Reflections on biased selection and future directions.
D003256:Community Participation / Q000191:economics*; D003657:Decision Making; D006264:Health Benefit Plans, Employee / Q000706:statistics & numerical data*; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data*; D006801:Humans; D007348:Insurance, Health / Q000706:statistics & numerical data*; D014481:United States