FOLCROM Trial: Foley Catheter in Rupture of Membranes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for FOLCROM Trial: Foley Catheter in Rupture of Membranes (NCT01973036), a randomized na study. The primary outcome is Time From Induction of Labor Until Delivery.

2. Clinical Question

The central statistical comparison is the mean duration in the group assigned Foley catheter plus oxytocin against the mean duration in the group assigned oxytocin alone. The randomized, parallel-group design makes the assigned groups the basis for this comparison. The registry record describes a multicenter trial and identifies premature rupture of membranes as the condition under study.

The primary result is a comparison of group means, not a report of the time experienced by every individual participant. It therefore describes an average difference and its uncertainty, rather than guaranteeing that an individual delivery will take a particular amount of time. Other posted outcomes address delivery within specified time windows, labor stages, selected complications, and maternal length of stay. Those secondary outcomes add context but do not replace the primary question.

3. Trial Design

FOLCROM was a randomized, parallel-group clinical trial sponsored by Geisinger Clinic. The registry record lists an enrollment of 201 and describes the study as multicenter. Participants were assigned to oxytocin alone or to Foley catheter and oxytocin. The masking status is listed as none, so the registry record does not describe the trial as masked. The phase is listed as not applicable.

The population was women with term or near-term premature rupture of membranes who were not in labor and were undergoing induction. The interventions therefore differ by the addition of a Foley catheter to oxytocin in one group. The record describes concurrent use of the catheter and oxytocin in that group. The detailed arm descriptions in the registry record are incomplete, so further procedure or administration details are not reported in the registry record.

The recorded start was 2014-03, primary completion was 2016-07, and the status is completed. The trial record lists a primary outcome of time from induction to delivery, measured in hours and summarized as a mean with standard deviation. The primary description defines induction as the start time of Foley catheter or oxytocin and says the measure was analyzed for all deliveries.

There are 18 outcome measures listed, with 17 secondary outcomes posted in the results information. The registry record includes group summaries for the primary outcome and several secondary outcomes, but lists no reported analyses. Details such as the allocation sequence method, concealment procedures, eligibility criteria beyond the summary description, and the original statistical design assumptions are not reported in the registry record. Randomization is stated, but those additional safeguards and design choices cannot be inferred from that label alone.

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 Time From Induction of Labor Until Delivery, measured over Time from induction to delivery (average 14.2 hours).

The primary endpoint measures elapsed time, in hours, from the start of induction to delivery. For the Foley catheter group, the timing begins with catheter placement; for the oxytocin group, it begins with oxytocin initiation. The registry description says the outcome was analyzed for all deliveries and reports the mean and standard deviation in each group.

Time to delivery is a continuous outcome: it can take a range of values rather than only indicating whether an event occurred. Summarizing it with a mean allows a direct comparison of average duration between randomized groups. The standard deviation describes how spread out individual observations are around each group mean; it is not the uncertainty of the estimated difference itself.

As a measure of the induction-to-delivery interval, this endpoint addresses the duration of the process being compared. It does not by itself describe delivery mode, complications, or the experience of any individual participant. The registry record does not report a rationale explaining why this endpoint was selected over other possible measures, so its stated use as the primary outcome is known, while the selection rationale is not reported in the registry record.

7. Results Posted in the Registry

• Foley Catheter and Oxytocin: mean 13.90 versus 14.40 on control; difference -0.50 (95% CI -2.55 to 1.55), standardized effect d = -0.07; z-test p = 0.632.

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.

Number of Participants With Vaginal Delivery Within 12 Hours From Placement of Foley Catheter or Start Time of Oxytocin

• 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:
  • Foley Catheter and Oxytocin: 36.6% (34/93) versus 42.6% (46/108) on control; risk difference -6.0 percentage points (95% CI -19.6 to 7.5), risk ratio 0.86 (0.61–1.21); unadjusted two-proportion z-test p = 0.384.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Foley Catheter and Oxytocin and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants With Vaginal Delivery Within 24 Hours From Placement of Foley Catheter or Start Time of Oxytocin

• 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:
  • Foley Catheter and Oxytocin: 65.6% (61/93) versus 74.1% (80/108) on control; risk difference -8.5 percentage points (95% CI -21.2 to 4.2), risk ratio 0.89 (0.74–1.07); unadjusted two-proportion z-test p = 0.190.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Foley Catheter and Oxytocin and the control. The interval gives the range of effects that remain compatible with the data.

Rate of Failed Induction of Labor as the Indication for Cesarean

• 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:
  • Foley Catheter and Oxytocin: 32.0% (8/25) versus 28.6% (6/21) on control; risk difference 3.4 percentage points (95% CI -23.2 to 30.0), risk ratio 1.12 (0.46–2.71); unadjusted two-proportion z-test p = 0.801.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Foley Catheter and Oxytocin and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover several different questions: vaginal delivery within specified time windows, labor duration and stages, selected maternal complications, failed induction as the indication for cesarean, length of stay, and a neonatal score threshold. The available posted results cover only some of the listed secondary outcomes. For the secondary comparisons with posted numerical estimates, the point estimates do not all point in the same direction. Their confidence intervals are broad and include no difference, so they do not form a consistent, precise pattern that clarifies the primary result.

The early vaginal-delivery outcomes are related to time to delivery, but they are not interchangeable with the primary continuous endpoint. A threshold outcome counts participants who delivered before a specified cutoff and discards information about how long delivery took for those on either side of that cutoff. A participant just beyond a cutoff and one with a much longer interval are both outside that binary event count. The primary mean and the threshold outcomes can therefore differ in what they emphasize.

The secondary results do not resolve the uncertainty in the primary mean comparison. They add outcome-specific observations, but each estimate concerns a separate endpoint and may use a different denominator. The posted summaries should be interpreted individually rather than combined into an overall claim about all outcomes.

Unadjusted secondary comparisons carry less weight as a group when many outcomes are examined. General: with repeated statistical tests, the chance of at least one apparently unusual result can increase even when no real effects are present. A multiplicity procedure can address that issue, but one is not reported in the registry record. Here, the posted secondary analyses are unadjusted and the record lists no reported analyses. Their results are consequently best treated as exploratory descriptions, not as a set of independent confirmatory tests.

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

• Number of Participants With Chorioamnionitis
• Number of Participants With Vaginal Delivery Within 12 Hours From Placement of Foley Catheter or Start Time of Oxytocin
• Number of Participants With Vaginal Delivery Within 24 Hours From Placement of Foley Catheter or Start Time of Oxytocin
• Duration of First, Second and Third Stage of Labor (Minutes) for Those Undergoing Vaginal Deliveries
• Rate of Failed Induction of Labor as the Indication for Cesarean
• Rate of Endomyometritis
• Maternal Length of Stay, From Admission to Discharge (Days)
• Rate of Five Minute Apgar Score < 5

9. Statistical Interpretation

10. Statistical Methods Explained

What does the primary comparison estimate?

The primary comparison is a difference between two group means. The group assigned Foley catheter plus oxytocin has a posted mean of 13.9 hours, and the group assigned oxytocin has a posted mean of 14.4 hours. The estimate is -0.5 hours when the combination group is subtracted from the oxytocin group in the order specified for the comparison: combination minus oxytocin. A negative value therefore points toward a lower observed mean in the combination group. This is an unadjusted comparison based on posted summaries, not an adjusted model estimate.

General: a mean describes the average of observed values, while a standard deviation describes the spread of those values around the mean. The two group standard deviations, 6.9 and 7.9 hours, describe participant-level variation. They are different from the standard error, which describes how much an estimated group mean or contrast would vary across repeated samples under a statistical model.

What does the confidence interval add?

The unadjusted 95% confidence interval for the mean difference is -2.546 to 1.546 hours. General: a confidence interval is a range of estimates generated by a procedure that, under its assumptions and repeated use, has a specified coverage property. It is not a range containing a stated proportion of individual participants, and it is not a probability statement that the particular true value lies in the interval. For this comparison, the interval includes zero, so the posted summaries do not exclude a zero mean difference. Its endpoints also allow differences in either direction.

The confidence interval is especially useful because it shows both the estimate and its precision. A point estimate alone would not reveal how uncertain the comparison is. Here, the range is broad relative to the observed estimate, which means the data do not provide a sharply determined estimate of the direction or size of the difference. The interval is unadjusted, and no adjusted analysis is reported in the registry record.

How should the p-value be understood?

The unadjusted p-value for the primary comparison is 0.632. General: a p-value measures the compatibility of the observed data, or data more extreme under a stated test, with a null hypothesis and its statistical assumptions. It is not a measure of effect size, clinical importance, or the probability that a hypothesis is true. A relatively large p-value does not establish that there is no difference; it indicates that these posted data do not strongly distinguish the observed result from the null model under the unadjusted test.

The registry record lists no reported analyses, so the analysis details for a sponsor-conducted primary test are not reported in the registry record. The reported estimate, interval, and p-value are unadjusted recalculations from the posted summaries. Since the record does not flag a discrepancy, no conflict with a sponsor analysis is indicated in the available result information.

What do binary outcome comparisons express?

Several secondary outcomes count participants with an event, such as vaginal delivery within a specified time window or failed induction as the indication for cesarean. Their posted comparisons use risk differences. General: a risk difference subtracts the proportion with the event in one group from the proportion in another. A value of zero corresponds to equal observed proportions. Its confidence interval describes uncertainty in that absolute difference, subject to the calculation's assumptions. Risk differences are distinct from relative measures, such as a risk ratio or odds ratio, because they express an absolute rather than relative contrast.

For the posted binary comparisons, the confidence intervals include zero. These comparisons are unadjusted and are accompanied by no reported analyses in the registry record. The groups used for a particular secondary outcome may have different denominators than the primary outcome; the failed-induction outcome, for example, has posted denominators of 21 and 25. Outcomes with a restricted denominator should not be casually interpreted as if they used the full primary-outcome population.

Why can variation affect precision?

General: greater variability within groups makes a mean contrast harder to estimate precisely when the amount of information is otherwise similar. Binary outcomes can also be imprecise when event counts are limited. The standard deviations and counts describe features relevant to precision, but they do not justify assuming a specific distribution or analysis model beyond what the registry record states. The record does not report model diagnostics, transformations, covariate adjustment, or methods for handling unusual or missing observations.

All recalculated comparisons should be read as descriptive statistical summaries rather than a reconstruction of a complete prespecified analysis plan. The randomized design supports comparing assigned groups, but the registry record does not report the analysis population or procedures used to preserve that comparison in the presence of missing outcomes, deviations, or exclusions. Those details are important for evaluating how closely a reported estimate corresponds to the effect of assignment.

11. Confidence Intervals and Precision

The primary mean difference is -0.5 hours, with an unadjusted 95% confidence interval from -2.546 to 1.546 hours. This interval is centered around the estimated difference and extends across zero. It therefore does not resolve whether the average induction-to-delivery time was shorter or longer in the combination group. The span of possible values is an important part of the result, not a secondary detail.

In general, precision describes how tightly data estimate a quantity. A narrower interval indicates greater precision under the method's assumptions; a wider interval indicates more uncertainty. The primary interval allows a range of differences on either side of zero, so the estimate is not precise enough to establish direction. The posted group means and standard deviations help characterize the observed data, but do not turn the interval into a prediction for any individual's delivery time.

The secondary risk-difference intervals also indicate uncertainty. For vaginal delivery within 12 hours, the interval is -0.196 to 0.075; within 24 hours, it is -0.212 to 0.042. For failed induction as the indication for cesarean, it is -0.232 to 0.300. Each interval includes zero, and the endpoints permit differences in either direction. The last comparison has smaller posted denominators than the primary comparison, which is relevant context when considering its precision.

These are unadjusted recalculated intervals, not intervals from reported sponsor analyses. Confidence intervals do not settle whether a difference would matter clinically; that judgment requires context and thresholds that are not reported in the registry record. They also do not establish equivalence. No equivalence margin or noninferiority margin is reported, and an interval that includes zero alone cannot support either conclusion.

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 illustrations based on the observed effects, not the original trial design. For these outcomes, the displayed figures are participants per arm, not total events. The assumptions listed for the illustrations are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set at the stated fraction of the observed effect: 100%, 75%, or 50%.

The 80% power column indicates the number of participants per arm that the illustration estimates would be needed to have an 80% chance of detecting the specified effect if that effect were true, under the listed assumptions. The 90% power column uses a higher target chance of detection and therefore generally calls for more participants per arm. These are planning calculations, not observed power. They do not describe the probability that the completed trial detected a real effect, nor do they alter what the observed estimates show.

The planning display includes the primary continuous outcome and selected binary secondary outcomes. For the primary outcome, the figures rise as the assumed effect is reduced from 100% to 75% to 50% of the observed effect. The same general pattern appears for the displayed binary outcomes. Smaller effects are harder to distinguish from ordinary variation, so detecting them under otherwise unchanged assumptions requires more participants. The illustrations also depend strongly on the particular observed effect, which can be unstable when estimates are uncertain.

The registry record does not report the trial's own original sample-size assumptions or justification. Consequently, the planning figures should not be read as the actual target that investigators used, as evidence that the trial was adequately powered, or as a replacement for a design calculation based on a prespecified clinically meaningful effect. They simply show how sample-size requirements would vary under the stated illustrative assumptions.

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

Worked calculation for this trial

1. Observed difference Δ = -0.500; pooled standard deviation σ = 7.454.
2. n = 2 × (1.96 + 0.842)² × 7.454² / -0.500² = 3,489.2, rounded up to 3,490 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 <- -0.5                      # observed difference in means
sigma <- 7.45438052052105                     # 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(1973036)
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 = 3,490 (80% power), 4,671 (90% power)
 75% of observed effect: n per arm = 6,203 (80% power), 8,304 (90% power)
 50% of observed effect: n per arm = 13,957 (80% power), 18,684 (90% power)
power.t.test: 3490.1 
Simulated power at n = 3,490 per arm: 0.798 (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.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists 18 outcome measures and identifies 17 secondary outcomes in the posted results information. It contains no reported analyses. The record does not report a multiplicity strategy, such as a hierarchy of outcomes, an adjustment to control the chance of false-positive findings across multiple comparisons, or a designation of selected secondary outcomes as confirmatory. In the absence of those details, the unadjusted secondary comparisons should not be read as if each were the sole, prespecified test.

General: multiplicity matters because repeated testing can make isolated small p-values more likely even when the null hypotheses are all true. Adjustments can reduce that risk, but often change how much evidence is needed for an individual comparison. The posted secondary p-values are unadjusted, and the registry record does not describe any correction. The primary outcome is separately identified, but its analysis plan and any relationship between primary and secondary testing are not reported in the registry record.

Missing-data methods are also not reported in the registry record. The primary description says the outcome was analyzed for all deliveries, but that wording does not specify how missing time measurements, withdrawals, or other incomplete records were handled. The record does not report imputation, complete-case rules, sensitivity analyses, or outcome-specific missingness. It is therefore not possible to assess from the registry record whether incomplete observations could have affected the estimates.

The analysis population is not reported in the registry record. Randomization is stated, but the record does not say whether analyses followed an intention-to-treat approach, were restricted to participants who received assigned care, or used another population definition. It also does not report participant flow, exclusions from the analyses, or reasons for any difference between randomized and analyzed denominators. The primary group counts are posted, but those counts alone do not identify the analysis rule.

Other details that would help assess the analyses—including model specifications, adjustment variables, subgroup analyses, interim analyses, and protocol deviations—are not reported in the registry record. These omissions limit evaluation of whether the posted comparisons followed a prespecified plan and how robust they are to analytic choices. They do not invalidate the descriptive summaries, but they restrict the conclusions that can be drawn from them.

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 5% reporting threshold.

The posted serious adverse event figures are zero in the oxytocin group and zero in the Foley catheter and oxytocin group. The record also lists zero other adverse events and zero deaths in each group. The numbers at risk for the serious-event summaries are 108 and 93, respectively; the same group counts are listed for other adverse events. No top serious adverse-event terms are listed.

These entries describe what the registry record reports, not proof that no adverse events occurred beyond the events captured and classified in those summaries. A zero count does not establish that an event is impossible or that the interventions have no safety risks. The registry record does not provide further event definitions, ascertainment details, follow-up completeness, or explanations of how adverse events were collected. The figures should therefore be read as registry reporting for this trial, with those reporting details in mind, rather than as a comprehensive estimate of safety.

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

The posted results describe a randomized comparison of oxytocin alone with Foley catheter plus oxytocin among women with term or near-term premature rupture of membranes who were not in labor. For the primary endpoint, the observed means are 14.4 hours and 13.9 hours, and the estimated mean difference is -0.5 hours. The unadjusted confidence interval includes differences in both directions, and the unadjusted p-value is 0.632. The data therefore do not give a precise estimate of which group had the shorter average time.

This is not evidence that the two approaches are identical. Demonstrating equivalence requires an appropriate design, a prespecified margin, and an analysis suited to that question. Those details are not reported in the registry record. Likewise, the primary comparison does not establish that one approach is better or worse for outcomes that were not its endpoint. The secondary outcomes are separate comparisons, with their own uncertainties and limitations.

The findings also do not determine what would happen for any particular participant. Group means summarize the observed distributions, while the standard deviations show variation among participants. A group average cannot predict an individual's induction-to-delivery interval. The record does not supply enough information to evaluate all eligibility, analysis, missing-data, or implementation details that may matter when applying a trial result to a different population or setting.

For the secondary outcomes with posted comparisons, uncertainty remains substantial, and their unadjusted nature makes them less conclusive as a collection. The registry safety entries report zero serious events, other events, and deaths in both groups, but the available record does not establish that risks are absent. The balanced interpretation is that the posted data do not show a clear, precise difference in the primary mean outcome; they do not establish equivalence, broad safety, or an effect on every secondary outcome.

17. Why This Trial Matters Statistically

This trial offers a useful example of why a randomized comparison still needs careful interpretation of effect size and precision. The mean time-to-delivery estimate is straightforward to describe, but the confidence interval is essential: it shows that the observed difference is not estimated tightly enough to determine the direction of a possible group difference. Focusing only on the point estimate or the p-value would omit that central feature.

The record also illustrates the distinction between a continuous endpoint and related threshold outcomes. Mean time retains information across the range of observed durations, while a cutoff-based outcome answers whether a participant delivered within a particular window. These endpoints can complement one another, but they are not interchangeable and need not provide identical summaries.

Another statistical lesson is that many secondary outcomes call for caution. Their individual estimates may be informative, but unadjusted testing across multiple outcomes raises interpretive concerns, especially when no analysis plan or multiplicity approach is reported. A coherent pattern across outcomes and prespecified methods would strengthen interpretation; the registry record does not provide those details.

Finally, the planning illustrations show why a trial's observed estimate should not be mistaken for a design target. Planning numbers based on an observed effect are sensitive to that estimate and are not evidence of observed power. The original design assumptions are not reported in the registry record. Keeping design information, estimates, uncertainty, multiplicity, and missing-data handling distinct is necessary for a statistically responsible reading of clinical trial results.

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 registry record leaves several trial-specific details unclear. Although it identifies a randomized multicenter study, the method of sequence generation and allocation concealment are not reported in the registry record. Masking is listed as none, so participants and study personnel should not be assumed to have been masked. The record also does not report the full eligibility criteria, participant flow, or reasons for any exclusions from outcome analyses.

The arm descriptions are incomplete in the record, which limits evaluation of how induction procedures were implemented across sites. Further details about adherence, crossover, treatment deviations, or consistency of care are not reported in the registry record. These issues could be relevant to interpreting a comparison of assigned strategies, but their frequency or effect cannot be inferred.

The statistical information is limited. The original sample-size justification, prespecified analysis plan, outcome handling rules, covariate adjustments, interim analyses, subgroup plans, and missing-data procedures are not reported in the registry record. No sponsor-reported analyses are listed. The posted recalculations are useful summaries, but they cannot answer questions that require those missing design and analysis details.

The primary result is imprecise, and the secondary comparisons are unadjusted. Some secondary outcomes use outcome-specific denominators, making it important not to assume that every comparison represents the same analysis population. The record does not explain those denominators or provide a complete participant accounting. Safety reporting is also limited to the listed counts, without further descriptions of definitions or ascertainment. These limitations constrain both causal interpretation and the extent to which the results can be generalized beyond the trial population.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: FOLCROM Trial: Foley Catheter in Rupture of Membranes — NCT01973036.
• Registry record last updated 2018-09-24; status last verified 2018-07.
• Results first posted 2018-09-24.
• 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

FOLCROM, sponsored by Geisinger Clinic, is a completed randomized, parallel-group, unmasked multicenter trial of labor induction in women with term or near-term premature rupture of membranes who were not in labor. The registry record lists enrollment of 201, a start date of 2014-03, and primary completion in 2016-07.

The primary endpoint is mean time from induction to delivery. The posted means are 14.4 hours with oxytocin and 13.9 hours with Foley catheter and oxytocin; the unadjusted mean difference is -0.5 hours, with a 95% confidence interval from -2.546 to 1.546 and p = 0.632. The interval includes zero and permits differences in either direction.

Secondary outcomes include time-window delivery counts and other maternal and neonatal measures. The registry record lists no reported analyses, and does not report the original design assumptions, missing-data methods, or multiplicity strategy. Posted adverse-event counts are zero for serious events, other events, and deaths in each group.