Overall, the effects of hearing loss prevention programs are unclear.[24] Better use of hearing protection as part of a program but does not necessarily protect against hearing loss. The 2017 Cochrane review concluded that in order to prevent NIHL in the workplace the quality of the implementation of prevention programs, particularly on the hearing protection component of the program, affects results, and that better quality of studies, especially in the field of engineering controls, and better implementation of legislation are needed. While the review concluded there is a lack of conclusive evidence it highlighted that this should not be interpreted as evidence of lack of effectiveness.