Impact and Cost of a Pharmacist Pneumococcal Vaccination Program With PNEUMOVAX® 23 at an Urban Senior Center: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Impact and Cost of a Pharmacist Pneumococcal Vaccination Program With PNEUMOVAX® 23 at an Urban Senior Center (NCT01944462), a na phase 4 study. The primary outcome is Knowledge and Awareness of Pneumococcal Disease.

2. Clinical Question

3. Trial Design

This is a completed phase 4, single-group study sponsored by Thomas Jefferson University. The registry record lists enrollment of 203 and describes the intervention as a pharmacist-delivered educational program at a collaborating urban senior center. The program also aimed to provide pneumococcal vaccine to eligible participants. The study started in 2014-01, had primary completion in 2014-11, and is listed as completed.

Allocation is recorded as not applicable, and masking is listed as none. There is no randomized allocation or concurrent control group described. The primary outcome was assessed at baseline, immediately after the intervention, and at 3 months. These repeated observations can describe how scores changed among participants who were assessed, but by themselves they do not separate program effects from other influences over time.

The title refers to adults aged 65 years or older or those with defined risk factors for invasive pneumococcal disease. A condition entry says the study is open to seniors age 50 or older. The record does not clarify how these descriptions map onto eligibility or the enrolled population. The primary outcome population is called the intention-to-treat sample, but details defining that sample are not reported in the registry record.

The stated hypotheses also include trust in pharmacists as vaccine providers, satisfaction with vaccine information, intervention cost, and pharmacist activation and satisfaction. The registry lists six outcome measures, but no analysis entries. Detailed results for these outcomes, the methods used to analyze repeated measurements, and any comparator-based estimates 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: Pre/post design (no groups). Inclusion criteria were age ≥50; able to attend a 1.5-hour session; cognitively intact (abbreviated mental test score ≥7); speak \& read English at ≥4th grade (ability to read a brief passage). Additionally, program attendees wishing to participate in the study signed consent forms prior to the start of the program.

PPPP Educational Program

Reasons for not completing this period:

Optional Vaccination

Analysis population for the primary outcome, as defined in the registry: Intention-to-treat (ITT) sample

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 Knowledge and Awareness of Pneumococcal Disease, measured over Baseline, post-test, 3 months.

The primary endpoint is knowledge and awareness of pneumococcal disease, measured with the Pneumonia Knowledge Questionnaire, an instrument developed by investigators. Its content covers susceptibility to infection, symptoms, severity of illness, and vaccination, with emphasis on vaccine efficacy, safety, and eligibility. The instrument consists of 5 “mark all that apply” items and one “mark the best response” item. Scores range from 0 (no correct responses) to 28 (all responses correct), and a higher score means better knowledge and awareness.

The endpoint was assessed at baseline, immediately after the educational intervention, and at 3 months. Repeated measurement is relevant to the stated primary hypothesis because it permits assessment of knowledge at more than one time point, including whether an immediate post-test pattern is also present at follow-up. The record describes the measurement schedule but does not report scores, changes, variability, or estimates comparing time points.

As a knowledge measure, this endpoint captures responses to questionnaire items, not vaccination uptake, disease incidence, or clinical outcomes. It is intended to assess the educational goal directly. The registry record does not report validation evidence for the investigator-developed instrument, so its measurement properties beyond the stated content and score interpretation are not available.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods can only be described to the extent that the registry record specifies them. It identifies a continuous primary measure summarized as a mean with standard deviation, and lists assessment at baseline, immediately after the intervention, and at 3 months. It does not identify a model, a test, an adjustment strategy, or a prespecified contrast between time points. The count of analysis entries is zero. The points below explain general statistical concepts that are relevant to interpreting the stated design and measure; they do not describe unreported analyses as if they had been performed.

What does a mean score describe?

In general, a mean is a measure of the center of a set of numerical observations. For the questionnaire, it would describe the average score among the participants included at a specified assessment time. The registry record says that the measure ranges from 0 (no correct responses) to 28 (all responses correct), with higher values indicating better knowledge and awareness. A mean alone would not show how individual scores are distributed or whether the average reflects similar experiences across participants.

In general, a standard deviation describes how spread out individual observations are around their mean. It is not the same as the uncertainty in the estimated mean. To assess uncertainty about a mean or a change, readers would usually need an estimate such as a confidence interval, together with the relevant sample size and analysis method. None of those outcome estimates is reported in the registry record.

Why do repeated assessments matter?

Measurements at baseline, immediately after the intervention, and at 3 months are repeated observations on participants over time. In general, observations from the same person are related; a statistical method for repeated measurements should account for that dependence rather than treating every score as if it came from a different person. The choice of method also depends on the research question: one might estimate change from baseline at each later assessment, describe the overall time pattern, or test a defined contrast. The registry record does not report which question was used for analysis or which method addressed the repeated measurements.

Follow-up results also depend on who contributes observations at each time. In general, a comparison of means based on different sets of participants can reflect both changes in scores and changes in the composition of the assessed group. A repeated-measures analysis may use available observations under assumptions about missingness, while other approaches may require additional assumptions or sensitivity analyses. The registry record does not report the number assessed at each time, reasons for missing data, or methods for handling missing outcomes. No particular missing-data approach should therefore be inferred.

What does the single-group design allow?

In general, a single-group before-and-after study can estimate how a measured outcome varies over time in the participants observed. It lacks the concurrent comparison needed to distinguish the effect of the intervention from changes that might have occurred without it. Masking is listed as none, and no randomized comparator is described. This does not make descriptive score changes meaningless, but it limits causal interpretation: an observed change would be an association with the period in which the program occurred, not an isolated estimate of its effect.

The registry record’s primary hypothesis is directional, but it does not report a test, a statistical significance threshold for that primary analysis, or a confidence interval. The general purpose of a confidence interval is to express the range of effect estimates reasonably compatible with the data and specified analysis. It communicates precision as well as direction and magnitude; a p-value alone would not show the size or practical importance of an effect. Neither type of estimate is available in the registry record.

How should planning illustrations be understood?

The record describes planning illustrations that use an observed effect, two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. In general, a sample-size calculation estimates the number of observations needed under stated assumptions about the target effect, variability, error rates, allocation, and analysis. Changing the target effect changes the planning requirement. Such a calculation is conditional on those assumptions and is not a statement about the probability that a completed study has detected an effect.

The record explicitly characterizes these calculations as planning illustrations rather than the study’s own design. The actual study is listed as single-group, not as an equal-allocation two-arm trial. The observed effect used for the illustration and the numeric planning results are not reported in the registry record. Any such illustration is not observed power, and it cannot supply the absent primary outcome estimate.

What can be said about multiplicity?

The primary outcome is knowledge and awareness, and the record also names secondary outcomes concerning trust, activation, satisfaction, cost, and pharmacist satisfaction. When multiple outcomes or repeated comparisons are tested, general statistical practice considers the possibility of chance findings arising across tests. A prespecified hierarchy, adjustment method, or distinction between confirmatory and exploratory analyses can help readers understand how that issue was handled. No multiplicity strategy is reported in the registry record. With no analysis entries or outcome results, there is no basis to infer whether adjustment was used or to judge the impact of multiple testing.

10. Multiplicity, Missing Data and Analysis Populations

The registry record names one primary outcome, knowledge and awareness of pneumococcal disease, and several secondary outcomes: trust in pharmacists as vaccine providers, activation, satisfaction with the program, intervention cost, and pharmacist satisfaction. It lists six outcome measures overall and zero analysis entries. The registry record does not report whether a testing hierarchy, multiplicity adjustment, or other plan was used to address the several outcomes and repeated assessment times.

In general, evaluating multiple outcomes or multiple comparisons increases the opportunity for chance findings. A prespecified strategy helps distinguish the main confirmatory question from other analyses and clarifies how evidence should be interpreted. Since no outcome estimates, p-values, or analysis details are reported in the registry record, multiplicity cannot be assessed for this study. The presence of several stated hypotheses alone does not show that any particular adjustment was required or applied.

The primary outcome population is labeled the intention-to-treat sample. The registry record does not define that population further or report how many participants contributed data at baseline, immediately post-intervention, or 3 months. It also does not report missing-data reasons, imputation, or sensitivity analyses. Enrollment of 203 is not enough to determine the number included in each outcome analysis or whether follow-up was complete. Any assumptions about missing observations or the composition of the analyzed sample would therefore be speculative.

For these reasons, the posted record does not permit evaluation of whether missing data or multiplicity influenced the findings. Outcome values and analysis methods are not reported in the registry record.

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.

The safety entry is labeled “PPPP Participants - Vaccine Recipients.” It lists 20 participants at risk for serious adverse events and 0 affected by serious adverse events. For other adverse events, it also lists 20 at risk and 0 affected. The death field is null, and the record lists no top serious adverse-event terms.

These figures describe what the registry safety entry reports; they do not establish that no adverse events occurred outside the categories or reporting period represented by that entry. A count of 0 affected is not a complete safety profile, and the number at risk does not show how adverse events were defined, collected, or assessed. Those details are not reported in the registry record.

The null death field should not be interpreted as a reported count of zero deaths. The number of deaths is not reported in the registry record. The safety group label uses “PPPP,” whereas the intervention name is PPVP; the record does not explain that naming difference. The listed figures should be read narrowly as registry entries, not as a comparison with another treatment group or as a basis for broad safety conclusions.

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

The record establishes that a pharmacist-led pneumococcal vaccine education program was studied at an urban senior center and that the primary outcome was questionnaire-based knowledge and awareness assessed at baseline, immediately after the program, and at 3 months. It also states the program’s primary hypothesis and lists additional goals involving trust, satisfaction, cost, and pharmacist activation. These details show what the study set out to examine.

The record does not report the primary scores, changes over time, or statistical analyses. It therefore does not establish whether knowledge increased, how large any change was, whether it persisted to 3 months, or how precisely an effect was estimated. The absence of posted results is not evidence for either benefit or no benefit. It leaves the direction, size, and uncertainty of the primary outcome unknown.

Even if within-person score changes had been reported, the single-group design would not by itself demonstrate that the program caused them. Without a concurrent comparator, changes over time cannot be cleanly distinguished from other influences. The absence of masking is also part of the recorded design, while the record does not describe procedures that might reduce measurement or response bias.

The questionnaire score is a measure of knowledge and awareness, not a direct measure of vaccination coverage, disease prevention, or clinical outcomes. The record’s safety entry lists no serious or other adverse events among the 20 at risk in each category, but the death field is not reported and details of safety ascertainment are absent. Those entries should not be extended beyond the specific registry fields.

Overall, the registry record supports a description of the program, population framing, and planned measurement approach, but not a conclusion about the observed effect or its clinical implications. Results for the primary and secondary outcomes are not reported in the registry record.

13. Why This Trial Matters Statistically

This study raises a practical statistical question about evaluating an educational and vaccination program in a community setting. The primary endpoint is aligned with the education goal: it measures knowledge and awareness using a score with a stated range and defined interpretation. Assessments at baseline, immediately after the intervention, and at 3 months could distinguish an immediate pattern from later follow-up if the corresponding results and methods were available.

The single-group design also illustrates a central distinction in clinical research: measuring change is not the same as estimating a causal effect. Repeated scores can describe the experience of participants over time, but a concurrent comparison is generally needed to separate intervention-related change from changes that might occur for other reasons. The registry record lists no comparator, so its design cannot support a randomized between-group contrast.

Another important issue is completeness of follow-up. Enrollment is listed as 203, but the number assessed at each time point and the handling of missing observations are not reported in the registry record. Without that information, readers cannot determine whether the available measurements represent a consistent participant group or how missingness may affect interpretation.

Finally, the registry record states multiple aims, while reporting no analyses or outcome estimates. This makes it impossible to assess precision, statistical evidence, or the relationship between the primary and secondary questions. The case is statistically instructive because it shows why a clearly defined endpoint and schedule are only part of an interpretable evidence record: estimates, uncertainty, analysis methods, and participant accounting are also needed.

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.

Several limitations follow specifically from the registry information. The study is listed as single-group, with allocation not applicable and masking none. There is no control group described, so the design does not provide a concurrent comparison to distinguish program-associated changes from other changes over time. The record also does not report the statistical model or comparison used for the repeated assessments.

The population description is not fully consistent across registry fields: the official title refers to adults aged 65 years or older or those with defined risk factors, while the condition entry says the study is open to seniors age 50 or older. The record does not clarify the eligibility criteria or which description applies to participants enrolled. It does not provide demographic characteristics, so the intended emphasis on older minorities cannot be evaluated against the enrolled sample.

The primary questionnaire was developed by investigators. Its content and score interpretation are described, but validation, reliability, and other measurement properties are not reported in the registry record. The number of participants contributing data at each time point, missing-data reasons, and methods for handling incomplete assessments are also not reported.

Most importantly, no outcome values or analysis entries are listed. The record therefore does not allow assessment of the magnitude, precision, or statistical evidence for the primary outcome or secondary outcomes. The safety entry has limited detail, and the death field is null rather than a reported zero. These limitations restrict both effectiveness and safety interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Impact and Cost of a Pharmacist Pneumococcal Vaccination Program With PNEUMOVAX® 23 at an Urban Senior Center — NCT01944462.
• Registry record last updated 2018-01-03; status last verified 2017-05.
• Results first posted 2018-01-03.
• 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

NCT01944462 is a completed phase 4, single-group study sponsored by Thomas Jefferson University. It lists enrollment of 203, a start in 2014-01, and primary completion in 2014-11. The intervention was a pharmacist pneumococcal vaccine education program delivered at an urban senior center, with the program also aiming to provide vaccine to eligible participants.

The primary outcome was knowledge and awareness of pneumococcal disease, measured by an investigator-developed questionnaire at baseline, immediately after the intervention, and at 3 months. The record lists six outcome measures and zero analysis entries. Primary and secondary outcome results, analysis methods, and missing-data details are not reported in the registry record.

The safety entry lists 20 at risk and 0 affected for serious adverse events, and 20 at risk and 0 affected for other adverse events. The death field is null. The registry record supports a description of study design and planned measures, but does not provide outcome estimates for judging the program’s observed effects.