For the investigation of a possible dose response relationship between psoriasis and MetS, medication was used as a surrogate marker of psoriasis severity (continuous variable of disease severity: 1, no prescription; 2, prescription without systemic medication; 3, prescription with systemic medication), and WChigher as a surrogate end point of MetS in the age-adjusted logistic regression model.
Numerical relationships between Odds ratio and PAR% of continuous markers and their RPB based on the data of three studies.
Hence, we encourage researchers to analyse and report results (e.g. hazard ratio) of continuous markers on their original continuous scale.
Glycated hemoglobin (HbA1c) is a continuous marker of glycemia, and levels >5.7% (39 mmol/mol) are associated with increased risk for developing type 2 diabetes as well as micro- and macrovascular events (1).
In order to use the proliferation metagene as a continuous marker of proliferation, we excluded all genes with a high correlation to the proliferation metagene (correlation >0.5) from the analysis prior to clustering.
Lipid accumulation product (LAP), a continuous marker of lipid over-accumulation calculated by using the waist circumference and triglyceride levels, has recently been proposed to be a good predictor for cardiovascular disease [ 19] and diabetes [ 20].
In model 1, we adjusted for age, BMI, BC, and apparent temperature (a marker of perceived temperature) as continuous variables as well as smoking status (never, current, former) and season of clinical visit (spring: March May; summer: June August; fall: September–November; winter: December February).
Indeed, the most appropriate analysis of continuous prognostic markers may require nonlinear modelling techniques, as highlighted by Sauerbrei et al (1999); consultancy with statisticians or others experienced with such techniques is recommended in this situation.
The main difficulty is that the huge number of markers in a metagenome-wide association study prevents the exhaustive search of combinations of microbial markers, and the continuous form of such markers prevents the application of highly efficient computational tricks such as bit-wise operations that have been adopted in existing methods in genome-wide studies.
