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 Study in Schizophrenic In-patients Treated With Quetiapine Prolong or Oral Risperidone at Flexible Dose (NCT00660595), a randomized phase 3 study. The primary outcome is Change From Baseline in Positive and Negative Symptoms Scale, Excitatory Subscale (PANSS-EC) Score (Time Frame: 3 Weeks).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00660595 |
| Phase | Phase 3 |
| Condition | Schizophrenic Disorders |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 29 |
| Arms in the primary outcome | n/a |
| Lead sponsor | AstraZeneca |
| Results posted | Yes |
2. Clinical Question
Population
In-patients with acute schizophrenic disorders, including schizophrenia, schizoaffective psychosis or schizophreniform psychosis as described in the registry summary. The study took place in Finland. The record gives an enrollment of 29.
Intervention
Oral quetiapine, identified in the record as Quetiapine and Seroquel. The official title describes flexible dosing and uses the name Quetiapine Prolong.
Comparator
Oral risperidone, identified in the record as Risperidone and Risperdal. The official title describes flexible dosing.
Primary question
The primary outcome was change from baseline in the Positive and Negative Symptoms Scale Excitatory Subscale (PANSS-EC) score at three weeks. The registry record does not report the outcome results, so it does not establish the direction or size of any difference between the treatment groups.
The trial was described as a pilot study of agitation in acute in-patients. Its primary endpoint focuses on the PANSS-EC, a symptom scale covering impulse control, tension, hostility, uncooperativeness and excitement. The research question can therefore be stated as whether change in this excitatory-symptom score over the stated three-week period differed between the randomized treatment groups. The registry record does not provide a numerical group comparison, an uncertainty interval or a significance test for that question.
The other named outcomes included the Clinical Global Impression scales, the Overt Aggression Scale and the overall PANSS score. These measures provide different views of symptoms and clinical status, but their presence does not substitute for a reported primary-outcome result. The record does not say which outcome, if any, was used to draw a formal conclusion about the comparison.
3. Trial Design
This was a randomized, parallel-group, open-label study. The registry lists the phase as Phase 3, while the official title and brief summary describe the study as a pilot. The allocation method is recorded as randomized, and masking is recorded as none. The two interventions were quetiapine and risperidone, both administered orally; the title specifies flexible doses.
The registry record gives an enrollment of 29 and identifies the setting as in-patient care in Finland. It lists the study as terminated. The start is recorded as 2008-09 and primary completion as 2008-12. The reason for termination, the number randomized to each group, and the number completing follow-up are not reported in the registry record. The record does not explain whether termination affected recruitment, follow-up, or the availability of outcome data.
The stated primary endpoint was change from baseline in PANSS-EC score at three weeks. The summary describes early visits on days 1, 2, 4 or 5, and 7 ± 1. Secondary outcomes were scheduled for repeated assessment over three weeks: CGI-S and CGI-I, OAS, and total PANSS score. The precise analysis schedule and the details of how those repeated measurements were incorporated into any statistical model are not reported in the registry record.
Randomization is intended to make treatment groups comparable on average, while a parallel design assigns participants to one group rather than having each participant receive both interventions. Open-label status means masking is recorded as absent; the record does not describe any masked assessment procedures. These design features help characterize the planned comparison but do not by themselves establish how well randomization worked in the enrolled sample. Group-level baseline characteristics and an account of allocation concealment 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: Site 01 pre-screened 19 subjects, two were randomised, 12 did not consent to participate and five were not included due to other reasons.One subject completed the study and the other discontinued from the study on Day 2 (subject escaped from the hospital).Site 03 pre-screened 10 subjects, of which only one completed the study.
Overall Study
| Stage | Seroquel | Risperdal |
|---|---|---|
| STARTED | 19 | 10 |
| COMPLETED | 1 | 1 |
| NOT COMPLETED | 18 | 9 |
Reasons for not completing this period:
| Reason | Seroquel | Risperdal |
|---|---|---|
| Lost to Follow-up | 0 | 1 |
| Did not consent to participate in study | 12 | 8 |
| Participant left hospital | 1 | 0 |
| Non Specified reasons | 5 | 0 |
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.
| Characteristic | Unit | Seroquel | Risperdal | Total |
|---|---|---|---|---|
| Participants analysed | 19 | 10 | 29 | |
| Age Continuous | years | 47 (47 to 47) | 51 (39 to 63) | 49 (47 to 63) |
| Gender: Female | Participants | 1 | 1 | 2 |
| Gender: Male | Participants | 0 | 1 | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Positive and Negative Symptoms Scale, Excitatory Subscale (PANSS-EC) Score (Time Frame: 3 Weeks), measured over baseline and 3 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | units on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was change from baseline in the Positive and Negative Symptoms Scale Excitatory Subscale (PANSS-EC) score over three weeks. The registry describes the endpoint as the difference between the baseline score and the score at three weeks. It does not give the endpoint results or clarify the sign convention used when reporting a change, so direction should not be inferred from the endpoint description alone.
The PANSS-EC comprises five items: poor impulse control, tension, hostility, uncooperativeness and excitement. Each item has descriptors rated on a seven-point scale, with 1 representing absence of a symptom and 7 representing extremely severe symptoms. A score on this subscale is intended to summarize these related aspects of excitatory symptoms rather than to represent a single symptom in isolation.
Change from baseline is used in clinical trials to describe how a measured score shifts during follow-up relative to the participant's starting score. Comparing changes between randomized groups can address whether their measured trajectories differed over the specified period. That interpretation depends on the actual group results and their uncertainty, neither of which is reported in the registry record. The endpoint description also does not specify whether the reported comparison was adjusted for baseline score or how incomplete measurements were handled.
The registry lists other clinical scales as secondary outcomes. They can offer additional perspectives, but they are distinct measures and cannot be treated as evidence for the primary endpoint in the absence of their own results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a planned randomized comparison and a prespecified primary outcome, but it does not provide a numerical primary-outcome estimate. No treatment-group means or changes, between-group contrast, confidence interval or test result are reported in the registry record. The record therefore does not permit a quantitative assessment of the size, direction or precision of the observed difference in PANSS-EC change.
The enrollment is 29, but that figure alone does not show how many participants were assigned to each treatment, contributed a baseline measurement, or had a three-week outcome recorded. Those counts are not reported in the registry record. A reader cannot determine from the enrollment figure whether all enrolled participants were included in an outcome analysis, or whether attrition differed between groups.
A confidence interval, when reported, describes a range of values compatible with the data under the analysis assumptions; its width communicates precision. No such interval for the primary comparison is reported. Likewise, no p-value or other inferential result is reported. It is not possible to label the comparison statistically significant or not statistically significant based on the information in this record.
The record lists four outcome measures: the primary PANSS-EC measure and secondary measures covering clinical global impressions, overt aggression and total PANSS score. Multiple outcomes or repeated assessments can create multiple opportunities for apparently notable findings. An analysis plan may address this through a prespecified primary outcome or an adjustment strategy, but the registry record does not report a multiplicity procedure or the results needed to assess its use.
The registry describes the study as a pilot and lists it as Phase 3, but neither label supplies evidence about the treatment comparison. The pilot designation signals the study's stated characterization; it does not explain the sample-size rationale or establish that the study was designed to estimate an effect precisely. The sample-size justification is not reported in the registry record.
The safety entries are also sparse. The record lists one participant at risk in each group, no serious adverse events in either group, no other adverse events for Seroquel, and one other adverse event for Risperdal. These entries should be read as registry-recorded counts, not as a complete estimate of comparative safety. The small listed at-risk counts and missing detail limit what can be inferred, and the record does not explain their relationship to the overall enrollment.
Overall, the record establishes what comparison and outcomes were planned, along with limited adverse-event counts. It does not report the efficacy analyses needed to interpret the primary question. Conclusions about relative symptom change, precision, or the consistency of secondary findings would go beyond the posted results.
9. Statistical Methods Explained
What does randomization contribute?
In general, randomization assigns participants to treatment groups by chance. Its purpose is to reduce systematic differences between groups at the point of assignment, including differences that may not be measured. It does not guarantee that the groups will be identical, particularly in a small study. Baseline characteristics and the actual allocation counts are useful for describing the enrolled groups, but these are not reported in the registry record.
This trial is recorded as randomized, parallel-group and open-label. Parallel-group means the design compares separate groups assigned to the respective interventions. Open-label means masking is recorded as absent. The registry record does not describe the random sequence method, allocation concealment or any use of masked outcome assessment, so those details should not be assumed.
How should change from baseline be understood?
In general, a change score represents a follow-up measurement relative to a baseline measurement. The primary endpoint description defines the relevant measurements as baseline and three weeks. To compare treatments, an analysis might compare average changes between groups or use a model that accounts for baseline and follow-up measurements. These approaches can have different assumptions and may yield different estimates. The registry record does not state which method was used.
The outcome is measured on the PANSS-EC, which contains five symptom items rated on a seven-point scale. The scale gives structure to clinical ratings, but the numerical score remains a measure of symptom severity rather than a direct count of events. Interpretation depends on the scoring and the comparison reported. Because the results and the direction convention are absent, no score change or group difference can be reconstructed from the endpoint description.
What would an estimate and confidence interval tell a reader?
In general, an effect estimate describes the observed contrast between groups on an outcome. A confidence interval conveys uncertainty around that estimate under the statistical model and its assumptions. A narrow interval indicates greater precision than a wide interval, but neither the estimate nor its interval is reported for the primary endpoint in the registry record. Without them, the magnitude and precision of the treatment comparison cannot be evaluated. A p-value, if reported, would address compatibility with a specified null model; it would not by itself describe the magnitude or practical importance of an effect. No p-value for the primary comparison is reported.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a model assumes. If a model underestimates variability, its uncertainty estimates can be too small and inferential results can appear more decisive than warranted. This concept is most relevant to particular kinds of data and models, such as counts, and does not establish that over-dispersion occurred in this trial. The registry record does not describe a model, a dispersion assessment or any adjustment for over-dispersion.
How should repeated measurements be handled?
The secondary-outcome descriptions indicate repeated assessments during the three-week period. Repeated observations from the same participant are generally correlated; they should not automatically be treated as independent pieces of information. Statistical methods for repeated measures can account for this dependence and may use measurements collected at more than one visit. The record does not specify the models, covariance assumptions, visit-selection rules or handling of missed visits. The visit schedule alone is not enough to identify the analysis method.
What does the planning illustration represent?
In general, a sample-size calculation is a planning exercise based on assumptions about the effect to detect, variability, significance level, allocation and analysis method. The registry record describes an illustration using a two-sided significance level of 0.05, equal allocation, a normal approximation and a stated fraction of an observed effect. It also distinguishes illustrations expressed as participants per arm from time-to-event illustrations expressed as total events. No numerical planning estimates or observed effect estimate are reported in the registry record.
Such an illustration is not an observed study result and is not observed power. It cannot establish that the enrolled study had a particular probability of detecting an effect. The trial's own sample-size justification and the assumptions used in its original design are not reported in the registry record. In general, power calculated after observing results is not a substitute for reporting an effect estimate and its uncertainty.
What can be inferred from the analysis count?
The record lists zero analyses. This indicates that no analysis results are represented in the registry entry; it does not establish that investigators performed no analyses outside the registry. Results may be unavailable for several reasons, but the reason for the absent analyses is not reported in the registry record. Statistical interpretation should therefore distinguish a missing registry result from a finding of no difference.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary PANSS-EC outcome and three secondary outcome descriptions: CGI-S and CGI-I, OAS, and total PANSS. The secondary descriptions also include repeated assessments. Examining several outcomes or time points can increase the chance of obtaining a seemingly notable result by chance if many comparisons are treated as confirmatory. In general, a prespecified primary outcome and a declared multiplicity strategy help clarify which comparisons are intended to support formal conclusions. A multiplicity adjustment or testing hierarchy is not reported in the registry record.
The record lists zero analyses and gives no primary or secondary outcome results. Thus, it is not possible to assess whether the stated endpoint was analyzed as planned, whether all measured outcomes were reported, or whether any adjustment was applied. The reason the analyses are absent is not reported in the registry record.
Missing-data handling is not reported in the registry record. The number of participants with baseline and follow-up measurements, reasons for missing assessments, and any imputation or model-based approach are also not reported. These details matter because participants who lack follow-up data may differ from those with observed measurements, and analytical choices can affect estimates and their uncertainty.
The analysis population is not reported in the registry record. It is therefore unclear whether analyses were intended to include all randomized participants, only participants with observed outcomes, or another defined group. The record also does not give the number randomized to each arm or the number retained for analysis. No conclusion about adherence to an intention-to-treat approach, a per-protocol approach or another population can be made from the entry.
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 |
|---|---|---|---|
| Seroquel | 0 | 1 | 0.0% |
| Risperdal | 0 | 1 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Seroquel | 0 of 1 |
| Risperdal | 1 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Seroquel | Risperdal |
|---|---|---|---|
| Muscle spasms | Musculoskeletal and connective tissue disorders | 0 of 1 | 1 of 1 |
| Elevated Prolactin Level | Endocrine disorders | 0 of 1 | 1 of 1 |
The registry lists serious adverse-event counts of zero for the Seroquel group and zero for the Risperdal group. It lists one participant at risk in each group. For other adverse events, it records zero for Seroquel and one for Risperdal, again with one participant at risk in each group. The record does not report deaths in these entries.
These are the registry-recorded figures and should not be read as a complete comparative safety analysis. The at-risk counts are much smaller than the overall enrollment of 29, and the registry record does not explain how these counts relate to enrollment, treatment assignment or safety follow-up. It does not give event descriptions, severity, timing, exposure duration or participant-level information. The absence of a listed serious event is not proof that no such event occurred outside the recorded data.
In general, adverse-event counts require denominators that reflect the participants actually monitored and definitions that are applied consistently across groups. A single recorded event cannot by itself establish a treatment-related pattern. The sparse entries and lack of explanatory detail prevent a reliable estimate of comparative event frequency or a broad safety conclusion.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, open-label comparison of oral quetiapine and oral risperidone was planned in in-patients with acute schizophrenic disorders, with change in PANSS-EC score at three weeks designated as the primary outcome. It also identifies several secondary clinical measures and gives an enrollment of 29. These registry entries describe the study question and design; they are not evidence of an outcome difference.
The primary results are not reported in the registry record. Consequently, the posted information does not show whether either group had a larger or smaller change, how large a between-group contrast may have been, or how precisely it was estimated. The absence of a reported analysis should not be interpreted as evidence that the treatments produced the same result, nor as evidence that one produced a better result.
The record also does not provide secondary-outcome results, an analysis population, follow-up completion counts or a missing-data approach. It is therefore not possible to assess whether other clinical measures were consistent with the primary outcome or whether missing observations could have affected the comparison. The listed adverse-event entries are limited and do not provide a comprehensive safety assessment.
In general, a randomized design can support a comparative interpretation when the allocation, follow-up and analysis are adequately reported. Here, the registry information is insufficient to evaluate the numerical treatment effect or its uncertainty. The trial's Phase 3 designation does not fill that gap, and the description as a pilot does not provide an effect estimate. Any conclusion about comparative efficacy or safety would require results and methods not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically notable because its record pairs a clear comparative question with a lack of posted analysis results. The randomized, parallel design and named primary endpoint identify the intended contrast: change in PANSS-EC score between oral quetiapine and oral risperidone over three weeks. Yet without the group estimates, uncertainty intervals and analysis details, readers cannot quantify the evidence bearing on that question.
The record also illustrates why enrollment is not a substitute for an analysis denominator. Enrollment is 29, but the group allocation counts, endpoint availability and analysis population are not reported. Those details are needed to understand how much information contributes to an estimate and whether participants were lost before outcome assessment. Their absence also makes it difficult to interpret the very small at-risk counts listed for adverse events.
Outcome multiplicity is another statistical consideration. The record names several clinical measures and repeated assessments, but does not report a multiplicity plan or results. A prespecified primary endpoint can help organize interpretation, while transparent reporting of secondary analyses clarifies whether their findings are supportive or exploratory. Without analyses, neither role can be evaluated.
The entry therefore provides a useful lesson in distinguishing design information from evidence. Randomization, phase designation and outcome definitions describe how a comparison was intended to work; they do not reveal what the comparison found. Statistical interpretation requires estimates, precision and transparent accounting of the participants analyzed. Those elements are not reported in the registry record.
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.
This trial-specific interpretation is limited chiefly by the absence of posted outcome analyses. The record does not report a primary-endpoint estimate, group-level summary, confidence interval, test result or secondary-outcome result. It is therefore impossible to describe an observed treatment contrast or its precision.
The registry lists an enrollment of 29 but does not report the number assigned to each arm, the number completing three-week follow-up, or the number included in any analysis. The reason for termination is not reported in the registry record. It is also unclear whether termination affected recruitment or the availability of outcome data.
The study is described both as a pilot and as Phase 3. The record does not explain this characterization or give the protocol details needed to understand the intended scope. The sample-size justification, primary analysis method, allocation procedure and handling of baseline scores are not reported. The record does not specify how repeated assessments were modeled or how missing observations were treated.
Several measures and time points are named, but no multiplicity strategy is reported. The available adverse-event entries contain very small at-risk counts relative to the stated enrollment and lack explanatory context, event descriptions and follow-up details. They cannot support a broad comparison of safety.
Finally, the registry summary identifies acute in-patients in Finland and flexible-dose oral treatment, but does not provide further participant characteristics, dose information or baseline group descriptions. These omissions limit assessment of the enrolled sample and the detail with which the intended comparison can be understood.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study in Schizophrenic In-patients Treated With Quetiapine Prolong or Oral Risperidone at Flexible Dose — NCT00660595.
- Registry record last updated 2010-09-17; status last verified 2010-08.
- Results first posted 2010-09-17.
- 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 registry record describes NCT00660595, a randomized, open-label, parallel pilot comparison of oral quetiapine and oral risperidone at flexible dose in in-patients with acute schizophrenic disorders. It lists Phase 3, enrollment of 29, and a terminated status. The recorded start is 2008-09 and primary completion is 2008-12.
The primary outcome was change from baseline in PANSS-EC score at three weeks. Secondary outcomes included clinical global impressions, overt aggression and total PANSS score. The record lists zero analyses and reports no primary or secondary results. It does not report the reason for termination, group allocation counts, analysis populations or missing-data handling.
Serious adverse-event entries list zero events for each group, while other adverse-event entries list zero for Seroquel and one for Risperdal; one participant at risk is recorded for each group. The limited context means these figures should not be treated as a complete comparative safety assessment.