Table 2.
Study | Unmeasured confounder simulated |
Source of bias parameter estimates |
Type of probability distribution assigned to bias parameters* |
Bias parameters for which assigned range of values were reported† |
Simulated iterations |
---|---|---|---|---|---|
Cohort studies | |||||
Albert et al. (2012)30 | Use of endocrine therapy (Binary) |
Not reported | Not reported | Prevalence of confounder in exposed and unexposed |
Not reported |
Bannister-Tyrell et al. (2014)31 | Severe labor pain intensity (Binary) |
Expert judgement (prevalence); prior studies (association) |
Trapezoidal | Prevalence of confounder in exposed and unexposed; association between confounder and outcome |
10,000 |
Corrao et al. (2011)32 | Depression (Binary) |
Prior studies | Not reported | Not reported | Not reported |
Corrao et al. (2014)33 | Obesity (Binary) |
Prior studies | Not reported | Not reported | Not reported |
Corrao et al. (2014)34 | Severity of hypercholesterolemia (Binary) |
Prior study | Not reported | Not reported | Not reported |
Case-control studies | |||||
Corrao et al. (2011)29 | Severity of hypertension; CDS; BMI (Multinomial) |
External dataset (prevalence); expert judgement |
Normal | Association between confounder and outcome |
5,000 |
Corrao et al. (2013)35 | Severe hypercholest- erolemia (Binary) |
Prior studies | Not reported | Not reported | Not reported |
Ghirardi et al. (2014)36 | Severity of osteoporosis (Binary) |
Not reported | Not reported | Not reported | Not reported |
Schmidt et al. (2010)37 | Smoking (Binary) |
Prior studies | Not reported | Association between confounder and outcome |
Not reported |
See eFigure 1 in the online supplementary appendix for further description of probability distribution types.
Bias parameters for unmeasured confounding include confounder prevalence in exposed and unexposed and strength of association between the confounder and outcome. We report whether investigators discussed the range of plausible values assigned to bias parameters