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 Effects of Niacin Therapy on Lipoprotein Composition and Function (NCT02322203), a na na study. The primary outcome is Mean Percent Change in High-density Lipoprotein Protein Concentration.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02322203 |
| Phase | NA |
| Condition | Cardiovascular Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 22 |
| Arms in the primary outcome | n/a |
| Lead sponsor | National Heart, Lung, and Blood Institute (NHLBI) |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes adults aged 18 and older with fasting HDL-C below 60 mg/dL as eligible. The primary-endpoint description says that 14 participants completed the study and that 11 were included in the analysis after 3 participants were classified as non-responders and excluded. The record also describes the participants as healthy in the arm title, while listing cardiovascular disease as a condition. These descriptions do not fully resolve who the study population represents.
Intervention
Participants received extended-release niacin. The arm description specifies 500 mg/day for 1 week, then 1000 mg/day for 1 week, then 2000 mg/day for 14 weeks. The study is described as a single-group study, so the registry does not identify a concurrent control group.
Comparator
No separate comparator is reported. The study therefore does not provide a randomized, like-for-like comparison of niacin with a control treatment. Changes are considered in the context of the study’s own single-group design, rather than as a contrast between treatment arms.
Primary question
The primary endpoint is the mean percentage change in high-density lipoprotein protein concentration, with a stated timeframe of 20 weeks. The registry’s endpoint description refers to the effect of niacin monotherapy on HDL protein concentration. The numerical estimate of the mean change and its standard deviation are not reported in the registry record, so the magnitude and precision of the posted primary result cannot be assessed from the record.
3. Trial Design
This completed study, NCT02322203, evaluates extended-release niacin in a single-group design. The registry lists an enrollment of 22 and identifies the intervention as a dietary supplement. Allocation is listed as not applicable and masking as none. The record does not describe a randomized comparison or a concurrent control arm. Its start date is 2015-03-25, and its primary completion date is 2019-04-07.
The registry’s brief description outlines four clinic visits. Participants were to complete a 7-day food journal before visits 1 and 3. The described assessments include questions about diet, exercise, medical history, medications and vitamins; vital signs and body mass index; a Cardio-Ankle Vascular Index test; blood pressure measurements; heart monitoring; and blood draws. The description also notes pregnancy testing for women. These are planned procedures in the registry description; it does not report how completely each procedure was carried out.
The described niacin schedule begins at 500 mg/day for 1 week, increases to 1000 mg/day for 1 week, and then to 2000 mg/day for 14 weeks. The brief description says participants would stop taking niacin at visit 3 and return for visit 4 after 4 to 6 weeks. The primary endpoint nevertheless has a stated timeframe of 20 weeks. The registry does not provide further detail reconciling that timeframe with the visit schedule.
The record gives no phase beyond NA and no statistical analysis entry. It also does not report a protocol rationale, target enrollment justification, or details of any changes to the planned design.
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 | Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function |
|---|---|
| STARTED | 22 |
| COMPLETED | 14 |
| NOT COMPLETED | 8 |
Analysis population for the primary outcome, as defined in the registry: Out of the 14 participants that completed study, 3 participants were considered to be non-responders and not included in data analysis. Therefore, 11 participants were included in data analysis.
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 | Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function |
|---|---|---|
| Participants analysed | 22 | |
| Age, Continuous | years | 38.5 (SD 13.6) |
| Sex: Female, Male: Female | Participants | 14 |
| Sex: Female, Male: Male | Participants | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 20 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 |
| Race (NIH/OMB): White | Participants | 16 |
| Race (NIH/OMB): More than one race | Participants | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 22 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Percent Change in High-density Lipoprotein Protein Concentration, measured over 20 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Percentage Change |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is mean percentage change in high-density lipoprotein protein concentration, described over a 20-week timeframe. HDL is a lipoprotein, and protein concentration describes a component of its composition. The endpoint is intended to quantify how that measured component changes during the study’s niacin monotherapy regimen.
Using percentage change can express a change relative to a participant’s starting measurement, rather than only in the original concentration units. The registry identifies the endpoint as a continuous measure and specifies a mean with standard deviation as its summary. In general, a mean describes the average measured change in the analyzed group, while a standard deviation describes how dispersed participant-level changes are around that average. Neither quantity alone establishes that a change is attributable to treatment, particularly in a single-group study without a control group.
The endpoint description reports that 14 participants completed the study, that 3 were classified as non-responders and excluded from data analysis, and that 11 were included in the analysis. The numerical mean percentage change and its standard deviation are not reported in the registry record. The record also does not explain the exact calculation of percentage change, the reference measurement, or the handling of repeated measurements for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the primary outcome as a continuous mean percentage change in HDL protein concentration over 20 weeks. It also identifies the analyzed population: 11 participants, after 3 of the 14 completers were considered non-responders and excluded. However, the registry record does not report the numerical mean change or standard deviation. Without those estimates, the direction and size of the observed average change cannot be described, and the spread of participant-level changes cannot be assessed.
Precision is also not assessable from the posted primary endpoint information. A confidence interval, if reported, would describe a range of estimates compatible with the data under the stated statistical method. No confidence interval or other uncertainty estimate for the primary mean is reported in the registry record. A standard deviation is named as the dispersion measure, but its numerical value is not reported either. It would therefore be inappropriate to characterize the result as precise, imprecise, statistically significant, or not statistically significant.
The single-group design limits what the primary endpoint can establish. A measured change during treatment would not, by itself, separate a treatment-associated change from changes that might occur over time for other reasons. There is no randomized comparison in the registry record, and the record does not identify a control group. Accordingly, the endpoint is descriptive of the analyzed group rather than a direct estimate of a treatment contrast.
Excluding participants described as non-responders is important to interpretation. The registry does not report when or how that classification was made, whether it was prespecified, or whether the outcome was examined in all completers as well. If inclusion depends on the observed response, the analyzed mean may not represent the experience of all participants who began or completed the study. The record does not provide enough detail to determine the size or direction of any such effect.
The registry labels the population in several ways: eligibility refers to adults with fasting HDL-C below 60 mg/dL, the condition is cardiovascular disease, and the arm title refers to healthy participants. These descriptions leave uncertainty about the intended population. This limits how specifically the findings could be generalized even if the numerical endpoint result were available.
9. Statistical Methods Explained
The registry describes a continuous primary endpoint summarized as a mean and standard deviation. It does not provide a numerical endpoint estimate, a confidence interval, a p-value, or an analysis description. The following statistical concepts explain how such measures are commonly interpreted; they do not establish which methods were used for this study.
What does a mean change describe?
In general, the mean is the arithmetic average of the participant-level values included in an analysis. For a change endpoint, the values represent changes defined by the study’s measurement and calculation rules. The mean can describe the group’s average change, but it can conceal variation: participants may have changes that differ in direction or size. The registry names mean percentage change as the primary measure but does not describe the exact formula, the reference visit, or the participant-level data used to calculate it.
Because the study has a single group, the mean is not a comparison between niacin and a concurrent control. A before-and-after change can be informative as a description of the group over time, but it does not isolate the effect of treatment from other influences that also change over time. A randomized control group can support a different kind of inference by offering a concurrent comparison, but no such group is identified in this record.
What does the standard deviation add?
In general, the standard deviation describes the spread of individual measurements around the mean. A smaller standard deviation indicates that the observations are more concentrated around the mean; a larger one indicates greater spread. This is not the same as the precision of the mean. Precision also depends on the amount of information contributing to the estimate and on the analysis method. The registry identifies standard deviation as the dispersion measure but does not report its value.
Over-dispersion is a general concern when observed data vary more than an assumed statistical model allows. If a model understates variability, uncertainty estimates can be too narrow and tests can be poorly calibrated. That issue is most relevant when an analysis uses a model with a specified variance structure. The registry does not report a model, distributional assumptions, or an over-dispersion assessment, so it is not possible to say whether this issue applied to the primary analysis.
How should uncertainty be read?
In general, a confidence interval communicates the uncertainty around an estimated quantity under its analysis assumptions. It is not a guarantee that the true value lies in the particular interval, nor does it correct for limitations in design or selection. A p-value, when reported, measures compatibility of data with a specified null model under stated assumptions; it does not quantify the size or importance of an effect. Neither a confidence interval nor a p-value for the primary endpoint is reported in the registry record.
For this study, even an uncertainty interval around the single-group mean would not create a treatment-versus-control estimate. It would describe uncertainty around the analyzed group’s mean change, subject to the endpoint definition and analysis population. The absence of a concurrent comparator remains a design limitation regardless of how narrow an interval might be.
What do the planning assumptions mean?
The registry includes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. These are planning assumptions, not evidence that the actual study used a two-arm design: the registered study is single-group and does not report a comparator. The record does not report the numerical planning outputs in the registry record for this analysis.
In general, a sample-size planning calculation estimates the amount of information needed to detect a prespecified effect under assumed conditions. Its result depends on the assumed effect, variability, allocation, significance level, and statistical model. A planning illustration does not show that the completed study had adequate power, and it is not an observed treatment effect. For this single-group study, assumptions framed around equal allocation between two arms should not be mistaken for the registered design.
The record does not report the primary statistical test, any model covariates, the method used to handle repeated observations, or whether the analysis was prespecified. Without those details and without the numerical endpoint result, the statistical evidence for the primary question cannot be independently evaluated from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 2 outcome measures and 0 analyses. It does not report a multiplicity plan, such as how testing across outcomes or time points would be handled. In general, testing multiple hypotheses can increase the chance of obtaining an apparently notable result by chance if no adjustment or hierarchy is planned. The record does not establish whether multiplicity was relevant to the sponsor’s analysis or how it was addressed.
The primary-endpoint description states that 14 participants completed the study and that 3 were considered non-responders and excluded, leaving 11 included in data analysis. This is the only explicit description of the primary analysis population. The registry does not report the reasons that other enrolled participants did not complete the study, or provide a complete accounting of missing primary measurements. The difference between enrollment and completion should not be interpreted as a count of withdrawals or missing outcomes without those details.
Handling of missing data is not reported in the registry record. It is not stated whether missing values were excluded, imputed, or addressed through another method. The record also does not say whether the primary analysis included all participants who started treatment, all completers, or another population beyond the 11 analyzed participants.
The exclusion of participants categorized as non-responders raises an additional analysis-population concern. The registry does not report the definition, timing, or prespecification of that category. In general, excluding participants according to their observed response can make an analyzed group differ systematically from the population initially enrolled. The direction and magnitude of any resulting bias cannot be determined from the information reported.
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 |
|---|---|---|---|
| Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function | 0 | 22 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function | 0 of 22 |
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 |
|---|---|
| Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function | 5 of 22 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Niacin ER in Healthy Participants and Its Effects on Lipoprotein Composition and Function |
|---|---|---|
| Palpitations | Cardiac disorders | 1 of 22 |
| Diarrhea | Gastrointestinal disorders | 1 of 22 |
| CPK increased | Investigations | 1 of 22 |
| Low Thyroid Function | Investigations | 1 of 22 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 1 of 22 |
The registry reports safety figures for the niacin group with 22 participants at risk. It records 0 serious adverse events, 5 other adverse events, and 0 deaths. These counts are registry summaries; the record does not provide event descriptions for the other adverse events in the registry record. No serious adverse-event terms are listed.
These figures should be read as counts recorded for the specified group, not as a comparison with another treatment or with an untreated group. The study is single-group, and the registry does not identify a concurrent safety comparator. The counts therefore do not show whether events occurred more or less often than they would have without niacin.
Zero reported serious adverse events and zero deaths do not establish that there was no risk. Safety interpretation depends on what was monitored, how events were defined and collected, how long participants were followed, and how completely events were reported. The registry does not provide enough detail to evaluate those aspects. The 5 other adverse events are not characterized by type, severity, timing, or relationship to treatment in the information available.
These registry counts describe recorded events in this study; they are not medical guidance and should not be treated as a guarantee about safety in other populations or settings.
12. What the Result Does, and Does Not, Mean
The posted record establishes that a completed single-group study evaluated extended-release niacin and named mean percentage change in HDL protein concentration as its primary endpoint. It also reports that 14 participants completed the study and that 11 were included in the primary analysis after 3 were classified as non-responders and excluded. The planned dose schedule is described in the registry.
The primary numerical result is not reported in the registry record. There is no numerical mean change, standard deviation, confidence interval, or p-value in the registry record for this analysis. Consequently, the direction, magnitude, variability, and statistical uncertainty of the primary endpoint cannot be stated. No conclusion about the observed primary result should be inferred from the endpoint title or from the fact that a study was completed.
Even if a numerical before-and-after change were available, the single-group design would not provide a randomized comparison with a control. The record therefore cannot distinguish a treatment-associated change from other explanations for change over time. The exclusion of participants categorized as non-responders also means the analyzed group is not described as all completers; the impact of that decision cannot be assessed without its definition and supporting analyses.
The registry’s population descriptions are not fully aligned: eligibility specifies adults with fasting HDL-C below 60 mg/dL, the listed condition is cardiovascular disease, and the arm title refers to healthy participants. This ambiguity, along with the absence of a numerical primary result and limited analysis details, constrains interpretation and generalizability. The record supports describing the study’s design and analysis population, but not making a claim that niacin did or did not produce a particular effect.
13. Why This Trial Matters Statistically
This study illustrates why a registry record needs to be read as more than a list of outcomes. The design determines what an endpoint can answer. A single-group mean change can describe measurements over time in the analyzed participants, but it is not the same estimand as a difference between randomized treatment groups. Without a concurrent comparator, causal interpretation is limited even when an outcome is measured as planned.
The analysis population also matters. The record distinguishes 14 completers from the 11 participants included in the primary analysis, with 3 completers classified as non-responders and excluded. That decision could affect the meaning of the reported average. A reader needs the operational definition, timing, and prespecification of the exclusion to judge whether the analyzed population is aligned with the intended research question. Those details are not reported in the registry record.
The registry also demonstrates the difference between naming an endpoint and reporting its result. It identifies mean percentage change in HDL protein concentration and names standard deviation as its dispersion measure, but the numerical estimate and its uncertainty are not reported. Without them, the reader cannot judge magnitude or precision. A planning illustration cannot fill that gap: planning assumptions are not observed evidence from the completed study.
Finally, consistent population descriptions and transparent missing-data and multiplicity methods are important for assessing relevance and reliability. The record’s descriptions of eligibility, condition, and healthy participants do not fully align, and several analysis details are absent. These are statistical interpretability issues, not merely matters of presentation, because they shape which population and which quantity the result can represent.
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 numerical primary endpoint result is not reported in the registry record. Although the endpoint is identified as mean percentage change in HDL protein concentration over 20 weeks, the mean and standard deviation are absent. The record also does not provide an uncertainty interval, test result, or numerical estimate that would permit assessment of magnitude or precision.
The single-group design has no concurrent comparator reported. Any measured change would therefore be difficult to attribute specifically to niacin rather than to other changes over time. Allocation is listed as not applicable and masking as none, and the record does not describe a randomized or blinded comparison.
The analysis population requires caution. Of 14 completers, 3 participants described as non-responders were excluded, leaving 11 in the analysis. The definition and timing of non-responder classification are not reported. Reasons for noncompletion, a complete accounting of missing measurements, and the missing-data method are also not reported. The potential effect of these decisions on the estimate cannot be evaluated.
The record does not report the endpoint calculation details, the reference measurement, the statistical test or model, covariate adjustment, handling of repeated measures, or a multiplicity strategy. It also does not report a protocol-based sample-size justification. The available planning assumptions are framed around equal allocation between two arms, which does not match the registered single-group design and should not be read as evidence of the study’s analysis plan.
Population descriptions are not fully consistent: eligibility refers to adults with fasting HDL-C below 60 mg/dL, the listed condition is cardiovascular disease, and the arm title describes healthy participants. The registry does not resolve this ambiguity, which limits clarity about the population to which the study was intended to apply.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effects of Niacin Therapy on Lipoprotein Composition and Function — NCT02322203.
- Registry record last updated 2025-03-14; status last verified 2020-07.
- Results first posted 2025-03-14.
- 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
NCT02322203 is a completed, single-group study of extended-release niacin titled Effects of Niacin Therapy on Lipoprotein Composition and Function. The registry lists an enrollment of 22, with masking listed as none and allocation as not applicable. The primary endpoint is mean percentage change in HDL protein concentration over 20 weeks.
The endpoint description reports 14 completers, 3 of whom were classified as non-responders and excluded; 11 participants were included in the primary analysis. The numerical mean change and standard deviation are not reported in the registry record. The record does not identify a concurrent control group or provide the primary analysis method, missing-data approach, or multiplicity plan.
Safety figures report 0 serious adverse events, 5 other adverse events, and 0 deaths among 22 at risk. The registry’s eligibility, condition, and arm descriptions do not fully resolve the intended population. These limitations restrict interpretation of the study’s results.