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 Parent/Nurse Controlled Analgesia in the Neonatal Intensive Care Unit (NCT01823497), a randomized na study. The primary outcome is Morphine Consumption.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01823497 |
| Phase | NA |
| Condition | Abdominal Surgery, Thoracic Surgery |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 36 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Medical College of Wisconsin |
| Results posted | Yes |
2. Clinical Question
Population
The clinical question concerns neonates receiving morphine after surgery. The registry lists abdominal surgery and thoracic surgery as the conditions and describes the primary endpoint as measuring morphine consumed post-surgery. The endpoint result does not specify the characteristics of the neonates included in each group beyond the posted group sizes. Further details about the analyzed population are not reported in the registry record.
Intervention
The intervention is morphine delivered through Parent/Nurse Controlled Analgesia. The registry describes parents or nurses as the controllers of the delivery method. The comparison is about how morphine is administered, not about morphine versus a different drug. The record does not provide further details about the delivery protocol or the circumstances in which a parent or nurse could administer morphine.
Comparator
The comparator is continuous opioid infusion, also using morphine. The registry describes this as the method used to deliver morphine to the comparison group. Both arms therefore concern postoperative morphine delivery, with the method of delivery distinguishing the groups. Further details about dosing rules or adjustments are not reported in the registry record.
Primary question
The primary endpoint is morphine consumption in mg/kg/hr over 5 days post surgery, summarized by the median and interquartile range. The substantive question is whether the posted consumption summaries differ between Parent/Nurse Controlled Analgesia and Continuous Opioid Infusion. The registry states a study aim of examining the safety and effectiveness of the two delivery systems and describes a hypothesis about morphine consumption and side effects. However, the record does not report an inferential analysis of the primary endpoint, so the summaries alone cannot establish whether the observed group difference is statistically distinguishable from chance.
3. Trial Design
The registry describes a randomized, parallel-group trial with no masking. It is titled as a preliminary randomized controlled trial of parent/nurse-controlled analgesia for postoperative pain management in neonates. The listed study status is completed. The registry lists enrollment of 36, with a study start of 2013-04 and primary completion of 2019-03. Phase is listed as NA, and the sponsor is Medical College of Wisconsin.
The two arms differ in morphine delivery method. Parent/Nurse Controlled Analgesia is the intervention arm, and Continuous Opioid Infusion is the comparator. The posted primary endpoint summaries include 16 participants in the Parent/Nurse Controlled Analgesia arm and 9 in the Continuous Opioid Infusion arm. Those group counts do not account for the full registry enrollment; the reason for the difference is not reported in the registry record. The registry does not state how participants were randomized, whether allocation was concealed, or what procedures were used to implement either delivery method.
The primary endpoint is morphine consumption, measured in mg/kg/hr over 5 days post surgery and summarized using a median with interquartile-range dispersion. The registry lists three outcome measures and one posted secondary outcome, the Revised-FLACC Scale. It does not provide a posted analysis for the primary outcome or a group comparison for the secondary outcome. The registry record does not report a detailed statistical analysis plan, sample-size justification, interim analyses, or analysis populations. These omissions limit what can be concluded about how the trial was designed to evaluate its stated hypotheses.
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 | Parent/Nurse Controlled Analgesia | Continuous Opioid Infusion |
|---|---|---|
| STARTED | 19 | 17 |
| COMPLETED | 16 | 9 |
| NOT COMPLETED | 3 | 8 |
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 | Parent/Nurse Controlled Analgesia | Continuous Opioid Infusion | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 9 | 25 | |
| Age, Categorical: <=18 years | Participants | 16 | 9 | 25 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | days | 4 (1.3 to 12.0) | 2 (0.0 to 59.0) | 4 (2.0 to 11.0) |
| Sex: Female, Male: Female | Participants | 9 | 5 | 14 |
| Sex: Female, Male: Male | Participants | 7 | 4 | 11 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 | 0 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 14 | 9 | 23 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 2 | 7 | 9 |
| Race (NIH/OMB): White | Participants | 14 | 2 | 16 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 16 | 9 | 25 |
6. Primary Endpoint
The registry lists the primary outcome as Morphine Consumption, measured over 5 days post surgery.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | mg/kg/hr |
| Endpoint classification | not reduced to a single comparison |
Morphine consumption is the primary endpoint. It measures the amount of morphine consumed after surgery, expressed in mg/kg/hr, over 5 days post surgery. The registry describes the endpoint as a measure of the amount consumed and specifies that it is summarized by the median with interquartile-range dispersion.
In general, a consumption endpoint can describe the amount of treatment received during a defined period, while the median represents the middle of the observed values rather than an arithmetic average. The interquartile range describes the spread of the central part of a distribution. These summaries can be useful when values are skewed or when a typical observation is more informative than an average. This is a general explanation of the statistics, not a claim about the observed distribution in this trial.
The registry lists a median of 0.014 for Parent/Nurse Controlled Analgesia and 0.036 for Continuous Opioid Infusion. The corresponding posted lower and upper values are 0.013 and 0.017 for the former arm, and 0.036 and 0.04 for the latter. The registry identifies the dispersion measure as the interquartile range. It does not report an inferential comparison, a confidence interval for the between-group effect, or a clinical threshold for interpreting the size of a difference. Therefore, the endpoint summaries describe the posted observations but do not alone establish the uncertainty or clinical importance of a group contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary endpoint summaries are medians of 0.014 mg/kg/hr for Parent/Nurse Controlled Analgesia and 0.036 mg/kg/hr for Continuous Opioid Infusion. The listed group sizes are 16 and 9, respectively. The registry describes the endpoint period as 5 days post surgery and specifies interquartile-range dispersion. Its posted lower and upper values are 0.013 and 0.017 for Parent/Nurse Controlled Analgesia, and 0.036 and 0.04 for Continuous Opioid Infusion.
Descriptively, the median consumption is lower in the Parent/Nurse Controlled Analgesia arm than in the Continuous Opioid Infusion arm. That statement describes the posted summaries only. The registry record reports no analysis of the primary outcome: the number of analyses is listed as 0, and the record notes that values are missing or not estimable for a two-arm comparison for another endpoint. No p-value, confidence interval for the group contrast, adjusted estimate, or test result for morphine consumption is reported. The record therefore does not establish whether the observed difference is statistically distinguishable from chance.
In general, a confidence interval for a group contrast would communicate the range of effect values compatible with the data and the analysis assumptions. It would help readers assess precision, separately from whether a test crossed a significance threshold. No such contrast interval is reported. The posted arm-level ranges should not be treated as a confidence interval for the difference between arms; they describe the endpoint dispersion within each arm.
The registry’s study summary describes an investigator hypothesis that neonates receiving morphine through Parent/Nurse Controlled Analgesia would receive less morphine and experience fewer side effects than those receiving continuous infusion. The primary summaries are directionally consistent with the stated consumption hypothesis, but no inferential result is posted to test it. Side effects also cannot be fully judged from the limited adverse-event counts: the registry reports other adverse events in both groups but does not supply event descriptions in the posted record. A direction of observed summaries is not equivalent to proof of a treatment effect.
The primary endpoint results include 25 participants across the two reported arms, while the registry enrollment is 36. The reason that these counts differ is not reported in the registry record. It is also not reported whether the endpoint summaries include all randomized participants, how missing endpoint data were handled, or whether analyses followed randomized assignment. These gaps matter because exclusions or missing observations can affect how representative the summaries are of the randomized groups.
In general, random assignment is intended to support fair comparisons by balancing prognostic factors across groups on average, but it does not guarantee that every realized comparison is balanced. The record does not provide baseline characteristics or an adjusted analysis that would help assess this. Accordingly, the available information supports a descriptive reading of the posted endpoint values, not a definitive causal or inferential conclusion.
9. Statistical Methods Explained
The registry identifies the study as randomized, parallel, and unmasked. In a randomized trial, assignment is intended to make treatment groups comparable on average with respect to factors that may affect outcomes. In a parallel design, each participant is assigned to one group rather than receiving both delivery methods in sequence. With no masking listed, the registry does not describe the trial as blinded. These design labels do not reveal the specific randomization procedure, allocation concealment, or safeguards against bias; those details are not reported in the registry record.
What does the median describe?
The primary outcome is morphine consumption in mg/kg/hr during 5 days post surgery. The registry specifies the median as the summary measure. In general, the median is the central observation after values are ordered. It is less influenced by extreme observations than the arithmetic mean, which can make it useful for data with skew or outliers. That general property does not establish whether the trial’s consumption data were skewed; distributional details are not reported in the registry record.
The endpoint is also described with interquartile-range dispersion. In general, an interquartile range describes the span from the lower to the upper quartile and focuses on the middle part of the observed distribution. The posted lower and upper values are 0.013 and 0.017 for Parent/Nurse Controlled Analgesia and 0.036 and 0.04 for Continuous Opioid Infusion. They should be read as within-arm dispersion values, not as an interval for the difference between groups. The record does not state a separate confidence interval for the contrast.
What would a group comparison add?
Arm-specific medians describe the groups separately. An inferential comparison would address uncertainty about the difference between the groups, using a statistical method suited to the endpoint and trial design. In general, a confidence interval for a contrast gives a range of effect values compatible with the observations under the method’s assumptions. A hypothesis test can assess how compatible the data are with a specified null hypothesis. Neither kind of result is reported for the primary endpoint in the registry record. No p-value or test statistic for the primary comparison is posted.
The record lists 0 analyses. Thus, the posted medians and dispersion values should not be presented as results of an adjusted model or a formal test. The registry record does not report whether the investigators planned a rank-based test, a model for repeated measurements, an adjustment for baseline characteristics, or another method. No such approach should be inferred from the endpoint’s summary statistics.
Why can over-dispersion matter?
In general, over-dispersion occurs when outcome variability exceeds what a chosen statistical model assumes. If a model underestimates variability, its standard errors and uncertainty intervals may be too narrow, making evidence appear more precise than it is. This concept is relevant when selecting models for some types of clinical data, but the registry does not report a model for the primary endpoint or evidence of over-dispersion. It is therefore a general methodological consideration, not a finding about this trial.
What do the sample-size illustrations mean?
The registry record describes planning illustrations based on the observed effect, with two-sided significance level 0.05, equal allocation, and a normal approximation. It also states that the effect to detect is a stated fraction of the observed effect. Such illustrations are planning exercises under assumptions; they are not the trial’s observed power and do not establish that the original trial was adequately planned. The record does not report the trial’s own sample-size justification or show that these illustration assumptions were the assumptions used in the original design. No planning sample-size values are stated in the registry record.
What can be learned from the posted group sizes?
The endpoint summaries list 16 participants in the Parent/Nurse Controlled Analgesia arm and 9 in the Continuous Opioid Infusion arm. In general, smaller analyzed groups can leave estimates less precise, but the precision of a particular contrast also depends on the data distribution and the analysis method. The registry does not give a confidence interval for the contrast or explain why the endpoint group counts differ from the enrollment of 36. The reasons for this difference and the handling of missing observations are not reported in the registry record.
General statistical interpretation separates the observed effect estimate from its uncertainty and from clinical importance. Here, the posted medians describe the observed endpoint in each group. The absence of an inferential comparison means uncertainty in the between-group effect cannot be assessed from a reported test or contrast interval. The registry also gives no threshold for a clinically important difference. A reader should therefore avoid treating a descriptive contrast as a confirmed treatment effect.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures and identifies one secondary outcome, the Revised-FLACC Scale. It also lists 0 analyses, and no analysis results for the secondary outcome are reported. The registry record does not report a multiplicity strategy, such as a hierarchy of outcomes or an adjustment for testing several outcomes. In general, when several hypotheses are tested, the chance of at least one false-positive result can rise unless the analysis plan addresses multiplicity. That general concern cannot be quantified for this trial from the posted record, and no multiplicity adjustment should be assumed.
Missing-data handling is also not reported in the registry record. The primary endpoint summaries list 16 participants in the Parent/Nurse Controlled Analgesia group and 9 in the Continuous Opioid Infusion group, compared with registry enrollment of 36. The record does not explain the difference, state how many participants were randomized to each arm, describe missing endpoint values, or identify any imputation or sensitivity analysis. The population included in the primary endpoint summaries is not otherwise specified.
In general, analysis populations clarify whether results include all randomized participants, only participants who began assigned treatment, or a subset with available outcome data. Different choices can affect interpretation, particularly if missingness or exclusions are related to outcomes. The registry does not identify an intention-to-treat population, a per-protocol population, or another analysis set. It also does not report interim analyses or a statistical analysis plan. These are limitations of the available record, not evidence that a particular procedure was or was not used in the conduct of 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 |
|---|---|---|---|
| Parent/Nurse Controlled Analgesia | 0 | 16 | 0.0% |
| Continuous Opioid Infusion | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Parent/Nurse Controlled Analgesia | 0 of 16 |
| Continuous Opioid Infusion | 0 of 9 |
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 |
|---|---|
| Parent/Nurse Controlled Analgesia | 7 of 16 |
| Continuous Opioid Infusion | 5 of 9 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Parent/Nurse Controlled Analgesia | Continuous Opioid Infusion |
|---|---|---|---|
| Sedation | Respiratory, thoracic and mediastinal disorders | 7 of 16 | 5 of 9 |
| Naloxone, reintubation, or methadone | Respiratory, thoracic and mediastinal disorders | 0 of 16 | 0 of 9 |
The posted serious adverse-event counts are 0 among 16 participants in the Parent/Nurse Controlled Analgesia group and 0 among 9 participants in the Continuous Opioid Infusion group. Deaths are reported as 0 in both groups. These counts describe the recorded events in the listed groups; they do not establish that serious events could not occur or that the delivery methods have identical safety.
The registry also reports other adverse events in 7 of 16 participants in the Parent/Nurse Controlled Analgesia group and 5 of 9 participants in the Continuous Opioid Infusion group. The record does not provide the terms for those other events in the posted results. No serious adverse-event terms are listed. It is therefore not possible to characterize the nature, severity, timing, or relation to treatment of the other events from these counts alone.
In general, adverse-event counts are interpreted in relation to the number of participants assessed, the definitions used, and the period of follow-up. The record does not provide those details beyond the group counts and the primary endpoint’s timeframe. It also does not report a statistical comparison of adverse events. The safety figures should be read as descriptive registry counts, not as evidence that one method is safer or that either method has no risk.
12. What the Result Does, and Does Not, Mean
The record documents a randomized comparison of two ways to deliver morphine after surgery in neonates: Parent/Nurse Controlled Analgesia and Continuous Opioid Infusion. For the primary outcome, the posted median consumption is 0.014 mg/kg/hr in the Parent/Nurse Controlled Analgesia arm and 0.036 mg/kg/hr in the Continuous Opioid Infusion arm, over 5 days post surgery. The listed endpoint group sizes are 16 and 9. These are descriptive summaries of the participants represented in the posted outcome results.
The summaries do not, by themselves, show whether the observed difference is statistically reliable. The registry record does not report a primary-outcome test, a confidence interval for the group contrast, or an adjusted estimate. The posted ranges describe dispersion within each arm, not uncertainty in a between-group effect. No threshold for clinical importance is reported, so the size of the descriptive difference cannot be classified as clinically important using the registry information alone.
The registry’s study summary states a hypothesis about lower morphine consumption and fewer side effects with Parent/Nurse Controlled Analgesia. The observed median consumption is in the direction of that stated consumption hypothesis. However, a result consistent in direction with a hypothesis does not demonstrate that the delivery method caused the difference. The record does not report an inferential analysis, and the reasons for the difference between enrollment of 36 and the endpoint group counts are not reported.
The adverse-event data are also descriptive: no serious adverse events or deaths are listed in either group, while other adverse events are reported in both groups. The record does not name those other events or report a comparative safety analysis. These observations do not establish absence of risk or equivalent safety. Overall, the posted results support a limited account of observed group summaries, not a definitive claim about effectiveness or safety.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of why an observed difference and an inferential conclusion are not the same thing. Its primary endpoint summaries show different medians for the two morphine delivery groups, but the registry record reports no analysis of the primary comparison. Without an inferential estimate or uncertainty interval, readers cannot assess the precision of the group contrast from the posted results.
The endpoint is summarized by medians and interquartile-range dispersion, rather than means and standard deviations. In general, that choice can be appropriate for outcomes whose distributions are skewed or include influential extreme values. The record does not explain why this summary was selected or provide distributional detail. This makes the example useful for distinguishing what a summary measure communicates from what it does not: the median describes a central value, and the interquartile range describes within-group spread, but neither supplies a test of the difference between arms.
The registry also lists enrollment of 36 while the primary endpoint summaries include 16 participants in one arm and 9 in the other. Without an account of the analyzed population and missing-data handling, readers cannot determine how those summaries relate to the full enrolled group. This illustrates the importance of reporting participant flow, analysis populations, and reasons outcome data may be unavailable.
Finally, the registry states a study hypothesis but does not report an analysis plan, sample-size justification, interim analyses, or multiplicity strategy. Planning illustrations based on an observed effect are not a substitute for the original design rationale and are not observed power. Taken together, the record illustrates how trial design labels and descriptive endpoint values can be read carefully while keeping uncertainty and reporting gaps visible.
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 main limitation for interpreting this trial from the registry record is the absence of an inferential analysis for the primary endpoint. The record gives arm-level medians and dispersion values but no p-value, confidence interval for the contrast, test statistic, or model estimate. It is not possible to assess the statistical precision of the difference using a reported comparison.
The endpoint summaries cover 16 participants in the Parent/Nurse Controlled Analgesia group and 9 in the Continuous Opioid Infusion group, whereas enrollment is listed as 36. The reason for the difference is not reported in the registry record. The record does not report how many participants were randomized to each arm, whether all randomized participants were included in the endpoint summaries, or how missing observations were handled. This leaves uncertainty about the relationship between enrollment and the reported outcome population.
Other study details needed for fuller interpretation are not reported in the registry record, including the randomization procedure, allocation concealment, baseline characteristics, dosing and delivery protocols, and the detailed statistical analysis plan. The record also does not state a sample-size justification, interim-analysis approach, or multiplicity strategy. These reporting gaps should not be taken as evidence about what procedures were used; they limit what can be assessed from the registry entry.
The posted safety information is limited to counts of serious and other adverse events and deaths. The other event terms are not listed, and the record does not describe ascertainment, follow-up, or a comparative safety analysis. The only posted secondary outcome is the Revised-FLACC Scale, but no analysis result is reported for it. Consequently, the registry record supports descriptive interpretation of the primary endpoint and event counts, but not a broad assessment of efficacy or safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Parent/Nurse Controlled Analgesia in the Neonatal Intensive Care Unit — NCT01823497.
- Registry record last updated 2020-09-02; status last verified 2020-08.
- Results first posted 2020-09-02.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01823497 is a completed, randomized, parallel-group, unmasked trial titled Parent/Nurse Controlled Analgesia in the Neonatal Intensive Care Unit. The listed enrollment is 36. The registry lists abdominal surgery and thoracic surgery as conditions, Medical College of Wisconsin as sponsor, and study dates of 2013-04 to 2019-03. Phase is listed as NA.
The trial compares morphine delivered by Parent/Nurse Controlled Analgesia with morphine delivered by Continuous Opioid Infusion. Its primary endpoint is median morphine consumption in mg/kg/hr over 5 days post surgery. The posted medians are 0.014 for Parent/Nurse Controlled Analgesia and 0.036 for Continuous Opioid Infusion, with endpoint group sizes of 16 and 9. The registry reports no analysis of the primary comparison. It lists three outcome measures and one secondary outcome, the Revised-FLACC Scale, without a posted secondary analysis.
Serious adverse events and deaths are listed as 0 in both groups. Other adverse events are reported in both groups, but their terms are not posted. The registry record does not report the sample-size justification, detailed analysis plan, missing-data handling, or the reason the endpoint group counts differ from enrollment.