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 Raltegravir With Optimized Background Therapy (OBT) in Multiple Experienced HIV-infected Patients (NCT01190124), a registered phase not stated study. The primary outcome is HIV-RNA Levels.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01190124 |
| Phase | Phase not stated |
| Condition | HIV Infections |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 151 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Doroana, Maria Manuela, M.D. |
| Results posted | Yes |
2. Clinical Question
Population
Adult, multiple-experienced people with HIV who needed to change antiretroviral therapy and began raltegravir with optimized background therapy through the Early Access Program. The registry also describes HIV-2 participants and participants whose therapy changed because of investigator-determined unacceptable toxicity. The recorded enrollment is 151, but the analysis population for each outcome is not reported in the registry record.
Intervention
Raltegravir used with optimized background therapy. The regimen is described in the context of an expanded-access program. The registry does not report the specific background drugs, how the background regimen was selected, or details of dose and treatment duration.
Comparator
No like-for-like control comparison is described. The record does not state an allocation method, and it identifies the study as not a randomized comparison. The listed cohort therefore cannot be read as a randomized contrast between raltegravir and a separate control treatment.
Primary question
The stated aim is to evaluate viral suppression and CD4 cell-count change at week 24 and week 48, including in specified subgroups. However, the registered primary outcome measure is patients with undetectable viral load at baseline, defined as confirmed HIV RNA < 50 copies/mL. That baseline measure does not itself report the planned week 24 or week 48 results. Those outcome results are not reported in the registry record.
3. Trial Design
The registry identifies a completed study with enrollment of 151. Its official title describes a retrospective analysis of a Portuguese cohort treated within the Expanded Access Program. The start is recorded as 2010-04 and primary completion as 2010-07. These record entries describe the study timeline, but do not establish the duration of follow-up for individual participants.
The cohort is described as adult, multiple-experienced people with HIV who needed to change antiretroviral therapy and initiated raltegravir with optimized background therapy. The record also discusses HIV-2 participants and people who changed treatment because of toxicity, including participants who replaced T20. These are described as study interests or subgroups; detailed criteria for membership and subgroup analysis are not reported in the registry record.
The intervention is raltegravir alongside optimized background therapy. The record does not provide the individual background regimens or explain how they were optimized. No randomized comparator is specified, and allocation is not stated. The registry cautions that the arms are not a like-for-like control comparison. Consequently, differences between any listed groups cannot be interpreted as randomized treatment effects.
The stated study aim concerns the proportion with undetectable viral load and mean CD4 cell-count increase at week 24 and week 48. Additional aims concern those needing therapy changes for unacceptable toxicity and HIV-2 participants. The registered primary measure, however, is undetectable viral load at baseline. The registry record does not report outcome values for the stated follow-up times, the analysis populations, or a detailed statistical analysis plan. A completed status indicates the registry lists the study as completed; it does not by itself establish that every planned outcome is reported.
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: 197 patients were included in the database. However, only 151 patients were included in the analysis, as 46 did not meet inclusion/exclusion criteria
Overall Study
| Stage | HIV-1 at Virologic Failure | HIV With Need for Therapy Change | HIV-2 With Therapeutic Failure |
|---|---|---|---|
| STARTED | 107 | 24 | 20 |
| COMPLETED | 90 | 24 | 19 |
| NOT COMPLETED | 17 | 0 | 1 |
Reasons for not completing this period:
| Reason | HIV-1 at Virologic Failure | HIV With Need for Therapy Change | HIV-2 With Therapeutic Failure |
|---|---|---|---|
| Death | 3 | 0 | 0 |
| Therapeutic Failure | 12 | 0 | 1 |
| Lost to Follow-up | 2 | 0 | 0 |
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 | HIV-1 at Virologic Failure | HIV With Need for Therapy Change | HIV-2 With Therapeutic Failure | Total |
|---|---|---|---|---|---|
| Participants analysed | 107 | 24 | 20 | 151 | |
| Age Continuous | years | 44.0 (full range 10.2) | 45.5 (full range 12.7) | 52.5 (full range 11.6) | 45.0 (full range 10.9) |
| Sex: Female, Male: Female | Participants | 22 | 5 | 10 | 37 |
| Sex: Female, Male: Male | Participants | 85 | 19 | 10 | 114 |
6. Primary Endpoint
The registry lists the primary outcome as HIV-RNA Levels, measured over Baseline.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The registered primary outcome is the number of patients with undetectable viral load at baseline, defined as confirmed HIV RNA < 50 copies/mL. This is a binary measure: each person is classified according to whether the stated viral-load criterion is met. It describes viral status at baseline rather than a change after treatment or a result at week 24 or week 48.
Viral load is used in HIV research as a measure of circulating virus. A threshold-based outcome can make a clinical state easier to describe than a continuous laboratory value, but it also discards information about how far values lie above or below the threshold. The registry does not report the baseline count meeting this definition, the corresponding denominator, or follow-up values for this primary measure.
The study description separately identifies the proportion with undetectable viral load and mean CD4 cell-count increase at week 24 and week 48 as efficacy aims. CD4 cell count reflects a different aspect of HIV status and is a continuous measurement. Its mean change would require a defined starting value, follow-up value, and analysis population; those results are not reported in the registry record. Thus, the primary measure as registered should not be confused with the broader follow-up aims in the study description.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record supports a description of the study question and setting, but not an assessment of the observed efficacy results. It identifies a completed retrospective Portuguese cohort treated through an expanded-access program and records enrollment of 151. It also states an aim to examine viral suppression and CD4 cell-count change at week 24 and week 48. It does not report the outcome counts, mean changes, or uncertainty estimates needed to characterize those follow-up results.
The registered primary measure is undetectable viral load at baseline, defined as confirmed HIV RNA < 50 copies/mL. A baseline measure can describe participants’ status at entry, but it cannot establish whether status changed after starting the study regimen. The record does not give the number meeting the baseline definition or its denominator. Accordingly, the primary outcome cannot be quantified from the registry information.
The study description includes subgroup questions involving HIV-2 and participants who changed antiretroviral therapy because of unacceptable toxicity, including replacement of T20. Subgroup questions can be informative, but their interpretation depends on the number of participants and outcome events in each group, the definitions used, and how missing observations were handled. These details and subgroup outcome results are not reported in the registry record.
The study is not described as a randomized comparison, and allocation is not stated. The record explicitly cautions that the arms are not a like-for-like control comparison. In a cohort, observed outcomes can reflect participant characteristics, treatment history, background therapy, and clinical decisions as well as the treatment being studied. Without an appropriate control and a clearly described analysis, the cohort’s observations do not isolate a causal treatment effect.
Uncertainty matters even when an outcome estimate is available. A confidence interval, in general, expresses a range of values compatible with the data under the analysis assumptions; it conveys precision as well as direction. No confidence intervals or other uncertainty estimates for the primary or follow-up outcomes are reported in the registry record. The available safety counts likewise should be read as recorded events, not as a complete basis for comparing risks across treatments.
The record’s hypotheses describe expected suppression and CD4 increase, but hypotheses are not results. The registry status is completed, yet the outcome findings needed to evaluate those hypotheses are not reported in the registry record. Conclusions should therefore remain limited to the design description, registered measures, and safety figures that are actually recorded.
9. Statistical Methods Explained
Statistical methods determine how observations are converted into estimates and how much uncertainty accompanies those estimates. The registry record does not report a detailed statistical analysis plan. The explanations below describe general principles relevant to the stated outcomes; they should not be taken as confirmation that a particular method was used in this study.
What does a binary outcome estimate?
The primary measure classifies participants according to whether confirmed HIV RNA is below the stated threshold, < 50 copies/mL, at baseline. For a binary outcome, a proportion is generally the number meeting the criterion divided by the number assessed. The numerator and denominator both matter: the same event count can imply different proportions when the number assessed differs. Neither value for the primary outcome is reported in the registry record, so the proportion cannot be interpreted from the recorded endpoint definition alone.
A binary outcome is straightforward to describe, but it does not retain all the information in the underlying viral-load measurement. Participants just on opposite sides of a threshold are classified differently, while different values on the same side are grouped together. The cutoff is part of the endpoint definition, not evidence that a participant’s measurement is known with unlimited precision.
How does a continuous outcome differ?
CD4 cell count is described as a continuous measure, and the study aims refer to mean increase or mean change. A mean summarizes the average observed change in the participants included in the calculation. It does not show how varied individual changes were. Interpretation ordinarily also depends on the spread of observations, the number assessed, and uncertainty around the mean. The registry record does not report the CD4 results, their variability, or the analysis population used.
Changes from baseline can be analyzed in different ways. An analysis may compare follow-up values, calculate individual changes, or adjust for baseline measurements and other variables. These approaches can answer related but not identical questions. The registry does not state which approach was used, whether adjustment was made, or how repeated follow-up measurements were handled.
Why do denominators and missing observations matter?
A reported count is interpretable only with a clear denominator and definition of who was assessed. In follow-up studies, participants may not have a measurement at every visit. If the people with available measurements differ from those without them, a result based only on observed values may not represent the full enrolled cohort. Statistical approaches can make different assumptions about missing observations, and those assumptions can affect estimates. The registry record does not report missing-data counts, reasons for missingness, or the method used to handle missing values.
Analysis populations also matter. An analysis might include everyone enrolled, only participants who began treatment, or participants meeting specified follow-up criteria. These choices can alter the population to which a result applies. Although the record states enrollment of 151, the number included in each outcome analysis and the analysis-population definitions are not reported in the registry record.
What can a confidence interval tell a reader?
In general, a confidence interval communicates uncertainty around an estimate under a specified statistical model and sampling framework. A narrow interval indicates greater precision than a wide interval, but does not resolve biases caused by study design or measurement. An interval’s interpretation depends on the chosen method and assumptions. No confidence intervals for the efficacy outcomes are reported in the registry record, so their precision cannot be assessed.
What do the planning illustrations represent?
The record describes a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is expressed as a stated fraction of the observed effect. The note specifies that time-to-event calculations use total events, while other calculations use participants per arm. These are planning assumptions, not the trial’s own documented design or evidence of observed power. The registry does not report a sample-size justification for the cohort, nor does the planning description establish that the study was randomized or had comparable arms.
Power calculations are generally prospective tools: they explore the amount of information needed to detect an effect under stated assumptions. A calculation based on an observed effect is especially dependent on that effect estimate and should not be interpreted as a measure of whether the completed study proved a hypothesis. The assumptions do not replace outcome estimates, uncertainty intervals, or a transparent account of the analysis. The registry record does not provide enough efficacy results to judge the precision of the stated follow-up aims.
Why is over-dispersion relevant in general?
For count outcomes, a statistical model may assume a particular relationship between the average count and its variability. Over-dispersion means that observed variation is greater than the model expects. If it is ignored, uncertainty can be understated and inference can appear more precise than the data support. This is a general methodological concern, not a reported feature or analysis choice for this cohort. The primary endpoint recorded is binary, and the registry does not state that a count model or an over-dispersion adjustment was used.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple outcome measures, including HIV-RNA and CD4 cell-count measures, and describes aims at week 24 and week 48 as well as subgroup questions. When many outcomes, time points, or subgroups are examined, the chance of finding an apparently notable result by chance can increase. Statistical plans may address this through a prespecified primary comparison, adjustment procedures, or a clearly labeled exploratory interpretation. The registry record does not report a multiplicity strategy, so it is not possible to determine whether or how the several stated questions were prioritized in analysis.
The registered primary measure is baseline undetectable viral load. The study description also refers to follow-up efficacy at week 24 and week 48. This difference between the registered primary measure and the broader stated aims matters when interpreting which outcome was intended to anchor the study conclusions. The registry does not report a protocol-level explanation of the relationship between these measures or a detailed hierarchy of outcomes.
Missing data can affect both the estimated outcome and its precision. For the viral-load and CD4 measures, interpretation would benefit from knowing how many participants had measurements at each assessment, why measurements were absent, and whether any imputation or other missing-data method was used. These details are not reported in the registry record. The number enrolled cannot be assumed to equal the number assessed for each outcome.
Analysis populations are also not described in sufficient detail. The record does not state whether results were based on all enrolled participants, participants who initiated the regimen, or another defined group. It also does not report a statistical analysis plan or interim-analysis information. Neither the presence nor absence of interim analyses can be inferred from the record. These omissions limit assessment of selective reporting, precision, and the intended interpretation of the listed outcomes.
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 |
|---|---|---|---|
| HIV-1 at Virologic Failure | 3 | 107 | 2.8% |
| HIV With Need for Therapy Change | 0 | 24 | 0.0% |
| HIV-2 With Therapeutic Failure | 0 | 20 | 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 |
|---|---|
| HIV-1 at Virologic Failure | 7 of 107 |
| HIV With Need for Therapy Change | 1 of 24 |
| HIV-2 With Therapeutic Failure | 1 of 20 |
Most frequent serious adverse event terms
| Event term | Organ system | HIV-1 at Virologic Failure | HIV With Need for Therapy Change | HIV-2 With Therapeutic Failure |
|---|---|---|---|---|
| Edema of the lower extremities | Vascular disorders | 1 of 107 | 0 of 24 | 0 of 20 |
| Toxidermia | Skin and subcutaneous tissue disorders | 1 of 107 | 0 of 24 | 0 of 20 |
| Anemia | Surgical and medical procedures | 1 of 107 | 0 of 24 | 0 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | HIV-1 at Virologic Failure | HIV With Need for Therapy Change | HIV-2 With Therapeutic Failure |
|---|---|---|---|---|
| Somnolence | Nervous system disorders | 2 of 107 | 0 of 24 | 0 of 20 |
| Diarrhea | Gastrointestinal disorders | 2 of 107 | 0 of 24 | 0 of 20 |
| Elevated CPK | Metabolism and nutrition disorders | 1 of 107 | 0 of 24 | 1 of 20 |
| Hallucinations | Psychiatric disorders | 1 of 107 | 0 of 24 | 0 of 20 |
| Anemia | Blood and lymphatic system disorders | 1 of 107 | 0 of 24 | 0 of 20 |
| Elevated AST/ALT | Metabolism and nutrition disorders | 0 of 107 | 1 of 24 | 0 of 20 |
Serious events with the highest arm-level rate: edema of the lower extremities (0.9%), toxidermia (0.9%), anemia (0.9%).
The adverse-event record lists three groups: HIV-1 at virologic failure, HIV with need for therapy change, and HIV-2 with therapeutic failure. For the first group, the registry lists 107 at risk and 3 affected for the serious-event entry, and 107 at risk and 7 affected for the other-event entry. For the group with need for therapy change, it lists 24 at risk and 0 affected for the serious-event entry, and 24 at risk and 1 affected for the other-event entry. For HIV-2 with therapeutic failure, it lists 20 at risk and 0 affected for the serious-event entry, and 20 at risk and 1 affected for the other-event entry.
These are group-level registry counts, not a randomized safety comparison. The group labels describe clinical categories, and the record does not establish that they are treatment arms suitable for comparing event risks. The counts should not be added across groups or interpreted as a count of distinct people. The registry does not report deaths for these entries.
The listed serious-event terms are edema of the lower extremities, toxidermia, and anemia, each recorded as 0.9%. The registry record does not provide further detail on timing, severity grading, attribution, or whether these terms refer to unique participants. The percentages should therefore be read as the recorded figures, not as evidence of a comparative risk or a complete account of safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed retrospective Portuguese cohort examined raltegravir with optimized background therapy in multiple-experienced people with HIV treated through an expanded-access program. It records enrollment of 151 and describes interest in viral suppression and CD4 cell-count change, including at week 24 and week 48. It also identifies questions concerning HIV-2 and therapy changes associated with unacceptable toxicity.
Those aims are not equivalent to reported findings. The registered primary measure is undetectable viral load at baseline, defined as confirmed HIV RNA < 50 copies/mL. No result for that measure is reported in the registry record. The record also does not report the follow-up viral-load values, proportions meeting the suppression criterion, mean CD4 changes, or uncertainty estimates. Therefore, the stated hypotheses about suppression and CD4 increase cannot be evaluated from the outcome information recorded.
The nonrandomized cohort design also limits causal interpretation. Allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. Participants may differ in treatment history, clinical condition, background therapy, and reasons for changing treatment. Those differences can affect observed outcomes. Without an appropriate comparison and an analysis that addresses relevant differences, an observed outcome cannot be attributed solely to raltegravir.
The safety entries provide selected affected counts and serious-event terms, but they do not establish comparative safety. The group counts are not a substitute for a fully described safety analysis, and the record does not report deaths for the listed entries. Further details about event definitions, follow-up, attribution, and analysis populations are not reported in the registry record.
The most defensible reading is descriptive: the registry documents a cohort, its stated questions, the baseline primary-outcome definition, and selected safety entries. It does not report the efficacy results needed to say how outcomes changed over follow-up or how precisely they were estimated. A completed registry status should not be read as proof that the stated hypotheses were supported or refuted.
13. Why This Trial Matters Statistically
This cohort raises statistical issues common to studies conducted in expanded-access settings. The participants are described as multiple-experienced and as needing a change in antiretroviral therapy. In such a setting, treatment is not assigned as part of a stated randomized comparison. Clinical history and the reasons for changing therapy may be related both to the regimen received and to later outcomes. Statistical description can characterize what was observed, but it cannot by itself make groups comparable or remove unmeasured differences.
The record also illustrates the importance of keeping a registered primary outcome distinct from broader study aims. The primary measure is undetectable viral load at baseline, while the description emphasizes efficacy at week 24 and week 48. Baseline status and follow-up change are different questions. Clear reporting of endpoint definitions, assessment timing, denominators, and analysis populations is needed to connect a study objective to an interpretable estimate.
Subgroup questions add another layer. HIV-2 participants and those needing a therapy change may have different clinical contexts from the overall cohort. Subgroup estimates can be imprecise when few observations are available, and repeated exploration across outcomes can make chance findings harder to distinguish from stable patterns. The registry record does not provide the subgroup outcome results or a multiplicity plan.
Finally, the record shows why reporting outcome estimates alongside uncertainty and missing-data information is essential. Enrollment alone does not reveal how many observations contributed to a particular endpoint or how precise an estimate may be. Here, the stated follow-up results and their uncertainty are not reported in the registry record. These limitations do not erase the descriptive value of a cohort, but they define what statistical conclusions can reasonably be drawn from its registry entry.
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 study is described as a retrospective analysis of a Portuguese cohort treated within an expanded-access program. The registry does not describe a randomized allocation method, and allocation is not stated. It explicitly cautions that the arms are not a like-for-like control comparison. These features constrain causal interpretation and make treatment contrasts vulnerable to differences among participants and their clinical histories.
The registry’s primary outcome is baseline undetectable viral load, whereas the study description emphasizes viral suppression and CD4 cell-count change at week 24 and week 48. The outcome results needed to assess those follow-up aims are not reported in the registry record. The primary baseline count and denominator are also not reported. Thus, neither change over time nor the precision of the stated efficacy outcomes can be assessed from the recorded information.
The record does not report the background antiretroviral regimens, detailed eligibility criteria, outcome-analysis populations, or the number assessed at each time point. It does not describe missing-data handling, adjustment for participant differences, or a detailed statistical analysis plan. Criteria and analysis details for the HIV-2 and therapy-change subgroups are not reported in the registry record.
Safety reporting is also limited to the listed group counts and serious-event terms. Further information on event definitions, follow-up, attribution, and the interpretation of repeated or overlapping events is not reported. The record does not report deaths for the listed safety entries. These limits mean the safety figures cannot support a complete or comparative assessment.
The planning illustration is not evidence of the cohort’s power or a record of its original design justification. Its stated assumptions do not fill the gaps in observed outcome reporting, and the registry does not report a sample-size justification for the study.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Raltegravir With Optimized Background Therapy (OBT) in Multiple Experienced HIV-infected Patients — NCT01190124.
- Registry record last updated 2011-05-19; status last verified 2011-04.
- Results first posted 2011-05-19.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01190124 is listed as completed and is described as a retrospective analysis of a Portuguese expanded-access cohort. Enrollment is recorded as 151, with start in 2010-04 and primary completion in 2010-07. Participants are described as adult, multiple-experienced people with HIV who initiated raltegravir with optimized background therapy after needing a treatment change.
The study description focuses on viral suppression and CD4 cell-count change at week 24 and week 48, including questions about HIV-2 and therapy changes for unacceptable toxicity. The registered primary measure is patients with undetectable viral load at baseline, defined as confirmed HIV RNA < 50 copies/mL. Outcome results for the primary measure and the stated follow-up aims are not reported in the registry record.
The registry describes the study as nonrandomized, with allocation not stated, and cautions against treating the arms as a like-for-like control comparison. It records selected adverse-event counts and serious-event terms but does not report deaths for the listed entries. Detailed analysis populations, missing-data handling, and a statistical analysis plan are not reported in the registry record.