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Figure 1 Hazard Periods for Case-Crossover Analysis

The green-shaded portion of the timeline represents the hazard period during or after a driving episode. If an implantable cardioverter-defibrillator (ICD) discharge occurred during this window, the patient was considered exposed in the primary analysis. In secondary analyses, we examined the relative risk of ICD discharge within the 3 separate shaded components of the hazard period: the period during driving (A), the first 30-min interval (B), and the second 30-min interval (C) after a driving episode.