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Li Y, Cai X, Glance LG, Spector WD, Mukamel DB.Li Y, et al. Among authors: spector wd.Health Serv Res. 2009 Feb;44(1):79-102. doi: 10.1111/j.1475-6773.2008.00910.x.Health Serv Res. 2009.PMID: 19146565Free PMC article.