<Li> Some authors questioned the generalizability of comparisons of HMO and FFS care since data on the former were based on a "single, relatively small but well - managed" HMO in Seattle . </Li> <Li> One 2007 article suggested that the "large number of participants who voluntarily dropped out of the costsharing arms of the experiment" could have invalidated the RAND HIE's findings . In response, Newhouse and colleagues described the argument as "implausible". </Li> <Li> The RAND HIE did not study people without health insurance, so it could not determine how the presence or absence of health insurance affects health . </Li> <P> Nevertheless, the study opened the way for increased cost - sharing for medical care in the 1980s and 1990s . </P>

A major finding in the rand study is