Evaluation of Dalteparin for Long-term (One Year) Treatment of Blood Clots in Subjects With Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Dalteparin for Long-term (One Year) Treatment of Blood Clots in Subjects With Cancer (NCT00942968), a na phase 4 study. The primary outcome is Number of Participants With Major Bleeding Events Adjudicated by Central Adjudication Committee.

2. Clinical Question

The central statistical question is descriptive: how many participants in the specified safety population experienced a qualifying major bleed during the stated outcome window? Because there is only one treatment group, this design can describe events observed during treatment but cannot by itself establish how those outcomes would compare under an alternative treatment. The record does not report an observed primary-outcome count or a comparative estimate.

3. Trial Design

This was a completed Phase 4, open-label, single-group study of dalteparin sodium injection. The registry lists enrollment of 338 and identifies cancer as the condition. Its official title describes a multicenter study lasting 52 weeks and focused on understanding safety and efficacy in people with malignancies and symptomatic venous thromboembolism. The brief study description emphasizes long-term tolerability and safety.

There was no randomized allocation and no masking. Allocation is recorded as not applicable, and the trial model is single-group. The record describes no control arm. Consequently, there is no like-for-like comparison from which to estimate a treatment difference. The study began in 2009-06, reached primary completion in 2012-03, and is recorded as completed.

The primary outcome was a participant count for centrally adjudicated major bleeding, with a timeframe from Month 2 up to Month 6. The primary outcome population is defined as participants who received at least 1 treatment with dalteparin sodium. This definition is specifically attached to the safety population; the registry record does not report a separate analysis population for the other outcomes.

The record lists 18 outcome measures, including bleeding and venous thromboembolism outcomes. It lists no analysis entries. Although the study title refers to both safety and efficacy, the record does not give observed results for the primary outcome or the listed secondary outcomes. The enrollment figure should not be mistaken for the number included in every outcome analysis; outcome-specific denominators are not reported in the registry record.

Because the design has one open-label treatment group, its results are best read as observations within that study group. Without a concurrent comparator, differences attributable to treatment cannot be separated from other explanations using this design alone. The registry record does not report a statistical analysis plan or a sample-size justification for the trial itself.

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: Safety population included all participants who received at least 1 treatment with dalteparin sodium.

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.

Population: Safety population included all participants who received at least 1 treatment with dalteparin sodium.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Major Bleeding Events Adjudicated by Central Adjudication Committee, measured over Month 2 up to Month 6.

The primary endpoint is the number of participants with major bleeding events adjudicated by the central adjudication committee. It covers Month 2 up to Month 6 and is defined as a participant count, not as a rate or a comparison between groups. The registry record defines a major bleeding event as clinically overt bleeding that meets at least one of the listed criteria.

Those criteria include a decrease in hemoglobin of at least 2 gram per deciliter (g/dL), bleeding at a critical site (intraocular, spinal/epidural, intracranial, retroperitoneal, or pericardial), a transfusion of two or more units of packed red blood cells, or death. Central adjudication applies the specified event definition through committee review, rather than relying only on an investigator's event identification.

A participant count is useful for describing how many people experienced an outcome under the endpoint definition. On its own, however, a count does not show the event rate unless the relevant denominator and observation time are also available, and it does not quantify a treatment contrast in a single-group study. The primary outcome count and an outcome-specific denominator are not reported in the registry record, so the endpoint's observed frequency and precision cannot be assessed from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a count of participants meeting a defined event criterion. Such an outcome differs from a continuous measure, such as a laboratory value, because each participant is classified according to whether the specified event occurred. The endpoint definition requires clinically overt bleeding and at least one qualifying feature. The criteria include a hemoglobin decrease of at least 2 gram per deciliter (g/dL), bleeding at one of the listed critical sites, transfusion of two or more units of packed red blood cells, or death.

What does central adjudication contribute?

In general, central adjudication means that an independent committee reviews candidate events against the study's stated criteria. This can promote consistent classification across participants and sites. It does not eliminate all uncertainty: classification still depends on the information available for review and on how the criteria are applied. The registry record identifies central adjudication for the primary endpoint but does not report the committee's procedures, agreement measures, or adjudication results.

How should a participant count be read?

In general, a count answers how many people met an outcome definition in the population being assessed. A count alone does not indicate the proportion affected; that requires a relevant denominator. A rate may also account for differences in observation time, whereas a simple participant count does not. Here, the primary outcome is listed as a participant count for Month 2 up to Month 6, but neither its observed count nor an outcome-specific denominator is reported in the registry record. The enrollment figure should not be substituted for an endpoint denominator.

For a binary outcome, an estimate of the proportion affected is often accompanied by a confidence interval. In general, a confidence interval describes statistical uncertainty around an estimate under the method's assumptions; it does not guarantee that the true value lies within the interval. Its width depends in part on the amount of information available and the number of events. No primary-outcome proportion or confidence interval is reported in the registry record, so no precision estimate can be interpreted for this endpoint.

What can a single-group design estimate?

In general, a single-group study can summarize outcomes observed among participants receiving the study intervention. A comparative effect requires a suitable contrast, such as a control group, and a method for estimating the difference between groups. This trial is identified as single-group, open-label, with allocation not applicable. It therefore does not provide a randomized comparison. Even if an event count were posted, a count from this design would not isolate the effect of dalteparin from other factors that may influence outcomes.

The record lists no analysis entries. It does not report a statistical model, confidence intervals, hypothesis tests, or a plan for handling different follow-up times. The primary endpoint has a stated timeframe, but the record does not explain how participants with incomplete observation in that interval were handled. Those omissions matter when judging whether a count represents all participants eligible for the outcome or only those with sufficient follow-up.

How should planning calculations be distinguished from trial results?

In general, a sample-size planning calculation asks how much information a future study might need to detect a chosen effect under specified assumptions. It is not an observed result and is not observed power. The planning assumptions described for the illustrative calculations specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Those assumptions describe a planning illustration, not this trial's single-group design or its own reported statistical plan.

The stated planning approach uses total events for time-to-event calculations and participants per arm for other calculations. In general, time-to-event methods use event counts because the amount of information depends on events as well as enrollment. For count or binary-outcome planning, a proposed number of participants per arm depends on assumptions about the event frequency, effect to detect, significance level, and desired power. The registry record does not report the underlying observed effect or a trial-specific sample-size justification. Any planning figures should therefore be understood only as illustrations under their assumptions, not as evidence that the study had a particular probability of detecting an effect.

Over-dispersion is a general concern when event counts vary more than a simple statistical model expects; it can make standard uncertainty estimates too small if not addressed. The primary outcome is described as a count of participants with an event, not a repeated event count, and the registry record does not report an over-dispersion assessment or a model that would require one. More broadly, the absence of a reported analysis plan means readers cannot assess model choice, assumptions, or sensitivity analyses for the posted outcome data.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Dalteparin Sodium")
n      <- c(334)
events <- c(14)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Dalteparin Sodium  334  14  4.2  2.3  6.9  2.5  6.9  2.5  6.9

11. Multiplicity, Missing Data and Analysis Populations

The record lists 18 outcome measures, including multiple bleeding and venous thromboembolism outcomes. When a study examines multiple outcomes, general statistical practice recognizes that the chance of at least one apparently unusual result can increase if many separate tests are conducted. This concern is most directly relevant when inferential tests are performed. The registry record lists no analysis entries and does not report whether any multiplicity adjustment or hierarchy among outcomes was planned. It is therefore not possible to assess how multiple outcomes were handled statistically.

The registry record does not report a missing-data method, the extent of missing outcome information, or how incomplete follow-up was addressed. It also does not report whether participants who discontinued treatment remained under outcome follow-up. These details affect interpretation because participants may not all have the same opportunity for an event to be observed. No assumptions about missing outcomes can be inferred from the stated endpoint definition.

The primary safety population is defined as all participants who received at least 1 treatment with dalteparin sodium. That definition clarifies who belongs to the stated primary population, but it does not give an outcome-specific denominator or explain how missing observations were handled. The record does not report a separate analysis population for the listed secondary outcomes. Because no analysis entries are listed, there are no posted analysis-population details or missing-data procedures to evaluate.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: disease progression (8.7%), pneumonia (6.6%), pulmonary embolism (6.0%), febrile neutropenia (3.6%), cellulitis (3.6%).

The serious-adverse-event summary lists 334 participants at risk and 213 affected. The other adverse-event summary lists 334 participants at risk and 328 affected. These are descriptive safety fields; they do not provide a randomized comparison, and the registry record does not report an attribution analysis that would establish whether an event was caused by dalteparin.

The listed serious-event terms and percentages are disease progression, 8.7%; pneumonia, 6.6%; pulmonary embolism, 6.0%; febrile neutropenia, 3.6%; cellulitis, 3.6%; and pleural effusion, 3.0%. These terms are not interchangeable with the primary major-bleeding endpoint. The endpoint has a specific clinical definition and is centrally adjudicated during the stated timeframe; the serious-event list is a broader safety summary.

The adverse-event summary does not report a value for deaths, and the registry record does not report the observed result for the listed fatal-bleeding outcome. A missing death value should not be read as a finding of no deaths. The summaries describe reported events in the study group and cannot, without a comparator, establish comparative safety.

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

This study's design and outcome definitions establish what it set out to observe: safety and tolerability during long-term dalteparin treatment in people with cancer, including centrally adjudicated major bleeding from Month 2 up to Month 6. The registry record also identifies a range of secondary bleeding and venous thromboembolism outcomes. These details clarify the intended scope of measurement.

The record does not report the observed primary endpoint count, a primary endpoint proportion, a confidence interval, or a test result. As a result, it does not quantify the frequency or precision of major bleeding for the defined population and timeframe. A missing result is not evidence that the outcome did not occur. The listed secondary outcomes likewise should not be treated as findings when their observed results are not reported.

The record does show descriptive safety summaries, including numbers of participants at risk and affected and percentages for listed serious-event terms. Those figures describe events recorded in the study group. They do not show whether event occurrence differs from another treatment group, and they do not establish that the intervention caused any particular event.

More generally, a single-group study can contribute information about outcomes observed under its study conditions, but it cannot provide a direct treatment contrast. The open-label design also means treatment masking was absent. The record does not provide enough information to assess the potential influence of that feature on outcome observation. No statistical analysis entries are listed, so there is no reported inferential analysis to interpret.

These distinctions are important: study purpose, endpoint definitions, and descriptive event summaries are not the same as evidence of a comparative treatment effect. The record supports understanding how outcomes were defined and which safety summaries were recorded. It does not, as reported, support a quantified conclusion about the primary endpoint or a claim that dalteparin does or does not change risk.

14. Why This Trial Matters Statistically

The study illustrates why design and outcome reporting shape statistical interpretation. A clearly specified endpoint can make the intended event definition understandable: major bleeding required clinically overt bleeding and at least one stated criterion, and a central committee adjudicated the primary outcome. That specificity is useful when distinguishing the primary endpoint from broader adverse-event summaries.

The single-group, open-label design also makes the inferential boundary clear. It can describe events observed among participants receiving dalteparin, but it cannot provide a like-for-like control comparison. That limitation is not repaired by the size of an enrollment figure or by listing many outcome measures; a comparative treatment effect requires an appropriate comparator and an analysis that estimates the contrast.

There is also a practical distinction between registering an outcome and reporting its result. The registry record names the primary and secondary outcomes, but does not report the primary count or analysis entries. Without those results, readers cannot evaluate the observed frequency, uncertainty, or analysis choices for the primary endpoint. This makes complete outcome reporting essential to interpreting even a well-defined safety question.

Finally, safety summaries should be read in context. Counts and percentages can describe events recorded in the study group, while causal and comparative conclusions require more than descriptive figures. Separating those kinds of evidence helps prevent an event list from being mistaken for a treatment effect.

15. 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 most important limitation for interpreting this record is that the observed primary endpoint result is not reported. The registry record gives the endpoint definition and timeframe, but no event count, outcome-specific denominator, confidence interval, or test result. The primary endpoint's frequency and statistical precision therefore cannot be assessed from the record.

The single-group design has no concurrent control arm, and masking was absent. Consequently, the study does not provide a randomized treatment contrast. Descriptive safety findings cannot determine how outcomes would compare under another treatment. The record does not report methods for adjusting for other factors or for addressing potential differences in follow-up.

The enrollment figure does not establish how many participants contributed information to each outcome. The primary safety population is defined by receipt of at least 1 treatment, but the record does not report outcome-specific denominators, completeness of follow-up, or methods for handling missing data. It also does not report detailed adjudication procedures or analysis methods.

Although 18 outcome measures are listed, no analysis entries are reported. The record does not state whether multiplicity was addressed, how outcome analyses were prioritized, or whether analyses were adjusted. It also does not provide a trial-specific sample-size justification. These omissions limit assessment of the statistical plan and of the robustness of any outcome findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of Dalteparin for Long-term (One Year) Treatment of Blood Clots in Subjects With Cancer — NCT00942968.
• Registry record last updated 2024-04-18; status last verified 2024-04.
• Results first posted 2017-02-24.
• 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.

19. Record Summary

NCT00942968 is a completed Phase 4, open-label, single-group study of dalteparin sodium injection in people with cancer and symptomatic venous thromboembolism. The registry lists enrollment of 338. The official title describes a 52-week study, and the primary outcome is the number of participants with centrally adjudicated major bleeding from Month 2 up to Month 6.

The primary safety population includes participants who received at least 1 treatment with dalteparin sodium. The record lists 18 outcome measures and no analysis entries. It gives descriptive adverse-event summaries, but does not report the observed primary endpoint count, its uncertainty, or a comparative treatment effect. Because the study has no control group, its design supports description of the study group rather than a direct treatment comparison.