 To be sure, there can be no doubt that disability incurs additional personal and social costs in the form of impairment-related resources such as assistive technology (wheelchairs, hearing aids, and augmented communication devices); changes to make their world more accessible (curb cuts, audible stop lights, elevators, accessible toilets and disability parking); and social services such as income maintenance, disability pensions and vocational rehabilitation. By the same token the health care needs of persons with disabilities may be more costly to provide, given potential complications and co-morbidities as well as the accommodations that may be required to ensure access to health care (for example, that examination tables can accommodate persons with complete lower body paralysis). Because of this, however, people with disabilities will always have to face the converse of the indirect benefits problem: as a population, they incur health and non-health costs that, if factored into the cost of the health improvement associated with a health resource, would tilt the CEA efficiency calculation against them.