Gradient Biotech

Cohort outcomes

Compare a binary outcome between groups and analyze time-to-event, with effect sizes and explicit censoring reported alongside significance.

Research question

Do outcomes differ between two cohorts, and how do survival or time-to-clearance curves compare — as associations, not causal effects?

Who this is for

  • Infectious-disease researchers comparing treatment, exposure, or pathogen groups
  • Hospital epidemiology teams evaluating intervention-associated outcomes
  • Analysts needing risk ratios, odds ratios, and Kaplan-Meier curves

Data requirements

DataRequiredPurpose
Episodes with a grouping attributeYesDefines the two cohorts to contrast
Outcomes with event_observedYes (comparison)Binary risk, risk ratio, odds ratio, tests
Outcomes with time_to_event_daysYes (survival)Kaplan-Meier and log-rank

Workflow

Model episodes and outcomes → Cohort comparison (RR/OR + test)
  → Outcome analysis (Kaplan-Meier + log-rank)
  → AI interpretation

Step 1 — Cohort comparison

The Cohorts page compares a binary outcome between groups defined by a participant or episode attribute, reporting per-group risk, risk ratio, odds ratio, and a chi-square or Fisher test. Effect estimates are associational, never causal.

Step 2 — Time-to-event

The outcome analysis fits Kaplan-Meier survival with explicit censoring and, when a stratifying attribute is supplied, a log-rank test between strata.

Expected outputs

  • Per-group risk, risk ratio, and odds ratio with a p-value
  • Kaplan-Meier survival curves, overall and by stratum
  • Log-rank statistic and p-value between the first two strata

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