['To determine the effect of a practice guideline on the process of ED care in a health maintenance organization.', 'A prepost-intervention comparison with a one-year pre-intervention phase followed by a one-year post-educational intervention phase was used to study the effect of the guideline on ED care. Emergency physicians and nurses were provided the details of the guideline during a two-week interval between the two periods.', 'During the two years of the study, 1,140 pre-intervention and 759 post-intervention patients met study eligibility criteria. More patients were diagnosed as having had falls due to loss of consciousness, stroke, and seizures during the post-intervention period (pre-intervention 3.8% vs post-intervention 8.4%, p < 0.001). There was a significant improvement in documentation of six of ten history items: cause of fall (64.5% vs 72.9%), location of fall (54.7% vs 60.5%), ability to get up unassisted (5.4% vs 12.5%), long lie after fall (1.5% vs 10.1%), prescription medications (79.0% vs 92.2%), and Pneumovax immunization status (20.8% vs 43.0%); and two of the four physical examination items: visual acuity (1.5% vs 3.2%) and the "get up and go test" (1.3% vs 11.2%). Prescribing of calcium and vitamin D increased from 0% to 6.6%.'] Does effect of a practice guideline on the process of emergency department care of fall in elder patients?