title: Repeat emergency medical services use by older adults in a rural community: impact on research methods and study length.
abstract: OBJECTIVE
  To evaluate the proportion of emergency medical services (EMS) requests in a rural community made by unique, noninstitutionalized older adults, or individuals making their first request for EMS assistance during the study period, and the impact on research parameters.
  
  
  METHODS
  This study was a retrospective chart review of patients aged 65 years and older cared for by the Geneseo Fire Department Ambulance between February 2004 and May 2005 (period 1) and between July 2006 and October 2007 (period 2). The Geneseo Fire Department Ambulance response territory is a rural community in Upstate New York. We obtained demographic information including age, race, gender, call location, and the frequency of EMS use from the medical record, as well as clinical information including level of prehospital care, chief complaint, and disposition. Descriptive statistics were used for the analysis, along with 95% confidence intervals.
  
  
  RESULTS
  Over two 16-month periods, approximately 70% of the EMS calls by community-dwelling (noninstitutionalized) older adults were from unique individuals. The monthly proportion ranged from 75-100% during the first four months to 43-80% for the remaining 12 months for both groups.
  
  
  CONCLUSIONS
  In rural, prehospital studies that enroll older adults and last more than four months, approximately 70% of EMS requests are made by unique older adults, or individuals making their first request for EMS assistance. Investigators must consider these results when estimating the enrollment period for prehospital studies.
authors.affiliation: Department of Emergency Medicine, University of Rochester Medical Center, Rochester, New York, USA. manish.shah@rochester.edu
authors.forename: Manish N
authors.initials: MN
authors.lastname: Shah
authors.forename: Peter
authors.initials: P
authors.lastname: Swanson
authors.forename: Karthik
authors.initials: K
authors.lastname: Rajasekaran
authors.forename: Ann
authors.initials: A
authors.lastname: Dozier
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003153:Community Health Services / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D009518:New York; D012106:Research; D012189:Retrospective Studies; D019035:Rural Health Services / Q000706:statistics & numerical data*; D013997:Time Factors