Read the paper at https://academic.oup.com/aje/article/189/12/1573/5859287
Models to Assess the Association of a Semiquantitative Exposure With Outcomes
A semiquantitative risk factor has 2 components: any exposure (yes/no) and the quantitative amount of exposure (if exposed). We describe the statistical properties of alternative analyses with such a risk factor using linear, logistic, or Cox proportional hazards models.