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 Assessment of the Fungal Infection Incidence Across Canada for High Risk Participants With Hematological Disease (P07501) (NCT01254318), a registered phase not stated study. The primary outcome is Percentage of Participants With Non-Candida Invasive Fungal Infections at a Single Institution.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01254318 |
| Phase | Phase not stated |
| Condition | Mycoses, Leukemia |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 130 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merck Sharp & Dohme LLC |
| Results posted | Yes |
2. Clinical Question
Population
The primary population was all enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia. The study also describes high-risk participants, including people receiving high dose chemotherapy for leukemia. The number of enrolled participants who met the primary population definition is not reported in the registry record.
Intervention
The registry lists Standard Care as the intervention. The study itself is described as a retrospective review of hospital records, rather than a prospective assignment to a treatment. Details about specific care received are not reported in the registry record.
Comparator
No like-for-like control group or randomized comparison is described. The registry record does not report an assigned comparator; its focus is estimating fungal-infection percentages, including a primary outcome at a single institution and secondary outcomes concerning pathogens and Canada-wide infection percentages.
Primary question
Among the defined high-risk participants, what percentage had a non-Candida invasive fungal infection during the period from the chemotherapy or transplant-conditioning index date through 365 days afterward? The endpoint is an observed percentage, not a comparison of treatment effects.
The study’s broader intent was to generate regional and national incidence data for non-Candida invasive fungal infections among high-risk participants. The registry describes participants receiving stem cell transplant and high dose chemotherapy for leukemia; the primary outcome specifically concerns the percentage with an infection at a single institution. These descriptions give the question a descriptive, surveillance-oriented character. They do not define a causal question about whether one treatment prevents or causes infection.
The registry lists Mycoses and Leukemia as conditions and describes high-risk participants in relation to hematological disease and treatment. The full eligibility details are not reported in the registry record. In particular, the record does not establish which clinical criteria were used to confirm an invasive fungal infection or to distinguish non-Candida infections from other fungal conditions.
3. Trial Design
This is a completed retrospective study based on chart reviews at major institutions across Canada. The registry describes the intended purpose as generating regional and national incidence data for non-Candida invasive fungal infections in high-risk participants. The study start is recorded as 2013-03, and primary completion as 2014-11. Recorded enrollment is 130.
For the primary outcome, information was extracted from hospital records beginning at the index date, defined as the start of chemotherapy or the conditioning regimen for stem cell transplant, and continuing through 365 days after that date. The primary population is described as all enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia. The record does not report how many enrolled participants met that definition or contributed data to the primary outcome.
The registry lists Standard Care as an intervention, but it does not describe random assignment or a comparative treatment design. The study’s retrospective chart-review description and stated aim are consistent with measuring the occurrence of infections in clinical records, not testing a randomized intervention against a control. The registry explicitly flags that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The allocation method is not reported in the registry record.
The primary outcome concerns the percentage of participants with non-Candida invasive fungal infections at a single institution. Secondary outcomes concern the percentage with a specific fungal pathogen at a single institution and the percentage with invasive fungal infections in Canada. The record does not describe the participating institutions, the number of sites, how sites were selected, or whether the national outcome uses the same eligibility and case definitions as the primary outcome.
The study status is recorded as completed. Although the registry identifies three outcome measures, it does not report numerical outcome findings or analysis results. A study’s completed status indicates its registry status, but does not by itself supply estimates or establish how completely the planned data collection was achieved.
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
| Stage | Participants at High Risk for IFI |
|---|---|
| STARTED | 130 |
| COMPLETED | 78 |
| NOT COMPLETED | 52 |
Reasons for not completing this period:
| Reason | Participants at High Risk for IFI |
|---|---|
| Lost to Follow-up | 5 |
| Death | 47 |
Analysis population for the primary outcome, as defined in the registry: All enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia.
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 | Participants at High Risk for IFI |
|---|---|---|
| Participants analysed | 130 | |
| Age, Continuous | Years | 55.28 (SD 15.26) |
| Sex: Female, Male: Female | Participants | 51 |
| Sex: Female, Male: Male | Participants | 79 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With Non-Candida Invasive Fungal Infections at a Single Institution, measured over 365 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with non-Candida invasive fungal infections at a single institution. The registry says hospital-record data were extracted from the index date through 365 days afterward. The index date is the start of chemotherapy or the stem-cell-transplant conditioning regimen. The specified population is all enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia.
For a percentage endpoint, the numerator represents participants meeting the infection outcome definition, and the denominator represents the participants included in the outcome population. This is a general description of how percentages are formed; the registry does not report the actual numerator, denominator, or estimated percentage. It also does not provide the operational case definition, diagnostic confirmation requirements, or rules for handling a participant with more than one infection.
A percentage is useful for describing how often an event was recorded within a defined group and observation period. It is not the same as an incidence rate based on person-time, and the registry labels the endpoint as a percentage of participants. The 365-day follow-up window gives the outcome a stated period of observation, while the hospital-record approach identifies the source of the data. The record does not explain how complete those records were or whether infections diagnosed outside the reviewing institution were captured.
The endpoint’s accompanying dispersion measure is a 95% confidence interval. In general, a confidence interval conveys statistical uncertainty around an estimate, with its width depending on the estimate and the information available. No confidence-interval limits or endpoint estimate are reported in the registry record, so the precision of the observed percentage cannot be assessed from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes what the primary outcome was intended to measure: the percentage of a defined high-risk population with non-Candida invasive fungal infections during follow-up through 365 days. It does not report the resulting percentage, its 95% confidence interval, or the underlying event and denominator counts. Consequently, the magnitude of the observed burden and the precision of its estimate are not reported in the registry record.
That absence matters for interpretation. A study objective and outcome definition describe what investigators sought to measure; they are not evidence of the measured frequency. No conclusion about whether infections were common or uncommon can be drawn from the outcome description alone. Nor can the registry record establish whether observed percentages differed across institutions, regions, pathogens, or clinical subgroups.
The intended regional and national data are relevant context, but the primary endpoint is explicitly described as a single-institution percentage. The secondary outcomes refer to a specific fungal pathogen at a single institution and invasive fungal infections in Canada. Their labels do not supply their estimates or explain the method used to produce national figures. The record does not report site-specific results or the degree to which the primary and secondary outcome populations overlap.
The retrospective design also sets the scope of the evidence. The endpoint comes from hospital-record extraction rather than a stated prospective, randomized comparison. The registry does not describe a control group suitable for comparing treatment strategies, and it flags the arms as not being a like-for-like comparison. The outcome therefore should be read as a descriptive measure of recorded infections in the defined setting, not as an estimate of a causal treatment effect.
The confidence interval is named as the endpoint’s dispersion measure, but no interval limits are recorded. In general, an interval helps distinguish a relatively precise estimate from one with substantial uncertainty; without the limits and event counts, that assessment is unavailable. The record also does not report whether any adjustment was made for differences among institutions, patient characteristics, or incomplete observation.
Recorded enrollment is 130, but that figure should not be treated as the primary outcome denominator. The primary population requires receipt of both stem-cell transplant and high dose chemotherapy for leukemia, and the registry does not state how many enrolled participants satisfied that definition or had usable follow-up. The outcome result and its analysis population therefore remain undetermined from the registry record. The completed status does not resolve these missing result details.
9. Statistical Methods Explained
The primary measure is a percentage, a descriptive statistic for a binary outcome: each participant either meets the stated infection outcome definition during the observation period or does not. This is a general explanation of the measure. The registry describes the outcome as the percentage with non-Candida invasive fungal infections, but it does not report the number meeting the definition or the number included in the analysis. Without those components, the percentage cannot be reconstructed or interpreted for precision.
The registry identifies a 95% confidence interval as the measure of dispersion for the primary percentage. In general, a confidence interval expresses uncertainty about an estimate under the assumptions of the statistical method. A narrower interval usually indicates greater precision, while a wider interval indicates less precision. The registry record does not report the interval limits, the method used to calculate the interval, or whether any method accounted for differences among institutions. The interval’s presence in the endpoint description is not itself an observed result.
The outcome window is defined from an index date through 365 days after it. That index date is the start of chemotherapy or the conditioning regimen for stem cell transplant. A fixed observation window makes clear which period is intended to contribute to the outcome. In practice, a retrospective review must also determine whether the records cover that period sufficiently and how to classify participants whose records are incomplete or whose care occurs outside the reviewed institution. Those procedures are not reported in the registry record.
The wording of the endpoint is important. A percentage of participants with an event is a proportion over a defined population and follow-up period. An incidence rate, by contrast, generally uses accumulated time at risk in its denominator. The primary endpoint is identified as a percentage, not a person-time rate. Although the study’s broader purpose uses the word incidence, the registry does not describe a person-time analysis for the primary outcome.
There is a separate planning illustration described with the record. It uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; its target effect is a stated fraction of an observed effect. These assumptions describe a planning calculation, not the retrospective study’s allocation or analysis. They do not establish that the study enrolled randomized arms, and they are not observed power. The registry record does not report that these assumptions were the study’s original design rationale or sample-size justification.
As a general matter, planning calculations ask how many participants might be needed under chosen assumptions about the target effect, variability, allocation, and statistical threshold. A calculation based on a fraction of an observed effect is an illustration tied to that assumed effect, rather than a measure of the probability that a completed study detected a true effect. Because this study is not described as a randomized comparison and no comparative estimate is reported, such a planning framework should not be mistaken for a trial-based treatment-effect analysis.
The retrospective data source also affects the statistical interpretation. Hospital records can reflect the timing and completeness of documentation, and outcome ascertainment depends on the criteria used to identify infections. In general, differences in documentation or diagnostic practice across sites can affect measured percentages. Whether the study used consistent case definitions, central review, or site-level adjustments is not reported in the registry record. It is therefore not possible to judge from the record how those issues were handled.
Where participants are drawn from multiple institutions, their outcomes may be related because they share local practices or populations. In general, statistical methods that treat all observations as independent can understate uncertainty when such dependence is present. Whether observations were clustered by institution, and whether the confidence interval or any other method accounted for clustering, is not reported in the registry record. The record also does not report an analysis plan, model, or adjustment strategy.
The registry lists three outcome measures and zero analyses. The record names the primary outcome and two secondary outcomes, but does not include numerical estimates or analysis descriptions. It therefore does not show whether the reported outcome was calculated as planned, whether subgroup or adjusted analyses were conducted, or whether sensitivity analyses were used. Statistical interpretation must remain at the level of the stated outcome and design rather than implying unreported analytic choices.
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.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Participants at High Risk for IFI | 130 | 42 | 32.3% | 24.4% to 41.1% | 24.9% to 40.8% | 24.9% to 40.8% |
R code and output
arm <- c("Participants at High Risk for IFI")
n <- c(130)
events <- c(42)
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 Participants at High Risk for IFI 130 42 32.3 24.4 41.1 24.9 40.8 24.9 40.811. Multiplicity, Missing Data and Analysis Populations
The registry identifies three outcome measures: the primary percentage of participants with non-Candida invasive fungal infections at a single institution, plus secondary measures concerning a specific fungal pathogen at a single institution and invasive fungal infections in Canada. It lists zero analyses and does not report outcome estimates. The outcomes’ prespecified status, hierarchy beyond the primary label, and any multiplicity strategy are not reported in the registry record.
Multiplicity refers generally to the interpretive issue that arises when several outcomes or comparisons are examined. Testing or estimating multiple outcomes can increase the chance of findings that appear noteworthy by chance, depending on the analysis and the claims being made. The record does not say whether any adjustment, prioritization rule, or other approach was planned or used. Since no statistical results are reported, it is not possible to assess how multiplicity may have affected the findings.
The primary population is defined as all enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia. The number meeting that definition is not reported. The registry also does not report whether every eligible participant had records available through the intended observation period, how missing records or incomplete follow-up were handled, or whether participants with incomplete information were excluded from a particular analysis.
In general, missing outcome information can affect a percentage if the participants with missing records differ from those whose outcomes are observed. The record does not describe imputation, assumptions about missingness, or sensitivity analyses. It also does not report whether the analysis population was defined in advance beyond the stated primary population. These omissions limit assessment of the denominator and the potential effect of incomplete ascertainment.
12. What the Result Does, and Does Not, Mean
The study addresses a descriptive question about non-Candida invasive fungal infections among high-risk participants with hematological disease. Its retrospective hospital-record design and stated 365-day observation period define the intended setting and time frame. The registry’s stated aim of producing regional and national incidence data explains why the outcome may be relevant to understanding infection patterns across participating Canadian institutions.
However, the registry record does not report the primary outcome estimate, its confidence interval, or the event and denominator counts. It therefore does not establish the observed frequency or the precision of that frequency. No numerical conclusion about the primary endpoint can be drawn from the record. The secondary outcome descriptions likewise do not include results.
The study does not provide a like-for-like randomized comparison. The registry lists Standard Care, but does not describe a control group or randomized allocation, and explicitly notes that the arms are not a suitable control comparison. The endpoint should therefore not be interpreted as evidence that a particular treatment caused, prevented, or changed infection occurrence. It is a proposed descriptive percentage based on chart review.
Even a reported percentage would apply to the population and records included in the analysis, not automatically to every person with leukemia or every person receiving stem-cell transplant or high dose chemotherapy. The registry does not report the number meeting the primary population definition, the full eligibility criteria, or the site-selection process. Those details would be important when judging how well an estimate represents other settings.
More generally, a confidence interval can help communicate how much statistical uncertainty surrounds an estimate, but it cannot address all sources of uncertainty. In a retrospective study, case definitions, record completeness, and differences in documentation can also shape the observed measure. The registry record does not describe how these potential issues were handled. The completed status and recorded enrollment alone do not fill in the missing outcome evidence.
13. Why This Trial Matters Statistically
This study is statistically interesting because its question is about describing infection occurrence in a high-risk clinical population rather than comparing assigned treatments. Clear definitions of the population, index date, follow-up period, and outcome are central to interpreting a percentage from retrospective records. The registry provides some of these elements: the primary population is defined by receipt of stem-cell transplant and high dose chemotherapy for leukemia, the index date is specified, and follow-up extends through 365 days.
The distinction between the stated primary endpoint and the broader aim is also important. The primary outcome concerns a single institution, while the study aims to generate regional and national data, and the secondary outcomes include a Canada-wide percentage. Those scales of inference are not interchangeable. Site coverage, consistent outcome definitions, and the way findings are aggregated would matter when interpreting a regional or national estimate, but those methods are not reported in the registry record.
The record also illustrates why enrollment alone is not enough to judge an outcome analysis. Although enrollment is recorded as 130, the primary analysis population is restricted by treatment history, and the record does not state how many participants met its definition or contributed outcome information. The denominator and the completeness of follow-up are necessary to understand both the percentage and its precision.
Finally, the registry identifies a 95% confidence interval but does not report the interval or the primary estimate. Without results, readers cannot assess the magnitude or precision of the measured outcome. This makes the distinction between a completed study record and an interpretable results report especially consequential: the design and objective clarify what was intended, but do not supply the statistical evidence needed to quantify the outcome.
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 main limitation for interpretation is that the registry record does not report the primary percentage, its 95% confidence interval, event counts, or the denominator used. It also does not give numerical results for the secondary outcomes. As a result, the outcome’s magnitude and precision cannot be assessed, despite the record’s completed status and recorded enrollment.
The primary population is defined as enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia, but the number meeting that definition is not reported. The description of high-risk eligibility is incomplete in the registry record, and the number and identities of participating institutions are not stated. The record also does not explain how sites were selected or how the single-institution primary outcome relates to the intended regional and national estimates.
Outcome ascertainment relied on retrospective hospital records. The registry does not report the diagnostic criteria for invasive fungal infection, the rules distinguishing Candida from non-Candida infections, or whether case review was standardized across institutions. It also does not report how records were checked for completeness, whether infections diagnosed outside the reviewing institution were captured, or how incomplete follow-up and missing outcome data were handled.
The design does not support a like-for-like randomized comparison, as the registry itself notes. Standard Care is listed, but the allocation method and any comparative analysis are not reported. The record does not state whether estimates accounted for institutional differences, participant characteristics, or possible correlation among participants treated at the same institution. It also does not report a statistical analysis plan or a multiplicity approach for the three outcome measures.
These limitations do not establish that the study’s procedures were inadequate; they identify information not reported in the registry record. They constrain what can be concluded from the record about the outcome, its precision, and its generalizability.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Assessment of the Fungal Infection Incidence Across Canada for High Risk Participants With Hematological Disease (P07501) — NCT01254318.
- Registry record last updated 2016-11-02; status last verified 2016-09.
- Results first posted 2016-11-02.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed retrospective chart-review study of non-Candida invasive fungal infections among high-risk participants with hematological disease in Canada. Its recorded enrollment is 130. The study start is 2013-03, and primary completion is 2014-11.
The primary outcome is the percentage of participants with non-Candida invasive fungal infections at a single institution, assessed from the index date through 365 days. The primary population is described as enrolled participants who received stem-cell transplant and high dose chemotherapy for leukemia. Secondary outcomes concern a specific fungal pathogen at a single institution and invasive fungal infections in Canada.
The registry lists Standard Care and does not describe a randomized, like-for-like comparison. It identifies a 95% confidence interval for the primary percentage but does not report the estimate, interval limits, counts, or analysis results. The number meeting the primary population definition, missing-data procedures, and statistical analysis methods are not reported in the registry record.