PT - JOURNAL ARTICLE AU - Michael C. Klein TI - Association Not Causation: What Is the Intervention? AID - 10.1370/afm.729 DP - 2007 Jul 01 TA - The Annals of Family Medicine PG - 294--297 VI - 5 IP - 4 4099 - http://www.annfammed.org/content/5/4/294.short 4100 - http://www.annfammed.org/content/5/4/294.full SO - Ann Fam Med2007 Jul 01; 5