Invasive Candidiasis in Saudi ICUs: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Invasive Candidiasis in Saudi ICUs (NCT01490684), a registered phase not stated study. The primary outcome is Hospital Mortality.

2. Clinical Question

The broader aim is descriptive: to characterize the epidemiology of invasive Candida infection, explore risk factors, and describe outcomes among critically ill patients in Saudi Arabia. The registry lists ICU mortality, duration of mechanical ventilation, length of stay in the ICU, and length of stay in the hospital as secondary outcomes. These are clinically relevant dimensions of illness and care, but the record does not post results for them in the information available for this analysis.

This cohort can describe what occurred among the participants observed, subject to the completeness and definitions of the registry data. It cannot, by itself, establish that an exposure or clinical factor caused an outcome. The registry does not identify a randomized intervention or a comparable control group, so causal treatment-effect questions are outside what the posted record can answer.

3. Trial Design

The registry describes a prospective cohort study of critically ill patients in Saudi Arabia, with invasive candidiasis as the condition of interest. It lists Hasan Al-Dorzi as sponsor and records enrollment of 162 participants. The study status is completed. The recorded start is 2012-08, and primary completion is listed as 2016-05.

In a prospective cohort, participants are followed over time and information about exposures and outcomes is collected as events occur or are recorded. General statistical context: this design can help characterize the frequency and timing of outcomes and examine associations between patient features and outcomes. Since exposure is not randomly assigned, differences between groups may reflect underlying patient or care differences, as well as the exposure being studied. An association in such a cohort should not automatically be interpreted as a causal effect.

The brief description says the study aimed to determine epidemiology, risk factors, and outcomes of invasive Candida infection in critically ill patients in Saudi Arabia. The listed secondary outcomes are ICU mortality, duration of mechanical ventilation, length of stay in the ICU, and length of stay in the hospital. The primary outcome is titled hospital mortality. Its timeframe describes follow-up while patients are in the ICU and recording vital status at ICU discharge; the description further says hospital mortality is censored at 180 days after study entry for patients staying alive in hospital longer than that.

The registry does not describe recruitment procedures, eligibility criteria, the specific exposure groups, the measurement schedule, or how clinical factors were defined. Those details are not reported in the registry record. No randomized allocation is described, and the registry cautions that arms are not a like-for-like control comparison. Thus, any apparent differences between groups should be read as observational comparisons rather than randomized treatment contrasts.

The completed status indicates that the study is no longer listed as ongoing; it does not establish that all planned outcomes or analyses were reported. The registry lists zero analyses. It does not report a sample-size justification for the cohort’s planned objectives or describe the protocol’s statistical analysis plan.

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

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 Hospital Mortality, measured over Patients will be followed while in the ICU and the vital status at the time of discharge from the ICU will be noted. The expected stay in the ICU is 10 days on average..

The primary endpoint is hospital mortality, specified as a count of participants. The registry’s description places an important qualification on how the outcome is ascertained: patients are followed while in the ICU, with vital status recorded at ICU discharge, and patients who remain alive in hospital beyond 180 days after study entry are considered alive for the stated hospital-mortality definition.

Mortality is an outcome that records whether a participant died during a defined observation period. General statistical context: a clear observation window matters because participants followed for different lengths of time have different opportunities for an event to be observed. Censoring marks the end of the period during which the outcome is counted; it is not itself evidence that an event occurred. Here, the registry’s stated 180-day rule sets a limit for classifying prolonged hospital stays, while the timeframe also emphasizes ICU follow-up and status at ICU discharge.

These descriptions do not align perfectly on their face: the endpoint title says hospital mortality, but the timeframe says vital status at ICU discharge, and the description refers to hospital mortality censored at 180 days. The record does not provide further clarification of the operational definition or explain which source of vital status determined the posted primary result. That clarification is not reported in the registry record.

Mortality can be used to describe a major outcome of critical illness without requiring a judgment about treatment benefit. However, no primary endpoint estimate, analysis, or uncertainty measure is reported in the information available for this analysis. The adverse-event summary separately lists 95 deaths, but the registry information does not establish that this count is the primary hospital-mortality result or specify its observation window.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a prospective observational cohort and lists hospital mortality as the primary outcome. It does not provide a statistical analysis plan or an outcome analysis. The methods discussion below therefore distinguishes what the record states from general statistical principles that help explain how such a study could be interpreted.

What does a cohort design contribute?

General statistical context: a cohort follows participants and records outcomes over a period of observation. In a prospective cohort, measurement is planned while follow-up is underway, which can support orderly collection of clinical information. A cohort can describe outcomes in the observed population and examine whether measured characteristics are associated with those outcomes. It does not automatically isolate causal effects: patients with different exposures or risk factors may also differ in severity, care, or other prognostic characteristics.

The registry describes an observational study of critically ill patients in Saudi Arabia and records enrollment of 162 participants. It does not report the eligibility criteria, the enrollment process, the details of exposure classification, or the follow-up schedule beyond the descriptions attached to the outcomes. These design details are not reported in the registry record. Without them, readers cannot assess how representative the cohort is or whether exposure and outcome measurements were applied consistently.

How should a binary outcome be understood?

The primary measure is defined as a count of participants and the outcome is a mortality event, making the intended result a binary participant-level outcome: each participant is classified according to whether the specified event occurred during the defined observation period. General statistical context: a count alone does not give the probability of an event unless its denominator and analysis population are clearly stated. A proportion or model-based estimate may describe event frequency, while an interval estimate can express uncertainty. The registry record does not post a primary-outcome count, an analyzed denominator, an estimate, or an interval.

The adverse-event summary lists 95 deaths, but this count does not come with an explanation linking it to the primary endpoint definition. The primary outcome description refers both to vital status at ICU discharge and to a hospital-mortality rule that considers patients alive beyond 180 days as alive. The precise relationship between these statements and the adverse-event death count is not reported in the registry record.

Why does the observation period matter?

General statistical context: an endpoint is interpretable only when the time at risk and the event definition are clear. Participants who are followed for different periods may have different chances for an event to be recorded. Censoring occurs when the event is not observed during the defined period and follow-up for that endpoint ends. Censoring is not the same as an event-free outcome for all future time. The registry specifies a 180-day rule for prolonged hospital stays, but does not report further operational detail about how follow-up, discharge, or unavailable vital status was handled.

The timeframe says the expected ICU stay is 10 days on average. This is a protocol description, not a reported summary of the cohort’s observed ICU stays. It should not be interpreted as the cohort’s actual average length of stay. The registry also lists length of stay and duration of mechanical ventilation as secondary outcomes but does not post their results in the record information.

What does the analysis record tell us?

The registry lists zero analyses. It does not report statistical models, covariate adjustment, hypothesis tests, confidence intervals, handling of clustering, or strategies for missing measurements. Those methods are not reported in the registry record. General statistical context: adjusted analyses can account for measured differences between participants, but adjustment cannot remove bias from unmeasured factors and depends on appropriate model specification. Since the record does not describe an adjusted analysis, no adjusted association should be inferred.

Multiplicity refers to the interpretive problem created when many outcomes, comparisons, or hypotheses are examined. General statistical context: as the number of tests increases, the chance of finding a nominally unusual result by chance can increase unless the analysis plan addresses that issue. This study lists a primary and several secondary outcomes, but the record does not report a multiplicity strategy or results for those outcomes. The absence of a documented strategy is not evidence that an adjustment was or was not performed outside the registry.

What do the sample-size assumptions mean?

The stated sample-size assumptions describe a planning illustration computed from an observed effect, with two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. General statistical context: these calculations can illustrate the sample size needed under chosen assumptions, but they depend on the assumed effect and design. They are not evidence that the cohort was planned or analyzed as a randomized two-arm comparison. The registry does not report a protocol sample-size justification, and planning sample sizes are not observed power.

The registry does not report the observed effect used in those assumptions in the information available for this analysis. It also does not describe how a two-arm planning illustration relates to the observational cohort. Thus, those assumptions should not be used to infer that the completed study had a particular ability to detect an effect or that a null result was established.

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("The Whole Cohort")
n      <- c(162)
events <- c(95)
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  The Whole Cohort  162  95  58.6  50.6  66.3  50.9  65.9  50.9  65.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome, hospital mortality, and secondary outcomes covering ICU mortality, duration of mechanical ventilation, length of stay in the ICU, and length of stay in the hospital. It records zero analyses. No outcome-specific results, analysis populations, missing-data summaries, or multiplicity procedures are reported in the registry record.

General statistical context: multiplicity arises when several outcomes, comparisons, or statistical tests are considered. A prespecified primary outcome can help focus interpretation, while a stated testing strategy can clarify how multiple tests are handled. The registry does not report whether any family-wise error or false-discovery approach was planned, whether secondary outcomes were exploratory, or how outcomes were prioritized beyond the primary and secondary labels. No conclusion about adjustment for multiple testing is possible from the posted information.

The record gives enrollment of 162 participants and the adverse-event summary uses 162 as the number at risk. It does not state the number of participants included in a primary endpoint analysis, whether every enrolled participant had complete follow-up, or how participants with unavailable vital status were classified. Missingness and the analysis population are not reported in the registry record. General statistical context: excluding participants with missing outcomes can affect an estimate if missingness is related to prognosis or exposure; appropriate interpretation depends on knowing the extent and handling of missing data.

The description of mortality includes vital status at ICU discharge and a 180-day rule for prolonged hospital stays, but it does not explain how missing status, transfer, or withdrawal was treated. No intention-to-treat or per-protocol population is identified, and no participant flow is reported. These omissions prevent assessment of whether the analysis population matched the enrolled cohort or whether incomplete follow-up could have influenced the result.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The registry’s adverse-event summary is for the whole cohort. It lists 162 participants at risk for serious adverse events and 162 at risk for other adverse events; zero participants are recorded as affected in each category. The same summary lists 95 deaths. No serious adverse-event terms are listed.

These fields should be read as registry reporting, not as proof that no adverse events occurred. The record does not explain whether zero affected participants means that no events were observed, that events were not entered, or that a particular reporting threshold or collection method was used. Definitions, monitoring procedures, and event-attribution rules are not reported in the registry record.

The death count appears in the adverse-event summary, but the record does not specify its timing or establish that it is the primary hospital-mortality result. The endpoint description uses a particular follow-up and censoring rule, and the adverse-event summary does not clarify whether the same rule applies. The death count should therefore not be converted into a mortality rate or treated as an endpoint estimate without a stated denominator and compatible outcome definition.

General statistical context: safety summaries depend on how events are defined, elicited, coded, and followed over time. A count of zero affected participants is meaningful only in relation to the completeness and scope of surveillance. The registry does not provide enough detail to judge those aspects.

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

The registry record establishes that a prospective observational cohort concerning invasive candidiasis in critically ill patients in Saudi Arabia was completed, with 162 participants enrolled. It identifies hospital mortality as the primary outcome and lists ICU mortality, mechanical ventilation duration, and ICU and hospital length of stay as secondary outcomes. These details describe the study’s purpose and structure.

They do not establish the frequency of the primary outcome, the strength of any association, or the precision of an estimate. No primary analysis is listed, and the record does not report a mortality estimate, confidence interval, or statistical test. The 95 deaths listed in the adverse-event summary should not be treated as the primary endpoint result because the registry does not link that count to the endpoint definition or observation period.

General statistical context: an observational study can provide useful descriptive evidence about a defined cohort and can generate or examine associations. Its findings do not, without appropriate design and analysis, demonstrate that a risk factor caused an outcome. Confounding and selection can influence observed patterns. The registry does not report the analysis needed to assess those possibilities.

The study’s stated objectives include epidemiology, risk factors, and outcomes. However, the absence of posted outcome analyses means the information in the record does not answer those objectives quantitatively. A completed status is not itself evidence that the results were complete, precise, or statistically conclusive.

Planning illustrations, if considered alongside the study, are not observed power. Their assumptions involve equal allocation between two arms and a normal approximation, while the study is described as observational and no like-for-like control comparison is identified. Such illustrations cannot be interpreted as evidence that the cohort could detect a particular effect.

The careful conclusion is limited: this is a registered completed cohort with stated outcomes and an adverse-event summary, but the available registry information does not support a quantified interpretation of the primary endpoint or causal conclusions about exposures and mortality.

14. Why This Trial Matters Statistically

This study is statistically relevant because it addresses an observational cohort in a population the registry describes as not well studied with respect to invasive candidiasis. The record states objectives related to epidemiology, risk factors, and clinical outcomes in critically ill patients in Saudi Arabia. A clearly characterized cohort can contribute descriptive information about the population under observation and identify questions for further investigation.

The record also illustrates why outcome definitions and follow-up windows matter. The primary endpoint is titled hospital mortality, while its timeframe emphasizes vital status at ICU discharge and its description specifies a 180-day rule for prolonged hospital stays. Without clarification of how these statements were implemented, readers cannot be certain that a reported count would correspond to a single, consistently applied endpoint definition.

Another statistical point is the distinction between a registry’s stated objectives and its posted analyses. Enrollment of 162 participants and completion status do not reveal the primary outcome frequency, the degree of uncertainty, or whether associations were adjusted for relevant differences. The record lists zero analyses, so conclusions about effect magnitude and precision are not supported by the available results.

The study also makes a useful teaching case for observational inference. In a cohort without randomized allocation, comparisons across exposures may be affected by confounding and selection. Statistical adjustment can sometimes address measured differences, but it cannot guarantee causal interpretation. Since the record does not describe its analysis plan or models, readers should avoid assuming that these issues were handled.

Finally, the safety summary demonstrates that event counts need context. The record lists zero participants affected by serious or other adverse events while also listing 95 deaths, but it does not explain the relationship among those entries, the endpoint definition, or follow-up. Reading each field within its stated scope—and recognizing what remains unreported—is essential to accurate interpretation.

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 main limitation for interpreting this cohort from the registry record is the absence of posted outcome analyses. Although hospital mortality is designated as the primary outcome and 162 participants are enrolled, no endpoint estimate, analysis denominator, interval estimate, or statistical test is reported. The registry lists zero analyses, so the primary outcome’s magnitude and precision cannot be assessed.

The mortality definition is not fully clear from the record. The endpoint title refers to hospital mortality, the timeframe describes vital status at ICU discharge, and the description specifies a 180-day rule for prolonged hospital stays. The record does not clarify how these statements were reconciled in outcome collection or analysis. The 95 deaths in the adverse-event summary cannot resolve this ambiguity because their timing and relationship to the endpoint are not reported.

Important cohort details are absent, including eligibility criteria, recruitment procedures, the measured risk factors, exposure definitions, and completeness of follow-up. The registry does not report the handling of missing outcome data, participant withdrawals, transfers, or the analyzed population. It is therefore not possible to assess selection, attrition, or the representativeness of the enrolled participants from this record alone.

The observational design does not support a randomized treatment comparison. Allocation is not stated, and the record cautions that arms are not a like-for-like control comparison. The registry does not describe adjustment for confounding or other modeling choices, limiting any assessment of associations between risk factors and outcomes.

Finally, safety-event definitions and collection methods are not reported, despite the summary listing zero affected participants in both adverse-event categories. The record does not provide a protocol sample-size justification or a statistical analysis plan. These omissions leave substantial uncertainty about how the intended analyses were conducted and how completely results were reported.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Invasive Candidiasis in Saudi ICUs — NCT01490684.
• Registry record last updated 2018-08-24; status last verified 2017-11.
• Results first posted 2018-08-24.
• 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

The registry record describes a completed prospective observational cohort titled “Invasive Candidiasis in Saudi ICUs,” with the official title “Invasive Candidiasis in Critically Ill Patients in Saudi Arabia: A Prospective Cohort Study.” Enrollment is 162 participants. The recorded study start is 2012-08 and primary completion is 2016-05. Hasan Al-Dorzi is listed as sponsor.

The primary outcome is hospital mortality, recorded as a participant count. The registry lists ICU mortality, duration of mechanical ventilation, and ICU and hospital length of stay as secondary outcomes. The study’s stated objectives concern epidemiology, risk factors, and outcomes of invasive Candida infection in critically ill patients in Saudi Arabia.

The record lists zero analyses and does not report a primary outcome estimate or analysis. Its adverse-event summary lists 95 deaths, with 162 participants at risk and zero affected participants for serious and other adverse events. The record does not clarify the relationship between that death count and the primary endpoint. Key details about missing data, analysis populations, outcome ascertainment, and statistical methods are not reported in the registry record.