“…In all eligible studies, the investigators used large administrative data sets and performed secondary data analysis, although one group of researchers also corroborated their methods with a developed survey and chart reviews (Bardenheier, Shefer, McKibben, Roberts, & Bratzler, 2004). In five studies, researchers used the MDS along with the Online Survey Certification and Reporting (OSCAR) database (Bardenheier, Gravenstein, Furlow, Ahmed, & Hogue, 2013;Bardenheier, Wortley, Ahmed, Gravenstein, & Hogue, 2011;Bardenheier, Wortley, Ahmed, Hales, & Shefer, 2010;Cai, Feng, Fennell, & Mor, 2011), in one study, the researcher used only the MDS (Bardenheier, Wortley, Shefer, McCauley, & Gravenstein, 2012), and in seven studies the researchers used the National Nursing Home Survey (NNHS) (Bardenheier, Shefer, et al, 2011;Bardenheier, Shefer, Tiggle, Marsteller, & Remsburg, 2005;Li & Mukamel, 2010;Luo, Zhang, Cook, Wu, & Wilson, 2014;Marsteller, Tiggle, Remsburg, Shefer, & Bardenheier, 2006;Marsteller et al, 2008;Strully, 2011). Each data source is described below along with the variables used in the studies reviewed.…”