Oxytocin Administration in BDD and OCD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Oxytocin Administration in BDD and OCD (NCT02671266), a randomized phase 2 study. The primary outcome is Emotion Recognition Questionnaire.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, double-masked, phase 2 crossover trial, marked completed. Enrollment was 41. The study started in 2014-12, and primary completion was recorded as 2017-10. Massachusetts General Hospital is listed as the sponsor.

In a crossover design, participants receive more than one study condition in a specified sequence, so comparisons may use within-participant information. The record lists two sequences: oxytocin followed by placebo, and placebo followed by oxytocin. The arm descriptions specify a one-week washout period before the second visit. The oxytocin spray is described as 24 IU, administered as 3 puffs per nostril; the placebo is described as a matching formulation without the active oxytocin ingredient.

Randomization means the sequence assignment was randomized; double masking indicates that the study was described as double-masked. The registry record does not explain who was masked or how masking was maintained. It also does not report the randomization method, the sequence allocation, or whether the analysis accounted for period, sequence, or carryover effects.

The study’s stated purpose was to investigate acute oxytocin relative to placebo on social cognitive impairments among people with BDD and OCD, compared with healthy controls. The primary-outcome description narrows the reported population: BDD and healthy control participants who completed at least one drug visit were included, while the OCD group was excluded from analyses because of recruitment difficulties. The enrollment figure should not be read as the number analyzed for the primary outcome; that analysis population is not fully quantified 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Data reported for BDD and healthy control participants who completed at least one drug visit. There was one patient in the oxytocin first arm who did not complete second placebo drug visit. OCD group was excluded from analyses due to difficulties with recruitment.

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 Emotion Recognition Questionnaire, measured over 45 minutes post nasal spray administration.

The primary outcome was the Emotion Recognition Questionnaire score, assessed 45 minutes after nasal spray administration. The questionnaire is described as having 48 items across 2 conditions: self-referent and other-referent. Each condition has its own score, based on the number of correct responses. Scores range from 0 (least accurate) to 24 (most accurate) for each condition.

Emotion recognition is used as a measure of social cognition: performance on the questionnaire reflects accuracy in recognizing emotions in the specified conditions. Reporting the two scores separately preserves the distinction between self-referent and other-referent performance rather than treating them as a single outcome.

The registry record does not give a single numerical primary-outcome comparison. It notes that the primary outcome has several categories or time points and was not reduced to one comparison. It also does not report the observed means, standard deviations, or an estimated oxytocin-versus-placebo effect for either condition. As a result, the endpoint description explains what was measured, but does not establish the size or precision of any difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a randomized, double-masked crossover trial and a continuous primary measure summarized as a mean with standard deviation. It does not report the statistical analysis plan, an analysis model, or a single primary-outcome comparison. The statistical ideas below are general context, not a description of analyses confirmed in the registry record.

What does randomization contribute?

In general, random assignment can help prevent systematic differences between study groups or treatment sequences at the point of assignment. In a crossover study, randomization concerns the order in which participants receive the conditions. It does not, by itself, remove bias from missing data, incomplete masking, period effects, or other features of how outcomes are measured and analyzed. The registry record does not report the randomization procedure or sequence balance.

Why does crossover analysis need care?

General statistical context: when each participant receives both conditions, observations from the same person are related rather than independent. A suitable analysis generally needs to preserve that pairing. It may also need to account for whether outcomes change between visits, whether treatment effects depend on sequence, and whether an earlier condition affects a later measurement. The record describes a one-week washout period but does not report how the analysis addressed these issues or whether carryover was assessed.

A mean summarizes the central value of a continuous outcome, while a standard deviation describes variation among observed scores. A mean difference can express the contrast between conditions in the score’s original units. A confidence interval, in general, describes a range of estimates compatible with the data and the assumptions of the method; narrower intervals indicate greater precision. The registry record does not report means, standard deviations, mean differences, or confidence intervals for the primary outcome, so these quantities cannot be interpreted for this trial from the recorded information.

What can a p-value say?

General statistical context: a p-value measures how incompatible the observed data are with a specified null hypothesis under the assumptions of a statistical model. It does not measure the probability that the null hypothesis is true, and it does not convey the size or practical importance of an effect. The registry record does not report a primary-outcome p-value or identify a model or hypothesis test for that outcome. No significance judgment can therefore be drawn from the record.

How should the listed planning assumptions be read?

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustration defines the effect to detect as a stated fraction of the observed effect. Such calculations concern hypothetical future planning under assumptions; they are not observed trial results and are not observed power. The record does not report the trial’s own sample-size justification, and no planning value should be mistaken for evidence about the primary outcome.

General statistical context: planning calculations depend on assumptions about the effect to detect, variability, allocation, and the chosen error rate. If those assumptions do not match a future study, the resulting planning figures may not apply. The registry’s planning assumptions do not establish that the completed trial was designed around the observed effect or that its analysis had a particular power.

What does the lack of a single comparison imply?

The registry record says that the primary outcome has several categories or time points and was not reduced to one comparison. This means the record does not identify one estimate that can stand in for all questionnaire results. Separate self-referent and other-referent scores are distinct outcomes, and results at different times would likewise need clear identification. No single direction or magnitude should be inferred from the endpoint description alone.

Multiplicity is the general issue of interpreting multiple statistical tests or outcomes. When many comparisons are considered, the chance of finding at least one apparently unusual result can increase unless the analysis plan specifies how comparisons will be handled. The registry record does not report a multiplicity adjustment, a prespecified hierarchy among the questionnaire outcomes, or which contrast was primary for inference. It is therefore not possible to assess how multiplicity was handled.

Finally, the crossover design and incomplete visit information make the analysis population important. The record notes one participant in the oxytocin-first arm who did not complete the second, placebo visit, but it does not report the analysis method for incomplete paired observations. General statistical context: methods for missing observations rely on assumptions, and different assumptions can affect estimates and uncertainty. Since the method and outcome data are not reported, the impact of incomplete visits cannot be quantified from the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The primary-outcome description covers separate self-referent and other-referent Emotion Recognition Questionnaire scores, and the registry record says the outcome has several categories or time points. It was not reduced to one comparison. The record does not report a hierarchy of outcomes, a prespecified primary contrast among these measures, or a method for adjusting for multiple comparisons. General statistical context: when multiple outcomes or contrasts are tested, multiplicity can make isolated findings harder to interpret unless the analysis plan accounts for the number and relationship of the tests.

The analysis population is described as BDD and healthy control participants who completed at least one drug visit. The OCD group was excluded from analyses because of recruitment difficulties. The record also notes that one patient in the oxytocin-first arm did not complete the second, placebo visit. It does not state how missing outcome observations were handled, whether partial questionnaire data were included, or whether a sensitivity analysis was conducted. The number analyzed for each condition is not reported in the registry record.

These details limit conclusions about completeness and generalizability. The registry record does not establish that all enrolled participants contributed to each endpoint, nor does it describe an intention-to-treat or per-protocol analysis. General statistical context: missing-data methods depend on assumptions about why observations are unavailable; the amount and pattern of missingness and the chosen method can affect estimates and uncertainty. Without the analysis details and outcome results, the impact cannot be evaluated.

11. 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.

Most frequent non-serious adverse event terms

The registry lists separate safety summaries for oxytocin and placebo. For serious adverse events, the at-risk counts are 34 for oxytocin and 33 for placebo; the affected counts are 0 in each group. Deaths are also listed as 0 in both groups. The record lists no serious adverse-event terms.

For other adverse events, the at-risk counts are 34 for oxytocin and 33 for placebo, with affected counts of 15 and 17, respectively. These are reported counts; they should not be turned into percentages or interpreted as a treatment comparison without the relevant analysis and context. The registry record does not explain how events were collected, whether the summaries count participants or event occurrences, or how exposure across crossover periods was handled.

These figures describe what the registry lists, not the certainty of a safety difference. Zero recorded serious events does not establish that serious events cannot occur, and the other-event counts alone do not show whether one condition caused more events than the other. The record does not provide an inferential comparison or detailed event terms for the other adverse events.

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

The record identifies a randomized, double-masked crossover study of acute intranasal oxytocin relative to placebo, with social cognition as its focus. It specifies an Emotion Recognition Questionnaire endpoint, with separate self-referent and other-referent scores, measured 45 minutes after administration. It also documents that the OCD group was excluded from analyses because of recruitment difficulties and that one patient in the oxytocin-first arm did not complete the second visit.

What the record does not establish is the direction or size of an oxytocin-placebo difference on the primary outcome. It does not report the numerical outcome summaries, an effect estimate, a confidence interval, or a p-value for a single primary comparison. Because the outcome was not reduced to one comparison, the questionnaire description cannot be treated as a result. The absence of a reported comparison is not evidence that the conditions were equivalent or that there was no effect.

The safety record lists no serious adverse events and no deaths in either treatment group, alongside other adverse-event counts. Those data are descriptive and do not by themselves establish a comparative safety effect. Likewise, the enrollment count does not identify how many participants contributed to each primary-outcome analysis.

General statistical context: estimates are most informative when read together with their uncertainty, analysis population, outcome definition, and model. Those elements are not fully reported for the primary comparison in this registry record. Conclusions should therefore remain limited to the study design, stated endpoint, described population, and safety counts rather than extending to an unreported treatment effect or to populations excluded from the analyses.

13. Why This Trial Matters Statistically

This trial raises a useful statistical issue: a crossover design can make within-participant comparisons relevant, but interpretation depends on the sequence of conditions and the handling of repeated measurements. The registry describes randomized treatment order, double masking, and a one-week washout period. It does not report whether the analysis accounted for pairing, period effects, sequence effects, or carryover. Those details are central to judging how a crossover comparison was estimated.

The study also distinguishes the population named in its purpose from the population described for primary-outcome data. The stated purpose includes BDD and OCD participants compared with healthy controls, whereas the primary-outcome description reports BDD and healthy control participants and says the OCD group was excluded because of recruitment difficulties. Keeping the target population and analyzed population distinct is important when considering what a result could apply to.

A further statistical point is that a multidimensional outcome does not necessarily yield one unambiguous comparison. The questionnaire has separate self-referent and other-referent scores, and the record notes several categories or time points without reducing them to one comparison. Without a stated analysis hierarchy or adjustment approach, the record does not show how multiple potential findings would be interpreted together.

Finally, the registry record makes clear that design details and endpoint definitions are not substitutes for outcome estimates. The posted information allows a reader to understand what the trial set out to measure and some limits on its analysis population, but not to assess the magnitude or precision of the primary contrast. That distinction is especially important when a record lists a completed study but does not report a single primary-outcome result.

14. 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 limitation for interpreting efficacy is that the registry record does not report a single numerical comparison for the primary outcome. The outcome includes separate questionnaire conditions and several categories or time points, but the record does not provide the corresponding means, standard deviations, estimates, confidence intervals, or p-values. It is therefore not possible to assess the magnitude or precision of a primary effect from the recorded information.

The primary-outcome description excludes the OCD group because of recruitment difficulties, so the described analysis population does not cover all groups named in the study purpose. One patient in the oxytocin-first arm did not complete the second, placebo visit. The record does not report the number analyzed for each outcome, how incomplete visits were handled, or whether sensitivity analyses addressed missing data.

Although the trial is described as randomized, double-masked, and crossover, the registry record does not report the randomization method, masking procedures, statistical model, or handling of period, sequence, and carryover effects. A one-week washout is described, but the record does not report an assessment establishing whether carryover was absent. The record also does not report a multiplicity strategy for the separate questionnaire conditions or other outcome measures.

The registry lists secondary outcomes involving interpretation, attention to threat cues, and monetary transfer in a trust game, but it does not report analyses for them. It lists 4 outcome measures and 0 analyses. The record does not provide the trial’s own sample-size justification or a statistical analysis plan. These omissions limit assessment of both the intended inference and the robustness of any result.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Oxytocin Administration in BDD and OCD — NCT02671266.
• Registry record last updated 2018-11-23; status last verified 2018-11.
• Results first posted 2018-11-23.
• 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.

18. Record Summary

The registry record describes NCT02671266, “Oxytocin Administration in BDD and OCD,” with the official title “Effect of Intranasal Oxytocin on Social Cognition.” It is listed as a completed, randomized, double-masked phase 2 crossover trial, sponsored by Massachusetts General Hospital. Enrollment was 41; the recorded start was 2014-12 and primary completion was 2017-10.

Oxytocin was compared with placebo in two treatment sequences, with a one-week washout described. The primary measure was the Emotion Recognition Questionnaire, assessed 45 minutes after nasal spray administration. The record describes BDD and healthy control participants in the primary-outcome data and states that the OCD group was excluded from analyses because of recruitment difficulties.

The registry does not report a single numerical primary-outcome comparison. Safety summaries list no serious adverse events or deaths in either group, and list other adverse-event counts of 15 for oxytocin and 17 for placebo.