Comparative User Experiences With BD Nano™ PRO 4mm x 32G Extra Thin Wall Pen Needle vs Three Commercially Available Pen Needles: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparative User Experiences With BD Nano™ PRO 4mm x 32G Extra Thin Wall Pen Needle vs Three Commercially Available Pen Needles (NCT03878758), a randomized na study. The primary outcome is Injection Site Pain for BD Nano PRO Needle Compared to Each of Three (3) Commercially Available Comparators.

2. Clinical Question

In statistical terms, the central question is whether the average relative rating favored BD Nano™ PRO or a comparator, and how precisely that average was estimated for each device comparison. The record reports three mean ratings with two-sided 95% confidence intervals. These estimates concern participants’ ratings in the stated study setting; they do not by themselves establish how users would rate the devices in other settings or with other injection procedures.

The registry describes a prospective, block-randomized study with partial blinding and a single visit. The record does not report the randomization sequence, the block sizes, or how partial blinding was implemented. It also does not report details that would establish whether each device comparison was conducted in an identical way beyond the paired-injection descriptions.

3. Trial Design

The registry classifies this as a randomized, single-masked, parallel study and describes it as prospective, block randomized, partially blinded, multicenter, and single visit. These descriptions indicate that allocation was randomized and that participants completed the study at one visit. The registry record does not explain the masking procedures, identify who was masked, or describe the allocation sequence or block sizes. The number and locations of study centers are not reported in the registry record.

The study compared BD Nano™ PRO with three commercially available pen needles: the 4mm x 33G Artsana Insupen® Extr3me, the 3.5mm x 34G Artsana Insupen® Extr3me, and the 4mm x 33G Simple Diagnostics Comfort EZ™. Each arm description says subjects were to perform two pairs of injections. For each pair, one injection used BD Nano™ PRO and the other used the relevant comparator. The record does not describe the ordering procedure for injections beyond noting that the primary analysis used a linear model to adjust for order effect.

The registry lists enrollment of 158. Its brief summary says the study would include up to 146 subjects, and the primary results list 154 in the per-protocol population for each comparison. These are different figures with different labels in the record; the registry does not explain their relationship. They should not be treated as interchangeable counts or used to infer exclusions or analysis flow.

The listed primary outcome was a relative VAS rating collected immediately after each paired injection. The record states that scores from 308 pairs for all participants were pooled and that a mean was calculated. The primary population is identified as per protocol. The timeframe is immediate post-injection assessment; follow-up beyond the single-visit setting is not reported in the registry record. Further details about recruitment, study sites, participant flow, and protocol deviations 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: Each subject received more than one treatment

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Per-protocol population

5. Baseline Characteristics

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

Population: the subject that withdrew was not counted in population because the subject withdrew before enrollment

6. Primary Endpoint

The registry lists the primary outcome as Injection Site Pain for BD Nano PRO Needle Compared to Each of Three (3) Commercially Available Comparators, measured over Scores were collected immediately after each paired injection.

The primary endpoint is described as injection-site pain for BD Nano™ PRO compared with each of three pen-needle comparators. However, the endpoint description specifies a relative VAS question: participants rated their preference between the two needles on a scale ranging from -75mm to 75mm. The BD Nano™ PRO needle was labeled at +75 mm and the comparator at -75mm; zero represents no preference. Positive scores indicate preference for BD Nano™ PRO, while negative scores indicate preference for the comparator. This is therefore a relative rating, rather than an absolute measure of pain intensity for either device on its own.

Scores were collected immediately after each paired injection. According to the registry, scores from the paired injections were pooled and a mean relative rating was calculated for each comparison, with a two-sided 95% confidence interval. The stated analysis used a linear model to adjust for order effect. The record gives the unit as millimeters and identifies the per-protocol population.

A relative scale is useful for directly expressing which of two options a participant preferred after a paired experience. It also makes the direction of the estimate interpretable: a positive mean favors BD Nano™ PRO on this scale, and a negative mean favors the comparator. As a general statistical point, a mean describes the central tendency of ratings, while the confidence interval conveys uncertainty around that estimate. Neither alone describes how much individual participants varied in their ratings.

The registry’s outcome title uses the term pain, but its detailed description defines the response as relative user preference. The record does not clarify whether participants were asked to judge pain, overall preference, or both, nor does it report a separate absolute pain score for each device.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the mean represent?

For a continuous outcome, the mean is the arithmetic average of the recorded values. In this study, the recorded value was a relative VAS rating, with zero defined as no preference, positive values indicating preference for BD Nano™ PRO, and negative values indicating preference for the comparator. The reported means are therefore average relative ratings for each device comparison. They are not the percentage of participants who preferred a device, and they do not reveal how many individual ratings were positive or negative.

As a general statistical point, an average can be influenced by the spread and shape of the individual observations. Different sets of participant ratings can produce the same mean while differing in how consistently participants responded. The registry reports the mean and confidence interval, but not a distribution or a standard deviation for the individual ratings. The record therefore supports interpretation of the average and its estimated precision, but not a detailed account of the range of experiences.

How should a confidence interval be read?

A confidence interval expresses statistical uncertainty about an estimated quantity. In general, a 95% confidence interval is generated by a method intended to capture the underlying quantity in 95% of repeated samples under the model assumptions. It is not a statement that 95% of participants had ratings within those limits, nor is it the probability that the fixed underlying mean lies inside this particular interval.

For the three comparisons, the posted intervals were 11.43 to 23.67, 11.28 to 23.51, and 3.01 to 15.25. Since each interval is entirely above zero, each is compatible with a positive mean relative rating under the analysis. The intervals provide a range of plausible values for the mean under the statistical method; they do not address possible bias from measurement, study conduct, selection, or analysis choices.

What does the order adjustment do?

The registry states that a linear model was used to adjust for order effect. In general, paired ratings may be influenced by the sequence in which alternatives are experienced, because a first or later experience can shape a response. An order adjustment aims to account for systematic differences associated with sequence when estimating the comparison. The registry does not report the model specification, the form of the order term, or the model diagnostics, so these details cannot be assessed from the record.

The outcome description says that scores from paired injections were pooled before a mean was calculated and that the analysis was adjusted for order. It does not explain how repeated ratings from the same participant were represented in the model, or whether within-participant correlation was accounted for. This matters in general because measurements from one participant may be more alike than measurements from different participants. The record does not report enough model detail to evaluate that issue.

What do the decision thresholds mean?

The registry describes two possible interpretations of the confidence interval. It states that a lower bound greater than zero can support superiority, and that a lower bound greater than -10cm can support non-inferiority. In general, a superiority threshold tests whether the estimated effect is compatible with a value above the no-difference point on the scale. A non-inferiority threshold asks whether the result excludes a difference worse than a prespecified margin. Such a margin needs a clear unit and justification to be interpretable.

The scale is given in millimeters, but the non-inferiority rule is written in centimeters. The registry record does not clarify this mismatch or report a rationale for the margin. Therefore, the positive lower bounds can be compared with zero as stated, but the non-inferiority rule should not be silently converted or treated as clear. The record also does not report a protocol or analysis plan that would establish when these criteria were specified.

Why can over-dispersion matter?

As a general statistical concept, over-dispersion occurs when observed variability is greater than a model assumes. A model that understates variability can produce confidence intervals that are too narrow. This concept is relevant to many types of data, especially counts, but the registry identifies this primary endpoint as continuous and does not report an over-dispersion analysis. No additional model adjustment for over-dispersion is reported in the registry record.

More broadly, confidence-interval precision depends on the statistical model and on how the observations are handled. The posted intervals should be read in light of the reported linear-model order adjustment and the limited model details in the record. The registry does not report sensitivity analyses that would show whether alternative assumptions yield similar estimates.

What is the role of planning illustrations?

Sample-size calculations are planning tools, not estimates of what a completed trial has demonstrated. In general, a planning calculation estimates how many participants per arm might be needed under specified assumptions about effect size, significance level, allocation, and model. The assumptions stated for the planning illustration use a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These calculations are based on the observed effect and are not the trial’s own design justification.

Such illustrations should not be described as observed power. Observed power is not a substitute for reading the estimate and its confidence interval, and it cannot resolve uncertainty about design assumptions. The registry does not report the trial’s sample-size justification or state that its planning illustration was used to design the study. Any planning values should therefore be treated as hypothetical illustrations rather than as outcomes observed in the trial.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 7 outcome measures and reports 3 secondary outcomes: needle bending, leakage, and force for BD Nano™ PRO versus each of the three comparator devices. It also lists 15 analyses. The primary endpoint itself involves three separate device comparisons. When multiple outcomes or comparisons are examined, the chance of obtaining at least one apparently positive result can increase. As a general statistical point, multiplicity procedures can control this issue, but the registry record does not report whether an adjustment was planned or applied.

The record does not report a hierarchy of tests, a family of hypotheses, adjusted confidence intervals, or adjusted p-values for the primary comparisons. It also does not state whether the superiority and non-inferiority criteria were treated as separate confirmatory claims. The three positive confidence intervals should therefore be interpreted as the posted comparison estimates, without assuming a particular multiplicity strategy.

The primary analysis population is identified as per protocol. The record does not report how that population was defined, how many participants were excluded from it, or reasons for exclusions. It lists the same per-protocol count for each comparison, but does not explain whether participants contributed data to every comparison or how incomplete paired data were handled.

Missing-data methods are not reported in the registry record. The record does not say whether missing ratings occurred, how missing or unusable responses were handled, or whether any imputation was performed. It also does not report sensitivity analyses for missing data. Without this information, the potential effect of incomplete data on the estimates cannot be evaluated.

These omissions do not establish that the analysis was inappropriate; they limit what can be checked from the registry record. The posted results describe the estimated means and intervals, but the registry does not report enough detail to assess the full multiplicity strategy, analysis-population rules, or missing-data assumptions.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The registry reports serious adverse events, other adverse events, and deaths separately for each of the four device groups. For BD Nano™ PRO, the record lists 157 at risk for serious adverse events and zero affected, 157 at risk for other adverse events and zero affected, and zero deaths. The corresponding entries for each of the three comparator groups also list 157 at risk, zero affected for serious and other adverse events, and zero deaths.

These are counts recorded in the registry, not evidence that no adverse events could occur. A zero count means no event of that listed type was recorded among the stated at-risk group in this study. It does not establish that the underlying risk is zero, and it does not determine whether the devices have equivalent safety profiles. The record does not provide event descriptions, follow-up beyond the single-visit study context, or details about how adverse events were elicited and assessed.

When a study records no events, comparative safety estimates may be limited because there are no observed events to distinguish the groups on that measure. The registry does not report a separate statistical comparison of adverse-event rates. These figures should be read as descriptive counts for the study record, not as a general safety conclusion.

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

The posted primary results describe positive mean relative VAS ratings for BD Nano™ PRO in each of its three comparisons. The 95% confidence intervals for all three means are entirely above zero. On the scale defined in the registry, that direction corresponds to an average preference for BD Nano™ PRO. The registry’s stated superiority criterion is a lower confidence bound greater than zero, and the reported intervals satisfy that condition.

This result concerns the average response on a relative rating scale immediately after paired injections in a single-visit study. It does not show that every participant preferred BD Nano™ PRO, because the record does not report the distribution of individual scores or the number of participants who favored each device. Nor does it establish the practical importance of the reported mean values; the registry does not provide an interpretation threshold for a meaningful difference on this scale.

The primary outcome title refers to injection-site pain, while the detailed description defines a relative preference response. That distinction limits how the estimates should be named: the posted measure is a relative rating as described, not a reported absolute pain score for each needle. The registry record does not clarify this difference.

The findings do not establish results for settings, users, or outcomes beyond those recorded. The study is described as prospective and single visit, and no longer-term follow-up is reported. The registry also does not report the detailed methods needed to assess the randomization process, missing data, multiplicity adjustment, or the full analysis model. These gaps affect how completely the estimates can be appraised, but they do not change the numerical values posted.

The non-inferiority statement requires particular caution because the stated margin is -10cm while the VAS is otherwise described in millimeters. The record does not resolve that unit discrepancy. The superiority interpretation relative to zero is clearer on the stated scale; the non-inferiority condition is not sufficiently clear to interpret as written.

13. Why This Trial Matters Statistically

This trial illustrates the importance of matching a statistical interpretation to the exact outcome definition. The primary outcome title refers to injection-site pain, yet the detailed description defines a relative preference scale with zero as no preference and values on either side indicating which device was favored. That distinction affects what the mean represents and what conclusions it can support. A relative rating should not be recast as an absolute pain measurement without clarification from the record.

The study also illustrates how confidence intervals support interpretation beyond a single point estimate. Each reported mean is positive, and each two-sided 95% interval is entirely above zero. That information communicates both direction and uncertainty for each comparison. At the same time, an interval for a mean does not describe the full distribution of participant ratings or the proportion with a particular preference.

Three comparator-specific estimates invite readers to compare their magnitudes, but formal ranking requires appropriate direct statistical tests. The registry does not report such tests between the three estimates. In addition, multiple outcomes and analyses raise a general question about multiplicity. The record lists several outcomes and analyses but does not report an adjustment strategy, so the estimates should be read as posted rather than assumed to have a particular family-wise interpretation.

Finally, the registry’s non-inferiority wording demonstrates why thresholds and units must be reported clearly. The scale is in millimeters, while the stated margin is in centimeters. Without clarification, that criterion is not readily interpretable. Transparent outcome definitions, analysis populations, missing-data methods, and prespecified statistical procedures make results easier to evaluate; several of those details 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.

The registry record leaves important details about the study conduct and analysis unreported. It identifies the trial as block randomized and partially blinded, but does not describe the allocation sequence, block sizes, who was masked, or how masking was maintained. The number and location of study centers and the participant eligibility criteria are not reported in the registry record. These omissions limit assessment of how participants entered the study and how the design was implemented.

The enrollment and analysis figures are not fully reconciled. The record lists enrollment of 158, the brief summary says up to 146 subjects, and the primary results list 154 for each per-protocol comparison. The registry does not explain the difference among these figures, define the per-protocol population, or describe participant flow. No inference about exclusions or the exact analysis set can be made from these counts alone.

The endpoint has a wording and unit concern. The title names injection-site pain, but the detailed scale is a relative preference rating. The non-inferiority threshold is written as -10cm while the scale is described in millimeters. The registry record does not resolve either issue. It also does not report the distribution of individual ratings, standard deviations, missing-data handling, model diagnostics, or sensitivity analyses.

The record lists multiple outcomes and analyses but does not report a multiplicity strategy or detailed prespecified analysis plan. It does not report a sample-size justification, interim analyses, or the rationale for the non-inferiority margin. The safety information is limited to event counts and at-risk figures; event descriptions and assessment procedures are not reported in the registry record. Together, these limitations constrain evaluation of the estimates and their broader interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Comparative User Experiences With BD Nano™ PRO 4mm x 32G Extra Thin Wall Pen Needle vs Three Commercially Available Pen Needles — NCT03878758.
• Registry record last updated 2020-03-09; status last verified 2020-02.
• Results first posted 2020-03-09.
• 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

The registry describes a completed, randomized, single-masked, prospective, single-visit, multicenter study comparing BD Nano™ PRO with three commercial pen needles in people with Type 1 or Type 2 diabetes. The primary outcome was a relative VAS rating collected immediately after paired injections, with positive values indicating preference for BD Nano™ PRO and negative values indicating preference for the comparator.

The per-protocol results report mean relative ratings of 17.55 versus the 34G Artsana Insupen® Extr3me, 17.39 versus the 33G Artsana Insupen® Extr3me, and 9.13 versus Simple Diagnostics Comfort EZ™. Each associated 95% confidence interval is entirely above zero. The registry lists zero serious adverse events, zero other adverse events, and zero deaths in each device group, with 157 at risk in each listed group.

The registry does not report several details needed for a fuller assessment, including the missing-data approach, multiplicity strategy, and detailed model specification. Its non-inferiority threshold also uses a unit that is inconsistent with the scale description. The posted estimates therefore support interpretation of the relative ratings as recorded, while leaving these methodological questions unresolved.