Free access

Definitions related to impairment assume importance, because terms associated with impairment evaluations may have special meanings in a legal context beyond their usual meanings in medical communications. This glossary provides a guide to the terms that should be used in reporting, analyzing, understanding, and discussing impairment evaluations and estimates carried out according to Guides criteria. It also defines important terms in the fields of disability, workers’ compensation, and short- and long-term disability and considers Social Security System disability determinations and the Americans with Disabilities Act of 1992.

Terms Used in Assessments According to Guides

  1. Impairment: Impairment is the loss, loss of use, or derangement of any body part, system, or function.

    Permanent impairment is impairment that has become static or well stabilized with or without medical treatment and is not likely to remit despite medical treatment.

    A permanent impairment is considered to be unlikely to change substantially and by more than 3% in the next year with or without medical treatment. If an impairment is not permanent, it is inappropriate to characterize it as such and evaluate it according to Guides criteria.

    Evaluation of permanent impairment is acquisition and analysis of information, including clinical evaluation, that is carried out according to Chapters 1 and 2 and other applicable parts of the Guides.

    Impairment rating consists of analyzing data accumulated in the course of an impairment evaluation and comparing those data with Guides criteria to estimate the extent of the impairment. Impairment ratings prepared according to Guides criteria are estimates of impairment.

    Impairment reporting is explaining the information acquired in the course of evaluating, analyzing, and estimating the extent of an impairment. An impairment report should be prepared according to the procedures described in Chapter 2 and other applicable parts of the Guides.

  2. Apportionment: This is an estimate of the degree to which each of various occupational or nonoccupational factors may have caused or contributed to a particular impairment. For each alleged factor, two criteria must be met:

    1. The alleged factor could have caused or contributed to the impairment, which is a medical determination (see “causation;” p. 316).

    2. In the case in question, the factor did cause or contribute to the impairment, which usually is a nonmedical determination. The physician’s analysis and explanation of causation is significant.p. 315

  3. Clinical Evaluation: This is the collection of data by a physician or other health care professional for the purposes of assessing the health status of an individual, formulating a medical management plan, and implementing a course of treatment. The data include information obtained by history; findings obtained from a physical examination; and findings from laboratory and other types of tests and diagnostic procedures, including roentgenograms, electrocardiograms, blood tests and chemistry studies, and tests of excreta and body fluids.

  4. Disfigurement: This is an altered or abnormal color, shape, or structure of a visible body part. Disfigurement may be the result of an injury or disease, or it may accompany a recurring or chronic disease or disorder of function. Disfigurement may produce social rejection, impairment of self-image with selfimposed isolation, alteration of life-style, or other adverse changes.

  5. Intensity and Frequency: The intensity and frequency of an individual’s symptoms or signs may be graded as shown below.


    1. Minimal: The symptoms or signs are annoying but have not been documented medically to cause appreciable diminution in an individual’s capacity to carry out daily activities.

    2. Slight: The symptoms or signs are tolerated by the individual and have been documented medically to cause some diminution in an individual’s capacity to carry out activities of daily living.

    3. Moderate: The symptoms or signs have been documented medically to cause serious diminution in an individual’s capacity to carry out activities of daily living.

    4. Marked: The symptoms or signs preclude carrying out activities of daily living.


    1. Intermittent: The symptoms or signs have been documented medically to occur less than one fourth of the time when the patient is awake.

    2. Occasional: The symptoms or signs have been documented medically to occur between one fourth and one half of the time when the patient is awake.

    3. Frequent: The symptoms and signs have been documented medically to occur between one half and three fourths of the time when the patient is awake.

    4. Constant: The symptoms and signs occur between three fourths and all of the time when the patient is awake.

    5. Medically Documented: This means that hospital and medical office records and ancillary records, such as those involving physiotherapy and occupational therapy, collected over a period of time, reflect a medical history and medical findings that support a diagnosis meeting established medical criteria and calling for medical management that is consistent with accepted principles and practice.

      To meet the above criteria, the medical records must contain entries that show an appropriately complete initial evaluation; follow-up visits at appropriate intervals describing the interval history, current findings on examination, and the individual’s response to treatment; vigorous use of medication and other treatment modalities if indicated; results of timely diagnostic tests and procedures; and appropriate referral for medical specialty evaluation. The records should document behavior of both the patient and the physician reflecting appropriate concern regarding the impact of the medical condition on the patient’s daily activities.

    6. Daily Living Activities: An impairment estimate based on Guides criteria is intended, among other purposes, to be an estimate of the degree to which an individual’s capacity to carry out daily activities has been diminished.

      The Table (p. 317) indicates some of the activities of daily living.

Aggravation, Recurrence, Causation, Disability, Workers’ Compensation, and Employability

  1. Aggravation: This means that a physical, chemical, or biologic factor, which may or may not be work related, contributed to the worsening of a preexisting medical condition or infirmity in such a way that the degree of permanent impairment increased by more than 3%.

    Causation means that a physical, chemical, or biologic factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following.

    1. The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination.

    2. The alleged factor did cause or contribute to worsening of the impairment, which is a nonmedical determination.

    In many benefit systems, causation and aggravation must be verified before awards are made. In contrast to traumatic injuries, which often can be p. 316related to an event that occurred at a particular time and place, the role of occupational or environmental factors in causing or aggravating disorders of the various body systems is difficult to document.

    Documentation of “aggravation” or “causation” will depend in large measure on the acquisition, review, and analysis of existing office and hospital records dating from the onset of the condition and including the initial evaluation for the condition; the results of tests or diagnostic procedures showing when and how the individual’s health was affected by an alleged physical, chemical, or biologic factor; and the results of occupational or environmental surveys, tests, or analyses. These include the following.

    1. Records of medical office or hospital visits that were specifically attributable to the injury or disease caused by alleged exposure to one or more factors and for which the individual was treated.

    2. Medical office or hospital records that show the individual suffered or is likely to suffer injury or harm as a result of the exposure.

    3. Reports of results of tests or diagnostic procedures showing specific sensitivity to a factor to which the individual was exposed.

    4. Reports of the results of an environmental survey or analysis showing the nature and intensity of factors to which the individual was exposed.

    5. Reports of the results of an analysis defining the minimal levels of exposure to a factor likely to cause injury or harm to the individual and discussion of the medical basis for the conclusions.

    6. Reports of the results of an analysis that indicates the individual was exposed in some place to factors to which he or she is sensitive, at intensities or durations equal to or greater than those to which the individual would have been exposed elsewhere, except that a physician or other responsible person restricted the exposure.

    7. Records containing an explanation of the medical basis for any conclusion that the individual experienced, or is likely to experience, progression or worsening of the condition as a result of continued exposure to physical, chemical, or biologic factors.

    Aggravation may involve both occupational and nonoccupational disorders in the following ways.

    1. An occupational disorder may be aggravated by a supervening nonoccupational disorder.

    2. An occupational disorder may be aggravated by a supervening occupational condition arising out of and in the course of employment by the same employer.

    3. An occupational disorder may be aggravated by a supervening industrial condition arising out of and in the course of employment by a different employer.

    4. An occupational disorder may be aggravated by a preexisting nonoccupational condition.

    5. An occupational disorder may aggravate a preexisting nonoccupational condition.

  2. Recurrence: A recurrence requires no identifiable incident as a trigger to the medical condition in question; rather, the patient has a resumption of symptoms or signs that can be related to the previously existing medical condition or injury.

  3. New Injury: With a new injury, an identifiable new incident must be shown to have caused the injury. If it is thought that a preceding factor or situation, such as one related to an illness or occupation, might have had a role in the injury’s development, then the causation must be established as described above.

  4. Disability: Disability is a decrease in, or the loss or absence of, the capacity of an individual to meet personal, social, or occupational demands, or to meet statutory or regulatory requirements.

    Permanent disability occurs when the degree of capacity becomes static or well stabilized and is not likely to increase despite continuing use of medical or rehabilitative measures. Disability may be caused by medical impairment or by nonmedical factors.

    Evaluation or rating of disability is a nonmedical assessment of the degree to which an individual does or does not have the capacity to meet personal, social, occupational, or other demands, or to meet statutory or regulatory requirements.p. 317

  5. Illness, Disease: An illness may be considered to be the summation of the physical, mental, and other kinds of factors that are involved in an individual’s less than optimal health status. A disease may be considered to be the specific pathophysiologic processes involved, which give rise to the individual’s signs and symptoms and their progression.1

  6. Employability: This is the capacity of an individual to meet the demands of a job and the conditions of employment associated with that job as defined by an employer, with or without accommodation.

  7. Employability Determination: This is an assessment by management of the individual’s capacity, with or without accommodation, to meet the demands of a job and the conditions of employment. The management carries out an assessment of performance capability to estimate the likelihood of performance failure and the likelihood of incurring liability in case of human failure. If either likelihood is too great, then the employer may not consider the individual employable in the job.

  8. Medical Determination Related to Employability: This is the process of evaluating the relationship of an individual’s health to the demands of a specific job as described by the employer, such as demands for performance, reliability, integrity, endurance, or prolonged service. The physician must ensure that the medical evaluation is complete and detailed enough to draw valid conclusions with respect to the individual’s capability of meeting the job’s demands and carrying out essential job functions.

    The physician’s tasks are to (1) identify impairments that could affect performance and determine whether or not the impairments are permanent; and (2) identify impairments that could lead to sudden or gradual incapacitation, further impairment, injury, transmission of a communicable disease, or other adverse occurrence.

    In estimating the risk factors, the physician should indicate whether or not the individual represents a greater risk to the employer than someone without the same medical condition and should indicate the limits of the physician’s ability to predict the likeli-hood of an untoward occurrence.

  9. Risk, Hazard: A risk represents the probability of an adverse event; a risk must be weighed together with the consequences of the adverse event. An individual’s activities or characteristics, and biologic, physical, or chemical factors, may increase the risk of morbidity or mortality.

    A hazard is a potential source of danger; to a woman contemplating crossing the Atlantic Ocean in a rowboat, the Atlantic presents a serious hazard. Excessive numbers of coliform bacteria or Shigella dysenteriae in the public water supply present a hazard to a city.

  10. Possibility, Probability: These are terms that refer to the likelihood or chance that an injury or illness was caused or aggravated by a particular factor. “Possibility” sometimes is used to imply a likelihood of less than 50%; “probability” sometimes is used to imply a likelihood of greater than 50%.


Activities of Daily Living, with Examples

Activity Example
Self-care, personal hygiene Bathing, grooming, dressing, eating, eliminating
Communication Hearing, speaking, reading, writing, using keyboard
Physical activity Intrinsic: Standing, sitting, reclining, walking, stooping, squatting, kneeling, reaching, bending, twisting, leaning
Functional: Carrying, lifting, pushing, pulling, climbing, exercising
Sensory function Hearing, seeing, tactile feeling, tasting, smelling
Hand functions Grasping, holding, pinching, percussive movements, sensory discrimination
Travel Riding, driving, traveling by airplane, train, or car
Sexual function Participating in desired sexual activity
Sleep Having a restful sleep pattern
Social and recreational activities Participating in individual or group activities, sports, hobbies

Social Security Disability Determinations

Although the Social Security system predated the first Guides edition and is not based on the Guides, a description of the system is included here to compare and contrast the ways in which medical information is used under each approach. The Social Security Administration (SSA) has national responsibility under Public Law 74-271 for the administration of both the Social Security disability insurance program (title II) and the supplemental security income (SSI) program (title XVI). Every person who pays into Social Security contributes to the Social Security Disability Trust Fund.

The title II program provides cash benefits to disabled workers and their dependents who have contributed to the trust fund through the FICA tax on their earnings. A person qualifies under the title II program because of financial need. The title XVI program provides for a minimum income for the needy, aged, blind, and disabled. Under that program, financial need is indicated by limitation of income and resources to a level that is equal to or less than an amount specified in the law.

Definitions and Terms

Under the title II and title XVI programs, the definitions of disability are essentially the same. The law defines disability as “the inability to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment that can be expected to result in death or has lasted or can be expected to last for a continuous period of not less than 12 months (Section 223 [d] [1] [A]). The law may apply to infants and children as well as adults. In terms of the law, a person is either disabled or not disabled.

To meet the definition of disability, an individual’s impairment or combination of impairments must be of such severity that he or she not only is unable to do the work previously done, but also cannot perform any other kind of substantial gainful work considering the individual’s age, education, and work experience (Section 223 [d] [2] [A]). Substantial gainful work means any work that involves significant and productive physical or mental activities and is p. 318performed for pay or profit to a specified level, currently $500 for disabled persons and $850 for blind persons.

The term “medically determinable physical or mental impairment” means that the impairment may be either physical or mental but it must be an impairment that can be demonstrated by the symptoms, signs, and laboratory findings reported by acceptable medical sources, which include licensed physicians.

Medical Basis of Disability

To qualify for payments under either the title II or the title XVI program, an individual must have a “medically determinable” impairment. This is defined as an impairment that has demonstrable anatomic, physiologic, or psychological abnormalities. Abnormalities that manifest themselves only as symptoms do not qualify.

Signs are defined as anatomic, physiologic, or psychological abnormalities that can be observed by using medically acceptable techniques. Laboratory findings are manifestations of anatomic, physiologic, or psychological phenomena that are demonstrable by replacing or extending the perceptiveness of the observer’s senses; they include chemical, electrophysiologic, roentgenographic, and psychological tests.

Listing of Impairments

Under the Social Security System, there is a sequence in evaluating disability claims that reflects the requirements of the law and regulations. This step-by-step procedure is known as the “sequential evaluation process” Initial steps in the process include a determination as to whether the claimant’s impairments meet or equal any impairment in the Listing of Impairments.

The Listing of Impairments is organized by body system as a set of medical evaluation criteria. For each body system, the medical evaluation criteria include key concepts used in evaluating impairments and a description of the type of medical evidence needed. The Listing is divided into two parts. Part A contains medical criteria that apply to persons 18 years old and older. These criteria also may be applied to impairments of persons less than 18 years old, if the disease process has a similar effect on adults and younger persons. Part B contains medical criteria that apply only to evaluating the impairments of persons under age 18 years.

The medical evaluation criteria in the Listing describe impairments in terms of specific signs, symptoms, and laboratory findings that are presumed to be severe enough to keep an individual from working for a year or longer or, in the case of a child, performing age-appropriate activities. The Listing describes Glossary more than 100 common diseases and disorders, which are so serious or life-threatening that if the claimant meets one of them and is not engaging in substantial gainful activity, he or she is deemed to be disabled.

If an individual has an impairment that does not meet the specific criteria described in the Listing but has an impairment equal in severity to a listed impairment, and is not engaging in substantial gainful activity, he or she is presumed to meet the definition of disability. Under the SSA system, no claimant is denied a determination of disability solely on the basis of not meeting or equaling the criteria of the Listing.

Collection of Medical Evidence

For a medical report to furnish the SSA with sufficient medical evidence, it should include (1) medical history; (2) clinical findings, such as results of a physical or mental status examination; (3) laboratory findings; (4) diagnosis based on signs and symptoms; (5) the treatment prescribed, with response and prognosis; and (6) a medical source statement based on the source’s own findings.

The medical evidence, including clinical and laboratory findings, should be complete and detailed enough to allow SSA personnel to make the disability determination. In addition, the report should enable them to determine the nature and limiting effects of the impairment(s), its probable duration, and the claimant’s remaining capacity to engage in work-related physical or mental activities.

The medical source statement, noted above, details what the claimant can do despite his or her impairment(s). It should describe such work-related activities as sitting, walking, lifting, carrying, hearing, speaking, and traveling. In cases involving mental impairments, the SSA must have a statement about the claimant’s capacity for understanding and memory; sustained concentration and persistence; social interaction; and adaptation.

Under the Social Security Act, disability is defined strictly in economic terms and ability to work, while in the Guides, disability is defined in terms of an individual’s capacity to meet personal, social, recreational, occupational, and other demands.

The Americans with Disabilities Act

This section provides background on the Americans with Disabilities Act (ADA) and compares and contrasts the concepts of the Guides with those of the Act. The provisions of the ADA governing employment-related decisions (title I) became effective on July 26, 1992, for private-sector organizations that employ 25 or more employees. Because the intent of the ADA is p. 319to compel organizations to employ qualified individuals with “disabilities,” it is likely that physicians will experience an increasing demand for giving guidance to employers with respect to an individual’s “disability” status. In addition, there will be questions regarding performance capability, acceptability of risk to oneself or others, the need for accommodation, and the type of accommodation that may be warranted. It is important to recognize that none of these is a medical issue.

The following definitions are based on the concepts of EEOC Title I Regulations and Interpretive Appendix (29 CFR 1630).

  1. Accommodation means modification of a job or workplace that enables a “disabled” employee to meet the same job demands and conditions of employment required of any other employee in the same, or a similar, job. Accommodation need be considered only with respect to the essential functions of a job. Reasonable accommodation means accommodation that does not result in undue cost or hardship to the employer.

  2. Disability means a physical or mental impairment that substantially limits one or more of the major life activities of the individual; or a record of such an impairment; or being regarded as having such an impairment.

  3. Essential functions of a job means the fundamental duties of the employment position that the disabled individual seeks or holds. Essential functions may be understood to be those elements of a job such that failure in one or more of the elements would be cause for removal from the job. “Essential functions” do not include marginal functions.

  4. Major life activities means such functions as caring for oneself, performing manual tasks, walking, seeing, hearing, speaking, breathing, learning, and working. A list of daily activities appears earlier in the Glossary (Table, p. 317).

  5. Physical or mental impairment means the following:

    1. Any physiologic disorder or condition, cosmetic disfigurement, or anatomic loss affecting one or more of the following body systems: neurologic, musculo-skeletal, special sense organs, respiratory (including speech organs), cardiovascular, reproductive, digestive, genitourinary, hemic and lymphatic, skin, and endocrine systems; or

    2. Any mental or psychological disorder, such as intellectual disability, organic brain syndrome, emotional or mental illness, and specific learning disabilities.

  6. Substantially limits means the following:

    1. The person is unable to perform a major life activity that the average person in the general population can perform; or

    2. The person is significantly restricted as to the conditions, manner, or duration under which he or she can perform a particular major life activity, compared to the conditions, manner, or duration under which the average person can perform the same activity.

The ADA uses the term “disability;” and its use of the concept is similar to the concept of “impairment” used in the Guides. It is important to note, however, that under the ADA, identification of an individual with a “disability” does not depend on the results of a medical evaluation. An individual may be identified as having a disability if there is a record of an impairment that has substantially limited one or more major life activities or, of greater concern, if the individual is regarded as having a disability.

In carrying out and reporting the results of an impairment evaluation, it is essential that the physician distinguish carefully between an impairment that is documented in accordance with Guides criteria and a presumed impairment that is based on nonmedical factors. Clearly, a question exists as to whether or not an impairment based on Guides criteria automatically will constitute a “record” of an ADA-covered disability or signify that the individual is “regarded” as having such a disability.

“Accommodation” is not a medical matter. Accommodation is the result of an employer’s decision regarding modifications of a job or workplace that are “reasonable” with respect to the employer’s cost and the degree of hardship imposed. The physician may be able to help an employer understand the relationships between a medical impairment, the demands made of an individual in the workplace, and the individual’s capabilities. The physician also can help the employer explore the need for accommodation. But it is not appropriate for the physician to recommend a specific accommodation.

Once the employer determines it is appropriate to accommodate an individual’s disability and redefines the job or workplace, the physician’s role is to answer the following question: “Is there a medical reason to believe it is not feasible or appropriate to assign these [specified] tasks and duties to this person under these [specified] working conditions?”



Jr Luck JV, DW. Florence A brief history and comparative analysis of disability systems and impairment rating guides. Orthoped Clin North Am. 1988;19:839-844.

  • Search Google Scholar
  • Export Citation
  • 1.

    Jr Luck JV, DW. Florence A brief history and comparative analysis of disability systems and impairment rating guides. Orthoped Clin North Am. 1988;19:839-844.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Full Text Views 26 26 13