcome, as defined in the registry: All patients in Per Protocol population

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 Delay in Therapy, measured over Patients evaluated at every IV check from time of enrollment to time of discontinuation of IV therapy or up to 7 days, whichever occurs first.

The primary endpoint, Delay in Therapy, is a continuous measure expressed as mean minutes of delay per 24 hours. A continuous endpoint can take a range of values rather than being limited to categories such as whether a complication occurred. The registry reports the group mean and standard deviation, which describe the average delay and the spread of individual measurements around that average.

Delay in therapy was selected as the direct primary measure for the trial’s stated comparison of IV care. A difference in group means summarizes how average delay differed between participants assigned to the device group and those assigned to standard care. It does not indicate whether every participant had a delay, how many had especially large delays, or what caused a delay.

The registry states that measurements were made at each IV check from enrollment until discontinuation of IV therapy or up to 7 days, whichever occurred first. The listed unit, minutes per 24 hours, expresses delay relative to a 24-hour period. The record does not provide additional detail on the operational definition of a delay, the method used to combine repeated checks for each patient, or the handling of incomplete observations.

The primary endpoint population is identified as the Per Protocol population, rather than all randomized participants. The record does not specify the criteria for that population. This distinction matters because an endpoint summary in a defined analysis population describes that population, and should not automatically be read as a summary of every person randomized.

7. Results Posted in the Registry

• SafeBreak Vascular Group: mean 10.89 versus 11.73 on control; difference -0.84 (95% CI -13.83 to 12.15), standardized effect d = -0.02; z-test p = 0.899.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean summarize?

For a continuous endpoint, the mean is the arithmetic average of the recorded values in a group. Here the endpoint is delay in therapy, expressed in minutes per 24 hours. The group means, 11.73 for control and 10.89 for SafeBreak Vascular, provide a concise comparison of average delay. A mean does not show whether values were clustered near the average or spread across a wide range.

The standard deviation describes that spread across measurements. The posted standard deviations are 36.56 in control and 41.45 in the device group. A larger standard deviation indicates more variation around the group mean; it is not an uncertainty interval for the mean. The relatively large spread compared with the mean difference is relevant because it helps explain why an average contrast can be estimated with limited precision.

What does the mean difference represent?

The posted mean difference is -0.84 minutes per 24 hours for SafeBreak Vascular versus control. This is an unadjusted comparison of group means, based on the posted summary statistics. A negative value means the device-group mean is lower than the control-group mean for the stated direction of comparison. The estimate is an average contrast, not a statement that each participant in the device group had less delay.

An unadjusted comparison does not account for covariates or other model-based adjustments. The registry record does not report an adjusted analysis or the sponsor’s statistical analysis plan. The posted comparison should therefore be understood as the simple group-level estimate described by the arm summaries, not as an adjusted causal estimate beyond the randomized group comparison.

How should the p-value be read?

The unadjusted p-value is 0.899. In general, a p-value describes how surprising data at least as inconsistent with a specified null model would be if that model and the test assumptions were correct. It is not the probability that the null model is true, nor does it measure the size or clinical importance of a difference. The registry does not state a p-value threshold for the trial’s own primary analysis, so the p-value is best read alongside the estimate and its interval.

A large p-value does not establish that two groups are identical. It can reflect an estimate near zero, substantial variability, limited precision, or a combination of these. To establish equivalence, a trial would generally need an appropriate design and a prespecified equivalence margin. Such a margin is not reported in the registry record.

What does an interval add?

The interval for the mean difference runs from -13.83 to 12.15 minutes per 24 hours. A confidence interval is a range of values produced by a statistical procedure to represent uncertainty about an estimate. It conveys more about precision and plausible effect sizes than a point estimate alone. The interval spans both negative and positive values, which means its range includes differences in either direction. The record does not specify the confidence level used for this interval.

Intervals depend on the data and the method used to calculate them. General statistical interpretation treats a confidence interval as a measure of the method’s repeated-sampling performance, not as a guarantee that a particular interval contains the true value. The interval also does not address sources of bias, missing data, or limitations in outcome measurement.

Why can over-dispersion matter?

For a continuous endpoint, substantial spread around the mean can reduce precision in estimating the difference between group averages. In general, greater variability makes a mean difference harder to distinguish from random variation unless supported by more information. Here the posted standard deviations are much larger than the point estimate of the mean difference. This context is important when interpreting the broad interval and the p-value.

Over-dispersion is often discussed for count outcomes when variability exceeds what a simple count model expects. The primary endpoint is continuous, not a count, so the relevant general concern is the broad variability of the measured delays rather than a count-model assumption. The record does not provide enough distributional detail to assess skewness, outliers, or alternative modeling approaches.

Which analyses are documented?

The registry identifies the primary endpoint population as all patients in the Per Protocol population. It does not define that population or explain exclusions, adherence criteria, or how incomplete measurements were handled. The posted outcome gives group summaries and an unadjusted comparison, while the record lists no analysis entries. No sponsor-specific modeling details, interim analyses, or multiplicity procedures are reported in the registry record.

Random assignment can support a fair comparison when the design and analysis preserve the assigned groups and when outcome data are handled appropriately. The posted primary analysis population is Per Protocol, however, and the registry does not state how that population relates to all randomized participants. This limits assessment of the analysis strategy. These omissions do not change the posted numerical result, but they matter when judging its scope and robustness.

10. Confidence Intervals and Precision

The mean difference estimate is -0.84 minutes per 24 hours, with an interval from -13.83 to 12.15. The interval is wide relative to the point estimate and includes zero. Its endpoints permit interpretations ranging from a lower average delay in the SafeBreak Vascular group to a higher average delay in that group. The estimate therefore has limited precision for determining either the direction or size of the group difference.

Precision is distinct from whether an estimate is statistically distinguishable from zero. An interval that includes zero does not prove there is no difference; it indicates that the data and method do not isolate a difference from zero within the interval’s range. The record does not state the confidence level for the interval, so no confidence percentage should be attached to it based on the registry record alone.

The variability in the endpoint is also relevant. Standard deviations were 36.56 in control and 41.45 in the device group, compared with a mean difference of -0.84. This signals substantial spread in the observed endpoint relative to the average contrast. The registry does not provide distributional detail to assess whether the means are affected by skew or extreme observations.

The interval captures sampling uncertainty under its calculation method, but does not quantify all uncertainty. It cannot account for possible measurement issues, missing observations, choices about the Per Protocol population, or unreported analysis decisions. The registry record does not describe those details, and the posted result should be interpreted as an estimate with a broad range rather than a precise determination of the group contrast.

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 illustrations based on the observed effect, not the trial’s original design assumptions. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each planning row considers an effect equal to 100%, 75%, or 50% of the observed effect. The registry record does not report the trial’s original sample-size justification or its own design assumptions.

The entries are participants per arm for 80% power and participants per arm for 90% power. For example, planning for 100% of the observed effect gives 34,011 participants per arm for 80% power and 45,531 participants per arm for 90% power. Planning for 75% of the observed effect gives 60,464 participants per arm for 80% power and 80,944 participants per arm for 90% power. Planning for 50% of the observed effect gives 136,044 participants per arm for 80% power and 182,124 participants per arm for 90% power.

In general, power is the chance that a study would meet its stated statistical criterion if a particular effect were truly present and the planning assumptions held. The 80% and 90% columns illustrate different target chances of detecting the specified effect; the higher target requires more participants under the same assumptions. Smaller effects are harder to distinguish from random variation, so the rows targeting smaller fractions of the observed effect require more participants per arm.

These figures are planning illustrations, not observed power. They should not be read as evidence that the completed trial had a particular probability of detecting an effect or as a retrospective judgment of its success.

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 = -0.840; pooled standard deviation σ = 39.099.
2. n = 2 × (1.96 + 0.842)² × 39.099² / -0.840² = 34,010.9, rounded up to 34,011 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 <- -0.84                      # observed difference in means
sigma <- 39.0993640902608                     # 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(4469218)
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 = 34,011 (80% power), 45,531 (90% power)
 75% of observed effect: n per arm = 60,464 (80% power), 80,944 (90% power)
 50% of observed effect: n per arm = 136,044 (80% power), 182,124 (90% power)
power.t.test: 34011.9 
Simulated power at n = 34,011 per arm: 0.799 (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 two outcome measures, with Delay in Therapy as the primary endpoint and an outcome concerning other peripheral IV complications as secondary. A trial that evaluates multiple outcomes or makes multiple comparisons can raise a multiplicity issue: the more opportunities there are to identify a result, the more important it is to know which analyses were planned and how interpretation was controlled.

The registry record does not report a multiplicity adjustment, a hierarchy of testing, or a statistical analysis plan. It does not explain how the secondary outcome would be analyzed, and it does not post an estimate for that outcome. The presence of one listed secondary outcome does not establish what other analyses may have been contemplated; those details are not reported in the registry record.

The primary endpoint result is presented for the Per Protocol population. The record does not explain how that population was defined, whether any randomized participants were excluded, or how the group summaries relate to an intention-to-treat analysis. It also does not report how missing endpoint measurements were handled, whether observations were available at every IV check, or how repeated checks contributed to the participant-level mean.

These omissions affect assessment of analysis choices and completeness, not the arithmetic description of the posted result. Without the population criteria and missing-data methods, readers cannot fully assess whether the endpoint summaries represent all randomized participants or how sensitive the estimate might be to analytic decisions. The record also does not report interim analyses or stopping rules. No inference about such procedures can be made from the posted result 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: chest pain (2.9%), unwitnessed fall (1.4%).

The registry lists serious adverse events among 69 participants at risk in the control group and 70 at risk in the SafeBreak Vascular group. Serious events affected 2 in each group. The registry also lists 0 deaths in each group. These are reported counts, not a comparison adjusted for exposure time or other factors.

The record lists other adverse events affecting 33 participants in control and 26 in the SafeBreak Vascular group, with the corresponding at-risk group counts listed as 69 and 70. The registry’s listed top serious-event terms are Chest Pain at 2.9% and Unwitnessed Fall at 1.4%. The record does not specify in the listed terms which group each percentage refers to, so they should not be assigned to an arm.

Adverse-event counts describe events recorded during the trial; they do not by themselves establish that the device caused or prevented an event. The registry record does not provide event timing, exposure-adjusted rates, severity details beyond the serious classification, or an analysis comparing safety outcomes. These figures should therefore be read as descriptive safety reporting, not as a definitive estimate of comparative risk.

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

The posted primary result estimates the difference in mean delay in therapy between the SafeBreak Vascular group and the control group in the Per Protocol population. The group means were 10.89 and 11.73 minutes per 24 hours, respectively, and the unadjusted mean difference was -0.84 minutes per 24 hours. The interval from -13.83 to 12.15 is broad and includes differences in either direction. The result is consequently uncertain about the magnitude and direction of the average contrast.

This result does not establish that the groups are equivalent, nor does it show that every participant experienced a similar delay. The endpoint summarizes an average, and the standard deviations indicate substantial variability. A group mean can conceal different patterns among individual patients, including differences in how frequently delays occur or how large they are. The registry does not post those distributions.

The findings are limited to the stated endpoint, its measurement period, and the Per Protocol population. They do not directly answer the secondary question about other peripheral IV complications because a secondary result estimate is not posted. The serious and other adverse-event counts are descriptive; they do not establish a causal relationship with the device.

The result should also be separated from the planning illustrations. Those calculations use fractions of the observed effect and specified planning assumptions; they are not the trial’s original design rationale and do not provide observed power. The registry record does not report the original sample-size justification, detailed analysis plan, missing-data approach, or definition of the Per Protocol population. These gaps limit how completely the statistical analysis can be evaluated, without changing what the posted endpoint summaries say.

16. Why This Trial Matters Statistically

This trial illustrates why interpreting a mean difference requires more than looking at which group’s mean is numerically lower. The estimate of -0.84 minutes per 24 hours is close to zero, while the interval extends from -13.83 to 12.15. The interval therefore communicates that the available estimate is compatible with differences in either direction, rather than precisely locating the group contrast.

The spread of the endpoint is also central to the interpretation. The standard deviations, 36.56 in control and 41.45 in the device group, are large compared with the mean difference. This is a practical example of how variability can make an average difference difficult to estimate precisely. Reporting the standard deviations alongside the means and interval helps readers see that the point estimate is not a complete description of the data.

The record also demonstrates the importance of the analysis population. The primary endpoint is specified for the Per Protocol population, but its criteria are not described. Knowing who contributed data is essential for understanding what a result represents. The registry’s lack of detail on missing observations and repeated-check aggregation further limits assessment of how the endpoint summaries were constructed.

Finally, the planning illustrations distinguish design planning from interpretation of a completed trial. They show how assumed effect size and target power affect participant requirements under stated assumptions; they do not establish the original design rationale or retroactively measure power. Together, the endpoint estimate, its precision, and the missing methodological details are all needed for a careful statistical reading.

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 identifies the primary endpoint population as Per Protocol but does not define its membership or inclusion criteria. The posted arm summaries therefore cannot be assumed to describe every randomized participant. Although the record lists enrollment as 148 and gives endpoint group counts of 69 and 70, it does not explain the relationship between the enrollment figure, randomization, and the Per Protocol analysis population.

The measurement description says assessments occurred at every IV check from enrollment until discontinuation of IV therapy or up to 7 days, whichever came first. The registry does not explain how repeated checks were combined into a participant-level value, how delayed therapy was operationally defined, or how incomplete sequences of checks were handled. Those details could matter for interpreting the mean minutes per 24 hours.

The endpoint has considerable observed variability relative to the estimated mean difference, and the registry does not post distributions, medians, or other summaries that would help assess skew or influential observations. The interval is wide and includes values on both sides of zero, limiting precision about direction and magnitude.

The record lists no analysis entries and does not describe an analysis plan, multiplicity handling, missing-data methods, interim analyses, or the original sample-size rationale. No secondary result estimate is posted despite the listed secondary outcome. These limitations concern the completeness of the registry record and the interpretability of the posted results; they do not establish that a particular unreported procedure was or was not used.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: A Clinical Trial Using a New Medical Device to Evaluate Its Impact on IV Care and Clinical Complications — NCT04469218.
• Registry record last updated 2024-01-16; status last verified 2023-12.
• Results first posted 2024-01-16.
• 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

NCT04469218, titled “A Clinical Trial Using a New Medical Device to Evaluate Its Impact on IV Care and Clinical Complications,” is the randomized, parallel-group DIPPER trial sponsored by Lineus Medical. The registry lists the study as completed, with enrollment of 148, and no masking. Participants were assigned to standard peripheral IV care or to care with SafeBreak Vascular attached to the line.

The primary endpoint was mean delay in therapy in minutes per 24 hours, assessed at IV checks from enrollment until therapy discontinuation or up to 7 days. In the Per Protocol population, the posted means were 11.73 for control and 10.89 for SafeBreak Vascular. The unadjusted mean difference was -0.84, with an interval from -13.83 to 12.15 and p = 0.899.

The registry lists one secondary outcome concerning other peripheral IV complications but does not post its result estimate. It also does not report the original sample-size justification, detailed analysis plan, Per Protocol criteria, or missing-data methods.