title: Extending gerontological research through linking investigators' studies to public-use datasets.
abstract: OBJECTIVE
  Public-use datasets can extend data collected by individual investigators in various ways: making external comparisons, providing additional data on individual respondents, and creating internal comparison groups. The authors describe the advantages and limitations of these methods and practical and conceptual issues in combining investigator-initiated and public-use datasets.
  
  
  METHODS
  These issues are illustrated with a study of functional decline among 674 patients following hospitalization for hip fracture that was augmented with data from a public-use dataset, the Established Populations for Epidemiologic Studies of the Elderly (EPESE).
  
  
  RESULTS
  By creating an internal comparison group of EPESE respondents, frequency matched to hip fracture patients on age, sex, and baseline functional limitations, the authors formed a single dataset and performed multivariable analyses of factors associated with functional decline.
  
  
  CONCLUSIONS
  Gerontological research may benefit by applying these methods to program evaluations and longitudinal analyses of health outcomes with numerous public-use datasets.
authors.affiliation: Department of Epidemiology and Biostatistics, Boston University School of Public Health, MA 02118, USA. lfredman@bu.edu
authors.forename: L
authors.initials: L
authors.lastname: Fredman
authors.forename: W
authors.initials: W
authors.lastname: Hawkes
authors.forename: S I
authors.initials: SI
authors.lastname: Zimmerman
authors.forename: J R
authors.initials: JR
authors.lastname: Hebel
authors.forename: J
authors.initials: J
authors.lastname: Magaziner
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection; D003627:Data Interpretation, Statistical; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment; D006620:Hip Fractures / Q000534:rehabilitation*; D006760:Hospitalization; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D012737:Sex Factors; D000071939:Stroke Rehabilitation; D016019:Survival Analysis; D013997:Time Factors