To determine the effect of black belt use on the incidence
of low back injury in home attendants, a cluster-randomized
trial involving employees of nine home attendant
agencies in New York City was conducted. Nine agencies
employing 12,772 home attendants between June 1997
and September 1999 were randomized into three
groups-one group received back belts with use instruction,
one group received lifting advice only, and one
group served as a control. I.ow back injury rates per 100
full-time equivalents and rate ratios adjusted for potential
confounders were estimated with random-effects Poisson
regression. The back-belt group had a lower rate of low
back injury than did those in both the advice-only and
control groups, though the differences were marginally
significant. Age, body mass index, history of back injury,
years worked as a home attendant, and level of exercise
were associated with risk of low back injury. The findings
suggest that use of back belts is associated with some
reduction in risk of low back injury.