intermittent users (used a program
≥2 times in 1 or more years enrolled but not all years), or nonusers
of EnhanceFitness or Silver Sneakers. The main outcome
was measured as time-to-first-fall requiring inpatient or out-ofhospital
medical treatment based on the International Classification
of Diseases, 9th Revision, Clinical Modification, Sixth Edition
and E-codes.