Three separate methods are used to identify FRIs in the claims data. Method 1 (the e-code only, or “ECO” method) is the one commonly used to identify FRIs in claims data and typically involves the ICD-9 e-codes 880, 881, 882, 884, 885, or 888.3 (link),6 (link),10 (link),16 (link)-20 Method 2 (e-code and diagnostic code, or “ECDC” method) uses the above e-codes plus a broad set of primary inpatient diagnostic codes indicating fractures, dislocations, sprains, strains, head injuries, and contusions (ICD-9 diagnostic codes 800-848, 850-854, and 920-924).4 (link),5 (link),10 (link) Method 3 (the adapted UCLA/RAND, or “AUR” method) employs an adaptation of the algorithm that identified ICD-9 inpatient primary diagnosis codes (for hip fractures, other nonvertebral fractures, head trauma, joint dislocations, and injuries identified by the above e-codes) as well as outpatient Current Procedural Terminology (CPT) codes (for imaging and repair procedures) as fall injuries.15 (link), 51 (link) To identify index FRIs, each of the three methods uses e-codes from inpatient, outpatient, and SNF claims data; the ECDC method and AUR methods additionally use ICD-9 codes from the Carrier file while the AUR method further uses CPT codes from outpatient settings. See Table 1 for additional details, including analytic sample sizes and size of FRI cohort using each identification method; note that differing total sample sizes resulted from use of the “washout” period—or 12-month period of time without an FRI required for inclusion in either of the cohorts—that excluded different numbers of respondents using each FRI identification method.