Safety and Pharmacokinetics of Clindamycin in Pediatric Subjects With BMI ≥ 85th Percentile: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Pharmacokinetics of Clindamycin in Pediatric Subjects With BMI ≥ 85th Percentile (NCT01744730), a na phase 1 study. The primary outcome is Pharmacokinetics (PK) - Clearance (Cl) in Participants Who Received Multiple Doses of Intravenous (IV) Clindamycin..

2. Clinical Question

The registry describes the study’s purpose as improving understanding of clindamycin pharmacokinetics in children with higher BMI. The primary analysis is not a direct test of whether treatment improves an infection outcome. It is a pharmacokinetic investigation, and the record also lists safety outcomes. Because no control arm is described for the trial itself, differences among the age and BMI strata should not be read as randomized treatment effects. The record’s broader modeling description includes participants from separate studies, so those pooled data also require interpretation in the context of their distinct study populations and purposes.

3. Trial Design

This was a phase 1, single-group study of intravenous clindamycin in pediatric participants with BMI at or above the 85th percentile. The registry lists enrollment of 22 and records the study as completed. The listed start was 2013-06, and primary completion was 2014-08. Allocation is recorded as not applicable, and masking is recorded as none. No randomized control group is described.

The intravenous treatment groups are organized by age and BMI category. They include children ages 2 to 11 and ages 12 to 17, with each age range divided into BMI 85th to less than 95th percentile and at or above the 95th percentile. The arm descriptions state a clindamycin schedule of 30-40 mg/kg/day, dosed every 6 or every 8 hours, with a maximum daily dose of 2.7 grams/day; the descriptions also contain an incomplete qualification about dosing above that maximum. The record does not give enough complete detail to clarify that qualification.

The primary endpoint is pharmacokinetic clearance after intravenous dosing. Sampling was described from after the first study dose through Day 14, with a minimum of 3 samples and a maximum of 6. The record says samples were collected on multiple days and averaged to produce a single value. The study description also explains that pharmacokinetic data from multiple studies were combined to build a model. That broader modeling dataset and the trial’s own enrolled population are not interchangeable: the record separately describes a subset used for an age-cohort comparison and specifies that the Staph Trio data were used only for modeling, not for comparison.

The registry lists 6 outcome measures and 0 analyses. It does not report the trial’s planned statistical analysis, sample-size justification, interim analyses, or a numerical primary endpoint result. The absence of those details limits assessment of how the analysis was prespecified and how the enrolled number relates to the study’s intended precision.

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: Patients between the ages (and inclusive of these ages) of 2 years to 17 years at time of first dose of study medication were screened for all other inclusion and exclusion criteria which includes must have body mass index (BMI) greater than or equal to 85th percentile for age and sex, based on Centers for Disease Control (CDC) recommendations.

Overall Study

Analysis population for the primary outcome, as defined in the registry: In order to determine the impact of obesity and the best weight measure for dosing, only children ≥ 2 years of age were compared (PTN\_Clinda obese study n = 21; PTN\_POPS study n = 104; and Staph Trio study n = 0). The PK model suggested dosing should be based on Total Body Weight (TBW) regardless of obesity status.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Pharmacokinetics (PK) - Clearance (Cl) in Participants Who Received Multiple Doses of Intravenous (IV) Clindamycin., measured over After first study dose of IV Clindamycin through Day 14 (minimum of 3 samples; maximum of 6)..

The primary endpoint is intravenous clindamycin clearance, expressed in L/h. Clearance is a pharmacokinetic measure of the volume of blood or plasma from which a drug is removed per unit of time; as a general concept, it characterizes drug elimination rather than a clinical benefit or harm. The registry describes the endpoint using a median and full range, which would summarize a central value and the observed spread without requiring the distribution to be symmetric.

The stated timeframe runs from after the first study dose of intravenous clindamycin through Day 14. The sampling schedule called for a minimum of 3 samples and a maximum of 6. The record says samples were collected on multiple days and averaged to arrive at a single value. It also describes empirical Bayesian estimates of clearance by age cohort, in the context of a pharmacokinetic model built using data from multiple studies.

The endpoint is relevant to the study’s stated pharmacokinetic question because clearance helps characterize how medication is handled by the body. It does not, by itself, establish whether treatment changes infection outcomes, nor does it directly answer whether a particular dose is appropriate. The registry record identifies the endpoint and its units but does not report the numerical median, full range, or age-cohort estimates. Consequently, the precision and pattern of the primary clearance results cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Pharmacokinetics describes how a drug is absorbed, distributed, and eliminated. In this study, the primary endpoint is clearance after intravenous clindamycin. Clearance is a rate measure, reported in L/h in the registry. As a general statistical concept, a clearance estimate summarizes drug elimination under the conditions of the sampling and model used; it is not itself a measure of clinical response.

The registry describes the primary endpoint with a median and full range. A median is the central observation when values are ordered, and is often useful when a distribution is skewed or contains extreme values. The full range gives the lowest and highest observed values, so it conveys the observed spread but does not describe how values are distributed between those endpoints. A range can also be sensitive to unusually low or high observations. No numerical median or range is reported for the endpoint in the registry record, so neither the center nor the spread can be assessed.

The sampling plan is described as extending from after the first intravenous study dose through Day 14, with a minimum of 3 samples and a maximum of 6. Samples were collected on multiple days and averaged to create a single value, according to the record. Repeated samples can provide information about drug concentration over time. In general, pharmacokinetic analysis uses the timing and concentration pattern to estimate quantities such as clearance. The registry does not report the actual concentrations, individual sampling completeness, or numerical estimates needed to assess that process directly.

The record says a pharmacokinetic model was built using data combined from three studies. It identifies the PTN Clinda Obese study with n = 21, PTN POPS with n = 178, and Staph Trio with n = 21 for model building. It further states that Staph Trio data were included only for pharmacokinetic modeling and were not intended to be compared in the analysis. A separate population description says that the comparison intended to examine obesity and the best weight measure for dosing included only children at least 2 years of age, listing n = 21 from PTN Clinda Obese, n = 104 from PTN POPS, and n = 0 from Staph Trio. These are distinct analytic descriptions: the model-building data are not the same as the stated comparison subset.

The comparison description refers to empirical Bayesian estimates, or EBEs, of clearance by age cohort. In general, an empirical Bayesian estimate combines information from an individual’s observed data with information from a population model. This can be useful when individual sampling is limited, because model-based information helps stabilize estimates. The resulting values depend on the model and its assumptions as well as on the participant’s observations. The registry record does not report the model specification, parameter estimates, diagnostic checks, or numerical EBE results. It also does not give enough information to assess how uncertainty in the model was reflected in the age-cohort estimates.

One general statistical issue in pooled pharmacokinetic modeling is that participants from different studies may have differences in sampling, eligibility, or clinical context. Combining data can increase the information available to estimate a model, but interpretation depends on whether the datasets are sufficiently comparable and whether the model accounts for relevant differences. The record says the sampling schedule details for PTN POPS and Staph Trio were comparable to the schedule for PTN Clinda Obese. It does not report further harmonization details or model diagnostics, so the adequacy of pooling cannot be judged from the registry entry alone.

The study itself is recorded as single group, with allocation not applicable and masking none. As a general principle, a single-group study can describe observations within treated participants but does not provide the protection against confounding that random assignment can offer in a between-group treatment comparison. The age and BMI strata are descriptive subgroups, not randomized arms. Apparent differences between such strata, if numerical estimates were available, would need to be interpreted cautiously because the registry does not describe a randomized design or report an adjusted analysis.

The record lists 6 outcome measures and 0 analyses. It does not report p-values, confidence intervals, or other uncertainty measures for the primary clearance endpoint. A confidence interval, as a general concept, expresses uncertainty around an estimate under a specified statistical procedure; no such interval is reported. The absence of an inferential result means that statistical significance and precision cannot be assessed. It also does not establish that no analyses were done; it means that analyses are not reported in the registry record.

Planning illustrations based on fractions of an observed effect, when used, are not observed power and do not reveal the study’s original design justification. The registry record does not report a sample-size justification or the numerical effect estimate needed to interpret such planning calculations. Such illustrations are hypothetical design calculations, not additional trial outcomes.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 6 outcome measures but does not report the statistical analysis plan, the prespecified hierarchy of outcomes, or how multiple outcomes or subgroup comparisons were handled. Multiplicity is a general concern when several hypotheses are tested: with more tests, the chance of at least one apparently notable result can increase unless the analysis plan addresses that issue. No multiplicity adjustment or testing strategy is reported in the registry record, so it is not possible to determine how this concern was handled.

Missing-data methods are also not reported in the registry record. The endpoint description specifies a minimum of 3 samples and a maximum of 6, but does not state how participants with fewer samples, incomplete sampling, or unusable measurements were treated. It does not report the number of participants contributing to the primary clearance analysis or describe imputation, exclusion, or sensitivity analyses. The overall enrollment of 22 should not be assumed to be the analysis denominator for every outcome.

The record does not define analysis populations such as an intention-to-treat or per-protocol set. This was a single-group study, but the pharmacokinetic description also involves pooled data and a separate age-at-least-2 comparison subset. The stated counts for those modeling and comparison purposes differ, and should be interpreted as referring to the described analysis sets rather than as interchangeable enrollment figures. No interim analysis plan is reported in the registry record. Without details about outcome selection, missing observations, and analysis populations, the robustness of the reported results cannot be evaluated; in addition, numerical primary clearance results are not reported.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: apnoea (25.0%).

The safety record lists four intravenous clindamycin groups by age and BMI category. Serious adverse events are recorded for 1 participant in the ages 2 to 11 group with BMI 85th to less than 95th percentile, and 0 in each of the other three clindamycin groups. Other adverse events are recorded for 2 participants in the ages 12 to 17 group with BMI at or above the 95th percentile, and 0 in each of the other clindamycin groups. The group sizes at risk are listed as 4, 3, 4, and 11, respectively. These are counts in small groups and should be read as descriptive safety reporting, not as a comparative estimate.

The registry also lists patients less than 21 years of age from NCT01431326 as a separate group, with 178 at risk and zero listed serious or other adverse events. This external group is not a randomized control group for the clindamycin trial. The record lists Apnoea at 25.0% as the top serious adverse-event term. Death counts are not reported in the registry record. The listed adverse-event counts do not establish causality, and the registry entry does not provide detailed timing, severity, or adjudication information for interpreting individual events.

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

The record supports a limited set of conclusions about what was studied and what was entered in the registry. It describes a completed phase 1, single-group study of intravenous clindamycin in children with BMI at or above the 85th percentile, with a primary pharmacokinetic endpoint of clearance. It also gives adverse-event counts across age and BMI strata. These design and reporting details are useful for understanding the scope of the investigation.

The primary clearance result itself is not reported numerically. The median, full range, and age-cohort empirical Bayesian estimates are not given, nor are confidence intervals or p-values. Thus, the posted record does not show the magnitude or precision of clearance estimates, or whether estimates differed across the described groups. It cannot support a quantitative conclusion about the pharmacokinetic effect of BMI from the primary endpoint as entered in the registry.

The registry describes modeling that combines data from more than one study, and a separate comparison subset restricted to children at least 2 years of age. It explicitly excludes Staph Trio data from the comparison while including those data for model building. This distinction matters: the pooled model dataset and the comparison population serve different purposes, and neither should be mistaken for a randomized control group within this trial.

The safety counts are descriptive and come from small clindamycin strata. They do not provide a comparative estimate of risk, establish that a listed event was caused by clindamycin, or establish the absence of unreported events. The separate NCT01431326 group is not a like-for-like randomized comparator. More generally, the registry entry does not report details that would permit assessment of missing data, outcome multiplicity, analysis populations, or the prespecified statistical plan.

In short, the record identifies a pediatric pharmacokinetic and safety investigation, but does not contain the numerical primary endpoint results needed to judge the size or precision of the clearance findings. It should not be interpreted as establishing a clinical benefit, a lack of benefit, or a dosing recommendation.

13. Why This Trial Matters Statistically

This study is statistically notable because it focuses on pharmacokinetic estimation in a pediatric population divided by age and BMI category, rather than on a randomized comparison of clinical outcomes. Clearance is a model-related quantity that depends on the timing and pattern of drug measurements. The record’s description of multiple sampling occasions, averaging, and empirical Bayesian estimates illustrates why analysis details matter when pharmacokinetic data are limited or gathered across different studies.

The distinction between data used to build a model and data used for a comparison is important. The registry describes a three-study modeling dataset, then gives a separate subset for comparison by age cohort and states that Staph Trio data were not used for that comparison. Keeping these analysis purposes distinct avoids treating every participant in a pooled modeling description as part of the same comparison group.

The study also illustrates a limitation of interpreting registry entries: an endpoint can be clearly named and defined while its numerical result is not reported. Without the clearance estimate and its uncertainty, readers cannot assess how precise the finding is, whether estimates vary across groups, or how much information the study contributed. The listed safety counts are likewise descriptive and do not replace a comparative analysis.

For biostatisticians and clinical researchers, the record underscores the value of transparent reporting of analysis populations, model specification, missing-data handling, uncertainty intervals, and subgroup methods. These details are especially important when a small study is interpreted alongside external datasets. The registry does not report those elements in enough detail to evaluate the model or the statistical strength of the primary conclusion.

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 interpretation is that the registry record does not report the numerical primary clearance result. Although it specifies a median and full range, neither is listed, and the age-cohort empirical Bayesian estimates are also absent. No confidence intervals or p-values are reported. The primary pharmacokinetic finding therefore cannot be assessed for magnitude, precision, or statistical evidence from the registry entry.

The enrollment was 22, and the safety strata are small. Counts from these groups are descriptive and may be imprecise; no uncertainty estimates are given. The registry does not report the number of participants contributing to every outcome, the completeness of pharmacokinetic sampling, or how missing or unusable measurements were handled.

The study is single group, with no randomized allocation or masking. The age and BMI categories do not constitute randomized treatment comparisons. The record’s broader pharmacokinetic modeling uses data from multiple studies, while a separate comparison uses a restricted population and excludes Staph Trio. Details of the model, diagnostics, adjustment for differences across studies, and uncertainty propagation are not reported in the registry record.

Other important design and analysis details are not reported in the registry record, including a sample-size justification, prespecified statistical plan, interim analyses, multiplicity handling, analysis-population definitions, and missing-data methods. The intervention descriptions also contain incomplete wording regarding an allowance above the stated maximum daily dose, so that qualification cannot be interpreted reliably from the registry text. These reporting limitations restrict conclusions about the robustness and generalizability of the recorded findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety and Pharmacokinetics of Clindamycin in Pediatric Subjects With BMI ≥ 85th Percentile — NCT01744730.
• Registry record last updated 2016-11-29; status last verified 2016-10.
• Results first posted 2016-10-19.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT01744730 is a completed phase 1, single-group study of intravenous clindamycin in pediatric participants with BMI at or above the 85th percentile. Enrollment was 22. The primary endpoint was clindamycin clearance, described as a median with a full range in L/h, with sampling after the first study dose through Day 14. The registry record does not report numerical primary clearance results.

The pharmacokinetic description discusses a model built from data from three studies and a separate age-cohort comparison subset. Safety counts are listed for four clindamycin age and BMI groups and a separate external group. The record does not describe a randomized control comparison, and the posted safety counts are descriptive. A sample-size justification, detailed statistical plan, missing-data methods, and numerical uncertainty estimates are not reported in the registry record.