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Heart Failure Phase 3 Randomized NCT03521934

SOLOIST-WHF: Complete Statistical Analysis of Sotagliflozin in Heart Failure

An independent statistical analysis of the randomized phase 3 SOLOIST-WHF trial evaluating sotagliflozin versus placebo in participants with type 2 diabetes mellitus and worsening heart failure, with emphasis on recurrent cardiovascular and heart-failure events, cardiovascular death, patient-reported outcomes, and renal function.

Phase 3  ·  Enrollment: 1222  ·  Study status: Terminated  ·  Primary completion: June 5, 2020
Independent analysis: This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
Scope of this record

Numerical trial results on this page are restricted to the information contained in the ClinicalTrials.gov record. The page separates reported registry results from statistical interpretation. Where the registry supplies an analysis method or effect estimate, that information is reported without reconstructing or recalculating the result.

1. Trial at a Glance

SOLOIST-WHF was a randomized, parallel-group, quadruple-masked phase 3 trial evaluating sotagliflozin versus placebo in participants with type 2 diabetes mellitus and heart failure. The registry reports 1222 enrolled participants and a primary endpoint based on the total number of cardiovascular death, hospitalizations for heart failure, and urgent heart-failure visits through 21.9 months.

1222
Enrollment
Registered participants
2
Arms
Sotagliflozin vs placebo
0.67
Primary HR
95% CI 0.52–0.85
< 0.001
Primary P-value
Two-sided 95% CI
FeatureSOLOIST-WHF
PhasePhase 3
Therapeutic areaCardiology
ConditionsHeart Failure; Type 2 Diabetes Mellitus
DesignRandomized, parallel-group
MaskingQuadruple
Primary purposeTreatment
Enrollment1222
InterventionsSotagliflozin and placebo
Primary endpoint typeCount / rate
Hypothesis typeSuperiority
Study statusTerminated
Start2018-06-15
Primary completion2020-06-05
Lead sponsorLexicon Pharmaceuticals
Sponsor typeIndustry

2. Clinical Question

The registered primary question can be framed statistically as whether sotagliflozin changes the rate of the combined cardiovascular and heart-failure event burden compared with placebo after randomization.

Population

Participants with type 2 diabetes mellitus and heart failure enrolled in the SOLOIST-WHF trial.

Intervention

Sotagliflozin.

Comparator

Placebo.

Primary question

Does sotagliflozin alter the total number of cardiovascular death, heart-failure hospitalization, and urgent heart-failure visit occurrences after randomization?

3. Trial Design

01
Enroll 1222 participants
02
Randomize Two parallel groups
03
Mask Quadruple masking
04
Follow Up to 21.9 months for primary endpoint
05
Analyze ITT and prespecified statistical models
Allocation
Randomized allocation to two treatment groups.
Design model
Parallel-group clinical trial.
Masking
Quadruple masking.
Primary purpose
Treatment.
TREATMENT ARM

Sotagliflozin

  • Drug intervention.
  • Compared with placebo in the randomized analysis.
  • Included in the ITT population for efficacy analyses.
CONTROL ARM

Placebo

  • Placebo intervention.
  • Compared with sotagliflozin in the randomized analysis.
  • Included in the ITT population for efficacy analyses.

4. Endpoints

The registry reports eight posted outcome measures and eight statistical analyses. The primary endpoint is a recurrent-event measure expressed as events per 100 person-years, while several secondary outcomes use the same Cox modeling framework for time-to-event comparisons.

EndpointRegistry time frameType / unitAnalysis
Number of Total Occurrences of Cardiovascular (CV) Death, Hospitalizations for Heart Failure (HHF) and Urgent Visits for Heart Failure (HF) Up to 21.9 months Count / rate; events per 100 person-years Cox proportional-hazards model
Total Number of Occurrences of HHF and Urgent HF Visits Up to 21.9 months Time-to-event; events per 100 person-years Cox proportional-hazards model
Total Number of Deaths From Cardiovascular Causes Up to 21.9 months Time-to-event; events per 100 person-years Cox proportional-hazards model
Total Number of Occurrences of CV Death, HHF, Non-fatal Myocardial Infarction and Non-fatal Stroke Up to 21.9 months Time-to-event; events per 100 person-years Cox proportional-hazards model
Total Number of Occurrences of HHF, Urgent HF Visit, CV Death, and HF While Hospitalized Up to 21.9 months Time-to-event; events per 100 person-years Cox proportional-hazards model
Total Number of Deaths From Any Cause Up to 21.9 months Time-to-event; events per 100 person-years Cox proportional-hazards model
Change From Baseline in Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) Scores at Month 4 Baseline to Month 4 Score on a scale ANCOVA
Change From Baseline in Estimated Glomerular Filtration Rate (eGFR) Baseline up to 21.9 months mL/min/1.73 m2 MMRM

Primary endpoint definition

The registered primary endpoint is the total number of occurrences of cardiovascular death, hospitalizations for heart failure, and urgent heart-failure visits after randomization. The registry specifies that both first and potentially subsequent occurrences are included and that events are calculated as the total number of events per 100 person-years of follow-up.

Important endpoint distinction: this is not simply a conventional time to first event endpoint. The registered definition explicitly includes first and potentially subsequent occurrences. The statistical analysis posted for the endpoint nevertheless reports a hazard ratio from a marginal Cox proportional-hazards model.

5. Statistical Methodology

Intention-to-treat analysis

The registry defines the efficacy analysis population as the ITT population, including all randomized participants. The treatment comparison is therefore anchored to randomized assignment rather than restricting efficacy analysis to participants who remained on treatment or who completed follow-up.

Marginal Cox proportional-hazards model

The primary analysis used a marginal Cox proportional-hazards model. The registry specifies stratification by region and ejection fraction, with non-cardiovascular death treated as a competing event.

Primary model structure
Treatment comparison → marginal Cox proportional-hazards model → stratification by region + ejection fraction → non-CV death as competing event

The reported effect measure is a hazard ratio with a two-sided 95% confidence interval.

ANCOVA for KCCQ-12

The change from baseline to Month 4 in KCCQ-12 score was analyzed using an ANCOVA model. Treatment group was included as a factor, while baseline KCCQ-12 score and randomization stratification factors were included as covariates.

MMRM for eGFR

The rate of decline in eGFR over time was analyzed using an MMRM. The registry describes absolute change in eGFR from baseline as the outcome, with a random intercept and fixed effects for treatment, baseline value, and time.

MethodRegistry-supported use in SOLOIST-WHFEffect measure
Cox proportional-hazards modelPrimary and several secondary time-to-event analysesHazard ratio
ANCOVAChange from baseline in KCCQ-12 at Month 4Registry reports hazard ratio
MMRMChange from baseline in eGFR over timeDifference in least squares means

6. Statistical Methods Explained

Why use an intention-to-treat population?

ITT preserves the randomized comparison. Once participants have been randomized, analyzing them according to their assigned group avoids selectively removing participants because of treatment discontinuation or other post-randomization events. In this registry, all randomized participants are included in the ITT definition used for the reported efficacy analyses.

Why use a Cox model for the primary endpoint?

The registry classifies the primary statistical analysis as a Cox proportional-hazards model and reports the endpoint as a time-to-event analysis in the statistical-analysis record. Cox regression provides a model-based comparison of event hazards over follow-up and expresses the treatment contrast as a hazard ratio.

What does a hazard ratio of 0.67 mean?

A hazard ratio of 0.67 means that the estimated hazard under the fitted model was 0.67 times the corresponding hazard in the comparator group. Expressed as a relative model-based quantity, this corresponds to an estimated 33% lower hazard, because 1 − 0.67 = 0.33.

It does not mean that exactly 33% fewer participants experienced an event, nor does it directly give an absolute reduction in the number of events. Those are different quantities.

Why is the confidence interval important?

The primary 95% confidence interval is 0.52 to 0.85. It describes statistical uncertainty around the estimated hazard ratio under the specified model and sampling framework. It does not describe the range of treatment effects that must occur for individual participants.

Why doesn't the p-value measure effect size?

The primary p-value is < 0.001. A p-value addresses evidence against the null hypothesis under the specified testing framework; it is not a measure of how large or clinically important the treatment effect is. The hazard ratio and its confidence interval provide the direct information about the estimated relative effect and its precision.

Why are region and ejection fraction included as strata?

The registry specifies that the marginal Cox model is stratified by region and ejection fraction. Stratification allows the baseline hazard to vary across the specified strata while estimating the treatment comparison within the model framework. The ClinicalTrials.gov record does not provide the numerical distribution of participants across those strata.

Why does competing risk matter?

The primary and several secondary Cox analyses specify non-cardiovascular death as a competing event. This matters because a participant who dies from a non-cardiovascular cause can no longer experience a later cardiovascular or heart-failure event. Treating that competing event explicitly changes how the time-to-event analysis accounts for the available event pathways.

7. Primary Result

Total Occurrences of Cardiovascular Death, HHF and Urgent HF Visits

The primary endpoint was analyzed in the ITT population using a marginal Cox proportional-hazards model stratified by region and ejection fraction, with non-cardiovascular death treated as a competing event.

Primary hazard ratio

0.67

95% CI: 0.52–0.85   ·   P < 0.001

Effect measure: Hazard Ratio  ·  Two-sided 95% CI  ·  Superiority hypothesis

Primary endpointAnalysis populationModelEstimate95% CIP-value
Total occurrences of CV death, HHF and urgent HF visits, up to 21.9 months ITT; all randomized participants Marginal Cox proportional-hazards model, stratified by region and ejection fraction, with non-CV death as competing event HR 0.67 0.52–0.85 < 0.001
Clinical Biostats interpretation

What the estimate means: the estimated hazard ratio of 0.67 indicates a lower estimated hazard for the sotagliflozin group relative to placebo under the reported Cox model. Numerically, 0.67 corresponds to an estimated 33% lower hazard relative to the comparator.

What it does not mean: it does not mean that 33% of participants were protected, that the number of events was reduced by exactly 33%, or that each participant experienced the same reduction in risk. Because the registered endpoint includes potentially subsequent events, the hazard ratio should not be casually translated into a simple proportion of participants having a first event.

What the confidence interval says: the two-sided 95% CI of 0.52–0.85 indicates uncertainty around the estimated hazard ratio. The interval remains below 1, but its width shows that the estimate is not known with perfect precision.

What the p-value says: the p-value < 0.001 provides evidence against the null hypothesis in the reported superiority analysis. It does not measure the magnitude of the treatment effect; the HR and CI do that.

Important modeling cautions: the result depends on the specified Cox model, its treatment of follow-up, the stratification variables, and the handling of non-cardiovascular death as a competing event. The ClinicalTrials.gov record does not provide enough information to independently assess the proportional-hazards assumption.

8. Secondary Endpoint Results

The registry reports seven secondary statistical analyses. Five use Cox proportional-hazards models for time-to-event outcomes, one uses ANCOVA for KCCQ-12 change at Month 4, and one uses MMRM for eGFR change over time.

Secondary endpointEstimate95% CIP-valueMethod
Total occurrences of HHF and urgent HF visits HR 0.64 0.49–0.83 < 0.001 Cox proportional-hazards model
Total deaths from cardiovascular causes HR 0.84 0.58–1.22 = 0.36 Cox proportional-hazards model
Total occurrences of CV death, HHF, non-fatal myocardial infarction and non-fatal stroke HR 0.72 0.56–0.92 Not reported Cox proportional-hazards model
Total occurrences of HHF, urgent HF visit, CV death, and HF while hospitalized HR 0.68 0.54–0.86 Not reported Cox proportional-hazards model
Total deaths from any cause HR 0.82 0.59–1.14 Not reported Cox proportional-hazards model
Change from baseline in KCCQ-12 scores at Month 4 4.1 1.3–7 Not reported ANCOVA
Change from baseline in eGFR −0.16 −1.3–0.98 Not reported MMRM

Total Occurrences of HHF and Urgent HF Visits

Hazard ratio

0.64

95% CI: 0.49–0.83   ·   P < 0.001

This secondary analysis used the ITT population and a Cox proportional-hazards model stratified by region and ejection fraction, with non-cardiovascular death treated as a competing event.

Total Number of Deaths From Cardiovascular Causes

Hazard ratio

0.84

95% CI: 0.58–1.22   ·   P = 0.36

The point estimate is below 1, but the 95% confidence interval extends from below 1 to above 1. The registry reports a two-sided p-value of 0.36 for this superiority analysis.

Composite of CV Death, HHF, Non-fatal MI and Non-fatal Stroke

Hazard ratio

0.72

95% CI: 0.56–0.92

The registry reports this endpoint as a time-to-event analysis in the ITT population, using a Cox proportional-hazards model. The reported confidence interval provides the registry-reported measure of precision around the hazard ratio.

Composite of HHF, Urgent HF Visit, CV Death, and HF While Hospitalized

Hazard ratio

0.68

95% CI: 0.54–0.86

This endpoint was analyzed with a Cox proportional-hazards model in the ITT population. The registry identifies region and ejection fraction as stratification factors and non-cardiovascular death as a competing event for this analysis.

Total Deaths From Any Cause

Hazard ratio

0.82

95% CI: 0.59–1.14

The registry reports a Cox proportional-hazards analysis in the ITT population. Unlike an endpoint restricted to cardiovascular death, all-cause mortality includes deaths from any cause. The ClinicalTrials.gov record does not provide a p-value for this analysis.

KCCQ-12 Change From Baseline at Month 4

Reported estimate

4.1

95% CI: 1.3–7

ANCOVA; baseline to Month 4

The registry states that the change from baseline to Month 4 was analyzed with ANCOVA, using treatment group as a factor and baseline KCCQ-12 score plus randomization stratification factors as covariates.

Registry labeling issue: the statistical-analysis record reports the effect measure for the KCCQ-12 ANCOVA as “Hazard Ratio (HR)” even though the analysis method is ANCOVA and the outcome unit is a score on a scale. The numerical estimate 4.1 and its 95% CI of 1.3–7 are therefore reproduced exactly as posted rather than reinterpreted as a different effect measure.

Change From Baseline in eGFR

Difference in Least Squares Means

−0.16

95% CI: −1.3–0.98

MMRM; baseline up to 21.9 months

The registry describes an MMRM with absolute change in eGFR from baseline as the outcome, a random intercept, and fixed effects for treatment, baseline value, and time. The reported effect measure is the difference in least squares means.

9. How to Read the Secondary Results

Relative event measures

The reported Cox hazard ratios for several cardiovascular and heart-failure endpoints are below 1, indicating lower estimated hazards for sotagliflozin under the corresponding models.

Cardiovascular mortality

The cardiovascular-death HR is 0.84 with a 95% CI of 0.58–1.22 and a p-value of 0.36, illustrating why the point estimate alone is not enough to characterize statistical uncertainty.

Patient-reported outcome

KCCQ-12 was analyzed using covariate-adjusted ANCOVA rather than a survival model, demonstrating that different endpoint types require different analytical frameworks.

Longitudinal renal outcome

eGFR was analyzed with an MMRM, which uses repeated observations over time rather than reducing the longitudinal record to a single time point.

10. Safety Results

The registry reports serious adverse events by randomized treatment arm using affected participants over the corresponding at-risk denominators.

Safety measureSotagliflozinPlacebo
Serious adverse events235/605251/611

Sotagliflozin

235 participants with serious adverse events among 605 participants at risk.

Placebo

251 participants with serious adverse events among 611 participants at risk.

The ClinicalTrials.gov record provides affected/at-risk counts rather than a formal between-group safety hypothesis test. Accordingly, this page does not attach a p-value or comparative effect estimate to the serious-adverse-event counts.

Safety interpretation: serious adverse events are an important component of the evidence but should not be collapsed into the efficacy analysis. The reported serious-adverse-event counts describe an observed safety outcome; they do not by themselves establish causality or provide a complete characterization of the safety profile.

11. Stratification and Covariate Adjustment

Stratification and covariate adjustment play different roles in the reported analyses. The Cox analyses use region and ejection fraction as stratification factors. The KCCQ-12 ANCOVA additionally adjusts for baseline KCCQ-12 score and randomization stratification factors.

AnalysisAdjustment / stratification specified in registryPurpose in interpretation
Primary Cox analysis Region and ejection fraction; non-CV death as competing event Defines the reported stratified survival-model comparison
Secondary Cox analyses Region and ejection fraction; non-CV death as competing event where specified Defines the corresponding time-to-event model
KCCQ-12 ANCOVA Baseline KCCQ-12 score and randomization stratification factors as covariates Accounts for baseline score and specified stratification variables when comparing change
eGFR MMRM Treatment, baseline value and time as fixed effects; random intercept Models repeated measurements over time

12. Time-to-Event Analysis and the Hazard Ratio

Several SOLOIST-WHF endpoints are represented in the registry as time-to-event analyses. The hazard ratio is a relative measure of the event hazard under a fitted survival model. It is particularly useful when follow-up times differ among participants and censoring occurs.

Conceptual interpretation
HR = estimated hazard in treatment group ÷ estimated hazard in comparator group

An HR below 1 indicates a lower estimated hazard in the treatment group under the model. An HR of 1 would correspond to equal hazards, while an HR above 1 would indicate a higher estimated hazard.

For the primary endpoint, the registry reports HR 0.67. This is a relative model-based measure. It is not an absolute event-rate difference, a risk ratio, a probability of avoiding hospitalization, or a statement about an individual participant's outcome.

Why person-years appear in the endpoint definition

The primary endpoint is described as total events per 100 person-years of follow-up. Person-time incorporates both the number of observed events and the amount of follow-up contributing to the analysis. This is particularly relevant when participants have different lengths of observation.

The ClinicalTrials.gov record does not provide Kaplan-Meier survival probabilities, median time-to-event estimates, cumulative-incidence curves, or participant-level event and censoring times. Those quantities are therefore not reconstructed here.

13. ANCOVA and Covariate Adjustment for KCCQ-12

The KCCQ-12 endpoint is fundamentally different from the recurrent cardiovascular event endpoint. It asks about change in a score from baseline to Month 4, so the registry uses ANCOVA rather than a time-to-event model.

Registered ANCOVA structure
Month 4 change = treatment effect + baseline KCCQ-12 + randomization stratification factors + residual variation

The registry specifies treatment group as a factor and baseline KCCQ-12 score plus randomization stratification factors as covariates.

Covariate adjustment can improve precision when baseline measurements explain part of the variation in the follow-up outcome. The important statistical distinction is that the treatment comparison is still based on randomized groups; the ANCOVA specifies how the continuous outcome is modeled.

14. MMRM for eGFR

The eGFR analysis illustrates a third statistical framework. Rather than analyzing only one follow-up measurement, the registry describes a mixed model for repeated measures using absolute change from baseline as the outcome.

Repeated observations

MMRM is designed for outcomes observed repeatedly over time, allowing the analysis to use the longitudinal structure rather than treating each time point as an unrelated analysis.

Random intercept

The registry specifies a random effect for the intercept, allowing the model to account for participant-level variation in the longitudinal outcome.

Fixed effects

Treatment, baseline value, and time are specified as fixed effects in the registered analysis description.

Reported estimate

The effect measure is the difference in least squares means: −0.16, with a 95% CI of −1.3 to 0.98.

The confidence interval spans zero, which is the reference value for a difference. The ClinicalTrials.gov record does not provide a p-value for this analysis, so no additional significance statement is assigned here.

15. Multiplicity and the Collection of Endpoints

SOLOIST-WHF has one registered primary endpoint and multiple secondary endpoints. The ClinicalTrials.gov record identifies the hypothesis type as superiority, but they do not provide an alpha-allocation strategy, hierarchical testing procedure, multiplicity-adjustment method, or interim-analysis alpha-spending plan.

Endpoint roleNumber reported in the ClinicalTrials.gov recordInterpretive role
Primary endpoint1Primary superiority comparison
Secondary statistical analyses7Additional efficacy and clinical outcome assessments
Total statistical analyses posted8Primary plus secondary analyses
Multiplicity caution: multiple secondary endpoints create multiple opportunities to observe statistically unusual results. The ClinicalTrials.gov record does not state how, or whether, multiplicity across these secondary endpoints was controlled. Therefore, the individual estimates should be interpreted as the reported analyses rather than automatically treating every secondary p-value as an independent confirmatory test.

16. Missing Data and Analysis Assumptions

The ClinicalTrials.gov record identifies the ITT population and the statistical methods, but they do not provide a missing-data or imputation strategy for the primary endpoint, KCCQ-12, or eGFR analysis.

That absence matters because different endpoint types create different missing-data problems. A time-to-event analysis can use available follow-up until an event or censoring, whereas a longitudinal score such as KCCQ-12 can be affected by missing Month 4 assessments. An MMRM similarly relies on assumptions about the observed longitudinal data and the missingness mechanism.

The ClinicalTrials.gov record does not provide enough information to determine the precise imputation or sensitivity-analysis framework. No such method is therefore attributed to the trial here.

17. Interim Analysis, Crossover, and Bayesian Methods

The ClinicalTrials.gov record does not report an interim-analysis method, crossover design, factorial structure, or Bayesian statistical method.

Design topicWhat the ClinicalTrials.gov record supports
Interim analysisNot reported in the ClinicalTrials.gov record.
Alpha spendingNot reported in the ClinicalTrials.gov record.
CrossoverNot reported in the ClinicalTrials.gov record.
Factorial designNo; the registered design model is parallel.
Bayesian methodsNot reported in the ClinicalTrials.gov record.
Non-inferiority marginNot applicable to the reported superiority hypothesis; no non-inferiority margin is reported.

18. Study Status and Premature Termination

The registry status is TERMINATED. The registry-reported limitations field states that the study was terminated prematurely due to a business decision.

Statistical consequence of premature termination: premature termination can affect the amount of information accumulated before the study ends. The ClinicalTrials.gov record specifically flag the possibility of small numbers of participants analyzed or technical problems leading to unreliable data. This is an important limitation when interpreting the reported estimates and their precision.

The registry also identifies limitations of the trial such as small numbers of participants analyzed or technical problems leading to unreliable data. Because the ClinicalTrials.gov record does not quantify these issues beyond that statement, this page does not assign an additional numerical adjustment or sensitivity estimate.

19. Limitations

20. Why This Trial Matters Statistically

SOLOIST-WHF is a useful statistical teaching case because a single randomized trial contains several distinct outcome structures and therefore several distinct analytical frameworks. The primary endpoint combines recurrent cardiovascular and heart-failure events, while secondary outcomes extend the analysis to mortality, additional composite events, a patient-reported score, and longitudinal renal function.

Statistical conceptHow it appears in SOLOIST-WHF
RandomizationRandomized allocation in a two-arm parallel design.
BlindingQuadruple masking.
Intention-to-treat analysisITT population includes all randomized participants.
Time-to-event analysisUsed for the primary and several secondary cardiovascular endpoints.
Hazard ratioPrimary effect measure and effect measure for multiple secondary Cox analyses.
Stratified analysisPrimary Cox model stratified by region and ejection fraction.
Competing riskNon-cardiovascular death treated as a competing event in the reported Cox analyses.
ANCOVAUsed for change from baseline in KCCQ-12 at Month 4.
Covariate adjustmentBaseline KCCQ-12 and randomization stratification factors included in the KCCQ-12 ANCOVA.
MMRMUsed to analyze change in eGFR over time.
Confidence intervalsReported for all eight statistical analyses in the ClinicalTrials.gov record.
Superiority testingRegistered hypothesis type for the primary and reported secondary analyses.

21. A Statistical Reading of the Primary Result

Estimate

The primary HR of 0.67 is a relative measure. Under the specified marginal Cox model, the estimated hazard in the sotagliflozin group is 0.67 times that in the placebo group.

Precision

The 95% CI of 0.52–0.85 shows the uncertainty around that estimate. It is substantially more informative than the point estimate alone because it indicates how precisely the treatment effect was estimated under the statistical framework.

Evidence against the null

The reported two-sided P < 0.001 indicates strong evidence against the null hypothesis used for the superiority comparison. It should not be interpreted as a probability that the treatment effect is exactly a particular size.

Absolute versus relative effects

The registry's primary result is presented as a hazard ratio rather than an absolute risk difference. Without additional event totals, cumulative incidence estimates, or other absolute measures in the ClinicalTrials.gov record, an absolute treatment effect should not be calculated or inferred.

22. Primary and Secondary Results in Context

The reported results show that the statistical evidence is not uniform across every endpoint. Several composite cardiovascular and heart-failure outcomes have hazard ratios below 1 with confidence intervals entirely below 1, whereas the cardiovascular-death analysis has an HR of 0.84 with a confidence interval extending above 1. The eGFR analysis likewise has a confidence interval that crosses zero.

This pattern illustrates why a clinical-trial statistical review should examine the endpoint definition, estimand, analysis method, effect estimate, confidence interval, and testing framework together. A collection of point estimates cannot be interpreted correctly without knowing what each endpoint measures and how it was analyzed.

QuestionPrimary endpointSecondary endpoint example
What is being measured?Total occurrences of CV death, HHF and urgent HF visitsChange in KCCQ-12 at Month 4
Outcome structureEvent-based / time-to-eventContinuous change score
ModelMarginal Cox proportional-hazards modelANCOVA
Effect measureHazard ratioRegistry labels estimate as HR despite ANCOVA method
Primary estimate0.674.1

23. Related Tutorials

Learn more about the statistical methods used in this trial:

24. Related Calculators

25. Sources

Continue with the statistical methods behind the trial

Explore the underlying survival, regression, longitudinal, and clinical-trial methods used to analyze endpoints such as those in SOLOIST-WHF.

26. Record Summary

SOLOIST-WHF provides a useful example of how a randomized clinical trial can require several statistical frameworks within one analysis plan. Its primary endpoint combines total occurrences of cardiovascular death, hospitalization for heart failure, and urgent heart-failure visits, including first and potentially subsequent occurrences. The primary analysis uses a marginal Cox proportional-hazards model stratified by region and ejection fraction, with non-cardiovascular death treated as a competing event.

The reported primary hazard ratio is 0.67 with a two-sided 95% CI of 0.52–0.85 and P < 0.001. Secondary analyses extend the statistical story to additional heart-failure and mortality endpoints, KCCQ-12 change analyzed by ANCOVA, and eGFR change analyzed by MMRM. The reported serious-adverse-event counts were 235/605 for sotagliflozin and 251/611 for placebo.

The most important statistical lesson is that these results should not be reduced to a single number. The primary hazard ratio, its confidence interval, the recurrent-event endpoint definition, competing-risk treatment, ITT population, stratification, secondary endpoints, ANCOVA adjustment, MMRM structure, and premature termination all contribute to the correct interpretation of the evidence.

Clinical Biostats methodology: A trial-results page should distinguish the numerical result from the statistical model that generated it. For SOLOIST-WHF, that distinction is especially important because the registry combines recurrent cardiovascular events, mortality endpoints, a patient-reported outcome, and a longitudinal renal measure under different statistical methods.