Mortality in active adults age 70-79 years in relation to performance in a long-distance corridor walk

The authors conducted the source study to determine if a brisk corridor walk of 400 meters could be used to classify the performance of active older adults and relate this performance to mortality and other outcomes over a 6-year follow-up. The cohort consisted of 3075 adults resident in designated ZIP codes in Pittsburgh, Pa, and Memphis, Tenn, participating in the Health Aging and Body Composition Study. Out of this cohort, 395 subjects were excluded after evaluation revealed abnormal vital signs or ECG findings, recent cardiac symptoms, recent surgery, recent chest pain, shortness of breath or fainting. Another 356 subjects were unable to complete the 400-meter walk. The 2324 subjects who completed the walk were divided into quartiles according to the time in seconds required for completion (the overall time required ranged widely from 201 to 942 seconds). These 3 groups were designated as "excluded," "stopped," and "completed." Outcomes reported for the 3075 subjects in the total cohort included mortality, new cardiovascular disease events, mobility limitation, and mobility disability. Cardiovascular events were reported for the 2234 subjects (73% of the total) who were free of cardiovascular disease at entry. Results in the article were given in tables and figures and included numbers of entrants, exposures, and events, annual event rates and hazard ratios with SDs. Out of the 3075 entrant subjects, 430 died in the 6 years of follow-up (FU). Excess mortality measured as excess death rate (EDR) was much higher in the excluded and stopped groups (about 22 per 1000 per year) compared with an EDR of 6.4 per 1000 in the completed group. The corresponding mortality ratios (MR), designated as a hazard ratio in the article were about 220% and 135%. Results for comparative morbidity are also given in this abstract.