"Proportional hazards" refers to a concept in statistics that measures how different factors can affect the likelihood of an event happening. It means that the relationship between these factors remains constant over time. Full definition
They analyzed four types of antihypertensive drugs: beta blockers, diuretics, angiotensin converting enzyme inhibitors (ACEi), and CCBs, and used Cox proportional hazard regression models to obtain hazard ratios for the association of the four types of medication with risk of pancreatic cancer. (aacr.org)
Cox Proportional Hazard Ratios (HR) for Sensitivity Analyses Including the Obese and Those With Major Risk Factors (jamanetwork.com)
Data analysis involved cox proportional hazards, generalized estimating equations models and Kaplan - Meier analysis. (sciencedaily.com)