Dutasteride 0.5mg For The Treatment Of Chinese Patients With Benign Prostatic Hyperplasia (BPH): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dutasteride 0.5mg For The Treatment Of Chinese Patients With Benign Prostatic Hyperplasia (BPH) (NCT00527605), a randomized phase 3 study. The primary outcome is Percent Change From Baseline in the Prostate Volume at Month 6.

2. Clinical Question

The clinical question is framed around a measured change in prostate volume, rather than a patient-reported symptom outcome. The study also assessed safety and included secondary measures of prostate volume, serum dihydrotestosterone (DHT), and the American Urological Association Symptom Index (AUA-SI). The primary comparison concerns the randomized, placebo-controlled phase. The official title describes a six-month parallel-group study followed by a 12-month open-label treatment phase. The registry record does not report the results of that later phase in the registry record for this analysis.

The endpoint is a comparison of group-level changes. It does not, by itself, describe how individual participants felt or establish the effect on every person in the study. The randomized comparison is informative about the assigned treatments during the controlled phase, while the posted outcome summaries describe the measured prostate-volume changes among participants with available data.

3. Trial Design

The record describes a Phase 3, randomized, double-blind, placebo-controlled, parallel-group study. It lists quadruple masking, but does not identify which groups of people were masked. The study compared dutasteride 0.5 mg taken orally once daily with matched placebo taken orally once daily. The enrollment was 253, and the study status is completed.

The official title describes a six-month treatment phase followed by a 12-month open-label treatment phase. The posted primary outcome is assessed at Month 6, and the registry summary likewise describes the initial six months as double-blind and placebo-controlled. The record gives a start date of 2007-10 and a primary completion date of 2009-03. The sponsor is GlaxoSmithKline.

The primary population is described as the ITT Population, comprising participants randomized after a 4-week placebo run-in who received at least one dose of study treatment. The Month 6 outcome summaries include 114 participants in the dutasteride group and 120 in the placebo group; some participants were missing Month 6 measurements. These endpoint counts are distinct from the recorded enrollment. The registry record does not explain the difference between enrollment and the participants included in the endpoint summaries.

The design supports a randomized comparison of the assigned treatments during the controlled phase. The registry record does not report the original sample-size justification, detailed procedures for allocation concealment, or a full statistical analysis plan. It also does not report how the open-label phase was analyzed in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT) Population: all participants who were randomized to study treatment (after the 4-week placebo run-in) and received at least one dose of study treatment. Some participants were missing Month 6 measurements.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Percent Change From Baseline in the Prostate Volume at Month 6, measured over Baseline and Month 6.

The primary endpoint is percent change from baseline in prostate volume at Month 6. The registry defines the calculation as the Month 6 prostate volume minus the baseline volume, divided by the baseline volume, and multiplied by 100. Prostate volume was measured by transrectal ultrasound. A negative change therefore represents a lower measured volume at Month 6 than at baseline.

Expressing the outcome as a percent change places the measured change in relation to each participant’s baseline volume. This can make change easier to compare across participants whose starting measurements differ. The endpoint is continuous, and the posted arm summaries report means and standard deviations. A group mean describes the average measured change within the analyzed group; the standard deviation describes the spread of participant-level measurements around that average.

Prostate volume is one measure relevant to the study’s assessment of BPH. It is not the same as a symptom score, a measure of quality of life, or a clinical event. The registry separately lists AUA-SI and other outcomes, which reflect different aspects of the study question. The primary endpoint therefore answers a specific measurement question: how the groups’ prostate-volume percentages changed from baseline to Month 6. It does not alone establish the meaning of those changes for every participant or address outcomes that were not reported.

7. Results Posted in the Registry

• Dutasteride 0.5 mg: mean -17.00 versus -2.77 on control; difference -14.23 (95% CI -20.18 to -8.28), standardized effect d = -0.61; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Percent Change From Baseline in the Prostate Volume at Month 3

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Dutasteride 0.5 mg: mean -12.02 versus -1.02 on control; difference -11.00 (95% CI -17.34 to -4.66), standardized effect d = -0.45; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dutasteride 0.5 mg than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change From Baseline in the Prostate Volume at Month 6

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Dutasteride 0.5 mg: mean -9.16 versus -1.20 on control; difference -7.96 (95% CI -11.23 to -4.69), standardized effect d = -0.62; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dutasteride 0.5 mg than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change From Baseline in the Prostate Volume at Month 3

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Dutasteride 0.5 mg: mean -7.11 versus -1.06 on control; difference -6.05 (95% CI -9.23 to -2.87), standardized effect d = -0.49; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dutasteride 0.5 mg than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes cover additional measurements of prostate volume, serum DHT, and AUA-SI. The posted summaries include Month 3 prostate-volume outcomes and changes in prostate volume at Month 3 and Month 6, alongside the broader list of secondary outcomes in the registry. The registry entries show a generally similar direction for the posted prostate-volume summaries: the dutasteride group averages are more negative than the placebo group averages. This is directionally consistent with the primary Month 6 percent-change result, while the different endpoints and time points remain distinct outcomes.

The secondary endpoints are not interchangeable with the primary outcome. Percent change and absolute change in prostate volume use different scales, and results at Month 3 address a different time point from the primary Month 6 endpoint. DHT and AUA-SI also measure different outcomes. Their results can add context to the study, but they do not redefine the primary question or independently establish the meaning of the primary comparison.

Unadjusted secondary comparisons should carry less weight when many outcomes are examined. The chance of obtaining at least one apparently notable result can increase as more comparisons are made, even when there is no true effect on some outcomes. The registry record lists 15 secondary outcomes, but does not report whether a multiplicity adjustment or a hierarchy of secondary hypotheses was used. The record also does not report a comprehensive set of sponsor analyses for the secondary endpoints in the registry record for this analysis.

Accordingly, the secondary results are best treated as supportive or exploratory context rather than as a set of independent confirmatory conclusions. Their direction can be considered alongside the primary result, but interpretation should account for differences in measurement, timing, missing information, and the unreported approach to multiple comparisons.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percent Change From Baseline in the Prostate Volume at Month 3
• Change From Baseline in the Prostate Volume at Month 6
• Change From Baseline in the Prostate Volume at Month 3
• Percent Change From Baseline in the Serum Dihydrotestosterone (DHT) at Month 6
• Percent Change From Baseline in the Serum DHT at Month 3
• Change From Baseline in the Serum DHT at Month 6
• Change From Baseline in the Serum DHT at Month 3
• Percent Change From Baseline in the American Urological Association Symptom Index (AUA-SI) Score at Month 6

9. Statistical Interpretation

10. Statistical Methods Explained

What is being compared? The primary outcome is a continuous measure: percent change in prostate volume from baseline to Month 6. The posted arm summaries give a mean and standard deviation for each group. A mean difference compares those group averages. With the contrast expressed as dutasteride minus placebo, a negative estimate means that the average percent change was more negative in the dutasteride group.

The recalculated unadjusted contrast is -14.23, with an interval from -20.18 to -8.281. This recalculation uses the posted group summaries and is not an adjusted model estimate. It does not incorporate participant-level information, covariate adjustment, or a model for missing outcomes. The registry record does not report those details for the primary endpoint.

What does the standard deviation describe? A standard deviation describes variation among participant measurements within a group. It is not the uncertainty in the group mean itself and is not a confidence interval. A larger standard deviation indicates that individual measurements are more dispersed around the group mean. In this study, the standard deviations for the primary outcome were 21.41 in the dutasteride group and 24.96 in the placebo group. The observed spread is relevant because it helps determine how precisely a group average and a difference between averages can be estimated.

What does a confidence interval mean? A confidence interval gives a range of values compatible with the data and the assumptions of the analysis. It conveys uncertainty about the estimated contrast, rather than showing the range of individual participants’ outcomes. The recalculated interval for the primary mean difference runs from -20.18 to -8.281. The sponsor’s reported analysis gives a 95% confidence interval from -20.23 to -8.22 for its median difference in final values. Because the two analyses are labeled differently, their intervals should be interpreted in relation to their own analysis summaries.

What does a p-value describe? A p-value measures how surprising data at least as incompatible with a specified null hypothesis would be, if that null hypothesis and the test assumptions were true. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of the observed difference. The recalculated comparison is reported as unadjusted p <0.001. The registry separately reports the sponsor’s two-sided t-test with p < 0.001. Those values come from analyses with different stated descriptions and should not be merged into a single test result.

Why does the analysis label matter? The arm summaries report means of percent change from baseline. The sponsor’s analysis is labeled “Median Difference (Final Values)” and reports a two-sided t-test. A mean change and a median difference in final values are not generally interchangeable summaries. The matching point estimates do not remove that distinction. The registry record does not provide further details that would reconcile the sponsor’s analysis label with the posted arm summaries.

What does randomization contribute? Random assignment is intended to make the treatment groups comparable, on average, with respect to characteristics known and unknown at assignment. A randomized, placebo-controlled comparison can therefore support an estimate of the contrast between assigned groups during the controlled phase. It does not guarantee that every characteristic is balanced in a particular study, and it does not resolve uncertainty from missing outcome data or limitations in how outcomes are analyzed.

What is not described? The record identifies the endpoint population and notes that some Month 6 measurements were missing, but the missing-data method is not reported in the registry record. The original sample-size justification, interim analyses, detailed covariate adjustment, and full statistical plan are also not reported in the registry record. These omissions limit how fully the reported inferential results can be reconstructed from the registry summaries.

11. Confidence Intervals and Precision

The primary mean difference is -14.23, with a recalculated interval from -20.18 to -8.281. The interval communicates uncertainty about the group-level contrast under the assumptions used for this unadjusted re-calculation. Its values are all negative, consistent with a more negative average percent change in the dutasteride group than in the placebo group. The interval does not describe the spread of individual participant outcomes; the group standard deviations, 21.41 and 24.96, describe that within-group spread.

The sponsor’s reported 95% confidence interval is -20.23 to -8.22 for a median difference in final values. That interval is close to the recalculated interval, but it belongs to an analysis labeled differently. The sponsor’s estimate is -14.23 and its p-value is < 0.001, while the recalculated mean comparison is reported with p <0.001. These are separate reported analyses, not a single combined estimate.

Precision depends on both the amount of information and the variability in the outcome. Endpoint counts were 114 in the dutasteride group and 120 in the placebo group. Missing Month 6 measurements are noted, but the record does not explain their number or handling beyond the posted endpoint counts. Without those details, the interval cannot address possible effects of missingness that are not represented in the calculation.

A confidence interval does not establish that the true effect is exactly at its center, nor does it make every value in the interval equally likely. It summarizes statistical uncertainty under the analysis assumptions. It also does not by itself decide whether the observed contrast is clinically important. That judgment would require context beyond the numerical result, and the registry entries do not provide a threshold for a clinically meaningful difference.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on the observed effect, not the original trial’s design calculation. For these continuous outcomes, the listed figures are participants per arm, not total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the target effect is the stated fraction of the observed effect. The trial’s own original design assumptions are not reported in the registry record.

The 80% power column gives the number of participants per arm that the planning calculation estimates would be needed to detect the specified effect with 80% power under those assumptions. The 90% power column gives the corresponding number per arm for 90% power. Power describes a design-stage probability of detecting an effect of the specified size if that effect and the calculation assumptions hold. These figures are not observed power.

The rows use the full observed effect and smaller fractions of that effect. When the effect to detect is smaller, more participants are needed to distinguish it from background variability at the stated significance level and power. For example, the primary-outcome planning estimates are 43 participants per arm for 80% power and 57 for 90% power at 100% of the observed effect; at 75%, they are 75 and 101; at 50%, they are 169 and 226. These are illustrative values derived from the observed study result, not evidence about the sample-size rationale used to design this trial.

Planning estimates depend on the assumptions and variability used in the calculation. They do not account for unreported features of the original protocol, and should not be read as a retrospective measure of whether the completed study was adequately powered.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -14.230; pooled standard deviation σ = 23.299.
2. n = 2 × (1.96 + 0.842)² × 23.299² / -14.230² = 42.1, rounded up to 43 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -14.23                      # observed difference in means
sigma <- 23.2985723349056                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(527605)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 43 (80% power), 57 (90% power)
 75% of observed effect: n per arm = 75 (80% power), 101 (90% power)
 50% of observed effect: n per arm = 169 (80% power), 226 (90% power)
power.t.test: 43.1 
Simulated power at n = 43 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry reports the sponsor’s primary analysis as a two-sided t-test, labeled “Median Difference (Final Values).” It gives an estimate of -14.23, a 95% confidence interval from -20.23 to -8.22, and p < 0.001. The re-calculation from posted arm summaries gives an unadjusted difference in mean percent change of -14.23, an interval from -20.18 to -8.281, and p <0.001.

The estimates are numerically close, with the same stated point estimate, but their labels are not the same. The re-calculation compares group means for percent change from baseline, whereas the sponsor’s analysis is labeled as a median difference in final values. The registry record does not provide further detail on the relationship between those summaries. The numerical match should not be taken to mean that the methods or estimands are identical.

The sponsor’s reported analysis is the trial’s own posted inferential result. The re-calculation is a simple, unadjusted analysis of summary statistics and serves as a separate statistical check, not a replacement for the sponsor’s analysis. Since the record does not flag a discrepancy, both results can be described while keeping their definitions distinct.

15. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates multiple outcomes, time points, or comparisons. Even if each individual test uses a fixed threshold, conducting many tests can increase the chance that at least one result appears statistically notable by chance. This is why a statistical plan may specify a primary endpoint, an order for testing secondary outcomes, or an adjustment to the interpretation of multiple tests.

The registry identifies one primary outcome and lists 15 secondary outcomes. Several involve prostate volume at different time points or expressed as percent and absolute change; others concern serum DHT and AUA-SI. The registry record does not report whether the sponsor adjusted for multiplicity, used a testing hierarchy, or designated any secondary outcomes as confirmatory. The posted unadjusted secondary comparisons should therefore not be read as if they necessarily retained the error control of a single prespecified test.

Missing outcome data also affect interpretation. The ITT population is defined as participants randomized after a 4-week placebo run-in who received at least one dose of study treatment. The record states that some participants were missing Month 6 measurements. It does not report the missing-data method, reasons for missingness, or sensitivity analyses addressing the possible effect of missing values. The endpoint counts are reported, but the registry entries do not establish whether missingness was related to treatment or outcome.

The registry record does not report interim analyses, the original sample-size justification, or a full statistical analysis plan. It reports the sponsor’s primary analysis as a two-sided t-test and gives the analysis label and result, but does not provide enough detail to reconstruct all analysis decisions. These gaps do not negate the posted results; they limit the ability to assess how the complete analysis strategy addressed multiplicity, missing data, and other prespecified decisions.

16. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: glaucoma (0.8%).

The registry reports serious adverse events for 0 of 126 participants at risk in the dutasteride group and 1 of 127 participants at risk in the placebo group. The most frequently listed serious term is Glaucoma, reported as 0.8%; the registry entries do not identify the group associated with that term. Death counts are not reported in the registry record.

Other adverse events are reported for 27 of 126 participants at risk in the dutasteride group and 25 of 127 in the placebo group. These are participant counts, not a description of event severity or duration. The registry entries do not provide further details about the events, their timing, or their relationship to study treatment.

Serious adverse-event counts are uncommon in these posted data, but the counts alone do not establish whether there is a meaningful safety difference. The group sizes are limited, and interpretation depends on event definitions, follow-up, and the completeness of reporting. The figures describe the adverse-event information in the registry record and should not be treated as a comprehensive safety assessment.

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

The primary result describes a difference in average prostate-volume change between randomized groups at Month 6. The dutasteride group’s mean percent change was -17.0, compared with -2.77 for placebo; the recalculated unadjusted mean difference was -14.23. The reported interval and p-value summarize statistical uncertainty and evidence against a null comparison under the analysis assumptions.

This result does not show that every participant experienced the group-average change. Individual outcomes varied, as reflected by the reported standard deviations, and some participants were missing Month 6 measurements. The registry record does not give enough detail to determine how the missing measurements might affect the estimate. The result also does not state the probability that the treatment caused a particular participant’s change.

The primary endpoint is an ultrasound-measured volume outcome. It does not directly report symptom relief, quality of life, or other outcomes that matter to participants. The study lists secondary symptom and laboratory outcomes, but the available the registry entries do not support treating those as interchangeable with the primary result. Nor does a statistical difference alone determine whether its magnitude is clinically meaningful; no clinical-importance threshold is reported.

The trial was conducted in Chinese patients with BPH and used a randomized, placebo-controlled design during the initial six-month phase. Conclusions should remain anchored to that population, treatment period, endpoint definition, and reported analysis. The official title includes a subsequent 12-month open-label phase, but the registry entries available do not provide results from that phase. The primary result therefore does not describe longer-term comparative outcomes.

In short, the posted data show a more negative mean change in prostate volume in the dutasteride group than in the placebo group at Month 6, with an unadjusted comparison whose interval excludes zero. They do not by themselves establish broader clinical benefit, individual response, long-term effects, or conclusions beyond the study population and reported outcomes.

18. Why This Trial Matters Statistically

This trial provides a useful example of how to distinguish an endpoint’s definition from its statistical summary. The primary outcome is percent change in prostate volume from baseline, while the sponsor’s reported analysis is labeled as a median difference in final values. The numerical estimates match, but the labels indicate that the summaries should not be assumed to represent precisely the same analysis.

It also illustrates why a point estimate is only one part of an interpretation. The group means, standard deviations, endpoint counts, confidence intervals, and p-values each describe different features of the result. The estimate describes the observed contrast; variability indicates spread in participant measurements; and the interval communicates uncertainty about the group-level contrast. These pieces should be considered together without treating any one as a complete account.

The registry record makes the trial’s primary population definition and missing Month 6 measurements visible, but leaves the missing-data method and multiplicity strategy unreported. That distinction matters: a reader can describe the posted comparison while also recognizing the limits on reconstructing the full analysis. The 15 listed secondary outcomes further show why a clear distinction between primary and secondary evidence is important.

Finally, the sample-size illustrations demonstrate how planning estimates depend on the effect size selected. Smaller target effects require more participants per arm under the stated assumptions. Because these estimates are based on the observed effect, they are not a substitute for the original design rationale and should not be used as a measure of the completed study’s observed power.

19. 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 registry entries do not report the original sample-size justification or the assumptions used to plan the trial. The planning illustrations based on the observed effect cannot fill that gap. The record also does not provide a full statistical analysis plan, including details of any covariate adjustment, testing hierarchy, or multiplicity correction.

The primary endpoint population is defined, and some participants were missing Month 6 measurements, but the handling and reasons for missingness are not reported in the registry record. The reported endpoint counts therefore do not, by themselves, establish whether missing data could have influenced the estimate. Sensitivity analyses for missing outcomes are not reported in the registry entries.

The sponsor analysis is labeled as a median difference in final values, whereas the posted arm summaries and recalculation concern means of percent change from baseline. Although the estimates are numerically the same, the registry entries do not explain the correspondence between those approaches. The distinction complicates direct interpretation of the sponsor’s interval alongside the recalculated interval.

The registry lists multiple secondary outcomes, but the approach to multiplicity is not reported. Secondary findings therefore have less confirmatory force than the designated primary outcome. Safety reporting is also limited in the registry entries: serious-event counts are given, but the details and group attribution for the listed serious term are not fully described. Death counts are not reported in the registry record.

The official title describes a 12-month open-label phase after the controlled phase, but results from that phase are not included in the registry record for this analysis. These limitations concern what can be established from the registry record; they do not independently establish that the trial’s conduct or analyses were inadequate.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Dutasteride 0.5mg For The Treatment Of Chinese Patients With Benign Prostatic Hyperplasia (BPH) — NCT00527605.
• Registry record last updated 2012-03-21; status last verified 2011-05.
• Results first posted 2010-03-11.
• 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.

23. Record Summary

NCT00527605 is a completed Phase 3 randomized, double-blind, placebo-controlled, parallel-group study sponsored by GlaxoSmithKline. It enrolled 253 Chinese patients with BPH and compared oral dutasteride 0.5 mg once daily with matched placebo. The official title describes a six-month controlled phase followed by a 12-month open-label phase.

The primary endpoint was percent change from baseline in prostate volume at Month 6, measured by transrectal ultrasound. Mean changes were -17.0 for dutasteride and -2.77 for placebo. The recalculated unadjusted mean difference was -14.23, with an interval from -20.18 to -8.281 and p <0.001. The sponsor reported a median difference in final values of -14.23, a 95% confidence interval from -20.23 to -8.22, and p < 0.001.

The registry also lists secondary outcomes and adverse-event counts. The missing-data method, multiplicity approach, original sample-size rationale, and results from the open-label phase are not reported in the registry record.