The illusion of improved physical fitness and reducedmortality

Journal Article · Wed Sep 18 00:00:00 EDT 2002 · Medicine and Science in Sports and Exercise

OSTI ID:894965

gov, PTWilliams@lbl

Recent claims that men who increase cardiorespiratoryfitness over time lower their mortality risk may be largely explained bystatistical artifact. The claims are based on prospective epidemiologicalstudies that compare the difference in fitness between two separatebaseline surveys, separated in time, with subsequent mortality. In onecase we show that the imprecision of the fitness measurement alone (i.e.,measurement error) is sufficient to produce an apparent risk reduction of55 percent in initially unfit men who get reclassified as fit in asubsequent clinic visit. This statistical artifact will apply to otherstudies that use this design.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Director, Office of Science; National Institutes ofHealth
• DOE Contract Number: DE-AC02-05CH11231; NIH:HL-58621
• OSTI ID: 894965
• Report Number(s): LBNL-51505; R&D Project: 862T1A; BnR: 400412000
• Journal Information: Medicine and Science in Sports and Exercise, Vol. 35, Issue 5; Related Information: Journal Publication Date: 2003
• Country of Publication: United States
• Language: English

Related Subjects

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statistics measurement error fitness