Parikh R, Taychakhoonavudh S, White C, Franzini L. Sources of spending variation in professional services among Texas Hospital Referral Regions: an analysis of private insurance population. Poster presented at the 2011 ISPOR 16th Annual International Meeting; May 2014. Montreal, Canada. [abstract] Value Health. 2014 May; 17(3):A18. doi: 10.1016/j.jval.2014.03.116