Ahern, Thomas P; Bosco, Jaclyn LF; Silliman, Rebecca A; Yood, Marianne Ulcickas; Field, Terry S; Wei, Feifei; Lash, Timothy L
(Dove Medical Press, 2009-8-9)
BACKGROUND: Comorbidity indices summarize complex medical histories into concise ordinal scales, facilitating stratification and regression in epidemiologic analyses. Low subject prevalence in the highest strata of a ...