Effects of Aromatherapy on Patient Satisfaction With Surgical Abortion at Less Than 10 Weeks Gestation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Aromatherapy on Patient Satisfaction With Surgical Abortion at Less Than 10 Weeks Gestation (NCT04969900), a randomized na study. The primary outcome is Patient Satisfaction With Anesthesia.

2. Clinical Question

The question is about a difference in reported satisfaction scores, not a direct measure of whether the procedure was completed or whether a particular anesthetic approach was adequate. Satisfaction can reflect several aspects of the experience, including pain, perceived safety, and nausea, because these are among the questionnaire items. The registry describes the study as investigating aromatherapy alongside usual procedural care, including paracervical block and/or oral medications, but it does not report detailed use of those co-interventions for each participant.

3. Trial Design

The registry record describes a completed, randomized, triple-masked, parallel-group clinical trial sponsored by University of Colorado, Denver. The brief description characterizes it as a single-site, double-blinded, placebo-controlled trial; the structured record lists masking as triple. The registry record does not explain the distinction between those masking descriptions. The trial enrolled 144 participants and lists a start date of 2021-05-13 and primary completion date of 2022-04-26.

Participants were assigned to a lavender-oil blend or jojoba-oil placebo. The arm descriptions state that assignment was to occur just before the abortion procedure and describe a permuted-block randomization scheme stratified by sedation category. The description names no sedation and oral sedation as categories, but the available arm text is incomplete, so further operational details are not reported in the registry record.

The primary outcome was a continuous satisfaction score, reported as a group mean with standard deviation, at 15 minutes post-procedure. The analytic arm summaries list 57 participants in the lavender group and 55 in the placebo group. These numbers should be read as the group sizes attached to the posted primary outcome summaries, not as a complete account of every participant enrolled or randomized. The record says 32 participants were excluded from analysis and gives reasons for those exclusions.

The record lists maximum procedural pain and acceptability-related outcomes as secondary outcomes, but does not include their result values in the posted results described for this trial. Further details about recruitment, adherence, and the conduct of masking 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.

Before assignment: From May 2021 through April 2022, we assessed 196 participants for eligibility. We excluded 51 potential participants, the majority of whom declined to participate. Of 144 participants consented and enrolled, 73 were randomized to aromatherapy and 71 were randomized to placebo.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 32 participants were excluded from analysis: 30 were enrolled prior to posting the study on ClinicalTrials.gov; 1 had an undiagnosed ectopic pregnancy, and one had a protocol deviation (did not receive study product).

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.

Population: 32 participants were excluded from analysis: 30 were enrolled prior to posting the study on ClinicalTrials.gov; 1 had an undiagnosed ectopic pregnancy, and one had a protocol deviation (did not receive study product).

6. Primary Endpoint

The registry lists the primary outcome as Patient Satisfaction With Anesthesia, measured over 15 minutes post-procedure.

The primary endpoint is patient satisfaction with anesthesia during the abortion experience, measured 15 minutes after the procedure using the Iowa Satisfaction with Anesthesia Scale (ISAS). The registry describes an 11-item self-reported questionnaire, with items such as “I hurt,” “I felt safe,” and “I had nausea.” Responses use a Likert-type scale from “Disagree very much” to “Agree very much,” and the answers are scored from -3, least satisfied, to +3, most satisfied. An average composite score is then calculated.

A composite score provides a single continuous summary of responses across the questionnaire items. The endpoint therefore captures the participant's overall reported satisfaction according to this scale, rather than treating any individual item as the primary result. The registry reports the outcome as a mean and standard deviation for each group. A difference in group means is a way to describe how the average scores compare, while the standard deviations describe variation in scores among participants.

The record does not report additional information about how the questionnaire was administered, how incomplete item responses were handled, or what score difference would be considered important to participants. Those details are not reported in the registry record.

7. Results Posted in the Registry

• Investigational Product - A 10% Dilute Lavandula Angustifolia - Jojoba Oil Essential Oil Blend: mean 0.72 versus 0.46 on control; difference 0.26 (95% CI -0.10 to 0.62), standardized effect d = 0.27; z-test p = 0.156.

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports a continuous primary outcome summarized by group means and standard deviations. The listed contrast is an unadjusted mean difference: it compares the average satisfaction score in the lavender group with the average in the placebo group. The posted means are 0.72 and 0.46, and the mean difference is 0.26 points. This describes the direction and size of the contrast on the ISAS score scale; it does not by itself explain why the groups differed or establish that the contrast is important to patients.

What does a mean difference describe?

In general, a mean difference is the difference between two group averages when the outcome is measured on a numerical scale. It preserves the outcome's units, so the estimate is expressed in satisfaction-score points. A positive estimate in this comparison corresponds to a higher average score in the lavender group than in the placebo group. The individual scores can still overlap substantially even when group averages differ; a group mean does not describe every participant's experience.

What do the standard deviations add?

The reported standard deviations are 0.96 for the lavender group and 0.98 for the placebo group. In general, a standard deviation describes how spread out observations are around their group mean. It is not the uncertainty in the mean difference itself, and it is not a range containing every participant's score. The posted comparison also lists a pooled standard deviation of 0.970. In general, pooling combines information about within-group variability for a two-group standardized comparison; it is distinct from comparing the scores in their original units.

How should the p-value be read?

The unadjusted p-value is 0.156. In general, a p-value measures how unusual results at least as incompatible with a specified null model as the observed result would be, assuming that model and the statistical assumptions are correct. It is not the probability that the null hypothesis is true, and it does not measure the probability that the observed difference arose “by chance.” The registry record does not report the complete test specification or a decision threshold for the trial's primary analysis. The result should therefore be read alongside the effect estimate and confidence interval, rather than as a stand-alone verdict.

What does the confidence interval convey?

The listed 95% confidence interval for the mean difference runs from -0.099 to 0.619. In general, a confidence interval is a range of estimates compatible with the data under the method's assumptions. Its width reflects uncertainty: a narrower interval indicates greater precision than a wider interval on the same scale. Because this interval crosses zero, the posted summary does not rule out a zero mean difference using this interval. It also spans positive and negative values, so the direction of the underlying contrast is not determined precisely by the estimate alone.

What is and is not documented about the analysis?

The registry record lists no formal analysis entries for this outcome. The displayed comparison is unadjusted and uses summary statistics. The record does not report a model specification, covariate adjustment, a plan for handling missing outcome data, or details about diagnostic checks. These omissions do not show that such procedures were or were not used outside the registry; they mean the procedures are not reported in the registry record. The group summaries and the unadjusted comparison can be interpreted on their own terms, without assuming additional analysis steps.

Why do planning calculations use assumptions?

General sample-size planning translates a target effect and design choices into an approximate number of participants required per arm. The planning illustration associated with this trial uses a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Its target effect is a stated fraction of the observed effect. These are planning assumptions for the illustration, not documented assumptions for the trial's original design. The trial's own original sample-size justification and analysis plan are not reported in the registry record.

The observed standardized effect listed with the comparison is 0.268, and the planning rows consider 100%, 75%, and 50% of the observed effect. As a general principle, targeting a smaller effect requires more participants to distinguish that effect from random variation at the same planned operating characteristics. These calculations do not alter the observed primary outcome, and the planning figures are not a measure of the probability that the trial detected an effect.

10. Confidence Intervals and Precision

The primary mean difference is 0.26 satisfaction-score points, with a 95% confidence interval from -0.099 to 0.619. This interval is a direct expression of uncertainty around the estimated group contrast. It extends from a small negative difference to a positive difference, and includes zero. Consequently, the direction and magnitude of the underlying mean contrast are not estimated with high precision by the posted comparison.

In general, a confidence interval describes a range of values compatible with the data and the assumptions of the method used to construct it. It is not a range of participant scores, and it does not mean that a fixed proportion of individual outcomes falls within its limits. The interval concerns the group-level mean difference. Its interpretation also depends on the comparison and data-handling methods, details that are not fully reported in the registry record.

The group standard deviations, 0.96 for lavender and 0.98 for placebo, describe variability in observed scores. They are not confidence limits. The registry also lists standard errors for the group means, 0.127 and 0.132, respectively; these describe uncertainty in each group mean, rather than variability among individuals. The posted mean-difference interval is the more direct measure of uncertainty for the between-group contrast.

The interval should be considered together with the unadjusted p-value of 0.156 and the absence of a reported threshold for a meaningful score difference. Statistical compatibility with a range of effects is not the same as evidence that every value in the range is equally plausible, nor does it determine clinical importance. The registry record does not report a prespecified meaningful-difference threshold or a more detailed analysis plan.

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 participants per arm, not total participants and not total events. The calculation is a planning illustration based on the observed effect, rather than a report of the trial's original design justification. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect varies across rows: the illustration considers 100%, 75%, and 50% of the observed effect.

The 80% power column gives the approximate participants per arm needed under those assumptions for an 80% chance of detecting the specified effect if that effect is the true one and the assumptions hold. The 90% power column gives the corresponding planning count for a 90% chance. These are design calculations, not guarantees for a future study. They depend on the assumed effect and other planning choices.

The illustration lists 219 participants per arm for planning around 100% of the observed effect, 389 per arm for 75% of the observed effect, and 874 per arm for 50% of the observed effect in the 80% power column. For 90% power, the corresponding figures are 293, 520, and 1,170 participants per arm. The pattern reflects a general statistical principle: smaller effects are harder to distinguish from random variation, so more participants are needed when the other assumptions remain fixed.

This is not observed power. It is a forward-looking illustration using an effect estimated from the trial, not a retrospective measure of how likely the completed trial was to find an effect.

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 = 0.260; pooled standard deviation σ = 0.970.
2. n = 2 × (1.96 + 0.842)² × 0.970² / 0.260² = 218.4, rounded up to 219 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 <- 0.26                      # observed difference in means
sigma <- 0.969869719460956                     # 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(4969900)
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 = 219 (80% power), 293 (90% power)
 75% of observed effect: n per arm = 389 (80% power), 520 (90% power)
 50% of observed effect: n per arm = 874 (80% power), 1,170 (90% power)
power.t.test: 219.4 
Simulated power at n = 219 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.

13. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome, patient satisfaction with anesthesia, and three secondary outcomes: maximum procedural pain, acceptability, and patient acceptability of lavender aromatherapy in procedural abortion. Values for the secondary outcomes are not reported in the posted results described for this trial. The record therefore does not support interpretation of their effect estimates or uncertainty.

When a study tests multiple outcomes or multiple hypotheses, the chance of at least one apparently notable result can increase. In general, multiplicity procedures can be used to control that issue, or investigators can specify one primary outcome and treat other analyses as secondary or exploratory. The registry record does not report whether multiplicity was addressed, how the secondary outcomes were prioritized, or whether any testing hierarchy was prespecified. No correction should be assumed from the outcome listings alone.

The registry states that 32 participants were excluded from analysis: 30 were enrolled before the study was posted on ClinicalTrials.gov, one had an undiagnosed ectopic pregnancy, and one did not receive study product because of a protocol deviation. Those reasons are reported, but the record does not describe how the analysis population was otherwise defined or whether participants were analyzed according to randomized assignment.

Missing-data methods are not reported in the registry record. In particular, the record does not explain whether any primary questionnaire data were missing, how incomplete questionnaires were scored, or whether imputation or another missing-data procedure was used. It also does not report sensitivity analyses assessing the effect of missingness or exclusion decisions. These gaps limit assessment of how the analysis population and unobserved outcomes may affect the result; they do not establish that missing data occurred or that a particular method was used.

The record lists no analysis entries for the primary comparison. It does not report a prespecified statistical analysis plan, covariate adjustments, interim analyses, or a sample-size justification for the original trial. The sample-size illustration is separate from those unreported design and analysis details.

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.

The registry's adverse-event summaries list 71 participants at risk in the placebo group and 73 in the lavender-oil group. For each listed group, the serious adverse event count is 0, the other adverse event count is 0, and the number of deaths is 0. These are the counts recorded for the categories shown, alongside their corresponding at-risk group sizes.

Zero reported events in these summaries means that no events were recorded in those categories for the listed groups in the registry record. It does not establish that the risk is absent, and it does not show that the groups have identical underlying risk. Rare or unobserved events cannot be ruled out solely from zero counts. The registry record does not provide event descriptions, a more detailed safety-analysis method, or further context about the duration or completeness of adverse-event ascertainment.

The at-risk figures are not the same as the group sizes listed for the primary outcome summaries. The registry record does not explain the relationship between those safety denominators and the primary analysis population. These adverse-event counts should therefore be read as the posted safety summaries, not used to infer outcome-group membership or the completeness of the satisfaction analysis.

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

The posted results describe the average satisfaction scores observed among participants included in the primary outcome summaries. The average was 0.72 in the lavender-oil group and 0.46 in the jojoba-oil placebo group, with an unadjusted mean difference of 0.26 points. The confidence interval, from -0.099 to 0.619, includes zero and spans values in both directions. The result therefore leaves uncertainty about the size and direction of the underlying mean difference.

These figures do not establish that lavender aromatherapy improves satisfaction, or that it has no effect. The unadjusted p-value of 0.156 is not proof for either conclusion. The record does not provide a threshold for interpreting how large a score change would matter to participants, so statistical estimates cannot be mapped to a stated criterion of practical importance from this record alone.

The endpoint is a self-reported composite score collected 15 minutes after the procedure. It reflects the questionnaire's items and scoring approach, not every dimension of care or every possible clinical outcome. The trial also lists procedural pain and acceptability-related secondary outcomes, but their results are not reported in the posted results. The primary satisfaction comparison cannot be used as a substitute for those outcomes.

Interpretation is also bounded by the analysis population. The registry says 32 participants were excluded from analysis and explains the reasons, but does not report a full missing-data strategy or a detailed analysis-population definition. The primary result should be understood as a comparison of the posted outcome groups, not necessarily as an estimate for every enrolled participant.

More broadly, one trial's registry results do not by themselves settle how a finding applies in other settings or populations. The record describes a single-site trial in adult women having surgical abortion before 10 weeks and 0 days gestation. It does not report enough information to determine how representative the enrolled participants were of people receiving care elsewhere.

16. Why This Trial Matters Statistically

This trial illustrates several statistical issues that are common in clinical research. Its primary endpoint is a continuous patient-reported score, so the main contrast can be expressed in the scale's own units as a difference between group means. That makes the estimate directly interpretable in score points, while the confidence interval communicates uncertainty about that contrast.

The result also shows why the estimate, interval, and p-value should be read together. The observed difference is positive, but the confidence interval includes zero and values in both directions. The p-value of 0.156 does not answer whether the difference is important to patients, and the record does not state a threshold for an important difference. A numerical result can therefore be informative without providing a definitive conclusion about practical importance.

Planning from an observed effect raises another general issue: an effect estimate from a completed trial is uncertain. The planning illustration explores smaller fractions of the observed effect and shows that smaller targets require larger per-arm sample sizes under the stated assumptions. This is useful for understanding how planning depends on the target effect, but it is not evidence about the original design rationale, which is not reported in the registry record.

Finally, the record makes the analysis population and reporting scope important to assess. It identifies exclusions, lists secondary outcomes without their result values, and does not report detailed missing-data or multiplicity procedures. These are not merely administrative details: they affect how confidently readers can assess the full set of results and the population to which the primary estimate applies. Transparent reporting of estimates, uncertainty, analysis populations, and methods helps distinguish what a trial's posted data can support from what remains unknown.

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 record has several limitations for interpreting this specific trial. It describes the trial as single-site, which limits direct assessment of how well the findings apply to other settings. The population is described as adult women having a surgical abortion before 10 weeks and 0 days gestation; the record does not provide enough information to assess representativeness beyond that description.

The primary outcome is a self-reported satisfaction composite. While the record describes its items and scoring, it does not report a threshold for a meaningful score difference, additional measurement-performance information, or how incomplete item responses were handled. The result therefore cannot be interpreted against a stated participant-important benchmark using the registry record alone.

The record reports that 32 participants were excluded from analysis, with stated reasons, but does not give a complete account of missing primary outcome data or the analysis population. The safety denominators differ from the primary outcome group sizes, and their relationship is not explained. The registry also lists three secondary outcomes without reporting their result values in the posted results described for this trial.

Important design and analysis details are not reported in the registry record, including the original sample-size justification, the complete statistical analysis plan, a missing-data strategy, and whether multiplicity was addressed. The record gives both a brief description of double blinding and a structured masking classification of triple, without explaining the difference. It also does not report whether masking was assessed or maintained. These reporting limits call for caution in extending the posted mean comparison beyond its stated outcome and analyzed groups.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Effects of Aromatherapy on Patient Satisfaction With Surgical Abortion at Less Than 10 Weeks Gestation — NCT04969900.
• Registry record last updated 2025-08-03; status last verified 2025-07.
• Results first posted 2025-08-03.
• 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

NCT04969900 is a completed randomized, parallel-group trial of lavender aromatherapy versus jojoba-oil placebo during surgical abortion before 10 weeks and 0 days gestation. The registry lists University of Colorado, Denver as sponsor, enrollment of 144, a start date of 2021-05-13, and primary completion on 2022-04-26.

The primary outcome was satisfaction with anesthesia on the Iowa Satisfaction with Anesthesia Scale, measured 15 minutes after the procedure. The posted group means were 0.72 for lavender and 0.46 for placebo; the unadjusted mean difference was 0.26, with a 95% confidence interval from -0.099 to 0.619 and p = 0.156. The record reports 32 exclusions from analysis and lists zero serious adverse events, zero other adverse events, and zero deaths in each safety group.

Secondary outcomes are listed, but their result values, detailed missing-data methods, multiplicity procedures, and the trial's original sample-size justification are not reported in the registry record.