Fig. 1From: The effect of second hand smoke in patients with squamous cell carcinoma of the head and neckCox proportional hazard model for recurrence (months). This plot estimates the cumulative hazard function for cancer recurrence among patients based on exposure to SHS. The hazard ratio for cancer recurrence among patient exposed to SHS is 2.36 (95% CI 1.06–5.26)Back to article page