This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Sodium Nitroprusside in Early Course Schizophrenia (NCT04986072), a randomized phase 2 study. The primary outcome is Positive and Negative Syndrome Scale (PANSS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04986072 |
| Phase | Phase 2 |
| Condition | Schizophrenia, Schizoaffective Disorder |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Beth Israel Deaconess Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with symptomatic early-course schizophrenia. The listed conditions are schizophrenia and schizoaffective disorder. Eligibility criteria and further details about the intended population are not reported in the registry record. Enrollment was 1, so the record documents only a single enrolled participant.
Intervention
The intervention was intravenous sodium nitroprusside at 0.5 μg/kg/min for 4 hours. The study description frames the treatment question around psychosis symptoms, cognition, and retinal measures, with retinal imaging considered as a possible biomarker related to treatment response.
Comparator
The comparator was the placebo arm, described as 5% dextrose at 0.5 μg/kg/min for 4 hours. The registry record identifies the study as randomized, quadruple-masked, and parallel. Further details about randomization procedures, masking roles, or treatment administration are not reported in the registry record.
Primary question
The primary outcome was the Positive and Negative Syndrome Scale (PANSS), with total, positive, and negative scores to be compared between sodium nitroprusside and placebo at hour 2. The registry record says that the outcome data will not be shown because of privacy concerns relating to the single participant. Consequently, the treatment comparison cannot be evaluated from the posted outcome results.
The study's broader purpose was to examine whether sodium nitroprusside affects psychosis symptoms, cognition, and retinal measures in symptomatic early-course schizophrenia. Its title also identifies a proof-of-mechanism question: whether a retinal biomarker could predict treatment response. The registry record describes the motivation in terms of peripheral inflammation, microvascular dysfunction, retinal imaging, and interest in sodium nitroprusside, while noting that earlier results for sodium nitroprusside were inconsistent. These are the rationale and aims, not findings from this trial.
The record does not report a treatment effect for PANSS, cognitive outcomes, or retinal measures. It therefore does not establish whether scores differed between the arms or whether retinal measures predicted response. Because enrollment was 1 and the PANSS data are withheld, the planned comparison is not available for statistical interpretation.
3. Trial Design
The registry classifies the study as Phase 2, randomized, quadruple-masked, and parallel. Its title describes a proof-of-mechanism study using a retinal biomarker to predict response to intravenous sodium nitroprusside in symptomatic early-course schizophrenia. The listed conditions are schizophrenia and schizoaffective disorder. The record names sodium nitroprusside and 5% dextrose as the interventions, and identifies the latter as the placebo arm.
The sodium nitroprusside arm is described as receiving 0.5 μg/kg/min for 4 hours. The placebo arm is described as receiving 5% dextrose at 0.5 μg/kg/min for 4 hours. Both are intravenous interventions according to the study title and summary. The record does not describe the practical procedures used to prepare or administer either infusion.
Enrollment was 1. The status is terminated. The recorded study start is 2022-03-14, and the primary completion date is 2024-06-01. These dates and status describe the registry record; they do not explain why the study ended or whether the planned conduct changed. The reason for termination is not reported in the registry record.
The primary outcome is PANSS, with total, positive, and negative scores compared between sodium nitroprusside and placebo at hour 2. The record states that the outcome data will not be shown because of privacy concerns related to the single participant. Although the study summary refers to cognition and retinal measures, the posted primary outcome entry does not provide results for them. Further outcome definitions and analysis details are not reported in the registry record.
Randomization and masking are design features, but the record does not describe the random sequence, allocation concealment, or which people were masked. It also does not report a planned sample size, a recruitment target, the reason for stopping, or whether any interim review occurred. Those matters cannot be inferred from the design labels or from the single recorded enrollment.
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
| Stage | Sodium Nitroprusside Arm | Placebo Arm |
|---|---|---|
| STARTED | 0 | 1 |
| COMPLETED | 0 | 1 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Due to privacy concerns of single participant, data will not be shown for this outcome
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: Study Terminated due to low enrollment
| Characteristic | Unit | Sodium Nitroprusside Arm | Placebo Arm | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 1 | 1 | |
| Age, Customized: Due to privacy concerns of single participant, data will not be shown for this outcome | Participants | — | NA | NA |
| Sex/Gender, Customized: Due to privacy concerns of single participant, data will not be shown for this outcome | Participants | — | NA | NA |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | — | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | — | 0 | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | — | 1 | 1 |
| Region of Enrollment: United States | participants | — | 1 | 1 |
| PANSS Total Score | score on scale | — | NA | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Positive and Negative Syndrome Scale (PANSS), measured over Measured at hour 2.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the Positive and Negative Syndrome Scale (PANSS). The registry record specifies comparisons between sodium nitroprusside and placebo for the total score and the positive and negative scores, measured at hour 2. Thus, the endpoint is intended to represent symptom-score differences between the two treatment arms at the stated assessment time.
Considering total, positive, and negative scores allows the study question to address an overall score as well as the two named symptom dimensions. In general, a scale score gives a structured way to record a measured feature and compare groups using the same outcome definition. For this trial, the registry record does not provide the PANSS score values, the scale's scoring details, or a result for any of the listed score categories.
The registry specifically states that data for this outcome will not be shown because of privacy concerns relating to the single participant. Consequently, readers cannot assess the observed scores, the size or direction of any difference, or the precision of an estimated comparison. No confidence interval or inferential result for PANSS is reported in the registry record. The hour 2 assessment is the only time point stated for this primary outcome entry; the record does not explain why that time point was selected.
The study summary also mentions cognition and retinal measures, and the title emphasizes a retinal biomarker and treatment response. Those aims provide context for the trial, but they do not replace the stated primary endpoint. The registry record does not report endpoint results for cognition or retinal measurements.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the registry record reports enrollment of 1 and withholds the primary PANSS outcome data because of privacy concerns. It lists no analyses. As a result, the posted record does not supply an estimated treatment difference, a confidence interval, or a statistical test for the primary comparison. There is no numerical estimate from which to assess the direction, magnitude, or precision of a sodium nitroprusside versus placebo contrast.
The PANSS comparison was intended to include total, positive, and negative scores at hour 2. Because these categories are not represented by a single reported comparison and the underlying data are withheld, the stated endpoint cannot be reduced to a quantitative result. The record's explanation about privacy is important: the absence of scores is not evidence that the treatments had identical scores, nor is it evidence of a particular response. It means the data are not available in the posted outcome entry.
The study's randomized, quadruple-masked, parallel design describes how the trial was classified, not what its results were. Randomization and masking can be features of a design intended to support fair comparisons, but they do not create an interpretable treatment estimate when the outcome observations and analysis are not reported. With only the enrollment count and no posted outcome analysis, the registry record does not permit readers to assess how well those design features operated in practice.
There are also no reported results for cognition or retinal measures in the record. The trial's stated interest in a retinal biomarker and treatment response therefore remains an aim rather than a demonstrated relationship in the posted results. No conclusion about prediction, mechanism, or clinical effect follows from the study description alone.
The adverse-event entries are limited and should be read in their recorded form. The sodium nitroprusside arm lists 0 participants at risk for serious adverse events and 0 affected; it also lists 0 at risk for other adverse events and 0 affected. The placebo arm lists 1 at risk for each category and 0 affected. Deaths are recorded as 0 in both arms. These counts do not provide a comparative safety estimate, particularly because enrollment was 1 and the recorded at-risk counts differ between arms. The registry does not supply explanatory detail that would clarify the zero at-risk entry for the sodium nitroprusside arm.
Overall, the posted record documents a planned comparison and a very limited set of outcome and safety entries, but not an evaluable efficacy analysis. The absence of a reported effect is not a null finding. It is not possible to distinguish no effect from an effect that is uncertain or simply unreported using these registry results.
9. Statistical Methods Explained
Statistical interpretation depends on separating a study's design, its measured outcomes, and its reported analysis. The registry classifies this study as randomized, quadruple-masked, and parallel. These terms describe aspects of the intended comparison. They do not provide the outcome observations, the analysis method, or evidence about the success of the design in this particular trial. The record gives no further account of sequence generation, allocation concealment, or which groups of people were masked.
What would an arm comparison represent?
In a parallel trial, each arm represents a treatment group, and the outcome is compared between groups. Here, the recorded arms are sodium nitroprusside and placebo, with each infusion described at 0.5 μg/kg/min for 4 hours. The primary comparison concerns PANSS total, positive, and negative scores at hour 2. A statistical contrast would summarize how the measured scores in one arm differ from those in the other, according to a specified analysis. The registry record does not report such a contrast.
Random allocation is generally used to reduce systematic differences between treatment groups at the point of assignment. Masking is generally intended to reduce the influence of knowledge about treatment assignment on conduct, assessment, or interpretation. These are general statistical and trial-design concepts; the record does not describe the specific procedures used. In particular, it does not state who was included in the quadruple masking designation or how treatment assignments were concealed.
What does a confidence interval communicate?
In general, a confidence interval expresses the uncertainty around an estimated quantity under a stated statistical procedure. Its width reflects precision: a wider interval indicates less precision, while a narrower interval indicates greater precision. A confidence interval can help readers judge which effect sizes remain compatible with the data and analysis. No PANSS estimate or confidence interval is reported in this registry record, so precision cannot be assessed. This general explanation does not imply that an interval was calculated for the trial.
Why does the missing analysis matter?
The registry reports zero analyses and withholds the primary outcome data because of privacy concerns associated with the single participant. Without the observed scores and an analysis result, there is no basis for determining whether the recorded groups differed. The design description cannot stand in for the analysis. Nor can the lack of a posted estimate be interpreted as a finding of no difference: no such estimate is available to evaluate.
The primary endpoint lists three score categories: total, positive, and negative. Statistical methods for multiple outcomes generally need to make clear which comparisons were planned and how the possibility of chance findings across multiple comparisons is addressed. That is the general reason multiplicity matters. The registry record does not report an adjustment strategy or an analysis plan. It also does not provide enough information to determine whether additional outcome measures were included in a formal multiplicity plan.
What can be said about planning calculations?
Planning illustrations can estimate the sample size needed for a future study under explicit assumptions. They are not observations from a trial and do not tell readers how many participants were actually enrolled. The stated assumptions for such illustrations are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. The record does not provide a trial-specific sample-size justification or identify those illustration assumptions as the design basis for this study.
There is no reported observed treatment effect to anchor an interpretation of effect-based planning rows. Any sample-size illustration should therefore be understood as planning rather than as evidence about treatment efficacy. Such an illustration is not observed power, and it cannot recover the missing PANSS results or explain why enrollment was 1.
Why can over-dispersion matter?
In general, over-dispersion means that observed variability is greater than a statistical model assumes. When a model does not account for that extra variability, standard errors may be too small and intervals or tests may be too optimistic. This is a general concept, not a claim about this trial: the registry record does not report a model, a dispersion assessment, or an analysis of count outcomes. The primary endpoint is reported as PANSS scores, but no score distribution or model details are available.
Similarly, statistical methods for time-to-event outcomes, repeated measurements, or missing observations require information about the outcome structure and analysis population. The posted record does not report such methods for this trial. The primary outcome entry states an hour 2 measurement, while the registry's outcome data are withheld. Readers therefore cannot determine whether any observations were missing, how they were handled, or which analysis population was used.
The sound interpretation is limited to the registered design, the specified outcome, the enrollment count, and the availability of reported results. The record gives no analysis from which to estimate a treatment effect or its precision, and no basis to reconstruct an unreported statistical plan.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome entry includes PANSS total, positive, and negative scores. The registry record does not report a multiplicity strategy for handling these categories or any additional outcomes. In general, multiplicity matters when several outcomes or comparisons are examined, because interpreting each test separately can increase the chance of a misleading positive result. This general issue does not establish that any particular adjustment was planned or needed in this study; the analysis plan is not reported.
The outcome entry states that data will not be shown because of privacy concerns related to the single participant. The registry record lists no analyses, and it does not report whether outcome observations were missing, whether any imputation was used, or how missing values would be handled. The reason for withholding the outcome values is stated, but that does not establish that the underlying measurements themselves were missing.
The analysis population is also not reported in the registry record. It is therefore not possible to tell whether the intended analysis would have followed randomized assignment, included only participants with observed outcomes, or used another population definition. With enrollment of 1, and without a posted outcome analysis, none of these analysis choices can be evaluated.
The record does not report interim analyses, a statistical analysis plan, or the reason for termination. Those omissions prevent assessment of whether the planned comparisons or analysis populations changed during the study.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Placebo Arm | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Sodium Nitroprusside Arm | 0 of 0 |
| Placebo Arm | 0 of 1 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Sodium Nitroprusside Arm | 0 of 0 |
| Placebo Arm | 0 of 1 |
The serious adverse-event entries list the sodium nitroprusside arm as having 0 participants at risk and 0 affected. The placebo arm lists 1 participant at risk and 0 affected. The record lists 0 participants at risk for other adverse events and 0 affected in the sodium nitroprusside arm; the placebo arm lists 1 at risk and 0 affected. Deaths are recorded as 0 in each arm. No serious adverse-event terms are listed.
These entries are counts in the registry record, not a comparative analysis. The sodium nitroprusside arm's recorded at-risk count is 0, so its zero affected count cannot be read as evidence about adverse events among an exposed group. The placebo arm has 1 recorded at risk and zero affected in the listed categories. Because the recorded counts are limited and differ by arm, they do not support a stable comparison of event rates or a broad safety conclusion.
The enrollment count is 1, and the record does not explain the arm-specific at-risk entries or give further adverse-event detail. In particular, the figures do not show how the sole enrolled participant relates to the posted arm counts. The most faithful reading is to report the recorded counts without inferring unlisted events or attributing a safety outcome to either treatment.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, quadruple-masked, parallel Phase 2 study was registered to compare intravenous sodium nitroprusside with 5% dextrose in symptomatic early-course schizophrenia. It records enrollment of 1 and a terminated status. The intended primary comparison was for PANSS total, positive, and negative scores at hour 2.
It does not establish whether sodium nitroprusside changed PANSS scores relative to placebo. The score data are withheld for privacy concerns relating to the single participant, and the registry lists no analyses. There is no reported effect estimate, uncertainty interval, or test result. An unreported result should not be interpreted as evidence of no difference, just as the study's stated rationale should not be interpreted as evidence of benefit.
The study description refers to cognition and retinal measures and identifies a retinal biomarker prediction question. Those aims are part of the study's rationale, but no corresponding results are reported in the registry record. The record therefore cannot establish whether retinal measurements predicted response, whether any proposed mechanism was supported, or whether cognition differed between treatment arms.
The adverse-event entries are too limited to provide a comparative safety estimate. Counts recorded as zero affected do not, by themselves, demonstrate an absence of risk, especially when the at-risk counts are 0 in the sodium nitroprusside arm and 1 in the placebo arm. The record does not explain those entries.
The record is informative about what was planned and what is available for public interpretation, but its posted results do not answer the treatment-effect question. The termination reason, trial-specific sample-size rationale, analysis plan, missing-data approach, and analysis population are not reported in the registry record. No conclusion beyond these recorded design and reporting details is warranted.
13. Why This Trial Matters Statistically
This trial illustrates why design labels and numerical results must be read separately. Randomization and masking describe intended protections against bias, while the treatment effect must be assessed from observed outcomes and an analysis. The registry identifies the design but does not provide an evaluable PANSS comparison. Readers cannot infer the result from the design alone.
Enrollment of 1 is central to interpreting the record. The primary outcome data are withheld because of privacy concerns related to the single participant, and no analyses are listed. This makes the record a useful example of the limits that can arise when reporting individual-level outcome information: privacy constraints can leave the planned scientific comparison unavailable to readers. The record does not explain the termination or give a reason for the recorded enrollment.
The intended endpoint also highlights the need to be clear about outcome structure. PANSS total, positive, and negative scores are all named, but no values or analysis are reported. A reader cannot judge the direction or precision of a group contrast, and cannot tell how multiple score categories would have been treated statistically. The trial's retinal biomarker objective likewise remains an aim without reported results.
The safety entries reinforce the importance of denominators and context. Counts of affected participants need to be read alongside the recorded numbers at risk; the values differ between arms, and the sodium nitroprusside arm lists no participants at risk. Treating a zero count as a comparative safety result would overstate what the record supports.
Statistically, the record demonstrates the distinction between an intended comparison, an observed result, and a conclusion. It documents the former, but does not make the latter two available. A disciplined reading preserves that distinction and avoids converting absent estimates into a claim of no effect.
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 most important limitation for interpretation is that the primary PANSS outcome data are not shown. The registry attributes this to privacy concerns involving the single participant. Without the outcome values or an analysis, no treatment contrast or measure of precision can be examined. The absence of reported results leaves the central efficacy question unanswered.
Enrollment was 1, and the study status is terminated. The reason for termination is not reported in the registry record. The record also does not explain how the single enrollment relates to the arm-specific adverse-event counts, including the sodium nitroprusside arm's zero at-risk entries. This limits interpretation of both the outcome reporting and the safety entries.
The registered primary endpoint contains total, positive, and negative PANSS scores, but the record does not provide scoring details beyond those labels or report results for any category. It does not report a statistical analysis plan, multiplicity approach, missing-data method, or analysis population. The trial-specific sample-size justification is not reported in the registry record, and the stated planning-illustration assumptions should not be mistaken for the study's own design rationale.
The study summary names cognition and retinal measures, but the posted result information does not include their outcomes. Details about the retinal biomarker measurement, the prediction analysis, and the definitions of cognitive outcomes are not reported in the registry record. The registry design labels also are not accompanied by details of the randomization procedure or the people included in quadruple masking.
These limitations mean that the record supports description of the trial's stated aims and design, but not a reliable assessment of efficacy, biomarker prediction, or comparative safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Sodium Nitroprusside in Early Course Schizophrenia — NCT04986072.
- Registry record last updated 2025-12-30; status last verified 2025-12.
- Results first posted 2025-12-10.
- 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.
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18. Record Summary
The record describes a Phase 2 randomized, quadruple-masked, parallel study titled Sodium Nitroprusside in Early Course Schizophrenia. It lists schizophrenia and schizoaffective disorder as conditions, and identifies sodium nitroprusside and 5% dextrose as the intervention and placebo. Each arm is described as an infusion at 0.5 μg/kg/min for 4 hours.
Enrollment was 1, and the study status is terminated. The recorded start date is 2022-03-14 and the primary completion date is 2024-06-01. The primary outcome is PANSS total, positive, and negative scores at hour 2. The outcome data are not shown because of privacy concerns related to the single participant; the record lists no analyses.
The study summary also discusses cognition and retinal measures, including a retinal biomarker response question, but no results for these aims are reported. Adverse-event counts are sparse, and the at-risk counts differ between arms. The reason for termination, analysis plan, and trial-specific sample-size justification are not reported in the registry record.