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 BATAR: Individuals Currently Taking Boosted Atazanavir as Part of an HIV Treatment Regimen Will be Evaluated to See if Substituting Raltegravir for Nucleoside Transcriptase Inhibitors Will be Safe and Well Tolerated. (NCT00931801), a randomized phase 4 study. The primary outcome is Maintenance of Virologic Suppression.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00931801 |
| Phase | Phase 4 |
| Condition | HIV |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 43 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Community Research Initiative of New England |
| Results posted | Yes |
2. Clinical Question
Population
Participants with HIV who were virologically suppressed on a standard regimen of boosted atazanavir, tenofovir and emtricitabine were the intended study population. The registry says all enrolled participants were included in the primary outcome analysis. Enrollment was 43.
Intervention
One study regimen combined atazanavir 300mg and ritonavir 100mg daily with raltegravir 400mg twice daily. The other used atazanavir 300mg twice daily with raltegravir 400mg twice daily. Both were intended as NRTI-sparing regimens.
Comparator
The control group continued its baseline regimen, described in the study summary as boosted atazanavir with emtricitabine/tenofovir. The record does not give a fuller control-arm description in the arm listing.
Primary question
At 48 weeks, did participants in the study groups maintain virologic suppression, defined as HIV RNA < 40 copies/mL? The registry describes this comparison but does not report the primary outcome counts or a statistical comparison, so its results cannot be assessed from the record.
3. Trial Design
This was a Phase IV, randomized, open-label, parallel-group pilot study. The registry lists enrollment of 43 and a completed status. The recorded start was 2009-12, and primary completion was 2012-02. The sponsor was Community Research Initiative of New England.
Participants were assigned to continue their baseline regimen or to receive one of two atazanavir–raltegravir regimens. One study regimen included atazanavir 300mg plus ritonavir 100mg daily and raltegravir 400mg twice daily. The other used atazanavir 300mg twice daily and raltegravir 400mg twice daily. The summary describes follow-up for 48 weeks, with six clinic visits after baseline for evaluation and laboratory testing.
“Randomized” means the study used chance-based assignment, but the registry record does not report the randomization method, allocation concealment, or whether assignment used equal numbers in the three trial groups. “Open-label” means masking was not used; the record lists masking as none. A parallel design means participants were assigned to a group and followed under that assigned regimen, rather than crossing between regimens as part of the described design.
The record lists four outcome measures. Besides maintenance of virologic suppression, the secondary outcomes concern change in CD4 from baseline to Week 48, adherence to the assigned study treatment from baseline to Week 48, and quality of life from baseline to 48 weeks. Numerical results for these secondary outcomes are not reported in the registry record. Nor does the record describe the study’s sample-size justification or a detailed statistical analysis plan.
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: There were 7 participants that did not meet eligibility criteria (either due to disallowed concomitant medication use or safety labs outside of the required parameters). 2 of those 7 subjects re-screened at a later date and were confirmed eligible. 2 subjects withdrew consent after the screening visit but prior to starting the assigned treatment.
Overall Study
| Stage | Control Arm | Intervention Arm No.1 | Intervention Arm No.2 |
|---|---|---|---|
| STARTED | 14 | 15 | 14 |
| COMPLETED | 13 | 14 | 10 |
| NOT COMPLETED | 1 | 1 | 4 |
Reasons for not completing this period:
| Reason | Control Arm | Intervention Arm No.1 | Intervention Arm No.2 |
|---|---|---|---|
| Adverse Event | 0 | 0 | 1 |
| Lost to Follow-up | 0 | 1 | 0 |
| Withdrawal by Subject | 1 | 0 | 0 |
| Confirmed Virologic Failure | 0 | 0 | 3 |
Analysis population for the primary outcome, as defined in the registry: All enrolled participants were included in this analysis of primary outcome measurement.
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 | Control Arm | Intervention Arm No.1 | Intervention Arm No.2 | Total |
|---|---|---|---|---|---|
| Participants analysed | 14 | 15 | 14 | 43 | |
| Age, Continuous | years | 43.5 (SD 11.6) | 47.6 (SD 11.5) | 46.6 (SD 6.6) | 45.9 (SD 10.1) |
| Sex: Female, Male: Female | Participants | 2 | 2 | 1 | 5 |
| Sex: Female, Male: Male | Participants | 12 | 13 | 13 | 38 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 6 | 2 | 5 | 13 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 8 | 13 | 9 | 30 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 0 | 0 | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 | 3 | 3 | 9 |
| Race (NIH/OMB): White | Participants | 9 | 12 | 11 | 32 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 0 | 1 |
| Region of Enrollment: United States | participants | 14 | 15 | 14 | 43 |
| Mean CD4 | cells/mm3 | 544.6 (SD 197.7) | 518.5 (SD 198.9) | 533.9 (SD 198.3) | 532.0 (SD 193.8) |
6. Primary Endpoint
The registry lists the primary outcome as Maintenance of Virologic Suppression, measured over 48 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is maintenance of virologic suppression at 48 weeks. The registry defines suppression as HIV RNA < 40 copies/mL and states that the endpoint is measured as a number of participants. It frames the question as comparing suppression among participants assigned to either of the two raltegravir-containing regimens with suppression among participants continuing their standard regimen.
A binary endpoint classifies each participant according to whether the specified condition is met. This can make a result easier to interpret as a count of participants who meet the clinical or laboratory definition. It also depends on a clear threshold and a defined assessment time: both are stated in the registry record for this endpoint.
For this study, the endpoint is intended to assess whether suppression is maintained during follow-up after assignment to the study regimens or continued baseline therapy. However, the registry record does not provide the numbers meeting the definition in each group, the numbers assessed at 48 weeks, or an estimated between-group contrast. It therefore supplies the endpoint definition but not the numerical primary result needed to judge how the groups compared.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record establishes the question the study intended to address, but it does not provide the primary outcome results. The endpoint is maintenance of HIV RNA < 40 copies/mL at 48 weeks. Although the record says all enrolled participants were included in the primary outcome analysis, it gives no group-specific counts for participants who met that definition, no group-specific denominators at the endpoint, and no statistical comparison. The primary outcome therefore cannot be interpreted as evidence for or against a difference between study groups using this record alone.
The safety information is more numerical. For serious adverse events, the registry lists 1 affected participant in the control arm, 2 in Intervention Arm No.1, and 2 in Intervention Arm No.2. The corresponding numbers at risk are 14, 15, and 14. For other adverse events, it lists 9, 13, and 13 affected participants, with 14, 15, and 14 at risk. These are descriptive counts; the record does not provide a comparative safety analysis or uncertainty estimates for them. The adverse-event record also lists serious-event terms with percentages, but does not provide enough context to attribute those percentages to a specific arm or assess whether participants could appear under more than one term.
The study was a pilot, and its enrollment was 43. That context does not establish what size of effect the study could reliably detect. A trial’s ability to distinguish an effect from random variation depends on design assumptions and the observed data; the registry record does not report a trial-specific sample-size justification or primary-outcome analysis. Any sample-size planning illustration based on the observed effect is not a substitute for the missing primary results and is not observed power.
The posted record does not report estimates of effect, confidence intervals, or p-values for the primary comparison. A confidence interval, in general, describes the uncertainty around an estimated effect; its width helps show how precisely the effect is estimated. Without an effect estimate and interval, the precision of the primary comparison cannot be judged. The registry also lists no analyses, so it does not document an inferential result for the primary endpoint.
Consequently, the defensible interpretation is limited: the record describes a randomized comparison of three regimens and reports some adverse-event counts, but it does not report the central efficacy outcome results. Neither the endpoint definition nor the trial’s completed status establishes what the results were. The record cannot support a conclusion about whether virologic suppression differed among groups.
9. Statistical Methods Explained
The methods information identifies a randomized, open-label, parallel-group design and a binary primary endpoint. It does not describe a detailed statistical analysis plan or report a primary outcome analysis. The concepts below explain how such data are generally considered; they are not claims about analyses performed in this trial.
What does randomization contribute?
In general, random assignment is intended to make the treatment groups comparable, on average, with respect to both measured and unmeasured characteristics. This supports interpretation of between-group differences as associated with assignment, provided the trial is conducted and analyzed appropriately. Randomization does not guarantee that groups will be identical, especially in a pilot with limited enrollment. The registry record does not describe how the random sequence was generated, how assignments were concealed, or whether any stratification was used.
How should a binary endpoint be analyzed?
In general, a binary endpoint records whether each participant does or does not meet a prespecified condition. For this study, the condition is HIV RNA < 40 copies/mL at 48 weeks. Common summaries include the number meeting the condition and the number assessed in each group. A comparison can then express the between-group contrast using an appropriate measure of association or difference, with an uncertainty interval. Which measure and model are appropriate depends on the analysis plan and data structure. The registry record does not report an analysis method or the endpoint counts needed to reproduce a comparison.
When interpreting a binary outcome, the denominator matters: a count has meaning only alongside the number of participants assessed and the handling of participants whose outcome is unavailable. The record states that all enrolled participants were included in the primary outcome analysis, but does not specify how missing 48-week measurements were treated, whether every enrolled participant had an evaluable measurement, or the denominators used in each group.
What does an uncertainty interval add?
In general, an estimate alone does not show how precisely a study has measured an effect. A confidence interval communicates a range of values compatible with the data and the method used to calculate it. A wide interval indicates less precision than a narrow interval. Such an interval should be read alongside the estimated effect and the clinical question; it does not by itself establish that an effect is important. No primary-outcome estimate or confidence interval is reported in the registry record.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a statistical model expects. If a model underestimates variability, its standard errors can be too small and its uncertainty intervals too narrow. This issue is especially relevant to count outcomes when the data vary more than a simple count model assumes. The primary endpoint in this study is described as a binary participant count, and the registry record does not identify an over-dispersion model or report any model-based analysis. This general concept should not be taken to mean that over-dispersion was present or that a particular method was used in this trial.
What do the planning assumptions mean?
The record describes planning illustrations based on fractions of an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that these are planning illustrations, not the trial’s own design. They are not observed power and should not be interpreted as proof that the trial could detect a particular effect. The record does not report the trial’s sample-size justification, and the primary outcome results needed to evaluate the observed effect are not reported. Planning illustrations are therefore distinct from the evidence generated by the trial.
What can the reported safety counts show?
In general, event counts describe what was recorded, while a comparative analysis considers both the counts and the numbers at risk or assessed. Counts alone do not quantify uncertainty or establish that a difference between groups is meaningful. The registry presents serious and other adverse-event counts by group, but does not report an inferential comparison, confidence intervals, or a detailed account of event ascertainment. These figures should be read descriptively rather than as a formal comparison of safety.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies a primary outcome and lists three secondary outcomes: change in CD4 from baseline to Week 48, change in adherence to the assigned treatment from baseline to Week 48, and change in quality of life from baseline to 48 weeks. Considering several outcomes can raise a multiplicity issue: the more comparisons examined, the greater the chance that at least one result appears unusual by chance. In general, a prespecified testing hierarchy or other adjustment can address this concern. The registry record does not report whether any multiplicity strategy was planned or used, and it does not provide numerical results for the secondary outcomes.
Missing-data handling is also not reported in the registry record. The primary outcome description says all enrolled participants were included in the analysis, but does not explain whether missing Week 48 measurements occurred, how any were handled, or whether the analysis used imputation, a missing-equals-failure assumption, or another approach. Those methods can affect a binary endpoint and should not be inferred from the statement about the analysis population.
The record does not provide a detailed definition of an intention-to-treat population, a per-protocol population, or exclusions after randomization. It says all enrolled participants were included in the primary outcome analysis, but does not give group-specific endpoint denominators. The record lists no analyses, and no primary-outcome estimates, uncertainty intervals, or p-values are reported. The statistical plan, including multiplicity control and missing-data procedures, is not reported in the registry record.
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 |
|---|---|---|---|
| Control Arm | 1 | 14 | 7.1% |
| Intervention Arm No.1 | 2 | 15 | 13.3% |
| Intervention Arm No.2 | 2 | 14 | 14.3% |
| Total | 5 | 43 | 11.6% |
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 |
|---|---|
| Control Arm | 9 of 14 |
| Intervention Arm No.1 | 13 of 15 |
| Intervention Arm No.2 | 13 of 14 |
| Total | 35 of 43 |
Most frequent serious adverse event terms
| Event term | Organ system | Control Arm | Intervention Arm No.1 | Intervention Arm No.2 | Total |
|---|---|---|---|---|---|
| Myocardial Infarction | Cardiac disorders | 1 of 14 | 0 of 15 | 0 of 14 | 1 of 43 |
| Prostate Cancer | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 14 | 1 of 15 | 0 of 14 | 1 of 43 |
| Hospitalization due to asthma | Respiratory, thoracic and mediastinal disorders | 0 of 14 | 1 of 15 | 0 of 14 | 1 of 43 |
| Hospitalization for Recurrent Depression | Psychiatric disorders | 0 of 14 | 0 of 15 | 1 of 14 | 1 of 43 |
| Deep Vein Thrombosis | Blood and lymphatic system disorders | 0 of 14 | 0 of 15 | 1 of 14 | 1 of 43 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Control Arm | Intervention Arm No.1 | Intervention Arm No.2 | Total |
|---|---|---|---|---|---|
| diarrhea | Gastrointestinal disorders | 0 of 14 | 3 of 15 | 3 of 14 | 6 of 43 |
| Headache | Nervous system disorders | 1 of 14 | 3 of 15 | 2 of 14 | 6 of 43 |
| Pharyngitis | Gastrointestinal disorders | 2 of 14 | 1 of 15 | 2 of 14 | 5 of 43 |
| STI | Infections and infestations | 1 of 14 | 2 of 15 | 2 of 14 | 5 of 43 |
| Depression | Psychiatric disorders | 2 of 14 | 1 of 15 | 1 of 14 | 4 of 43 |
| Allergic Rhinitis | Respiratory, thoracic and mediastinal disorders | 2 of 14 | 2 of 15 | 0 of 14 | 4 of 43 |
| Bronchitis | Respiratory, thoracic and mediastinal disorders | 0 of 14 | 3 of 15 | 1 of 14 | 4 of 43 |
| Upper Respiratory Infection | Respiratory, thoracic and mediastinal disorders | 0 of 14 | 1 of 15 | 3 of 14 | 4 of 43 |
| Skin Rash, unspecified | Skin and subcutaneous tissue disorders | 2 of 14 | 1 of 15 | 1 of 14 | 4 of 43 |
| gastroesophageal reflux disease | Gastrointestinal disorders | 0 of 14 | 1 of 15 | 2 of 14 | 3 of 43 |
Serious events with the highest arm-level rate: myocardial infarction (7.1%), hospitalization for recurrent depression (7.1%), deep vein thrombosis (7.1%), prostate cancer (6.7%), hospitalization due to asthma (6.7%).
The adverse-event figures are counts of participants affected, with a corresponding number at risk listed for each group. For serious adverse events, the registry reports 1 affected participant among 14 at risk in the control arm, 2 among 15 in Intervention Arm No.1, and 2 among 14 in Intervention Arm No.2. For other adverse events, it reports 9 among 14, 13 among 15, and 13 among 14, respectively.
These figures are descriptive. The registry record does not give a statistical comparison between groups, uncertainty intervals, or information about how event observation time was handled. It does not report deaths in the group listings. The listed serious-event terms include Myocardial Infarction and Hospitalization for Recurrent Depression at 7.1%, Deep Vein Thrombosis at 7.1%, Prostate Cancer at 6.7%, and Hospitalization due to asthma at 6.7%. The record does not make clear which group or denominator those percentages refer to, or whether terms could overlap for an individual participant. They should not be treated as arm-specific rates.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, open-label pilot study compared continued baseline therapy with two atazanavir–raltegravir regimens in participants with HIV who were virologically suppressed on a standard regimen. It also states the primary question and its threshold: whether suppression, defined as HIV RNA < 40 copies/mL, was maintained at 48 weeks. These details explain the intended comparison, not its result.
The record does not report the primary endpoint counts, group-specific denominators at 48 weeks, effect estimates, or a statistical comparison. It therefore cannot show from the posted results whether suppression was more or less common in any group, or how precise a between-group estimate would be. The study’s completed status does not fill this reporting gap.
The adverse-event counts describe events recorded in each arm, but are not accompanied by inferential comparisons or uncertainty estimates. They should not be read as proof that one regimen has a higher or lower risk. Likewise, the serious-event terms and percentages do not establish arm-specific rates because their group and denominator context is not reported.
More generally, absence of a reported comparison is not evidence that the groups were the same. It also does not establish that a difference existed. The information needed to assess either possibility—the primary outcome results and their statistical uncertainty—is not reported in the registry record. The secondary outcome names indicate what else the study intended to assess, but their numerical results are also not reported.
Accordingly, the record supports a description of the study design, endpoint, and selected safety counts. It does not support a conclusion about the comparative efficacy of the regimens, the precision of the primary outcome, or a definitive comparative safety assessment.
13. Why This Trial Matters Statistically
This trial is statistically notable as a randomized pilot that framed a focused binary outcome: maintenance of a defined virologic threshold at 48 weeks. The comparison included continued baseline treatment and two distinct atazanavir–raltegravir regimens. Keeping the endpoint definition and assessment time explicit is important because a binary result depends on both the classification threshold and when participants are assessed.
The record also illustrates the difference between a trial description and a report of trial results. Randomization and a completed status describe design and conduct, but they do not provide an effect estimate. For statistical interpretation, readers need the outcome counts, denominators, comparison method, and uncertainty. Those primary-result details are not reported in the registry record.
The pilot context matters when interpreting what can be concluded. Enrollment was 43, and the registry does not state a trial-specific sample-size justification. A small pilot can be useful for describing feasibility or generating information for later work, but the record does not report such findings in a way that permits a primary-outcome comparison. Planning illustrations based on an observed effect are not observed power, and they do not replace the missing results.
Finally, the safety listings show why counts require context. They give affected participants and numbers at risk by group, yet no comparative analysis or uncertainty estimates accompany them. The available record therefore offers design details and descriptive safety information while leaving the central statistical question unresolved in the posted results.
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 principal limitation for interpreting this study is that the registry record does not report the numerical results for its primary endpoint. It defines maintenance of suppression at 48 weeks but gives no group-specific outcome counts, endpoint denominators, estimated contrasts, or uncertainty intervals. Without these, the primary comparison cannot be evaluated.
The record also lacks a detailed statistical analysis plan. It does not describe the randomization procedure or allocation concealment, the planned model or effect measure, any adjustment for multiple outcomes, or the approach to missing data. It states that all enrolled participants were included in the primary outcome analysis, but does not clarify how the analysis population was defined in practice or how unavailable measurements were handled.
The trial is described as a pilot with enrollment of 43, but the registry does not report its own sample-size justification. The planning assumptions described in the record are not the trial’s design justification and do not establish observed power. Results for the listed secondary outcomes are also not reported.
Safety information is limited to participant counts by group and a list of serious-event terms with percentages. The record does not provide a comparative safety analysis, uncertainty estimates, event timing, or enough context to assign the listed term percentages to a specific group or denominator. These limitations constrain interpretation of both the primary question and the adverse-event listings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: BATAR: Individuals Currently Taking Boosted Atazanavir as Part of an HIV Treatment Regimen Will be Evaluated to See if Substituting Raltegravir for Nucleoside Transcriptase Inhibitors Will be Safe and Well Tolerated. — NCT00931801.
- Registry record last updated 2017-07-21; status last verified 2017-07.
- Results first posted 2013-03-11.
- 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.
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18. Record Summary
The registry describes a completed, randomized, open-label, parallel-group Phase IV pilot study sponsored by Community Research Initiative of New England. Enrollment was 43. The recorded start was 2009-12, and primary completion was 2012-02.
Participants were assigned to continue their baseline regimen or receive one of two atazanavir–raltegravir regimens. The primary endpoint was maintenance of virologic suppression at 48 weeks, defined as HIV RNA < 40 copies/mL. The record states that all enrolled participants were included in the primary outcome analysis, but does not report its numerical results or a group comparison.
Serious and other adverse-event counts are listed by group, along with selected serious-event terms and percentages. Secondary outcomes concern CD4, adherence, and quality of life. Numerical results for those outcomes and a detailed statistical analysis plan are not reported in the registry record.