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(Chest. 2002;122:1695-1700.)
© 2002 American College of Chest Physicians

Quality-of-Life Evaluation of Patients With Neuromuscular and Skeletal Diseases Treated With Noninvasive and Invasive Home Mechanical Ventilation*

Agneta Markström, MD, PhD; Kerstin Sundell, RNA;; Michael Lysdahl, MD;; Gillis Andersson, MD;; Ulla Schedin, MD, PhD; and Birgitta Klang, RN, PhD

* From the Department of Anesthesiology (Drs. Markström, Lysdahl, Andersson, Schedin, and Ms. Sundell), Respiratory Unit, and Department of Nursing Research (Dr. Klang), Karolinska Institute Danderyd Hospital, Stockholm, Sweden.

Correspondence to: Agneta Markström, MD, PhD, Department of Anaesthesiology, Respiratory Unit, Karolinska Institute, Danderyd Hospital (KIDS), SE-182 88 Stockholm, Sweden; e-mail: agneta.markstrom{at}ane.ds.sll.se


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Background: Home mechanical ventilation (HMV) is known to be a successful therapy for chronic respiratory insufficiency, with regard to long-term survival. However, the quality of life (QoL) of patients receiving HMV has not previously been systematically investigated. The purpose of this study was to assess the QoL of patients with neuromuscular disorders and skeletal deformities (ie, restrictive lung disease) receiving HMV.

Methods: Patients receiving HMV treated by tracheostomy or noninvasive ventilation (NIV). Three different, standardized, and validated questionnaires were used: the Sickness Impact Profile (SIP), the Health Index (HI), and the Sense of Coherence (SOC) scale. Underlying diseases were postpolio dysfunction (37%), neuromuscular disorder (20%), scoliosis (15%), and other diseases (28%).

Results: The group treated with tracheostomy had higher HI scores than the group treated with NIV. For the three main diagnosis groups treated with tracheostomy or NIV, the patients with postpolio dysfunction treated with tracheostomy had lower SIP scores than the patients with postpolio dysfunction treated with NIV. This was in contrast to the patients with neuromuscular disorders treated with tracheostomy, who had higher scores in the SIP, compared with patients with postpolio dysfunction treated with tracheostomy and patients with neuromuscular disorders treated with NIV. A SIP score > 10% indicates a functional disability of clinical importance, and a high score on the HI and SOC scale indicates good perceived health. For the three main diagnosis groups treated with NIV, the patients with scoliosis had no dysfunction of clinical importance (4.6 ± 3.7) on the SIP score compared with patients with postpolio dysfunction (15.5 ± 7.6) and patients with neuromuscular disorders (13.2 ± 5.2) [mean ± SD]. The men showed more dysfunction in the SIP score than the women.

Conclusion: Patients receiving HMV reported a good perceived health, despite severe physical limitations. The patients with postpolio dysfunction and the patients with scoliosis treated with tracheostomy perceived the best health, compared with NIV for this diagnosis.

Key Words: home mechanical ventilation • neuromuscular disorders • noninvasive ventilation • postpolio syndrome • tracheostomy


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
The second polio illness (ie, the postpolio syndrome) is characterized by increasing muscular debility and increasing muscular and joint pain. The unexpected complications are encountered in mid-life and beyond. The complications are often in previously unaffected areas and are frequently accompanied by functional changes in activities. A serious late complication is hypoventilation, which worsens during sleep.1 This hypoventilation is primarily responsible for the need of home mechanical ventilation (HMV) in patients with previous polio, 20 to 40 years after the acute stage of the disease.2 HMV is an acknowledged, successful treatment for patients with chronic respiratory insufficiency due to postpolio syndrome, kyphoscoliosis, and neuromuscular disorders with respect to long-term survival.3 4 5 However, the quality of life (QoL) of patients receiving HMV has not been systematically investigated previously.

At our respiratory unit, patients with chronic respiratory insufficiency have been treated with HMV for > 20 years. Patients with postpolio dysfunction represent the largest group, but patients with conditions such as neuromuscular disorder and kyphoscoliosis are also represented. Most of the patients have clinically severe dysfunction, especially regarding mobility. Mechanical ventilation is effected by tracheostomy or noninvasive ventilation (NIV), using a nasal mask. We wanted to elucidate how our patients with chronic respiratory insufficiency due to neuromuscular and skeletal diseases (ie, restrictive lung disease) receiving HMV perceived their life situation. The specific aim of this study was to assess the QoL of patients receiving HMV by using accepted QoL instruments.


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
All the patients in this study were in need of respiratory support and were all treated in ambulatory care settings. They were all living in the county of Stockholm, Sweden, and were all included in the Swedish health insurance system. One hundred twenty consecutive patients were invited to participate; 91 patients (76%) answered three questionnaires and sent them by mail to our clinic. Sixty patients were treated with NIV, and 31 patients underwent tracheostomy.

There are several definitions of the general QoL. In most definitions, the functional ability in daily life and the perceived health are important aspects. In this study, the three questionnaires used were the Sickness Impact Profile (SIP), the Health Index (HI), and the Sense of Coherence (SOC) scale. The HI is a useful clinical instrument for measuring perceived health status.6 7 The HI comprises 11 items: fatigue, energy, sleep, mobility, mood, loneliness, bowel function, vertigo, pain, health during the past week, and general health, compared with other people. Each item is rated on a scale ranging from 1 to 4, where 1 = very poor, 2 = poor, 3 = good, and 4 = very good. Nine of the items produced overall scores ranging from 9 to 36. The last two items were treated as a single item. The higher the score, the better the perceived health. The HI has been used in different groups of patients in Sweden, and has proved to be reliable, with {alpha} values ranging between 0.74 and 0.79, and valid by its high correlations to well-known QoL questionnaires.7 8 9

The Sickness Impact Profile (SIP) is a behavior-based measure of health-related dysfunction in a person’s daily life.10 It consists of 136 statements covering 12 different areas of activity: sleep and rest, eating, home management, recreation and pastimes, body care and movement, ambulation, mobility, emotional and affective behavior/alertness, social interaction, communication, and work. The respondent indicates whether each statement describes a limitation of function in relation to his or her health today. The scores from body care and movement, ambulation, and mobility form a single, physical dimension score. The subcategories emotional and affective behavior, social interaction, and communication form a psychosocial dimension score. Moreover, an overall score includes all 12 categories. Possible scores range from 0 to 100%; the higher the score, the more serious the dysfunction in daily life. A score > 10% indicates a clinical handicap. Reliability and validity have been established for the SIP10 and for Swedish use,11 with {alpha} values ranging between 0.94 and 0.97.

During the last few years, there have been discussions about the factors of importance in how people perceive their QoL. Antonovsky12 suggests that a person’s sense of coherence is a crucial determinant of his or her health status. The SOC scale, developed by Antonovsky,12 is intended to measure comprehensibility, manageability, and meaningfulness in stressful life situations. The 13 items are summarized to form an overall SOC scale ranging from 13 to 91. The higher the score, the stronger the sense of coherence and the better the perceived health. The SOC scale has been used in many different categories of patients in Sweden, and has proved to be reliable, with {alpha} values between 0.74 and 0.94, and valid by its high correlations to well-known QoL questionnaires.13 14 15

Statistical Analysis
Parametric methods were used when the variables were approximately normally distributed. Differences between groups were tested with Student’s t test for unpaired observations. Correlations between variables were tested with Pearson product-moment coefficients of correlation. A multiple regression analysis was also performed. Statistical significance was accepted at p <= 0.05.


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
The patients included 51 women and 40 men (mean age, 58.8 ± 1.6 years; range, 17 to 85 years) [mean ± SD]. Thirty-four patients (37%) were >= 65 years old, with 65 years being the age for retirement in Sweden. Of the remaining 57 patients, 15 patients (26%) performed some sort of work. Thirty-three patients (37%) had postpolio dysfunction, 16 patients (20%) from a neuromuscular disorder, 13 patients (15%) from scoliosis, and 29 patients (28%) had various diagnoses.

SIP and HI for the Two Treatment Groups (Tracheostomy vs NIV)
In all the patients (n = 91), functional disabilities in daily life > 10% were observed in the overall SIP. A SIP score >= 10% indicates a functional disability of clinical importance. There were no significant differences in the SIP score between the two treatment groups.

The health index (HI) indicated that more than half of all the patients had fatigue (55%), lack of energy (52%), and physical mobility problems (52%). The HI for the two treatment groups showed that the tracheostomy group had higher overall HI scores (27.8 ± 3.7) than the group receiving NIV (25.2 ± 3.6) [Table 1 ]. The higher the score in the HI, the better the perceived health (possible scores 9 to 36). There were no significant differences in the SOC scale between the two treatment groups (possible scores 13 to 91).


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  		Table 1.. Differences Between the Two Treatment Groups, Tracheostomy vs NIV*

 
SIP, HI, and SOC Scale for Different Diagnoses With Tracheostomy vs NIV
In the analysis of the three main diagnoses (Table 2 ), the results showed that the patients with postpolio dysfunction treated with tracheostomy had significantly lower SIP scores in the psychosocial dimension, emotional behavior, and alertness than the patients with postpolio dysfunction treated with NIV. A SIP score < 5% indicates no clinical dysfunction. This was in contrast to the patients with neuromuscular disorders treated with tracheostomy, who had scores > 10% in psychosocial dimension, emotional behavior, and social interaction, compared with the patients with postpolio dysfunction treated with tracheostomy and the patients with neuromuscular disorders treated with NIV. In the HI, both the patients with postpolio dysfunction and the patients with scoliosis treated with tracheostomy perceived the best health (29.0 ± 2.7 and 30.2 ± 1.2, respectively), compared with NIV for this diagnosis.


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  		Table 2.. SIP, HI, and SOC Scale for Different Diagnoses With Tracheostomy vs NIV*

 
Three Main Diagnosis Groups Treated With NIV
When the overall SIPs for the three main diagnosis groups (Table 3 ) treated with NIV were compared, the patients with scoliosis had no dysfunction of clinical importance (4.6 ± 3.7), compared with both the patients with postpolio dysfunction (15.5 ± 7.6) and the patients with neuromuscular disorders (13.2 ± 5.2). The same pattern was found in the SIP areas of physical dimension, sleep and rest, home management, and recreation and pastimes. In the psychosocial dimension, the patients with postpolio dysfunction had more dysfunction than both the patients with neuromuscular disorders and the patients with scoliosis.


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  		Table 3.. Three Main Diagnosis Groups Treated With NIV*

 
The most frequently marked items in the SIP questionnaire showed that 60% of the patients did not do any heavy work around the house, and 40% remained seated for most of the day. Forty percent of the patients used a wheelchair, 45% did not use public transportation, and 44% walked more slowly, for shorter distances, or often stopped to rest. Almost 40% of the patients did no house cleaning; 39% seldom went out for entertainment; 35% had trouble putting on shoes, socks or stockings; and 38% had a limited sex life. No differences were seen in the HI and the SOC scale for the three diagnosis groups treated with NIV.

Gender
Significant differences were found between men and women in the overall SIP and in the underlying areas of psychosocial dimension, communication, social interaction, physical interaction, eating, body care, and sleep and rest. In all these functional areas, the men had more dysfunction than the women (Table 4 ).


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  		Table 4.. Differences Between Men and Women*

 
With regard to perceived health, the men had significantly worse well-being with respect to bowel function and mobility than the women. No significant differences were found regarding the sense of coherence between men and women.

Sense of Coherence
In the regression analysis (Table 5 ), the independent variables (age, sex, diagnosis, treatment, sense of coherence) account for 18% of the functional disabilities in the SIP and for 32% of the perceptions of health (HI). On checking the independent variables, the results indicate that the men had more functional disabilities than the women. Patients with scoliosis are less likely to have functional disabilities than those with postpolio dysfunction and neuromuscular disorders. Furthermore, as the sense of coherence improves, functional disabilities appear to diminish and the health is perceived to be better. The patients treated with tracheostomy tended to perceive better overall health (ie, they achieved higher scores) [Table 1 ].


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  		Table 5.. Multiple Regression Analysis Between the Independent Variables and the Dependent Variables

 

   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
HMV for patients with chronic respiratory failure is known to prolong survival.16 17 Studies comparing intermittent positive pressure ventilation with NIV with tracheostomy are often conducted in patients with amyotrophic lateral sclerosis.3 18 This study focuses on HMV in patients with neuromuscular disorders and skeletal deformities (ie, restrictive lung disease).

The main findings were that the patients reported a high level of disability in most areas in the SIP, indicating severe functional disability, yet reported quite good perceived health in the HI. We found that patients treated with mechanical ventilation via a tracheostomy believed themselves to be in better health, had less sense of fatigue, and slept better than the patients treated with NIV via a mask (Table 1) .

Diagnosis, Treatment, and QoL
On comparing the three main diagnosis groups treated with tracheostomy or NIV, the patients with postpolio dysfunction treated with tracheostomy had lower SIP scores, indicating no dysfunction in emotional behavior (1.2 ± 3.2), alertness (1.2 ± 4.9), and psychosocial dimension (3.1 ± 3.5) than the patients with postpolio dysfunction patients treated with NIV (Table 2) . A SIP score < 5% indicated no dysfunction of clinical importance.9 11 14 Patients with postpolio dysfunction treated with tracheostomy also scored better in overall health in the HI (29.0 ± 2.7) and had stronger SOC scale results (73.7 ± 9.4).

In contrast to these findings, the patients with neuromuscular disorders treated with tracheostomy yielded SIP scores > 10%, indicating a dysfunction of clinical importance. They were more emotionally disturbed and less socially interactive, and showed greater dysfunction in the psychosocial dimension than patients with neuromuscular disorders treated with NIV and patients with postpolio dysfunction treated by tracheostomy (Table 2) . These findings must be interpreted with caution, as the number of patients with neuromuscular disorders is small, and there may have been a selection bias, since patients with a more severe disorder might be more likely to undergo tracheostomy.

In the separate items of the HI (the higher the score, the better the health), the patients with postpolio dysfunction treated with NIV felt more pain, were lonelier, had more fatigue, and were more depressed than the patients undergoing tracheostomy (Table 2) . It is known from other studies19 20 that patients with postpolio dysfunction describe a gradual deterioration in terms of general weakness, fatigue, and pain. When patients with postpolio dysfunction were compared with two samples from the Swedish general population, it was found that the patients with postpolio dysfunction reported a poorer functional status and poorer health-related QoL.21 However, they also had different coping strategies and believed that they led a good life, despite their handicap.20 Others researchers21 have found that patients with postpolio dysfunction were expected to manage in society despite their handicap, and such demands led to a "polio personality." This personality is characterized by overachievement at work, a strong endeavor to fit in and not to be different, and satisfaction with being able to live a perfectly adequate life.22 In our study, the higher scores on the SOC scale and the HI for the patients with postpolio dysfunction undergoing tracheostomy may be an indication of this.

Another interesting result of this study was that the patients with scoliosis expressed the best QoL in almost all instances. Only as regarded eating did the patients with scoliosis treated with tracheostomy report greater dysfunction than the patients treated with NIV. However, the SIP score was < 5%, indicating no dysfunction of clinical importance.

Three Main Diagnosis Groups Treated With NIV
In all the patients, fatigue and decreased energy and mobility were the most commonly indicated items on the HI questionnaire. Furthermore, the patients with postpolio dysfunction treated with NIV scored higher sense of fatigue than patients with postpolio dysfunction treated with tracheostomy. Fatigue and a badly fitting mask that leads to less effective nocturnal ventilation could also exacerbate the depleted energy.

The patients with postpolio dysfunction indicated the worst dysfunction in overall SIP for sleep and rest, home management, and recreation and pastimes. These findings are in agreement with other studies.19 20 21 Fatigue and depleted energy have been interpreted as being of muscular origin purely, but may be attributable to both central and peripheral causes.23 As shown in Table 3 , the scoliosis group indicated less dysfunction (SIP score < 10%) in almost every item. No differences in the HI and SOC scale scores were seen when the three main diagnosis groups treated with NIV were compared. The high HI and SOC scale scores may indicate a connection between coping and the available resources, both the patient’s own resources and the environmental resources. Being retrospective in nature, this study gives no indication as to which of them is the more important.

We speculate, however, that one reason for the better QoL of patients receiving HMV and treated with a tracheostomy may be related to the differences in management routines. At our respiratory unit, all patients who undergo tracheostomy also receive an individually fitted tracheostomy cannula. In order to make a well-fitting fenestration, we always use a fiberoptic laryngoscope, and the patients are seen once a month at the outpatient clinic to check the tracheostomy.

This is in contrast to the patients treated with NIV, who visit our clinic only once a year, once they have a well-tolerated ventilation via the mask. By visiting the respiratory clinic once a month, the patients with a tracheostomy have better opportunities to obtain social support from doctors and nurses alike. Several studies24 25 have shown the importance of good social support and its beneficial effects on patients and their rehabilitation. Also, the fact that a face mask may be less comfortable than a well-fitting tracheal cannula must also be considered.

Influence of Age and Gender on QoL
On checking the independent variables, the multiple regression analysis showed that age influenced the HI and the SIP scores a very small extent. This is in contrast to other studies,26 27 in which the age of patients with postpolio dysfunction was found to be closely correlated with physical abilities, except in the oldest age group. We have reason to believe that in persons with less than the normal number of functional motor units, as in postpolio dysfunction and neuromuscular diseases, the normal aging process would have exacerbated the decreased mobility. Perhaps our patients’ dysfunctions were so serious that age did not worsen them.

Significant differences were found between men and women in the overall SIP, in physical dimension, body care and movement, psychosocial dimension, communication, social interaction, eating, and in sleep and rest, but also in mobility and bowel function (Table 4) . In all these areas, the men noted more dysfunction or worse health. In the regression analysis (Table 5) , it may be seen that sex influenced the SIP score by 24%. However, several studies1 2 13 are not in agreement as to whether or the differences are based on gender or not. It should be noted that the SIP questionnaire merely asks about the patient’s perceived inability to carry out "tasks" in daily life. It does not take into account what the patient believes about his or her disability.

Sense of Coherence
In the regression analysis, the independent variables explain 18% of the functional disabilities in the SIP score and 32% in the perceptions of health. Interestingly, of the SIP and HI scores, 29% and 46% respectively were explained by the sense of coherence (Table 5) . This further supports the results and suggestions in other studies12 13 14 15 that indicate that the sense of coherence may be a predictor of an individual’s ability to manage his or her life situation and to cope with a chronic disease.

We conclude that patients treated with both NIV and invasive HMV reported a quite good QoL, despite severe functional limitations. The patients with postpolio dysfunction and patients with scoliosis treated with tracheostomy perceived the best health, compared with those treated with NIV for these diagnoses.


   Footnotes
 
Abbreviations: HI = Health Index; HMV = home mechanical ventilation; NIV = noninvasive ventilation; QoL = quality of life; SIP = Sickness Impact Profile; SOC = Sense of Coherence

Received for publication September 12, 2001. Accepted for publication April 17, 2002.


   References
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Halstead, LS, Rossi, C (1985) New problems in old polio patients: results of survey of 539 polio survivors. Orthopedics 8,845-850[ISI][Medline]
  2. Midgren, B, Olofson, J, Harlid, R, et al Home mechanical ventilation in Sweden, with reference to Danish experiences. Respir Med 2000;94,135-138[CrossRef][ISI][Medline]
  3. Bach, JR, Istikama, Y, Kim, H Prevention of pulmonary morbidity for patients with Duchenne muscular dystrophy. Chest 1997;112,1024-1028[Abstract/Free Full Text]
  4. Barthlen, GM Nocturnal respiratory failure as an indication of noninvasive ventilation in the patient with neuromuscular disease. Respiration 1997;64(suppl 1),35-38
  5. Willig, Robert D, Leger, P Long-term nasal ventilation in neuromuscular disorders: report of a consensus conference. Eur Respir J 1993;6,599-606[Abstract]
  6. Forsberg, C, Björvell, H Swedish population norms for the GHRI, HI and STAI-state. J Qual Life Res 1999;2,349-356
  7. Langius, A, Björvell, H, Lind, M Oral- and pharyngeal-cancer patients’ perceived symptoms and health. Cancer Nurs 1993;16,214-221[ISI][Medline]
  8. Nordström, GM, Nyman, GR, Theorell, T Psychosocial adjustment and general state of health in patients with ileal conduit urinary diversion. Scand J Urol Nephrol 1992;26,139-147[ISI][Medline]
  9. Klang, B, Björvell, H, Clyne, N Quality of life in predialytic uremic patients. J Qual Life Res 1996;5,109-116
  10. Bergner, M, Bobitt, RA, Carter, WB, et al The Sickness Impact Profile: development and final revision of health status measure. Med Care 1981;19,787-805[ISI][Medline]
  11. Sullivan, M The Sickness Impact Profile (SIP): an instrument for overall health assessment; a basic evaluation. J Drug Ther Res 1988;13,167-169
  12. Antonovsky, A The structure and properties of the sense of coherence scale. Soc Sci Med 1993;36,725-733[CrossRef][ISI][Medline]
  13. Klang, B, Björvell, H, Cronqvist, A Patients with chronic renal failure and their ability to cope. Scand J Caring Sci 1996;10,89-95[ISI][Medline]
  14. Forsberg, C, Björvell, H, Cedermark, B Well-being and its relation to coping ability in patients with colorectal and gastric cancer before and after surgery. Scand J Caring Sci 1996;10,4412-4414
  15. Langius, A, Björvell, H, Antonovsky, A The sense of coherence concept and its relation to personality traits in Swedish samples. Scand J Caring Sci 1992;6,165-171[Medline]
  16. Lönnberg, F, Madsen, M Late onset polio sequelae in Denmark: risk indicators of late onset polio sequelae; results of a nation-wide survey of 3607 polio survivors. Scand J Rehab Med 1993;28(suppl),17-23
  17. Leger, P, Jennequin, J, Gerard, M, et al Home positive pressure ventilation via nasal mask for patients with neuromuscular weakness or restrictive lung or chest-wall disease. Respir Care 1989;34,73-77
  18. Cazzolli, PA, Oppenheimer, EA Home mechanical ventilation for amyotrophic lateral sclerosis: nasal compared to tracheostomy-intermittent positive pressure ventilation. J Neurol Sci 1996;139(suppl),123-128
  19. Ahlström, G, Karlsson, U Disability and quality of life in individuals with postpolio syndrome. Disabil Rehabil 2000;22,416-422[CrossRef][ISI][Medline]
  20. Ahlström, G, Hansson, B Coping with chronic illness: a quality study of coping with postpolio syndrome. Int J Nurs Stud 1999;36,255-262[CrossRef][ISI][Medline]
  21. Kling, C, Persson, A, Gardulf, A The health-related quality of life of patients suffering from the late effects of polio (post-polio). J Adv Nurs 2000;32,164-173[CrossRef][ISI][Medline]
  22. Lönnberg, F Late onset polio sequelae in Denmark: socio-medical adaptation of polio survivors; results of a nation-wide survey of 3607 polio survivors. Scand J Rehab Med 1993;28(suppl),24-31
  23. Scheer, J, Luborsky, ML Post-polio sequelae: the cultural context of polio biographies. Orthopedics 1991;14,1173-1181[ISI][Medline]
  24. Cobb, S Social support as a moderator of life stress. Psychosom Med 1976;38,300-314[Abstract/Free Full Text]
  25. Kaplan, RM, Toshima, MT The functional effects of social relationship on chronic illness and disability. Sarason, BR Sarason, IG Pierce, GR eds. Social support: an interactional view 1990,427-453 John Wiley and Sons New York, NY.
  26. Diard, C, Ravaud, J-F, Held, J-P French survey of postpolio sequelae: risk factors study and medical social outcome. Am J Phys Med Rehabil 1994;73,264-267[CrossRef][ISI][Medline]
  27. Grimby, G, Jonsson, ALT Disability in poliomyelitis sequelae. Phys Ther 1994;74,415-424[Abstract/Free Full Text]



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