Part I: Impairment statistics Vision Blindness in both eyes, visual impairment in eyes, blindness in one eye accompanied by visual impairment in the other eye and blindness or visual impairment in one eye causes activity limitation for 1,294,000 people. Its recency (proportion with onset in the past year) is 5.4 percent, significantly lower than the average for all conditions (10.7 percent), signifying a higher degree of chronicity. As a cause of activity limitation, visual impairment is more prevalent than blindness and is more likely to be mentioned as a secondary cause of limitation. It should be noted that the coding is based on the stated cause of limitation - "blind," "can't see," "low vision," "trouble reading," etc. - and whether one or both eyes are involved. The survey questionnaire does not follow the usual refinement that the impairment must be present even when using corrective lenses. The "correction" refinement is important when ascertaining the presence of visual impairment in the general population, but it may not be of much consequence for the present analysis: people are probably unlikely to state that they are limited in activity because of a vision problem if that problem could be solved by corrective lenses. This assumption depends, however, on access to affordable and effective correction, which is not equally assured to all populations. Hearing Deafness in both ears limits 184,000 people and has low recency (2.2 percent had onset in the past year). Hearing impairment other than deafness ("hard of hearing") in both ears limits 498,000 people and also has low recency. Deafness or hearing impairment in only one ear limits 233,000 people. It is unfortunate that the NHIS combines prevalence for unilateral deafness and hearing impairment (in contrast to visual impairments, for which more specific breakdowns are available). For a significant number of people who report deafness or hearing impairment as a cause of limitation, it is not known whether one or both ears are involved. In this group, deafness limits 54,000 people, almost a third of the number known to be deaf in both ears, and hearing impairment limits 206,000 people. The latter is significantly lower than average in primacy, suggesting low severity. Both conditions are of average recency, unlike bilateral deafness or hearing impairment. Hearing impairments, including deafness, limit the activities of 1.2 million people. Speech, sensation, and learning Stammering or stuttering limit 50,000 people; other speech impairments limit 495,000 people. Speech impairments other than stammering or stuttering have almost twice the average rate of proxy reporting. Impaired or lost sensation limits 141,000 people. Learning disability limits 216,000 people and mental retardation 1.4 million - both have very high primacy as causes of disability. Over 50 percent of mental retardation mentioned as a cause of limitation in adults is proxy-reported. Activity-limiting mental retardation is lower than average in recency. Absence Absence or loss of an upper extremity limits 102,000 people. The most common is loss of one or more fingers (61,000); next most common is loss of one arm (25,000). Absence or loss of a lower extremity limits 256,000 people. The most common is loss of one leg (173,000); next is loss of one foot or toes on one foot (50,000). Absence or loss of a lung or kidney limits 83,000 people and has lower-than-average recency. The estimated prevalence of absence or loss of a lung is unreliable (38,000), and the category has been combined with loss of a kidney (45,000). Absence or loss of breast limits 44,000 people and is quite low in primacy, suggesting that it may be secondary to another condition, most likely cancer. Indeed, 89 percent are caused by neoplasms (see Appendix Table A-1). Absence or loss of rib, bone, joint, or muscle of the trunk of the body limits 303,000 people, and is low in proxy reporting. Complete paralysis Quadriplegia limits 44,000 people and has the highest primacy of all conditions - 95.5 percent of people limited by quadriplegia state that it is the main cause of their limitation. The proportion of quadriplegia that is proxy-reported is 2.6 times that of all conditions. Thus, quadriplegia - a condition generally recognized to be quite disabling - shows the highest primacy and ranks among the highest in the degree of proxy reporting. About 86 percent of cases are reported to be caused by injury. Hemiplegia (paralysis of one side of the body) limits twice as many people as quadriplegia (99,000), and it is much lower than average in primacy. Hemiplegia is often the result of a stroke or other brain injury, and those conditions would be expected to be mentioned more often as the main cause of limitation. In fact, 80 percent of cases are reported to be caused by stroke and 12 percent by injury. Complete paralysis of one or both upper extremities limits 47,000 people. About 45 percent are caused by stroke. Paraplegia (paralysis of both legs) limits 59,000 people. About 41 percent are caused by injury, 17 percent by stroke, and 17 percent by polio. Complete paralysis of one leg or one foot limits activity for 33,000 people, but since this figure is not statistically reliable, this condition was regrouped with paralysis in other sites, complete or partial.
Partial paralysis Cerebral palsy limits 211,000 people. It has higher primacy than average, twice the average proxy reporting rate, and very low recency, as would be expected given its congenital/developmental onset. Hemiparesis limits 227,000 and is of low primacy. Similarly to hemiplegia, 79 percent of cases are caused by stroke and 10 percent by injury. Partial paralysis in an upper extremity limits activity for 80,000 people and has low primacy. Stroke is the cause for 71 percent of cases. Paraparesis limits activity for 51,000 people, of which 61 percent of cases are caused by stroke. Other types of partial paralysis of a lower extremity limit activity for 73,000 people, most of whom are paralyzed in one leg (65,000), the rest in one foot or both feet. This category is low in primacy and recency, with 60 percent of cases caused by stroke. Paralysis in other sites, complete or partial, limits 180,000 people. This figure includes 33,000 with one paralyzed leg or foot, 35,000 with paralysis of the body trunk, 11,000 with facial paralysis. Some 50 percent are caused by stroke. Altogether, paralysis limits 1.1 million people, usually the result of stroke. Deformities Included here are specific structural deformities of limbs, trunk, or back described by respondents as contracture, atrophy, accessory (or extra feature), "short" or "shortness," "crippled," "shriveled," and other similar descriptors. Curvature or other deformity of the back or spine limits 435,000 people and has greater-than-average primacy and one-third the average recency. This category includes all structural deformities of spine or back, except for spina bifida, which is listed separately. About a quarter are congenital and 15 percent are caused by injury. Spina bifida limits 61,000 people and shows high primacy; all cases are congenital. Deformity or congenital dislocation of the hip and/or pelvis limits 42,000 people. Deformity of a lower extremity limits 246,000 people, with about a third congenital. This category includes such conditions as knock-knee, bowleg, flatfoot, clubfoot, etc., affecting one or both limbs. Deformity of neck, trunk bones, shoulder, or upper extremity limits 116,000 people, with about half of cases caused by injury. About a third involve neck or trunk, 20 percent shoulder or upper extremity, and the rest hands or digits. Altogether, deformities add to 900,000 limiting conditions; they are average in primacy, average in proxy reporting, and below average in recency. A high proportion of cases are congenital. Orthopedic Impairments Orthopedic impairments include such non-paralytic, non-deforming conditions indicated by respondents as limitation in motion, "stiffness," "instability," "weakness," "trouble," "pain," "swelling," etc., when not classifiable to a specific disease or condition (if so classifiable, the orthopedic condition is not coded). For example, a "disc condition" is coded as ICD 722, rather than as an orthopedic impairment of the back. Orthopedic impairments of the back (including neck) limit 3.8 million people, making this category one of the most prevalent limiting conditions. This classification has greater than average primacy, which suggests greater severity. It should be noted that impairments of the neck are included here; thus, not all cases involve lower back pain, which is often cited as one of the major causes of limitation. About two-thirds are caused by injury. If this group is combined with ICD 722, "disc conditions," the number of people with disabling back problems comes to 6.5 million, which amounts to 11 percent of all disabling conditions. Orthopedic impairment of the shoulder or upper extremity totals 1.2 million limiting conditions, and exhibits average primacy and proxy reporting, but higher than average recency. Many of the cases in this classification involve chronic effects from recent injuries. About 80 percent are caused by injury. Orthopedic impairment of the hip and/or pelvis limits 547,000 people, with 78 percent caused by injury. Orthopedic impairment of a lower extremity limits 2.8 million people, and is higher than average in both primacy and recency. About 71 percent are caused by injury. Orthopedic impairments of other and ill-defined sites limit 265,000 people. This category includes impairments of the ribs, trunk, or joints, limping, and other trouble walking. Around 60 percent of cases are caused by injury. Orthopedic impairments as a whole are about average in primacy and proxy and somewhat higher than average in recency. They constitute conditions that involve pain or difficulty, though they do not include paralysis or specified deformities. Together, they number 8.6 million activity-limiting conditions, of which about 44 percent involve the back or neck. A larger proportion are caused by injury. Other impairments limit 230,000 people. This group includes disfigurements or scars of the head and face, cleft palate, dentofacial abnormalities, and other conditions not otherwise classifiable to a particular site. About 20 percent are congenital. Altogether, 16.3 million impairments are reported to cause activity limitation. Impairments as a whole have high primacy and proxy reporting rates, but average recency.