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 Adherence and Intensification of Medications (AIM) Implementation Study (NCT00495794), a randomized na study. The primary outcome is Change in Systolic Blood Pressure.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00495794 |
| Phase | NA |
| Condition | Diabetes, Hypertension |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 4622 |
| Arms in the primary outcome | n/a |
| Lead sponsor | US Department of Veterans Affairs |
| Results posted | Yes |
2. Clinical Question
Population
Patients with diabetes and hypertension whose blood pressure was a target of the implementation study. The registry describes an intention-to-treat population for the primary analysis. It does not report further eligibility details or participant characteristics.
Intervention
Clinical pharmacist management, including adherence counseling and medication management. The pharmacists were trained in behavioral counseling approaches, including motivational interviewing.
Comparator
Usual care. The registry describes usual-care participants as receiving usual care and does not give further detail about its components.
Primary question
What change in systolic blood pressure was observed in the pharmacist-management group and usual-care group over the stated period, from 6 months prior to 6 months after the intervention period? The registry names this as the primary outcome but does not report the numerical outcome results or a between-group estimate.
The study addressed medication management for people with both diabetes and hypertension. Its rationale was that blood-pressure control can be difficult to achieve and that medication adherence problems or insufficient medication intensification may contribute. Those statements describe the study's background and motivation; they are not results of the randomized comparison.
The intervention was broader than a single medication or counseling message: the registry describes pharmacist-delivered adherence counseling and medication management. The study also listed glycemic and lipid control as secondary outcomes, and its objectives included adherence, regimen intensity, cost-effectiveness, implementation processes, and sustainability. The record does not provide numerical findings for these objectives.
The primary question therefore cannot be answered from the posted numerical results. The record identifies the outcome and intended analysis population, but does not give a change estimate, confidence interval, or test result with which to characterize the direction, size, or precision of the comparison.
3. Trial Design
The AIM Implementation Study is recorded as a completed, randomized, parallel-group study sponsored by the US Department of Veterans Affairs. Enrollment was 4622. The record lists the phase as NA and masking as none. Study dates are recorded as starting in 2008-08, with primary completion in 2010-03.
The two groups were pharmacist management and usual care. In the pharmacist-management group, eligible patients were assigned adherence counseling and medication management from a clinical pharmacist trained in behavioral counseling approaches, including motivational interviewing. The usual-care group received usual care. The registry does not describe the specific content or frequency of usual care, the duration or number of pharmacist contacts, or how intervention delivery varied across participants.
The registry identifies a parallel-group randomized design. An accompanying design note identifies the study as cluster-randomized and cautions that a simple individual-level re-analysis would be misleading. The identity of the randomized clusters, their number, and the details of the allocation procedure are not reported in the registry record. This matters because participants within the same cluster may have outcomes that are more alike than outcomes from different clusters. Analyses that ignore such clustering can give confidence intervals that are too narrow and tests that overstate precision.
The primary outcome was change in systolic blood pressure, expressed as a continuous mean, with a 95% confidence interval specified as the dispersion measure. The listed timeframe is 6 months prior to 6 months after the intervention period. The primary analysis population is described as intention to treat. A1c control and LDL control are named as secondary outcomes. Although the registry reports three outcome measures, further outcome details are not reported in the registry record.
The record contains no numerical primary outcome analysis. It therefore does not permit a quantitative comparison of the groups, even though it documents the study design, intervention, comparator, and intended primary endpoint.
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 | Pharmacist Management | Usual Care |
|---|---|---|
| STARTED | 2319 | 2303 |
| COMPLETED | 1797 | 2303 |
| NOT COMPLETED | 522 | 0 |
Reasons for not completing this period:
| Reason | Pharmacist Management | Usual Care |
|---|---|---|
| Pharmacist did not activate patient | 522 | 0 |
Analysis population for the primary outcome, as defined in the registry: intention to treat 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 | Pharmacist Management | Usual Care | Total |
|---|---|---|---|---|
| Participants analysed | 1797 | 2303 | 4100 | |
| Age, Continuous | years | 65.3 (SD 11.7) | 65.3 (SD 12.1) | 65.3 (SD 11.9) |
| Sex: Female, Male: Female | Participants | 547 | 721 | 1268 |
| Sex: Female, Male: Male | Participants | 1250 | 1582 | 2832 |
| Region of Enrollment: United States | participants | 1797 | 2303 | 4100 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Systolic Blood Pressure, measured over 6 months prior to 6 months after the intervention period.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | mmHg |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in systolic blood pressure, measured in mmHg. Systolic pressure is the higher of the two blood-pressure readings and is a continuous measurement, so the registry specifies a mean and a 95% confidence interval. The stated timeframe is 6 months prior to 6 months after the intervention period.
Blood pressure was selected as the primary outcome because the study aimed to evaluate whether a pharmacist-based approach to medication management was associated with a change in blood-pressure control among patients with diabetes and hypertension. The study background describes blood-pressure control as an important concern for this population. This explains the endpoint's relevance to the study question; it does not establish what effect the intervention had.
The registry does not specify the precise calculation used to define change, the measurement schedule within the stated timeframe, the instrument or clinical setting for measurement, or how repeated readings were combined. Those details are not reported in the registry record. It also does not provide the group means, mean change estimates, between-group contrast, confidence interval limits, or hypothesis-test result.
Accordingly, the endpoint name and units tell readers what the study intended to assess, but not the observed direction or magnitude of the result. Without a numerical estimate and its uncertainty, the posted record cannot show how precisely the groups' blood-pressure changes were compared.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes that the primary outcome was change in systolic blood pressure and that the intended primary analysis population was intention to treat. It does not report the numerical outcome estimate. In particular, no group-specific change, between-group contrast, 95% confidence interval limits, or primary-outcome test result appear in the record. The number of analyses is listed as 0. Thus, the study's primary comparison cannot be interpreted quantitatively from the posted results.
This absence is consequential for interpretation. An endpoint's name does not reveal whether the observed mean change favored one group, whether the groups were similar, or how uncertain the comparison was. A confidence interval would describe a range of estimates compatible with the data under the analysis assumptions. Without its limits and the estimate it accompanies, the precision of the result cannot be assessed. Nor can the record support a conclusion about statistical evidence for a between-group difference.
The study's rationale and objectives should also be distinguished from findings. The background discusses blood-pressure control and possible medication-adherence or intensification issues. The objectives include blood pressure, glycemic and lipid control, adherence, medication intensity, cost-effectiveness, implementation, and sustainability. These are reasons for conducting the study or outcomes it sought to evaluate; the registry does not report numerical findings for them. A1c control and LDL control are identified as secondary outcomes, but their results are not given.
The cluster-randomized design note is important when considering what an appropriate analysis would require. Participants assigned within a common cluster may share characteristics or care processes. As a general statistical principle, an analysis that treats all participants as independent when outcomes are correlated within clusters can understate uncertainty. The note explicitly warns that a simple individual-level re-analysis would be misleading. The cluster definition and sponsor analysis details are not reported in the registry record, so the actual adjustment and its adequacy cannot be evaluated from this information.
The registry lists zero serious adverse events among 2319 participants at risk in pharmacist management and 2303 at risk in usual care. It also lists zero other adverse events in each group. These are the posted counts, not evidence that every possible harm was absent: definitions, collection procedures, observation details, and completeness of reporting are not described. Death counts are null, which should not be read as zero deaths.
Overall, the record supports a description of the trial's design, intended outcomes, and posted adverse-event counts. It does not support an estimate of the intervention's effect on the primary endpoint or a judgment about the precision of that effect.
9. Statistical Methods Explained
What does a mean change describe?
Systolic blood pressure is a continuous measure. A mean summarizes the average measurement or average change in a group, but it does not show how values vary among individuals. A group mean can be useful for comparing groups, while still concealing differences in individual responses. The registry identifies the primary parameter as a mean and the outcome unit as mmHg. The precise change calculation and the individual-level distribution are not reported in the registry record.
To answer a comparative question, readers generally need an estimate that directly contrasts the groups, as well as its uncertainty. Separate group summaries may help describe each arm, but do not alone establish the size or precision of the between-group comparison. The registry does not post those summaries or a comparative estimate for this outcome.
What does a 95% confidence interval communicate?
In general, a confidence interval describes the uncertainty around an estimate under a specified statistical procedure and its assumptions. A narrower interval indicates greater precision than a wider interval, while the interval's location indicates which values are compatible with the estimate and procedure. It is not a guarantee that the true effect lies within the particular interval. The registry lists a 95% confidence interval as the dispersion measure for the primary outcome, but does not report numerical interval limits.
A confidence interval and a hypothesis test answer related but distinct questions. A test evaluates evidence relative to a specified null hypothesis and analysis procedure. An interval gives a range of plausible estimates and is often more informative about magnitude and precision. Neither can be interpreted without the numerical result and a clear definition of the contrast. Those results and the complete statistical plan are not reported in the registry record.
Why does clustering affect the analysis?
General statistical principle: when participants are grouped in clusters, their outcomes may be correlated because they share a setting, staff, or other cluster-level features. The effective information in clustered data can be less than it would be if every participant contributed fully independent information. An analysis generally needs to account for the design to estimate uncertainty appropriately.
The registry's design note identifies this as a cluster-randomized study and says that a simple individual-level re-analysis would be misleading. It also states that only the sponsor's own analysis is shown. The record does not identify the clusters, state how many there were, or describe the sponsor's model, variance calculation, or adjustment. Therefore, the stated design warning should be respected, but the specific analysis cannot be independently assessed from the registry information.
Over-dispersion is a related general concern when observed variation exceeds what a model assumes. If a model does not accommodate the relevant correlation or extra variation, its standard errors and confidence intervals may be unreliable. That general concept does not establish that over-dispersion occurred in this study; the registry does not report enough model details or outcome data to assess it.
How should the analysis population be read?
The primary outcome description names an intention-to-treat analysis. In general, intention-to-treat analysis seeks to compare participants according to their assigned group, rather than reclassifying them based on adherence to the assigned intervention. This can preserve the comparison created by random allocation. The meaning of the designation depends on how the analysis handles missing outcome measurements, cluster structure, and participants with incomplete follow-up.
The registry does not describe those implementation details. It does not report the number of participants with primary-outcome measurements, missingness by group, reasons for missing measurements, or any imputation or sensitivity analysis. The label alone is not enough to determine how complete or robust the analysis was.
What can a planning illustration establish?
In general, a sample-size calculation is a planning exercise that relates a chosen effect size, variability assumptions, significance level, allocation, and analysis method to a target level of power. It is not a result from the trial. The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation; the target effect is a stated fraction of the observed effect. For non-time-to-event outcomes, such illustrations are expressed as participants per arm.
These planning figures should not be called observed power. Post hoc power calculated from an observed result does not replace the effect estimate and confidence interval, and it cannot supply missing outcome evidence. The record states that the illustration is not the trial's own design. The numerical observed effect and numerical planning results are not reported in the registry record being described, so no specific planning requirement can be interpreted.
The cluster-randomized design also means that a planning calculation must be suitable for the unit of randomization and the correlation structure. A simple calculation based on independent participants may not reflect a clustered design. The available description does not state whether a cluster adjustment was incorporated into the planning illustration, and that detail is not reported in the registry record.
What analysis details remain unknown?
The record does not report a full statistical analysis plan, the model used for the primary outcome, any baseline adjustment, the cluster-level or participant-level variance method, or the handling of repeated blood-pressure measurements. It also does not report interim analyses or the rationale used to choose the sample size for the trial. These omissions prevent readers from checking the analysis against a prespecified plan or assessing whether the methods align with the design and endpoint.
Because the primary estimate and its uncertainty are absent, methods discussion must remain general. The record identifies the outcome type, confidence-interval convention, analysis population, and a design warning, but does not contain enough information to reconstruct or verify the sponsor's primary analysis.
10. Multiplicity, Missing Data and Analysis Populations
The study had several stated objectives, including blood pressure, glycemic and lipid control, medication adherence, regimen intensity, cost-effectiveness, implementation, and sustainability. The registry identifies change in systolic blood pressure as the primary outcome and A1c control and LDL control as secondary outcomes. It does not describe a formal strategy for handling multiple outcomes or multiple statistical tests. Multiplicity procedures, if any, are not reported in the registry record.
As a general statistical principle, examining several outcomes can increase the chance of a seemingly noteworthy result arising by chance if each is tested separately without an appropriate plan. This does not establish that such a problem occurred in this study. The relevant point is that the record does not say whether outcomes were prioritized beyond naming the primary endpoint, whether secondary outcomes were adjusted, or how multiple comparisons were interpreted.
The primary endpoint description specifies an intention-to-treat analysis population, but the record does not report the number with observed blood-pressure data, missing data by group, reasons for missingness, or methods used to address missing outcomes. It does not describe imputation, complete-case analysis, or sensitivity analyses. These details are not reported in the registry record.
Without those details, readers cannot assess whether missing data could have affected the comparison or whether the planned analysis was robust to different assumptions about missing outcomes. The same limitation applies to secondary outcomes: they are named, but numerical results and missing-data handling are not described.
The registry also does not report interim analyses, stopping rules, or a complete statistical analysis plan. Their presence or absence should not be inferred from the lack of detail. The primary result itself is not posted, so neither multiplicity handling nor missing-data methods can be evaluated against the observed estimate.
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 |
|---|---|---|---|
| Pharmacist Management | 0 | 2319 | 0.0% |
| Usual Care | 0 | 2303 | 0.0% |
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 |
|---|---|
| Pharmacist Management | 0 of 2319 |
| Usual Care | 0 of 2303 |
The registry lists serious adverse events for 2319 participants at risk in pharmacist management and 2303 at risk in usual care. The number affected is recorded as 0 in each group. The listed count for other adverse events is also 0 in both groups. No serious adverse-event terms are listed.
These figures describe what the registry record reports; they do not establish that no adverse events occurred under every definition or that safety was assessed with complete capture. The record does not describe the adverse-event definitions, surveillance method, reporting window, completeness of follow-up, or whether events were judged related to the intervention. It also does not provide event-level detail.
Deaths are recorded as null for both groups. A null value is not the same as a reported count of zero, so the death figures cannot be interpreted as confirming that there were no deaths. The zero affected counts should likewise be read as registry entries, not as proof of an absence of risk. The available safety information is limited to these posted counts and does not allow a fuller comparison of safety between groups.
12. What the Result Does, and Does Not, Mean
The record describes a randomized, parallel-group implementation study comparing clinical pharmacist management with usual care among patients with diabetes and hypertension. Its primary outcome was change in systolic blood pressure, and its primary analysis population was identified as intention to treat. These details clarify what the study set out to compare, but they do not provide the outcome result.
The registry does not report the primary estimate, group-specific changes, confidence interval limits, or a statistical test result. It therefore cannot establish the direction or size of the observed blood-pressure comparison or how precise that comparison was. The absence of numerical results is not evidence that the groups were the same, and it is not evidence that one group had a better outcome.
The listed secondary outcomes include A1c control and LDL control, while the broader study objectives also address adherence, treatment intensity, cost-effectiveness, implementation, and sustainability. Numerical findings for these questions are not reported in the registry record. The study rationale should not be treated as evidence that the intervention achieved its intended outcomes.
The posted safety entries show zero serious adverse events and zero other adverse events recorded among the participants listed at risk in each group. These entries do not resolve whether all events were captured or how adverse events were defined and monitored. Null death counts cannot be read as zero.
Sample-size planning illustrations, where presented, are not observed trial results or observed power. The record describes a planning approach based on the observed effect, but the design note warns against a simple individual-level re-analysis because the study was cluster-randomized. The numerical effect and analysis details needed to assess those illustrations are not reported in the registry record.
The defensible interpretation is therefore limited: the registry documents a clinically focused implementation question and its planned primary endpoint, but does not provide enough numerical outcome information to quantify the intervention comparison or its uncertainty.
13. Why This Trial Matters Statistically
This study raises statistical issues that are common in implementation research. The question is not only whether an intervention can be defined, but whether it can be delivered within a care system and evaluated using an analysis that reflects how the study was organized. Here, the registry describes pharmacist-delivered adherence counseling and medication management alongside usual care, with blood-pressure change as the primary outcome.
The cluster-randomized design note is especially important. In general, clustering can affect the amount of independent information and the precision of estimates. A participant-level analysis that ignores the grouping may misstate uncertainty. The record explicitly cautions against simple individual-level re-analysis, emphasizing that design details matter when interpreting results.
The endpoint also illustrates the distinction between an outcome definition and an outcome finding. Naming systolic blood-pressure change, its units, and a confidence-interval convention gives readers a framework for the intended analysis. Without the estimate and interval, however, it is not possible to assess magnitude or precision. A well-defined question is not a substitute for a posted result.
Finally, the study's objectives extend beyond a single clinical measure. It sought to examine glycemic and lipid control, adherence, medication intensification, cost-effectiveness, implementation, and sustainability. Such breadth makes clear why outcome priorities, missing-data methods, and multiplicity plans matter. Those statistical details and numerical findings are not reported in the registry record, limiting what can be concluded from it.
The study is therefore informative as an example of why design, analysis, and reporting must be read together. The registry offers context and design information, but its missing primary estimate prevents a statistical assessment of the central blood-pressure comparison.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation for interpreting this trial from the registry is the absence of numerical primary-outcome results. Although the endpoint, unit, timeframe, confidence-interval type, and intended analysis population are named, the record does not report group changes, a between-group estimate, interval limits, or a test result. The effect's direction, magnitude, and precision therefore cannot be assessed.
The design information also leaves important details unresolved. The record lists a randomized parallel-group study, while a design note identifies cluster randomization and warns against individual-level re-analysis. The clusters and allocation details are not reported in the registry record. The sponsor's model, cluster adjustment, variance estimation, and other analysis procedures are likewise not described.
The primary endpoint's operational definition is incomplete. The record gives a timeframe of 6 months prior to 6 months after the intervention period, but does not specify the calculation of change, measurement schedule, setting, or method for combining repeated readings. Participant characteristics, eligibility criteria, adherence to the intervention, and usual-care details are also not reported in the registry record.
Missing-data and multiplicity details are absent. The record does not report primary-outcome completeness by group, reasons for missing measurements, handling methods, sensitivity analyses, or a formal approach to multiple outcomes. It also does not report interim analyses or the sample-size justification for the trial. These omissions prevent evaluation of how analysis decisions might affect the results.
Safety information is limited to posted counts. Definitions, monitoring, follow-up, event attribution, and completeness of adverse-event collection are not described, and null death entries do not establish zero deaths. These limitations concern what can be learned from the registry record and should not be mistaken for evidence about unreported results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Adherence and Intensification of Medications (AIM) Implementation Study — NCT00495794.
- Registry record last updated 2015-04-28; status last verified 2014-07.
- Results first posted 2014-09-11.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes the completed AIM Implementation Study as a randomized, parallel-group comparison of pharmacist management with usual care. It enrolled 4622 participants and was sponsored by the US Department of Veterans Affairs. The listed study dates are 2008-08 to 2010-03.
The intervention involved pharmacist-delivered adherence counseling and medication management, with pharmacists trained in behavioral counseling approaches including motivational interviewing. The primary outcome was change in systolic blood pressure in mmHg, with a stated timeframe of 6 months prior to 6 months after the intervention period. The primary analysis population was intention to treat. A1c control and LDL control were named as secondary outcomes.
A design note identifies the study as cluster-randomized and cautions against simple individual-level re-analysis. Numerical primary and secondary outcome results, a full statistical analysis plan, and detailed missing-data methods are not reported in the registry record. Serious and other adverse-event counts are listed as zero in both groups; death counts are null.