title: Quasi-experimental evaluation without regression analysis.
abstract: Evaluators of public health programs in field settings cannot always randomize subjects into experimental or control groups. By default, they may choose to employ the weakest study design available: the pretest, posttest approach without a comparison group. This essay argues that natural experiments involving comparison groups are within reach of public health program managers. Methods for analyzing natural experiments are discussed.
authors.affiliation: Employee and Community Health, Mayo Clinic-Rochester, 200 First St SW, Rochester, MN 55905, USA. rohrer.james@mayo.edu
authors.forename: James E
authors.initials: JE
authors.lastname: Rohrer
mesh_terms: D003627:Data Interpretation, Statistical; D006302:Health Services Research / Q000379:methods*; D006801:Humans; D015397:Program Evaluation / Q000379:methods*; D011634:Public Health / Q000379:methods*; D012044:Regression Analysis