TY - JOUR
T1 - A graphical method for assessing risk factor threshold values using the generalized additive model
T2 - The multi-ethnic study of atherosclerosis
AU - Setodji, Claude Messan
AU - Scheuner, Maren
AU - Pankow, James S.
AU - Blumenthal, Roger S.
AU - Chen, Haiying
AU - Keeler, Emmett
N1 - Funding Information:
Acknowledgments The authors would like to thank the MESA investigators and staff for their flexibility on the use of their data for this work and the participants of the MESA study for their valuable contributions. This work was supported by the National Heart, Lung, and Blood Institute Grant 1 R21 HL081175-01A1. MESA was supported by contracts N01-HC-95159 through N01-HC-95165 and N01-HC-95169 from the National Heart, Lung, and Blood Institute.
PY - 2012/3
Y1 - 2012/3
N2 - Continuous variable dichotomization is a popular technique used in the estimation of the effect of risk factors on health outcomes in multivariate regression settings. Researchers follow this practice in order to simplify data analysis, which it unquestionably does. However thresholds used to dichotomize those variables are usually ad-hoc, based on expert opinions, or mean, median or quantile splits and can add bias to the effect of the risk factors on specific outcomes and underestimate such effect. In this paper, we suggest the use of a semi-parametric method and visualization for improvement of the threshold selection in variable dichotomization while accounting for mixture distributions in the outcome of interest and adjusting for covariates. For clinicians, these empirically based thresholds of risk factors, if they exist, could be informative in terms of the highest or lowest point of a risk factor beyond which no additional impact on the outcome should be expected.
AB - Continuous variable dichotomization is a popular technique used in the estimation of the effect of risk factors on health outcomes in multivariate regression settings. Researchers follow this practice in order to simplify data analysis, which it unquestionably does. However thresholds used to dichotomize those variables are usually ad-hoc, based on expert opinions, or mean, median or quantile splits and can add bias to the effect of the risk factors on specific outcomes and underestimate such effect. In this paper, we suggest the use of a semi-parametric method and visualization for improvement of the threshold selection in variable dichotomization while accounting for mixture distributions in the outcome of interest and adjusting for covariates. For clinicians, these empirically based thresholds of risk factors, if they exist, could be informative in terms of the highest or lowest point of a risk factor beyond which no additional impact on the outcome should be expected.
KW - Generalized additive model
KW - Recycled prediction
KW - Smearing estimates
KW - Threshold detection
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U2 - 10.1007/s10742-012-0082-1
DO - 10.1007/s10742-012-0082-1
M3 - Article
C2 - 22593642
AN - SCOPUS:84862791726
SN - 1387-3741
VL - 12
SP - 62
EP - 79
JO - Health Services and Outcomes Research Methodology
JF - Health Services and Outcomes Research Methodology
IS - 1
ER -