Quality of life in chronic fatigue syndrome

~ ) Pergamon Vol. 41, No. 10, pp. 1367-1372, 1995 Copyright © 1995 ElsevierScienceLtd Printed in Great Britain.All rights reserved 0277-9536/95 $9.50 + 0.00 Soc. Sci. Med. 027%9536(95)00124-7 QUALITY OF LIFE IN CHRONIC FATIGUE S Y N D R O M E ROBERT SCHWEITZER,* BRIAN KELLY, A M A N D A FORAN, DEBORAH TERRY and JOHN W H I T I N G Queensland University of Technology, Locked Bag No. 2, Red Hill, QId 4059, Australia Abstract--Whilst the debilitating fatigue experienced in patients suffering from Chronic Fatigue Syndrome (CFS) results in a subjective marked impairment in functioning, little research has investigated the impact of this disorder on quality of life. Forty-seven subjects with a confirmed diagnosis of CFS and 30 healthy controls were compared using the Sickness Impact Profile (SIP). A subgroup of subjects were interviewed regarding the impact CFS has had on their social and family relationships, work and recreational activities, Results from both the SIP and the interview revealed that CFS subjects had significantly impaired quality of life, especially in areas of social functioning. These findings highlight the importance of addressing the social isolation and loss of role functioning experienced by CFS sufferers. Key words--chronic fatigue syndrome, well-being, myalgic encephalomyelitis, ME Chronic fatigue syndrome (CFS) is a relatively new name for what has been variously termed in the past, myalgic encephalomyelitis (ME) [1], neuromyasthenia [2] and chronic Epstein-Barr virus infection [3]. More commonly within popular literature, CFS has also been referred to as the 'yuppie plague' or 'yuppie flu' [4]. The central defining characteristic of CFS is debilitating fatigue, being precipitated by only minimal physical activity. Aetiological theories have vacillated between CFS being an as yet unidentified physiological disorder, possibly caused by viral infection [5], and CFS being the result of psychological dysfunction [6]. In the preoccupation with a search for causes, there has been an almost total neglect in research concerning the quality of life of patients suffering from CFS. The current situation is instead "dominated by the harmful and non productive dichotomization between physical (labelled as 'real') and psychological (labelled as 'unreal') illnesses, and a clear commitment to emphasizing the organic dimensions of the syndrome" [7]. As a result, the impact of this disorder on more subjective dimensions of everyday functioning has been largely overlooked. Quality of life has been broadly referred to in the past by such terms as 'well-being' [8], 'functional status' [9], 'health status' [10] and 'life satisfaction' [11]. These variety of terms and measurements serves to highlight the lack of agreement within the literature regarding how quality of life should be defined and, indeed, exactly what 'quality of life' is [12, 13]. Measurements in the field have ranged from an assessment of physical activity and social activity to *Author for correspondence. employment, housing, loss of income, self-esteem, sexual activity and even to incontinence [14]. The quality of life approach in particular views illness as impacting upon the patient's everyday physical, psychological and social functioning. Whilst in practice it is difficult to separate these dimensions, the patient's 'physical' reality refers to such phenomenon as their general physical state and ability for self-care; 'psychological' to the presence of emotional distress; and 'social' or more accurately, social role functioning, to the patient's relationships with friends and family, parenting, homemaking, occupational functioning and participation in recreational activities. Quality of life measurements are useful not only in documenting the impact of illness, but in their potential to contribute to the improvement of patient welfare. As with most chronic illnesses, the realistic and immediate aim of CFS sufferers, rather than being treatment and cure, is a reduction in the impact of illness on everyday physical, psychological and/or social functioning [15]. Further exploration and clarification of the specific problems associated with the quality of life in patients with these disorders should prove beneficial to the understanding and management of this syndrome. The present research is an exploratory study which aims to examine the impact of CFS on patients' everyday physical, psychological and social functioning. It is hypothesized that patients with CFS will differ from a healthy control group on these three dimensions of quality of life. From this investigation it is expected that various negative consequences of CFS contributing to a reduction in quality of life will be identified, and their potential for intervention highlighted. 1367 1368 Robert Schweitzer et al. METHOD Subjects CFSgroup. A total of 47 voluntary subjects, 46 with a confirmed diagnosis of CFS according to the diagnostic criteria of Lloyd et al. [16] and one subject with an acute fatigue syndrome which later met the diagnostic criteria for CFS, participated in the study. Subjects were recruited from two sources: (i) 37 consecutively recruited volunteer subjects were referred by a specialist physician in infectious diseases; and (ii) 10 subjects had responded to a newspaper article describing the current research and requesting subjects. As a result of diagnostic screening, 10 persons from a self-referred group of 17 subjects were eligible to participate. The total group comprised 14 (30%) males and 33 (70%) females, who had a mean age of 38 years (SD = 12 years) and had an average formal educational level of 13 years (SD = 2.6 years). Control group. Thirty non-clinical subjects drawn from a university undergraduate student population similar in age, sex and education level to the CFS group served as controls for this study. Subjects who reported either a current or chronic illness were excluded from this group. Overall there were 8 (27%) males and 22 (73%) females. The average age of subjects was 29 years (SD = 10 years), being slightly lower than that of CFS subjects, and the average level of education was 14.2 years (SD = 4 years). The Sickness Impact Profile (SIP) of the present control group was very similar to that reported in the literature for similar non-clinical subjects [10]. subjects in keeping with the fluctuating nature of the disorder were instructed to answer in relation to when they were 'feeling the symptoms of Chronic Fatigue Syndrome', and for the control group, in relation to their 'general state of health'. Semi-structured interview. A qualitative assessment of the impact of CFS on the lives of subjects was evaluated by means of a semi-structured, open-ended interview. Four areas ofpsychosocial functioning were explored: (i) relationships with family members; (ii) social relationships; (iii) ability to participate in recreational activities; and (iv) ability to earn a living or perform work tasks. RESULTS Preliminary analyses A preliminary analysis between the average overall SIP score for CFS patients who were physician-referred (mean = 33.85) and those who were self referred (mean --- 41.3) revealed that these two groups were not significantly different on this measure. As these two groups were also comparable in terms of age, sex, education and self-reported length of illness, they were combined to form a single CFS group for analysis of both questionnaire and interview data. Additional demographic characteristics for this combined CFS group are given in Table 1. Materials Sickness Impact Profile Sickness Impact Profile. The SIP [17] is a 136 item self-report questionnaire designed to provide a measure of sickness-related dysfunction. This questionnaire is intended to reflect a subject's perception of their performance across a range of daily activities covered by 12 categories: ambulation; body care and movement; mobility; sleep and rest; eating; emotional behaviour; alertness behaviour; social interaction; communication; home management; recreation and pastimes; and work. Three aggregate scores can also be calculated. These reflect performance in physical (average of ambulation, mobility and body care and movement scores) and psychosocial domains (average of social interaction, communication, alertness and emotional behaviour scores), as well as an overall score (average of all 12 scores). The components of the SIP not regarded as assessing physical or psychosocial functioning are referred to as other life-quality scales (including sleep and rest, eating, home management, recreation and pastime and employment). The written instructions at the beginning of the SIP were modified in the present study to make them applicable to both the patient groups and the control group. In particular, rather than having r e s p o n d e n t s tick which statements described themself'today', CFS Scores on the SIP were first compared between the CFS group and the control group. The mean scores for the 12 categories as well as the overall SIP score for both groups are given in Fig. 1. It can be seen from Fig. 1 that subjects in the CFS group reported much higher impairment than the healthy control group Table 1. Demographic characteristics of CFS group Marital status Married Single Divorced Widowed 23 21 2 1 (49%) (45%) (4%) (2%) Present occupation Unemployed Professional Skilled Semi-skilled Student 23 13 4 4 3 (49%) (28 % t (8.5 % ) (8.5 % ) (6%) 6 26 4 3 8 ( 13% ) (55%) (9%) (6%) (17%) Previous occupation Unemployed Professional Skilled Semi-skilled Student Mean self-reportedlength of illness: 5 years (SD = + 5 years) range: 1 month-21 years. Mean length since diagnosis: 1.4 years (SD = + 1.2 years) range: 1 week-5 years. Quality of life in CFS Table 2. Standard multiple regression of demographic variables on overall SIP score Variable Age Sex Illness (years) Education (years) r /~ sr (unique) -0.24 0.07 -0.17 -0.01 -0.21 0.09 -0.11 0.00 -0.04 0.01 --0.01 0.00 R = 0.27 R = 0.07 across all the SIP categories. As would be expected from these results, there was a significant difference in the overall SIP score between the CFS and control group [t(75)= 5.06, P < 0 . 0 1 ] . Forty-six of 47 subjects in the CFS group obtained an overall SIP score > 20, placing them in the severe range of illness related impairment. None of the control group obtained an overall SIP score > 6. The results of the comparison between CFS and control subjects on the SIP dimensions indicate that the quality of life of patients with CFS is impaired on both the physical and psychosocial domains, as well as on the individual quality of life scores. The most severely affected areas were those related to psychosocial functioning, as evidenced also through interview responses. No significant differences were found in the quality of life of CFS subjects who were currently working and subjects who had reportedly retired from employment as a result of CFS. CFS group vs control group and multiple sclerosis sufferers. Scores of the CFS suffers on the SIP were also compared with SIP scores of a sample of 81 multiple sclerosis (MS) sufferers, similar in age and sex to the present sample [18]. This comparison was considered to be useful, given that MS, like CFS, is a debilitating disease of uncertain prognosis [18]. As shown in Fig. 1, this comparison revealed that, in general, CFS sufferers reported more dysfunction than the multiple sclerosis sufferers. Overall SIP scores were higher in the CFS group than among the MS group [t(126) = - 8.02; P < 0.001]; however this difference was not due to differences in physical functioning [t(126) = < I;NS], but due to differences in functioning on the measure of psychosocial functioning [t(126=-9.85; P < 0 . 0 0 1 ] , and on the other life-quality measures (with the exception of eating; significant t's ranged from - 3 . 4 9 to -7.51; all significant at P < 0.01). Prediction of SIP scores from demographic variables. As quality of life can be a function of certain demographic variables, a standard multiple regression analysis was performed to examine the relationship between overall SIP scores and the age, sex, education level and self-reported length of illness of CFS subjects. Table 2 shows the results of this analysis, indicating that overall SIP scores could not be significantly predicted from information on any of the independent variables [F(4,42)= 0.84, NS]. Overall SIP scores were therefore considered to be independent of the demographic variables tested above. A direct discriminant function analysis was performed in order to determine which SIP category 1369 scores reliably differed between the CFS and control group. All 47 cases from the CFS group and 30 cases from the control group were retained, having met the assumptions of linearity, normality, singularity and homogeneity of variance-covariance. The obtained discriminant function significantly separated the two groups [X (12)= 155.11, P < 0.001], accounting for 89% of the between group variability. Using this discriminant function it was possible to correctly classify 46 of the 47 CFS cases and all 30 of those in the control group. The percent of grouped cases correctly classified was 98.7%. The ability of each of the 12 SIP categories to discriminate between CFS and control subjects is shown in Table 3 as the correlation between each category and the discriminant function. As can be seen from this table, the best categories for distinguishing between the two groups were alertness, recreation and pastimes, home management, social interaction and work, in decreasing order. The categories of alertness, recreation and pastimes, home management, social interaction and work obtained a correlation (loading) of 0.40 or greater, making them at least 'fair' discriminating variables [19]. These categories will therefore be interpreted from the discriminant analysis, although it should be noted that the means for all 12 categories were significantly different between the CFS and control group. At least 50% of CFS subjects endorsed items in the five most discriminatory SIP categories. All of these items describe decrements in performance, whether it be an inability to remain alert, participation in fewer recreational activities, reduced management of the home, less social interaction or difficulty in functioning at work. Employed vs unemployed CFS group. As indicated by SIP responses, 22 (47%) of the subjects with CFS reported having to retire from employment as a result of the symptoms of CFS. A direct discriminant analysis was therefore performed on SIP scores to determine if impairment in functioning was significantly different between the employed and unemployed CFS respondents. Table 3. Results of discriminant function analysis of SIP categories between CFS and control group SIP Category Alertness Recreation and pastimes Home management Social interaction Work Sleep and rest Ambulation Body care and movement Emotional behaviour Mobility Communication Eating *P < 0.001. Correlation of SIP category with discriminant function Univariate F (1,75) 0.70 0.54 0.44 0.41 0.40 0.39 0.37 0.33 0.29 0.29 0.25 0.14 313.3 * 187.1 * 122.8 * 104.9* 102.5" 95.95* 87.84* 68. I I * 52.53* 52.09* 38.27* 12.06" 1370 Robert Schweitzer et al. All 25 employed and 22 unemployed subjects were retained for the analysis, having met the required assumptions. With the category 'work' not included in the analysis, no reliable differences were found between the two groups on the discriminant function [X-', (11) = 11.7, NS]. This suggests that, on average, retired CFS subjects had the same percentage of impairment in each of the SIP categories as those who were still working. Qualitative interview data Responses from the 23 interviews were coded according to a number of major themes which emerged across subjects. A reliability check on this coding across 25 % of the data revealed an interrater reliability of 0.81, using a blind coding procedure between raters. Qualitative descriptions are given below of the impact which CFS reportedly had on subjects' family relationships, social relationships, recreational activities and performance in work tasks. Family relationships Almost half (43%) of the CFS subjects sampled described their family's initial reaction to their illness as being one of non-acceptance. Relationships were reportedly strained and family members appeared unwilling or at least resentful of having to offer support, or indeed, accept that the illness was real. As one subject described, "My stepmother thought I had 'imaginitis'. My mother took 2 years before she would accept that it was real." Whilst two subjects indicated that this non-acceptance has continued, even to the point of divorce, the majority (65%) described family members as now being highly understanding, supportive and concerned for their welfare. Having CFS seemed to foster greater closeness between these subjects and their family, reporting improved communication and warmth in their relationship with family members. In 48% of cases sampled, subjects described how family members took more responsibility for the tasks which they would otherwise do and 'nursed' them when they were feeling ill. This support and renegotiation of role tasks was offset in 22% of cases where subjects described becoming angry, cranky or frustrated with family members, and usually for no apparent reason. Thirty-percent of subjects also described having less available energy to devote to family activities, especially those involving their children--'I'm not myself, don't want to play with them, lose patience easily 'and' don't want to help them with their homework'. Social relationships In describing their social relationships, the majority of subjects reportedly experienced a reduction in both the number of friends and the amount of time spent with others. Six subjects stated that they did not 'socialize' at all, whilst all other subjects described their social activities as being severely limited. If subjects did participate in social activities, the typical practice for at least 80% of subjects was to return home early with the onset of fatigue. As participation in outings was reduced, so were the number of friends. It was the experience of at least 10 of the 23 subjects (about 40%) that friends were 'lost' out of a lack of understanding or acceptance of CFS. For one subject, CFS "destroyed social relationships . . . no one understood what my illness was", and another now has "fewer friends since several dropped me [her] like a 'hot potato'". Eleven subjects described how friends made less effort to keep in contact with them or seek their companionship. By the same token 57% of subjects sampled did not maintain social relationships because they felt they lacked the energy which this would involve. There was also a tendency for some subjects (46%) to avoid or at least not seek the companionship of those whom they did not know well or expected would be unaccepting or ignorant of CFS. Overall, in the majority of cases (69%), having CFS appeared to result in a limiting of social relationships to a few close, supportive and understanding friends. Recreational activities There appeared to be severe disruption to subjects' ability to participate in recreational activities. Seventy percent of those interviewed indicated having been forced to completely stop all physically active pastimes because of the resulting exacerbation of symptoms. The remaining 30% described having to give up physical activities only to a degree. This impairment is highlighted in 47% of subjects who described having been previously involved in highly active pastimes, such as one man who "stopped ten pin bowling, swimming, bushwalking, dancing, gym and weights!" Eighty-seven percent of subjects compensated this loss by taking up or increasing less physically active pastimes, such as walking, gardening and reading. For some (41%), even attempting these less active pastimes was met with such difficulties as "energy loss, [problems in the] supporting of body or limbs, eye fatigue and pain". Work tasks All 23 subjects who were interviewed seemed to experience a reduction in either the quantity and/or quality of their work, both at home and in paid-employment. This reduction was described as being the result of physical and mental symptoms of fatigue which resulted in subjects having trouble meeting deadlines (45%), producing more mistakes (30%) and, for 20%, having to give up responsibilities of the job such as supervision and decision-making. The majority (76%) appeared unable to work the same number of hours (as prior to their illness), typically having 'lost days, half days or [having] to leave after a few hours'. When performing work tasks, this 76% described how they 'paced themself' by resting when feeling fatigued. To complete work Quality of life in CFS requirements, 12 subjects indicated that they took their work home, whereas nine subjects 'chose' to spend more time at their place of work despite physical and mental fatigue. DISCUSSION While the sample size is relatively small and cannot be considered fully representative of patients presenting with CFS to a range of agencies, they did provide some insight and support for a more fine-grained understanding of the impact of CFS on the lives of those who received this diagnosis. Forty-six of 47 patients diagnosed with CFS were classified as having severe illness related impairment, independent of their age, sex, education level or length of illness. It is noteworthy that this degree of impairment, as reflected by overall SIP scores, is more extreme than the overall impairment reported by patients with untreated hyperthyroidism [20], end-stage renal disease [21] and heart disease [22]. As shown in the present study, it is also more extreme than the overall levels of impairment reported by a comparable group of MS sufferers. Only in terminally ill cancer and stroke patients has the overall SIP score been found to reach the mid 30s as reported in the current study of CFS [211. In comparison to healthy subjects, CFS patients appear to be most disadvantaged in relation to areas of social and role functioning. In particular, CFS appeared to impact upon patients' recreation and pastimes, home management, social interaction and work. Whilst significant impairment in functioning was also evidenced in other areas of subjects' lives, especially sleep and rest, emotional behaviour, mobility and communication, there was great variability in the reports of patients as to how much these areas were affected by CFS. The discussion will therefore focus on the impact of CFS on areas related to social functioning, due to the reported magnitude and consistency of impairment in this dimension of quality of life. A picture emerges from the SIP questionnaire and interview responses as to how CFS impacted upon the social functioning of subjects. Firstly, regarding recreation, subjects were typically prevented from participating in any physical activities due to the possible exacerbation of symptoms. Instead, subjects engaged more often in pastimes requiring little physical exertion. Even the energy spent on these latter activities however had to be reduced at times. Home management and functioning at work was characterized by subjects not being able to achieve the same quantity and/or quality of work output as subjects found themselves resting more often because of physical and mental fatigue. At home this meant that chores, repair work, cleaning and shopping were frequently left unattended while less accuracy was achieved in performing required tasks at work. The social support network of subjects was typically 1371 reduced to family members and/or a few close friends. Subjects described severe reductions in their participation in social activities and that, frequently, social relationships could not be maintained. Most subjects therefore relied upon family members for the understanding and support which they appeared to give willingly. Given these severe social and role activity restrictions at work, play and in relationships, it might be argued that it is not surprising that psychological symptoms of depression are so common in CFS. High co-morbidity rates of CFS and depression have been reported by researchers, even to the extent of diagnosing 80% of CFS patients as clinically depressed [5]. In addition, CFS patients have been shown to score significantly higher on scales of general hypochondriasis and disease conviction [23]. Depressive disorders have been demonstrated to produce severe impairment in social and physical functioning greater than many common chronic medical illnesses [24]. This may play a role in the quality of life and functional problems reported by those with CFS. Rather than entering into the debate as to whether depression is a causal factor in CFS however, the current findings might be most valuable for recognising and understanding the interaction of depression and illness behaviour in CFS patients" quality of life. Two pervasive consequences of CFS impacting upon patients' lives highlighted in the present study are social isolation and the loss of valued roles. The significance of social support as a mediator in coping with the deleterious effects of illness has been widely noted by researchers [25], as has its potential for contributing to positive somatic outcomes [26, 27]. In this respect credit must be given to family members of CFS sufferers, where their provision of a "'sense of s u p p o r t . . . [and] role flexibility have been identified by a variety of researchers as increasing the strength of family functioning, the members' sense of mastery of the challenges of illness, and also can lead to a more positive medical outcome" [25]. The potentially active role of family responses in contributing to chronic, disability and impairments also needs to be considered as reinforcers to illness behaviour. Similar educational programs may be of particular benefit within the workplace. Almost half of the subjects indicated retiring because of CFS, suggesting that for many this illness means the abandonment of a highly valued role--a role which could be seen as "giving meaning and structure to the day and aiding the acquisition of other resources, predominately social contacts, self-esteem, and financial independence" [27]. This study does however provide a general assessment of the impact of CFS on the everyday functioning of CFS patients. This impact has been shown to be extensive, supporting the observations of significant disruptions in usual daily activities which are required for assigning a diagnosis of CFS. Given 1372 Robert Schweitzer et al. the absence of a proven effective treatment for this illness, it should be the aim of future research to identify more specifically the type and range of impairments created by CFS, especially in the areas of physical and psychological functioning. In this way, future clinicians will gain a greater understanding of the everyday consequences o f CFS, and be assisted in developing appropriate psychosocial interventions [281. REFERENCES 1. McEvedy C. P. and Beard A. W. A controlled follow-up of cases involved in an epidemic of benign myalgic encephalomyelitis. Br. J. Psychiat. 122, 141, 1973. 2. Salit I. E. Sporadic postinfectious neuromyasthenia. Can. Med. Assoc. J. 133, 659, 1985. 3. Buchwald D. Sullivan J. L., and Komaroff A. L. Frequency of "chronic active Epstein-Barr virus infection" in a general medical practice. J. Am. Med. Assoc. 257, 2303, 1987. 4. Johnson H. Journey into fear--the growing nightmare of EBV. Rolling Stone 505, 42, 1987. 5. Wakefield D., Lloyd A. and Hickie I. The chronic fatigue syndrome. Modern Med. Aust. 16, 1990. 6. Hickie I., Lloyd A., Wakefield D. and Parker G. The psychiatric status of patients with chronic fatigue syndrome. Br. J. Psychiat. 156, 534, 1990. 7. Abbey S. E. and Garfinkel P. E. Chronic fatigue syndrome and the psychiatrist. Can. J. Psychiat. 35, 625, 1990. 8. Andrews. F. M. and Withey S. B. Social Indicators of Well-Being. Plenum Press, New York, 1976. 9. Stewart A. L., Ware J. E. and Brook R. H. Advances in the measurement of functional status: construction of aggregate indexes. Med. Care 19, 473, 1981. 10. Bergner M. Development, testing and use of the Sickness Impact Profile. In Quality of Life: Assessment and Application (Edited by Walker S. R. and Rosser R. M.), pp. 79-94. MTP Press Limited, Lancaster, 1987. 11. Campbell A. The Sense of Well-Being in America. McGraw-Hill, New York, 1981. 12. Barofsky I. Function states: quality of life. Cancer 53, 2299, 1984. 13. De Haes J. C. and van Knippenberg F. C. The quality of life of cancer patients: a review of the literature. Soc. Sci. Med. 20, 809, 1982. 14. Bergner M. Quality of life, health status, and clinical research. Med. Care 27(Suppl.), S148, 1989. 15. Fava G. A. Methodological and conceptual issues in research on quality of life. Psychother. Psychosomatics 54, 70, 1990. 16. Lloyd A., Wakefield D., Boughton C. and Dwyer J. What is myalgic encephalomyelitis? Lancet 1, 1286, 1988. 17. Bergner M., Bobbitt R. A., Kressel S., Pollard W. E., Gilson B. S. and Morris J. R. The Sickness Impact Profile: conceptual formulation and methodology for the development of a health status measure. Int. J. Hlth Serv. 6, 393, 1976. 18. Zeldow P. B. and Pavlou M. Physical and psychosocial functioning in multiple sclerosis. Descriptions, correlations, and a tentative typology. Br. J. Med. Psychol. 61, 185, 1988. 19. Comrey A. L. A First Course in Factor Analysis. Academic Press, New York, 1973. 20. Rockey P. H. and Griep R. J. Behavioural dysfunction hyperthyroidism. Arch. Int. Med. 140, 1197, 1980. 21. Hart L. G. and Evans R. W. The functional status of ESRD patients as measured by the sickness impact profile. J. Chron. Dis. 40, 117, 1987. 22. Bergner L., Bergner M., Hallstrom A. P., Eisenberg M. and Cobb L. A. Health status of survivors of out-of-hospital cardiac arrest six months later. Am. J. publ. Hlth 74, 508, 1984. 23. Schweitzer R., Robertson D., Kelly B. and Whiting J. Illness behaviour of patients with chronic fatigue syndrome. J. Psychosomatic Res. 38, 41, 1994. 24. Klerman G. L. Depressive disorders: further evidence of increased medical morbidity and impairment of social functioning. Arch. gen. Psychiat. 46, 856, 1989. 25. Sargent J. and Liebiman R. Childhood chronic illness. Issues for psychotherapists. Commun. Mental Hlth J. 21, 294, 1985. 26. Felton B. J. and Revenson T. A. Coping with chronic illness: a study of illness controllability and the influence of coping strategies on psychological adjustment. J. Consulting clin. Psychol. 52, 343, 1984. 27. DeLongis A., Folkman S. and Lazarus R. S. The impact of daily stress on health and mood: psychological and social resources as mediators. J. Personality soc. Psychol. 54, 486, 1988. 28. Locker D. Coping with disability and handicap. In Disablement in the Community (Edited by Patrick D. L. and Peach H.),pp. 176-196. Oxford Medical Publications, Oxford, 1989.