Impairment and Disability: Current Issues

The chiropractic physician encounters many problems with patients in the realm of impairment and disability. This article will highlight current issues that should be considered in any patient undergoing long-term conservative care. The health care industry is moving rapidly towards outcome-based patient care. One of the chief determinants of outcome of treatment revolves around the patient's psychological status and its contribution to disability.

Approximately 569,000 workers annually leave their employment for at least five months because of a physical disability and only 48 percent of these persons will ever return to the workforce.¹ Back injuries leading to permanent impairments of the back and spine are the most frequent causes of disability in persons under the age of 45 and are the third most frequent cause of disability for persons over the age of 45.^2,3 According to the AMA "Guides to the Evaluation of Permanent Impairment," the term impairment means an alteration of an individual's health status that is assessed by medical means. Impairment represents what is wrong with the health of an individual. An individual who is impaired is not necessarily disabled. Disability is assessed by nonmedical means and refers to an alteration of an individual's capacity to meet personal, social, or occupational demands, or to meet statutory or regulatory requirements. Disability is the gap between what the individual can do and what the individual needs or wants to do.⁴ Disability is judged administratively and is based upon the patient's actual or presumed ability to engage in gainful activity. Therefore, disability must take into account the physical impairment as determined medically, the age of the patient, the sex of the patient, educational background, socioeconomic factors, experience, and culture.⁵

Disability is best assessed through the examination of activities of daily living. These assessments provide a basic and direct measure of the patient's function. Activities generally restricted by back disorders include bending and lifting, sitting, standing, walking, traveling, social activities, sex life, sleep, and dressing (especially footwear) when the low back is involved.⁶ Waddell has developed a series of nine questions which have proven to be of use in the clinical evaluation of a patient's disability. In this question battery (see list below), simple yes or no answers are recorded and added into a score reflecting the individual's current level of disability.⁶

Disability Questions

1. Do you require help or avoid lifting heavy items such as 30-40 pounds, a suitcase, or a 3-4 year old child?

    

2. Is your sitting generally limited to less than one-half hour?

    

3. Is your traveling in a car or bus generally limited to less than one-half hour?

    

4. Is standing in one place generally limited to less than one- half hour?

    

5. Is your walking generally limited to less than one-half hour?

    

6. Is your sleep regularly disturbed by back pain (2-3 times per week)?

    

7. Do you regularly miss or curtail social activities (excluding sports) because of back pain?

    

8. Do you have diminished frequency of sexual activity?

    

9. Is help required regularly with footwear, tights, tying shoes, putting on socks, etc.?

It is important to note that pain and disability are not synonymous. Typically, patients cannot describe their pain: they can only describe the disability which results from the pain.⁷ Furthermore, acute pain and chronic pain are fundamentally different in nature. Acute pain is directly related to a peripheral stimulus and to actual tissue damage. The patient's responses to the pain are proportional to the amount and duration of the pain. In contrast, chronic pain and chronic disability are associated with emotional distress, depression, disease conviction, and illness behavior. Chronic pain and disability become increasingly dissociated from the original physical focus of the injury as time passes.⁶ Psychopathology has long been implicated in the precipitation, perpetuation, and exacerbation of chronic back pain and disability.⁸ Factors such as age, sex, educational background, socioeconomic considerations, experience, culture, and illness behavior cannot be ignored as a cause for delayed recovery and as a contributing factor in chronic disability.^7,9,10 With this form of disability, there are three factors which must be considered: the patient's pain, the patient's reactions to the pain; and the situation prevailing at the time of the pain.⁷

The psychopathological component to disability and chronic back pain is strongly related to the length of time that the condition has been present. Clinical studies have confirmed the link between depression and chronic back pain, placing the association between the two clinical entities beyond dispute.¹¹ In a population of chronic low back pain patients, major depression was noted in 35.7 percent of the patients whose pain was classified as organic in origin and in 73.3 percent of patients whose back pain had nonorganic characteristics.¹² Depression reaches maximal levels between six months and three years after the onset of the pain.¹¹ McGill,¹³ found that the lower the period of disability for an industrial back problem, the lower the likelihood for that individual to return to work. When the worker was out for longer than six months there was a 50 percent chance for return to work. The probability for return to work dropped to 25 percent at one year and was almost non-existent after two years of disability. Rehabilitation measures for patients with chronic back pain become less successful, the longer the pain is left untreated.^14,15 Clinically, it has been shown that depression is a significant risk factor for poor response to treatment of and recovery from chronic pain.^6,18 Workers with minimal objective findings but greater than four months of lost time due to disability from a low back injury seldom return to work.⁶ Thus, this particular view of the disability dilemma places psychopathology as a consequence of delayed or prolonged treatment. An alternative viewpoint that must be considered in these situations places the psychological abnormality as the cause of the injury, not the result of the injury.

Work related injuries and chronic pain may serve as a resolution to psychological needs. Chronic disability develops as a means of assuming the "sick role" in a socially acceptable manner. Such maneuvering may address problems of dependency, feelings of inadequacy, depression, anxiety, job instability, or family difficulties. Therefore, instead of anxiety and depression being the presenting symptoms, the physical disorder resulting from the accident is the focus. In situations such as these, the underlying psychological problem(s) must be recognized and treated if the patient is to resolve his disability.16 It is imperative for the clinician dealing with these patients to recognize illness behavior as it presents in clinical practice. Failure to recognize illness behavior may result in misdiagnosis, and in some unfortunate cases, iatrogenic disability.¹⁷ Actual malingering is considered to be a relatively infrequent occurrence clinically, while psychopathological problems are considered to be much more common.¹⁹ Gender differences have been noted in chronic back pain patients with respect to depression. In females, depression is significantly related to self-reported pain severity. Males tend to show greater support through the use of activity/behavioral reports, with the greater the level of inactivity, the greater the depression.¹⁸

Strang,⁸ coined the term "chronic disability syndrome" to describe persons who are capable of returning to work but choose to remain disabled. The features of chronic disability syndrome include:

a. Out of work for at least six months consecutively, disability claim, and claim of financial compensation.

b. Subjective complaints disproportionate to objective findings

c. Psychological findings underlying subjective complaints and the perception of disability

d. Lack of motivation to recover and a negative attitude towards a return to work.

e. Other psychological features persist for at least six months and are not due to another medical or psychiatric condition.

In virtually all cases of chronic musculoskeletal pain there are reward contingencies operating in the patient's environment which tend to reinforce the maintenance of disability behavior.¹⁷ Financial compensation to the injured worker during the period of work-related disability can become a disincentive for returning to work as the disability extends into the chronic phase.²⁰ In other studies, third-party involvement, workers' compensation claims, or financial gain have been shown to increase the length of disability.²¹ The threshold for increased disability claims lies at approximately 55 percent of net income. If the income received by the injured worker while out of work due to an injury exceeds this amount, the number of claims received increases dramatically.¹⁴

Several socioeconomic risk factors have been implicated in the development of chronic low back pain and disability. In this regard, workers over the age of 40 are two times more likely to have disability following an injury than are workers under the age of 25. Those employees earning less than $1,000/month in 1984 had twice the risk of disability as those who earned more than $2,000/month. Divorced and widowed individuals without children posed a greater risk towards disability behavior as did blue collar workers, who had twice the risk for chronicity.²²

Job related risk factors which contribute toward the development of disability include a poor work history, a job history with recent unemployment, prior disability, a short duration on the job prior to injury, and a low performance evaluation by a supervisor within the past six months.^22,23,24 According to Nachemson,²⁵ various psychosocial factors contributing to low back disability include a disturbed personality, as demonstrated via the MMPI, alcoholism, divorce, lower education, religion, and job dissatisfaction. Attorney involvement also contributes to case chronicity and disability due to secondary gain.^{5,17,20,23,26}.

References

1. Tait DG: Worker's disability and return to work. Am J. Phys Med Rehabil, 71:92-96, 1992.

    

2. Andersson GBJ: Epidemiological aspects of low back pain in industry, Spine, 6(1):1981.

    

3. Bigos S, et al: Back injuries in industry: A retrospective study, II. Injury factors, Spine, 11(3):1986.

    

4. Engelberg AL: Guides to the Evaluation of Permanent Impairment, ed 3. American Medical Association, Chicago, 1988.

    

5. Aronoff GM: Chronic pain and the disability epidemic. Clin J. Pain, 7:330-338, 1991.

    

6. Waddell G, Allan DB, and Newton M: Clinical evaluation of disability in back pain, in Frymoyer, J.W. The Adult Spine: Principles and Practice, Raven Press, New York, 1991.

    

7. MacNab I, McCulloch J: Backache ed 2, Williams and Wilkins, Baltimore, 1990.

    

8. Atkinson JH, Slater MA: Behavioral medicine approaches to chronic back pain, in Rothman RJ and Simeone FA., Spine, Vol II, ed 2, pp 1961-1982, 1992, W.B. Saunders, Philadelphia.

    

9. Leavitt SS, Johnson TL, and Beyer RD: The process of recovery: Patterns in industrial back injury, 1. Costs and other quantitative measures of effort. Indiana Med Surg., 40(8), 1971.

    

10. Pheasant HC: Sources of failure in laminectomy. Ortho Clin North Am., 6:319, 1975.

     

11. Polatin PB: Affective disorders in back pain, in Mayer TG, Mooney V, Gatchel RJ, Contemporary Conservative Care for Painful Spinal Disorders, pp 149-154, 1991, Lea and Febiger, Philadelphia.

     

12. Ranga Rama Krishna K, et al: Chronic pain and depression. I. Classification of depression in chronic low back pain patients, Pain, 22:279-287, 1985.

     

13. McGill CM: Industrial back problems: A control problem. J. Occup Med, 10:174-178, 1968.

     

14. Nachemson A: Work for all. Clinical Orthopedics and Related Research, Number 179, October 1983.

     

15. Seres JL, Newman RI: Results of treatment of chronic low back pain at the Portland Pain Center. J Neurosurg, 45:32, 1976.

     

16. Hirschfield AH, Behan RC: The accident process: Etiological considerations of industrial injuries. JAMA, pp 193, October 19, 1963.

     

17. Ciccone DS, Grzesiak RC: Psychological dysfunction in chronic cervical pain, in Tollison CD, Satterthwaite JR, Painful Cervical Trauma, pp 79-92, 1992, Williams and Wilkins, Baltimore.

     

18. Haley WE, Turner JA, Romano JM: Depression in chronic pain patients: Relationship to pain, activity, and sex differences, Pain, 23:337-343, 1985.

     

19. Melzack R, Katz J, Jeans ME: The rate of compensation in chronic pain: analysis using a new method of scoring the McGill Pain Questionnaire, Pain, 23:101-112, 1985.

     

20. Barnes D: Social factors affecting back pain, in Mayer TG, Mooney V, Gatchel RJ: Contemporary Conservative Care for Painful Spinal Disorders, pp 143-148, 1991, Lea and Febiger, Philadelphia.

     

21. Wilkinson HA: The Failed Back Syndrome, Harper and Row, Philadelphia, 1983.

     

22. Volinn E, Van Koevering D, Loeser JD: Back sprain in industry: The role of socioeconomic factors in chronicity, Spine, 16(5):1991.

     

23. Kahanovitz, N: Diagnosis and Treatment of Low Back Pain, Raven Press, New York, 1991.

     

24. Bigos S, et al: Back injuries in industry: A retrospective study, III, employee related factors, Spine, 11(3):1986.

     

25. Nachemson A: The lumbar spine: An orthopedic challenge. Spine, 1(1), 1976.

     

26. Aronoff GM, et al: Pain treatment programs: Do they return workers to the workplace? Occupational Medicine: State of the Arts Reviews, 3(1), 1988.

Brad McKechnie, D.C., DACAN
Pasadena, Texas