Table 1 Independent variables in study
From: Bariatric surgery implementation trends in the USA from 2002 to 2012
Variable name | Definition | Source |
|---|---|---|
Environmental variables | ||
 Proportion of eligible patients | State-wide percent obesity | BRFSS [25] |
 CMS payment policy, NCD | Year prior to National Coverage Decision (NCD) or year post-NCD, a key regulatory legislation of 2006 that limited the eligibility of Medicare patients to specific types of bariatric surgery performed in certified centers of excellence [29] | CMS [29] |
 Volume of previous surgeries | Cumulative total volume of previous bariatric surgery rates | AHRQ HCUP SID [24] |
 Recession | Recession was present in 2001 and December 2007–June 2009 | Bureau of Labor Statistics [27] |
Population characteristics | ||
 Diabetes | State-wide percent diabetes | BRFSS [25] |
 Age | State-wide percent in age group 30–39, 40–49, 50–59, 60–69 | US Census Bureau [26] |
 Race | State-wide percent black | US Census Bureau [26] |
 Ethnicity | State-wide percent Hispanic | US Census Bureau [26] |
 Insurance coverage | State-wide percent private insurance | US Census Bureau [26] |
 Income | State-wide median family income | US Census Bureau [26] |
 Education | State-wide percent high school diploma or lower | US Census Bureau [26] |
Medical practice characteristics | ||
 MD champion | Number of published peer-review journals on bariatric surgery per state | Pub Med Systematic Literature Review |
 Number of CMS centers of excellence (COE) | Number of state-wide CMS centers of excellence | CMS [28] |