Predictors of Adoption of at least a “Basic” Electronic Medical Record System.*

*In this analysis, we used adoption of a “basic” electronic medical record system as the outcome. This definition was taken from Jha and DesRoches, and required a system to include electronic management of demographic information, computerized provider order entry, and lab and imaging results [3], [4]. We began our analysis by conducing bivariate analyses, to determine which of a series of candidate predictors appeared to have a relationship with the outcome variable. We used the following candidate predictors: patient age, gender, race/ethnicity, and source of payment, and, at the hospital level, region, metropolitan vs. non-metropolitan (i.e. urban vs. rural), ownership, and teaching status. Candidate predictors were eliminated from further consideration if bivariate chi-squared testing resulted in a p-value≥0.20. Remaining candidate predictors were fitted to a multivariate logistic regression model, constructed via stepwise backward elimination until all remaining independent covariates had p

本分析以「基础型」电子病历系统（electronic medical record system）的采纳情况作为结局变量。该定义源自Jha与DesRoches的研究，要求系统需包含人口统计学信息电子化管理、计算机化医师医嘱录入（computerized provider order entry）以及检验与影像结果管理功能[3][4]。本分析首先开展双变量分析，以筛选出与结局变量存在关联的一系列候选预测因子。本次研究所采用的候选预测因子包括：患者年龄、性别、种族/族裔、支付来源；以及医院层面的区域属性、都市与非都市（即城市与乡村）分类、医院所有制类型与教学资质。若双变量卡方检验的p值≥0.20，则该候选预测因子将被排除，不再纳入后续分析。将剩余候选预测因子拟合至多变量逻辑回归模型，通过逐步向后消元法构建模型，直至所有剩余独立协变量的p值。