Probability Ramp Control of Propofol for EGD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Probability Ramp Control of Propofol for EGD (NCT01838304), a randomized na study. The primary outcome is Number of Participants Requiring Adjustment in Propofol Dosing.

2. Clinical Question

The study focuses on the dosing process rather than a patient-centered clinical outcome. Its primary endpoint counts participants requiring an adjustment after the initial infusion rate was determined. The registry describes the procedure as brief, with a timeframe averaging 9 minutes. The rationale is that a need for repeated rate changes may indicate that an anesthesia provider must be immediately available to make them. The endpoint therefore addresses whether the software-guided approach and provider-managed approach differ in the frequency of dosing adjustments during EGD.

The registry reports 16 participants in the Monitoring arm and 2 in the PRC arm as requiring adjustment. The corresponding arm summaries list 19 and 20 participants, respectively. The comparison estimates a risk difference of 0.742 for Monitoring relative to PRC, with a confidence interval from 0.532 to 0.952 and an unadjusted p < 0.001. These results describe the endpoint as recorded; they do not by themselves establish how sedation quality, patient experience, or other clinical outcomes compare.

3. Trial Design

This was a prospective, randomized, parallel-group comparison of probability ramp control and provider-managed monitoring during EGD. The registry lists the allocation as randomized, the model as parallel, and masking as none. The study was completed, with enrollment of 40 participants. The listed study dates are 2013-03 for the start and 2013-05 for primary completion. The registry identifies the University of Pennsylvania as sponsor and lists the phase as not applicable.

The experimental arm used PRC software to titrate propofol to deep sedation. In the Monitoring arm, sedation was delivered as standard care by a CRNA, with drug dosing recorded manually. These descriptions identify the comparison as a software-guided dosing approach versus provider-managed dosing and monitoring. Because masking is listed as none, the record does not describe the study as blinded. Additional details about how randomization was generated or concealed are not reported in the registry record.

The primary endpoint was the number of participants requiring an adjustment in propofol dosing during the intraprocedure period, described as an average of 9 minutes. The primary arm summaries list 16 events among 19 participants in Monitoring and 2 among 20 participants in PRC. The registry reports a total enrollment of 40; details about the analysis population and the reason the listed arm counts differ from that total are not reported in the registry record.

The registry names three secondary outcomes: decrease in minute ventilation from baseline, time spent below a saturation of 80%, and procedure time. Numerical arm results and a comparison are posted for procedure time. Numerical results for the other named secondary outcomes are not reported in the registry record. Details of the trial's original sample-size justification, planned statistical methods, interim analyses, and missing-data procedures 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

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 Number of Participants Requiring Adjustment in Propofol Dosing, measured over Intraprocedure (average of 9 minutes).

The primary endpoint counts participants who required an adjustment to the propofol infusion rate after initial sedation. The registry describes the rate as initially determined by the CRNA in the Monitoring arm or by software in the PRC arm. The endpoint is assessed intraprocedure, over a timeframe described as an average of 9 minutes.

This measure is used to assess the frequency of dosing changes needed during the procedure. The registry's stated rationale is operational: when the initial rate is appropriate for the duration of the procedure, no adjustment is required; a greater need for changes suggests that an anesthesia provider needs to be immediately available to make them. In this sense, the endpoint captures a feature of titration and provider involvement rather than directly measuring sedation depth, patient comfort, or a clinical complication.

The registry reports that 16 participants in Monitoring and 2 in PRC required an adjustment. The posted comparative estimate is a risk difference of 0.742, with a confidence interval from 0.532 to 0.952 and an unadjusted p < 0.001. The endpoint is a count of participants with an event, not a count of the total number of dose changes. The record does not report how many changes each participant needed or a separate measure of the appropriateness of the initial rate.

7. Results Posted in the Registry

• Monitoring: 84.2% (16/19) versus 10.0% (2/20) on control; risk difference 74.2 percentage points (95% CI 53.2 to 95.2), risk ratio 8.42 (2.23–31.81); unadjusted two-proportion z-test p = <0.001.

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.

Procedure Time

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Monitoring: mean 9.03 versus 8.90 on control; difference 0.13 (95% CI -2.52 to 2.78), standardized effect d = 0.03; z-test p = 0.923.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Monitoring and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes named in the registry cover respiratory measures and procedure duration: decrease in minute ventilation from baseline, time spent below a saturation of 80%, and procedure time. Numerical results are posted for procedure time, but numerical results for minute ventilation and time below the stated saturation threshold are not reported in the registry record.

The procedure-time estimate is close to zero on the mean-difference scale, with a confidence interval that includes differences in either direction and an unadjusted p-value of 0.923. It does not provide clear evidence of an average procedure-time difference. The registry does not provide enough numerical information to characterize the overall direction or magnitude of the other named secondary outcomes. As a result, the secondary findings cannot establish whether the primary pattern was accompanied by differences in respiratory measures.

These secondary outcomes address different aspects of the procedure from the primary endpoint. Dose adjustment is a measure of the dosing process, whereas procedure time and respiratory measures describe other features of the procedure. Agreement across distinct outcomes could add context, but it should not be assumed when results are unavailable. The posted procedure-time result does not directly confirm or refute the primary finding about dose adjustments.

Unadjusted secondary results generally carry less evidential weight when several outcomes are examined. General statistical explanation: testing multiple outcomes increases the chance that at least one result appears noteworthy by chance. A prespecified multiplicity strategy can address that issue, but one is not reported in the registry record. The secondary p-value should therefore be interpreted as unadjusted, and the absence of posted numerical results for two named outcomes further limits an overall account of secondary evidence. The registry does not report whether these outcomes were prespecified in the analysis plan or how missing measurements were handled.

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

• Decrease in Minute Ventilation From Baseline
• Time Spent Below a Saturation of 80%
• Procedure Time

9. Statistical Interpretation

10. Statistical Methods Explained

What does the primary comparison estimate?

The primary endpoint is binary at the participant level: a participant either required an adjustment in propofol dosing or did not. A risk difference expresses the difference between the event probabilities in two groups. Its value of 0.742 is reported for Monitoring relative to PRC, with a confidence interval from 0.532 to 0.952. A positive value means the estimated event probability is higher in Monitoring. The interpretation is tied to this endpoint and to the arm direction used in the registry's comparison.

The relative risk compares event probabilities as a ratio, while the odds ratio compares the odds of an event. The registry reports a relative risk of 8.421, with a confidence interval from 2.229 to 31.81, and an odds ratio of 48.0, with a confidence interval from 7.096 to 324.7. These are different scales for expressing the contrast; they do not represent different endpoints. When event frequencies are quite different, the odds ratio can be farther from the null value than the relative risk. The risk difference remains useful because it expresses the absolute contrast on the probability scale.

What does the p-value tell the reader?

The primary unadjusted p-value is p < 0.001. A p-value measures how incompatible the observed data are with a specified null model, assuming that model and the test's conditions apply. It is not the chance that the result is due to random error, and it does not measure effect size. The registry does not report an adjusted p-value or a detailed description of the test used, so additional aspects of the inferential procedure are not reported in the registry record.

How should the procedure-time comparison be read?

Procedure time is a continuous outcome reported as a mean and standard deviation in each arm. Monitoring has a mean of 9.03 minutes and standard deviation of 3.75; PRC has a mean of 8.9 minutes and standard deviation of 4.75. The estimated mean difference is 0.13 minutes, with a confidence interval from -2.522 to 2.782 and an unadjusted p-value of 0.923. A mean difference describes the difference between group averages, while the standard deviations describe variation among individual procedure times within each arm. They are not confidence intervals for the means.

The confidence interval for the mean difference includes zero. That means the posted estimate is compatible with no average difference as well as with differences in either direction within the interval. The result should not be converted into a claim of equivalence: an equivalence conclusion requires a prespecified margin and a suitable analysis, neither of which is reported in the registry record.

Why can over-dispersion matter?

General statistical explanation: for count outcomes, a simple model may assume that variability follows a particular relationship to the mean. Over-dispersion occurs when actual variability is greater than that assumption allows. If it is ignored, standard errors may be too small and confidence intervals or p-values may give an overly certain impression. The primary endpoint is posted as a count of participants with an event, a binary outcome, rather than a count of repeated adjustments. The record does not describe a model for over-dispersion, and no such adjustment should be inferred.

What does randomization contribute?

General statistical explanation: random allocation aims to make treatment groups comparable, on average, with respect to both measured and unmeasured characteristics. In a small trial, chance differences between groups can still occur. Randomization does not remove the need to consider the endpoint definition, follow-up, missing data, or analysis choices. The registry identifies the study as randomized, but the method for generating or concealing the sequence is not reported in the registry record.

The registry lists no masking. This means the record does not describe participants or study personnel as blinded to the assigned approach. For a process outcome such as dose adjustment, knowledge of the approach could affect behavior or recording. The record does not provide information that would establish whether outcome ascertainment was independent of treatment knowledge.

What is known about analysis planning?

The original trial's sample-size justification and planned statistical analysis are not reported in the registry record. The registry does not report interim analyses, a prespecified adjustment for multiple comparisons, or details of missing-data handling and analysis populations. These omissions do not negate the posted estimates, but they limit evaluation of whether the posted analyses were prespecified and how all randomized participants were handled. The sample-size illustrations are based on the observed effect and stated planning assumptions, not on a documented original design calculation.

11. Confidence Intervals and Precision

The primary risk-difference estimate is 0.742, with a confidence interval from 0.532 to 0.952. A confidence interval describes a range of values compatible with the data and the interval procedure under its assumptions. It is not a guarantee that the true value lies within these particular limits, nor does it assign a probability to a single fixed effect. The interval is entirely above zero, matching the direction of the observed difference: more participants required adjustment in Monitoring than in PRC.

The interval also communicates uncertainty about the size of the difference. It spans a substantial range on the risk-difference scale, so the exact magnitude is not pinned down precisely, even though the direction is comparatively clear. The relative-risk interval, 2.229 to 31.81, and odds-ratio interval, 7.096 to 324.7, are especially broad. That breadth cautions against treating the point estimates of 8.421 and 48.0 as precise measurements of the relative contrast.

For procedure time, the mean-difference estimate is 0.13 minutes, with a confidence interval from -2.522 to 2.782. This interval crosses zero and allows for a difference in either direction. The estimate is therefore not precise enough to establish that procedure time is the same across approaches, or that any difference is small enough to be unimportant. The registry does not report a clinical or operational margin that would define a negligible difference.

Confidence intervals depend on the statistical method and assumptions used. The registry does not report all details of those methods for the primary endpoint. The limited sample and absence of additional methodological detail should therefore be kept in mind when interpreting precision. The intervals describe uncertainty in the posted estimates; they do not address unreported outcomes, systematic bias, or missing-data concerns.

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

For planning at 100% of the observed primary effect, the estimates are 6 participants per arm for 80% power and 8 participants per arm for 90% power. At 75% of the observed effect, the corresponding estimates are 11 and 14 participants per arm. At 50% of the observed effect, they are 23 and 30 participants per arm. These figures are hypothetical planning illustrations under the stated assumptions; they are not a claim about the power achieved by the completed trial.

The 80% column represents a planning target in which a study would have an 80% chance of detecting the specified effect if that effect were true and the model assumptions held. The 90% column uses a higher chance-of-detection target and therefore generally requires more participants. Smaller effects are harder to distinguish from random variation, so planning for a smaller fraction of the observed effect requires more participants per arm. The same interpretation applies to the procedure-time planning estimates, which are much larger because they use that endpoint's observed effect and variability.

For procedure time, the illustrations range from 17,010 participants per arm for 80% power and 22,772 for 90% power at 100% of the observed effect, to 68,040 and 91,086 at 50% of the observed effect. These estimates should be read as planning calculations under the stated assumptions, not as recommended study sizes. The registry's general note says time-to-event calculations would be reported as total events, while all other calculations are participants per arm. Neither posted endpoint is a time-to-event outcome, so the relevant figures are participants per arm.

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 = 0.100; treatment proportion p₁ = 0.842; average p̄ = 0.471.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.7059 = 1.3836.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4722 = 0.3974.
4. n = (1.3836 + 0.3974)² / (0.7421)² = 5.8, rounded up to 6 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 <- 0.1                          # control proportion
p1 <- 0.842105263157895                          # 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(1838304)
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 = 6 (80% power), 8 (90% power)
 75% of observed effect: n per arm = 11 (80% power), 14 (90% power)
 50% of observed effect: n per arm = 23 (80% power), 30 (90% power)
power.prop.test: 5.8 
Simulated power at n = 6 per arm: 0.836 (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. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary endpoint and names three secondary outcomes. It reports an unadjusted p-value for the primary comparison and an unadjusted p-value for procedure time. A plan for controlling type I error across multiple endpoints or analyses is not reported in the registry record. This matters because interpretation of a collection of statistical tests differs from interpretation of a single prespecified test: when more comparisons are made, chance findings become more likely unless the analysis accounts for that multiplicity.

The primary comparison is the central result because it is designated as the primary endpoint in the record. That designation does not establish whether the endpoint, analysis, or direction of testing was specified before the data were examined; those details are not reported in the registry record. The secondary procedure-time result should be treated as exploratory unless a prespecified analysis plan establishes otherwise. No multiplicity adjustment should be assumed.

Numerical results for decrease in minute ventilation from baseline and time spent below a saturation of 80% are not reported in the registry record. The record does not explain whether measurements were unavailable, analyses were omitted, or results were not entered. It also does not report the amount or pattern of missing data for the primary endpoint or procedure time, the analysis population used for each outcome, or any imputation method.

The registry lists randomized allocation and an enrollment of 40, while the primary arm summaries list 19 participants in Monitoring and 20 in PRC. The record does not explain the difference between total enrollment and those listed primary denominators. This should not be taken as proof that any particular participant was excluded or had missing data; the reason is not reported in the registry record. Details about intention-to-treat, per-protocol, or other analysis populations are also not reported.

The record does not report interim analyses, stopping rules, a full statistical analysis plan, or the original sample-size justification. These unknowns limit assessment of whether the reported analysis followed a prespecified protocol. They do not change the arithmetic of the posted estimates, but they affect how confidently readers can judge the analysis process and the completeness of the outcome record.

15. 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 non-serious adverse event terms

The registry reports serious adverse events for 20 participants at risk in each arm. No serious adverse events were reported in Monitoring or PRC. The reported death count is 0 in each arm. These are the figures recorded for the study; they do not establish that the approaches have identical safety profiles or that no event could occur outside the recorded period.

For other adverse events, 1 event was reported among 20 participants at risk in Monitoring and 0 among 20 at risk in PRC. The record does not provide additional detail about the non-serious event in the posted figures. No serious adverse event terms are listed.

Safety counts should be interpreted in the context of the trial's enrollment and the information recorded. With no serious events reported in either arm, this study cannot precisely characterize uncommon harms. The registry does not report detailed event descriptions, timing, relatedness assessments, or a broader safety analysis. The counts are descriptive and should not be used alone to infer a difference in risk.

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

The results describe a randomized comparison of two approaches to propofol dosing during EGD. The primary endpoint was the number of participants requiring an adjustment in the infusion rate. The posted counts and risk-difference estimate indicate that recorded adjustments were more frequent in Monitoring than in PRC. The confidence interval for the risk difference is entirely above zero, while the relative-measure intervals are broad, leaving substantial uncertainty about the exact magnitude of the relative contrast.

This is a finding about a specific process measure during a brief procedure. It does not directly measure whether sedation was at the intended depth throughout, whether patients experienced discomfort, or whether the approaches differed in outcomes that were not reported. The registry rationale links a greater requirement for rate changes to the need for an anesthesia provider to be immediately available, but the primary endpoint does not itself quantify provider time, workload, or the consequences of an adjustment.

The procedure-time result does not show clear evidence of an average difference, but its confidence interval includes values on both sides of zero. It should not be interpreted as proof that procedure time is equivalent. Numerical results for the named ventilation and saturation outcomes are not reported in the registry record, so conclusions about those outcomes cannot be drawn from the available record.

The trial was randomized and completed, but the registry lists no masking and does not report the randomization implementation, full analysis plan, multiplicity strategy, or handling of missing data. These limitations affect confidence in the completeness and interpretation of the evidence. The small enrollment and the lack of detailed safety reporting also mean that the posted data do not precisely characterize uncommon events.

Accordingly, the results support a description of the observed dose-adjustment difference in this trial, not a general claim about all settings, procedures, clinicians, or patient outcomes. No treatment recommendation follows from these statistics alone. Broader interpretation would require evidence on the unreported outcomes, study methods, and applicability beyond this particular EGD comparison.

17. Why This Trial Matters Statistically

This trial raises a statistical issue that is common in clinical research: a process measure can be informative about how an intervention is delivered, while remaining distinct from outcomes that matter directly to patients. The primary endpoint records whether a propofol dose adjustment was required. That makes the comparison straightforward to express as event counts and a risk difference, but it does not capture every dimension of sedation or care.

The contrast is large on the risk-difference scale, and the interval excludes zero. At the same time, the relative-effect intervals are broad, illustrating why statistical significance and precision are not interchangeable. The data provide a clear direction for the posted endpoint, but they are less definitive about the exact relative magnitude. Readers need both the point estimate and its uncertainty to interpret the result responsibly.

The trial also illustrates the limits of a completed registry record as a standalone account of analysis. It includes a primary result, one numerical secondary comparison, and basic adverse-event counts, but does not report numerical results for two named secondary outcomes or key details of the statistical plan. Missing analysis information can make it difficult to evaluate prespecification, multiplicity, and the handling of all randomized participants.

Finally, the planning illustrations demonstrate how sample-size requirements depend on the effect a future study aims to detect. Smaller target effects require more participants under the stated assumptions. These figures are planning aids rather than a retrospective measure of whether the trial was adequately powered. The registry's distinction between the observed study result and hypothetical future-study calculations is important when interpreting small randomized studies.

18. 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 primary endpoint is an operational measure of whether a participant required any dose adjustment. It does not distinguish one adjustment from multiple adjustments, quantify the size or timing of adjustments, or directly assess sedation depth. The registry's description gives a rationale for the measure, but does not report a separate validation or clinical threshold for interpreting it.

The trial enrolled 40 participants, and the primary arm summaries list 19 in Monitoring and 20 in PRC. The registry does not explain the difference between enrollment and the listed denominators. It also does not report the analysis population or how missing observations were handled, so the impact of any exclusions or unavailable data cannot be assessed from the record.

The registry lists no masking. For an outcome involving decisions to adjust a dose, awareness of the dosing approach could influence clinician behavior or how adjustments are recorded. The record does not report whether outcome ascertainment was standardized or independently reviewed. Details about random-sequence generation and concealment are also not reported in the registry record.

The study concerns EGD and a procedure timeframe described as an average of 9 minutes. Its results may not apply to other procedures or settings; the registry does not report evidence addressing that broader applicability. Numerical results for two of the three named secondary outcomes are not reported, and the record does not describe multiplicity control, interim analyses, the original sample-size justification, or a full analysis plan.

Adverse-event reporting is limited to counts, without detailed event descriptions or timing in the posted record. The absence of reported serious events in this trial does not precisely characterize uncommon events. The sample-size illustrations use observed effects and stated assumptions, not the original design rationale, and should not be used to infer the trial's achieved power.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Probability Ramp Control of Propofol for EGD — NCT01838304.
• Registry record last updated 2018-01-23; status last verified 2018-01.
• Results first posted 2018-01-23.
• 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.

22. Record Summary

The registry record describes a completed prospective, randomized, parallel-group comparison of probability ramp control and provider-managed monitoring for propofol sedation during EGD. It lists enrollment of 40, no masking, and the University of Pennsylvania as sponsor. The primary endpoint was the number of participants requiring a propofol dose adjustment during the procedure.

The posted primary counts are 16 participants in Monitoring and 2 in PRC. The estimated risk difference is 0.742, with a confidence interval from 0.532 to 0.952 and an unadjusted p < 0.001. Procedure time is the only secondary outcome with numerical results posted; numerical results for two other named secondary outcomes are not reported in the registry record.

The record reports no serious adverse events or deaths in either arm and reports 1 other adverse event in Monitoring and 0 in PRC. Important details about the statistical plan, analysis populations, missing data, and multiplicity are not reported in the registry record.