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 Safety and Efficacy of 0.5mg Dutasteride and 0.4mg Tamsulosin Combination Once Daily for Six Months for Benign Prostatic Hyperplasia (NCT01673490), a na phase 4 study. The primary outcome is Number of Participants With Any On-treatment Adverse Events (AEs) or Any Serious Adverse Event (SAEs) and Treatment-related AEs.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01673490 |
| Phase | Phase 4 |
| Condition | Prostatic Hyperplasia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 59 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerned patients with benign prostatic hyperplasia. The registry describes an intention-to-treat population comprising all enrolled participants, regardless of whether study treatment was administered. It lists an enrollment of 59. Further eligibility details are not reported in the registry record.
Intervention
Participants were assigned to an open-label, single-group treatment with dutasteride 0.5 mg plus tamsulosin 0.4 mg once daily. The planned treatment period was six months. The registry identifies the combination as Combodart/Duodart in the arm description.
Comparator
There was no comparator group. The trial model is single group, masking was none, and allocation is listed as not applicable. As a result, the design does not directly compare the combination with placebo, usual care, or another treatment.
Primary question
The primary objective was to assess safety by monitoring the category, frequency, and severity of adverse events during treatment. The primary outcome records the number of participants with any on-treatment adverse events or serious adverse events, and treatment-related adverse events, from the start of study medication until follow-up, up to seven months. Symptom improvement was a secondary objective, assessed through change in IPSS and Qmax. Those changes are not reported in the registry record.
These features define a descriptive safety and efficacy question rather than a controlled treatment-effect question. The record can describe events observed during treatment, but without a comparison group it cannot estimate how event frequency or symptom change differed from what would have occurred under another treatment or no treatment. The open-label design also means that masking of participants and investigators was not used.
3. Trial Design
This was a Phase 4, open-label, single-group trial of dutasteride 0.5 mg plus tamsulosin 0.4 mg once daily in patients with benign prostatic hyperplasia. The registry lists allocation as not applicable and masking as none. The planned treatment duration was six months. The record lists enrollment of 59 and a status of terminated.
The brief summary describes a plan to enroll 90 participants so that at least 57 would complete six months of treatment and be evaluable for analysis. The enrollment listed in the registry is 59. These figures refer to different things: enrollment is the record’s count, while 90 and at least 57 are targets described in the summary. Completion and evaluability counts are not reported in the registry record. The reason for termination is also not reported in the registry record.
The primary objective concerned safety, with adverse events monitored by category, frequency, and severity. Secondary objectives concerned symptom improvement, measured through changes in the International Prostate Symptom Score (IPSS) and maximum rate of urinary flow (Qmax). The registry lists these secondary outcomes, but their numerical results are not reported in the registry record.
Because this was a single-group study, there was no concurrent control group to help separate changes associated with treatment from changes over time, other care, or the natural course of symptoms. The open-label design means the treatment assignment was not masked. Allocation, randomization procedures, study sites, eligibility criteria, and reasons for the design choices are not reported in the registry record. The registered design therefore supports a description of outcomes among enrolled participants, but not a direct comparative estimate of treatment effects.
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: Eligible participants with benign prostatic hyperplasia (BPH) entered into a 6-month enrollment period followed by a6-month treatment period and a one-month follow-up period. The total duration of the study was 13 months.
Overall Study
| Stage | Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg |
|---|---|
| STARTED | 59 |
| COMPLETED | 52 |
| NOT COMPLETED | 7 |
Reasons for not completing this period:
| Reason | Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg |
|---|---|
| Lost to Follow-up | 1 |
| Adverse Event | 3 |
| Withdrawal by Subject | 3 |
Analysis population for the primary outcome, as defined in the registry: Intention-to-Treat (ITT) Population: all enrolled participants regardless of whether or not study treatment was administered.
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 | Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg |
|---|---|---|
| Participants analysed | 59 | |
| Age, Continuous | Years | 66.5 (SD 8.37) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 59 |
| Race/Ethnicity, Customized: Asian | Participants | 59 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Any On-treatment Adverse Events (AEs) or Any Serious Adverse Event (SAEs) and Treatment-related AEs, measured over From start of study medication until follow-up (up to 7 months).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants with any on-treatment adverse events or serious adverse events, as well as treatment-related adverse events. The registry defines an adverse event broadly as an untoward medical occurrence temporally associated with use of a medicinal product, whether or not considered related to that product. This includes unfavorable signs, symptoms, diseases, or abnormal laboratory findings, whether new or exacerbated.
A serious adverse event is defined by consequences such as death, a life-threatening event, hospitalization or prolonged hospitalization, disability or incapacity, a congenital anomaly or birth defect, or an important medical event that may require intervention to prevent such outcomes. The definition also includes events associated with liver injury and impaired liver function.
Safety endpoints of this kind are used to describe the occurrence and nature of harms during exposure. Counting participants rather than only listing event terms can indicate how many participants experienced an event, while categorizing events as serious or treatment-related addresses distinct aspects of safety. These categories should not be conflated: seriousness concerns the event’s consequences or clinical importance, while treatment relatedness concerns its assessed association with the medicinal product.
The stated observation window begins with study medication and extends through follow-up, up to seven months. The registry does not report detailed results for every component of the primary endpoint, nor does it provide a comparison group. The posted counts should therefore be read as descriptive observations in this study, not as comparative estimates or proof of causation.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry’s adverse-event figures list 1 serious adverse event among 59 participants at risk in the dutasteride 0.5 mg plus tamsulosin 0.4 mg group. The listed count for other adverse events is 0, and the reported serious-event term is “Hepatic Enzyme Increased,” at 1.7%. These are descriptive figures from a single-group, open-label trial. They do not establish whether the events were caused by treatment, and they do not show how event occurrence compares with another treatment or with no treatment.
The percentage attached to the serious-event term is a registry-reported value. It should be read alongside the participant count and the limited size of the enrolled group: a small number of observed events gives only a limited basis for characterizing the range or frequency of possible harms. The record does not provide a confidence interval or other uncertainty estimate for the safety figures. Without such an estimate, the precision of the reported percentage cannot be assessed directly from the posted results.
The brief summary identifies symptom improvement as a secondary objective, using changes in IPSS and Qmax after six months. The numerical changes, their uncertainty, and the corresponding analysis results are not reported in the registry record. It is therefore not possible to characterize the magnitude or precision of symptom changes from the information recorded. Listing an outcome as planned or measured is not itself evidence of a particular result.
The registry lists enrollment of 59, while the brief summary describes a plan to enroll 90 and have at least 57 complete treatment and be evaluable. The record does not provide the number who completed treatment or the number included in each outcome analysis. It also does not report why the trial was terminated. These omissions limit assessment of follow-up and the extent to which missing observations may have affected the results.
Overall, the posted data support a narrow description of the recorded safety counts. They do not support a comparative claim about treatment, a causal conclusion about the event, or a quantitative conclusion about the secondary symptom outcomes. The record’s open-label, uncontrolled design is central to interpreting what the observations can establish.
9. Statistical Methods Explained
What does a participant count tell us?
The primary safety outcome is expressed as a number of participants with specified adverse-event categories. A participant count is a direct description of how many people in the stated group met the outcome definition during the observation period. It is different from an event count: one participant may experience more than one event, while a participant-based measure counts that person once for the relevant category. The registry’s outcome title refers to participants, and the posted adverse-event figures list participants at risk and affected. No additional event-level detail should be inferred from those counts.
A percentage can make a count easier to interpret relative to the group at risk, but it does not remove uncertainty. When few events are observed, the underlying event frequency may be considerably less certain than a single percentage suggests. A confidence interval is a statistical range intended to communicate uncertainty around an estimate. It does not guarantee that the true value lies within the interval, and its width depends on the data and the method used. A confidence interval for these posted safety figures is not reported in the registry record.
Why does the single-group design matter?
General statistical context: a treatment comparison requires outcomes under more than one condition, with a design that supports a fair comparison. In a single-group study, the observed outcomes describe participants who received the study treatment; there is no concurrent control group to estimate what would have happened under an alternative. Changes from baseline, if reported, can describe change over time, but by themselves they cannot distinguish a treatment effect from other explanations for that change.
Random allocation, when used in a controlled trial, helps make comparison groups similar on average in both measured and unmeasured characteristics. This trial lists allocation as not applicable and has a single-group model, so there is no randomized treatment contrast to interpret. Open-label conduct also means treatment knowledge was not masked. General statistical context: expectations and knowledge of treatment can influence reporting, assessment, follow-up, or decisions about whether an observation is treatment-related. The extent of any such influence in this trial is not reported in the registry record.
What can be inferred from the adverse-event percentage?
The registry reports one serious adverse event and identifies “Hepatic Enzyme Increased” with a reported percentage of 1.7%. That percentage is a descriptive summary of the registry’s recorded data, not a measure of comparative risk. The group at risk is listed as 59. A percentage based on a limited number of observations can be sensitive to the occurrence or absence of individual events, so it should not be treated as a highly precise estimate of a broader population frequency.
Seriousness and treatment relatedness are separate classifications. The registry’s definition of serious adverse events is based on specified consequences or medical importance. Relatedness concerns whether an event is considered associated with the medicinal product. The available figures do not establish that the reported serious event was caused by treatment. Detailed adjudication procedures and the analysis used to classify relatedness are not reported in the registry record.
How should missing outcome information be understood?
General statistical context: missing outcome data can reduce the information available for an analysis and can introduce bias if participants with observed outcomes differ systematically from those without them. The effect depends on why data are missing and on how the analysis handles them. Investigators may use different approaches, but their assumptions and procedures need to be reported to assess the results. The registry defines an intention-to-treat population as all enrolled participants, whether or not study treatment was administered. That definition does not, by itself, explain how missing outcomes were handled or confirm which participants contributed to each analysis.
The brief summary gives a completion and evaluability target, but actual completion counts and methods for missing data are not reported in the registry record. A reader therefore cannot determine from the recorded information whether every enrolled participant contributed to every endpoint or how incomplete follow-up affected estimates.
What do the planning assumptions represent?
The registry includes assumptions for a planning illustration: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a fraction of the observed effect. These assumptions describe a hypothetical two-arm planning calculation, not the single-group design recorded for this trial. The resulting participant requirements are not reported in the registry record. Any sample-size illustrations based on these assumptions are planning scenarios, not observed power and not evidence that the trial had a particular probability of detecting an effect.
General statistical context: sample-size calculations depend on a specified outcome, target effect, variability or event frequency, significance level, and design assumptions. Altering those assumptions changes the planned sample size. A planning calculation does not establish that the observed results are unbiased or precise, and it cannot substitute for reporting estimates with uncertainty. The registry does not report a trial-specific statistical analysis plan or a sample-size justification beyond the brief summary’s enrollment and completion targets.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety outcome and secondary outcomes involving change in IPSS and Qmax. It does not report a statistical analysis plan describing how these outcomes were tested or interpreted together. In particular, the handling of multiple outcomes or multiple analyses is not reported in the registry record. When several outcomes are assessed, the chance of observing an apparently notable result by chance can increase if each is tested separately without an appropriate strategy. This is general statistical context, not a claim about analyses performed in this trial.
The record indicates three analyses, but the methods, outcome mapping, and inferential results for those analyses are not reported in the registry record. No p-values or confidence intervals for the outcomes described in the record are reported in the registry record. There is consequently no basis for determining whether any multiplicity adjustment was planned or used.
The intention-to-treat population is defined as all enrolled participants regardless of whether study treatment was administered. This definition identifies a population concept, but it does not tell readers how missing outcome values were treated, whether all enrolled participants were included in each analysis, or whether additional analysis populations were used. The number who completed treatment and the number evaluable for each endpoint are not reported in the registry record.
The summary’s planned target was 90 enrolled, with at least 57 completing six months and evaluable for analysis; the registry lists enrollment of 59. Actual completion and analysis counts are not reported. Methods for imputing, excluding, or otherwise handling missing observations are also not reported in the registry record. Without these details, readers cannot assess whether missingness affected the reported safety counts or any symptom-change analyses.
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 |
|---|---|---|---|
| Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg | 1 | 59 | 1.7% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg | 0 of 59 |
Most frequent serious adverse event terms
| Event term | Organ system | Dutasteride 0.5 mg Plus Tamsulosin 0.4 mg |
|---|---|---|
| Hepatic Enzyme Increased | Investigations | 1 of 59 |
Serious events with the highest arm-level rate: hepatic enzyme increased (1.7%).
The registry lists 59 participants at risk in the dutasteride 0.5 mg plus tamsulosin 0.4 mg group, with 1 serious adverse event and 0 in the other adverse-event count. The serious-event term listed is “Hepatic Enzyme Increased,” with a reported percentage of 1.7%. The outcome’s observation window runs from the start of study medication until follow-up, up to seven months.
These figures are descriptive. A serious adverse event is classified according to the consequences or medical importance described in the registry definition; the label does not by itself establish that the event was caused by the study medication. Treatment relatedness is a separate consideration. The posted figures do not provide enough detail to determine the assessment process or the causal attribution for the serious event.
The count of 0 for other adverse events should not be read as showing that no adverse events of any kind could occur. It is the count listed in the registry’s adverse-event figures, and the record does not supply additional event-level details that clarify its scope. A single-group study also offers no control-group rate for context. The registry does not report uncertainty estimates for these figures, so their precision cannot be judged from an interval estimate.
12. What the Result Does, and Does Not, Mean
The posted results describe safety observations during treatment with dutasteride 0.5 mg plus tamsulosin 0.4 mg in a single-group, open-label trial. The registry lists 1 serious adverse event among 59 participants at risk and reports “Hepatic Enzyme Increased” at 1.7%. Those observations characterize what was recorded in this study; they do not show that the treatment caused the event, nor do they determine how often similar events would occur in another group or setting.
The absence of a comparator is important. Without a concurrent group receiving another treatment or no study medication, differences attributable to treatment cannot be separated from other possible influences. The open-label design also means participants and investigators were not masked to treatment. These design features limit causal and comparative interpretation, even when the recorded event counts are clear.
The registry’s stated secondary objective was to assess symptom improvement through changes in IPSS and Qmax. Numerical results for these outcomes are not reported in the registry record. No conclusion about the magnitude, direction, or precision of those changes can be drawn from an outcome title or study objective alone.
The record lists enrollment of 59 and reports that the study was terminated. The number completing treatment, outcome-specific analysis populations, and reason for termination are not reported in the registry record. These gaps make it difficult to judge the completeness of follow-up and the scope of the analyzed data.
Accordingly, the results support a limited description of recorded safety counts, not a broad conclusion about comparative safety or efficacy. They neither establish benefit nor establish absence of benefit. The lack of reported symptom-change results and uncertainty estimates further limits interpretation of the clinical outcomes.
13. Why This Trial Matters Statistically
This trial illustrates how a clearly stated safety objective differs from a comparative treatment-effect question. Its primary endpoint focuses on adverse events observed among participants receiving a drug combination. Such descriptive monitoring can identify and characterize events recorded during treatment. However, a single-group study cannot estimate how those observations differ from a control condition, and an event recorded during treatment is not automatically an event caused by treatment.
The record also highlights the distinction between a planned enrollment target and observed enrollment. The brief summary describes a target of 90 enrolled and at least 57 completing treatment and evaluable for analysis, while the registry lists enrollment of 59 and a terminated status. Actual completion and analysis counts are not reported in the registry record. Without those counts, readers cannot fully assess the flow from enrollment to outcome analysis.
Another statistical lesson concerns the difference between listing an outcome and reporting its result. IPSS and Qmax are named as secondary outcomes, but their numerical changes are not reported in the registry record. The existence of a measured endpoint does not reveal the direction, size, or certainty of a result.
Finally, the record’s planning assumptions refer to a hypothetical two-arm calculation, while the registered trial has a single-group model. Planning assumptions need to be interpreted in the context of the design they describe. A sample-size illustration is not observed power and does not replace an analysis of the data actually collected. Together, these features show why design, analysis population, missing-data information, and uncertainty estimates are all necessary for a sound statistical reading.
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 trial’s single-group design is a central limitation for interpretation. There is no comparator, so observed safety outcomes cannot be contrasted with outcomes under another treatment or no treatment. The registry also lists no masking. These features limit causal interpretation and leave potential influences related to awareness of treatment unaddressed.
The registry lists enrollment of 59 and a terminated status, while the brief summary describes a larger planned enrollment and a completion target. Actual treatment completion and endpoint-specific analysis counts are not reported in the registry record. The reason for termination is not reported in the registry record. These missing details limit assessment of follow-up and whether the recorded outcomes represent all enrolled participants.
The available safety figures are limited to the listed participant counts and a serious-event term with its reported percentage. Uncertainty estimates and detailed event-level information are not reported in the registry record. The numerical results for the secondary IPSS and Qmax outcomes are also not reported. Without those results, the stated efficacy objectives cannot be assessed from the registry record.
The statistical analysis methods, missing-data procedures, outcome-specific analysis populations, and approach to multiple analyses are not reported in the registry record. The planning assumptions describe a hypothetical two-arm calculation rather than the registered single-group design, and the resulting participant requirements are not reported in the registry record. These limitations constrain assessment of precision, completeness, and the relationship between planned analyses and posted results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy of 0.5mg Dutasteride and 0.4mg Tamsulosin Combination Once Daily for Six Months for Benign Prostatic Hyperplasia — NCT01673490.
- Registry record last updated 2018-08-20; status last verified 2018-07.
- Results first posted 2015-12-17.
- 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 Phase 4, open-label, single-group trial of dutasteride 0.5 mg plus tamsulosin 0.4 mg once daily for patients with benign prostatic hyperplasia. The planned treatment period was six months. The record lists enrollment of 59 and a terminated status.
The primary objective concerned safety. The posted adverse-event figures list 1 serious adverse event and 0 in the other adverse-event count among 59 participants at risk; “Hepatic Enzyme Increased” is listed at 1.7%. The trial also named changes in IPSS and Qmax as secondary outcomes, but their numerical results are not reported in the registry record.
There was no comparator group, and masking was none. Actual treatment completion, outcome-specific analysis counts, missing-data methods, and the reason for termination are not reported in the registry record. The available information therefore supports a descriptive reading of the recorded safety figures, not a comparative estimate of treatment effects.