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- SUBJECTS AND METHODS
- AUTHOR CONTRIBUTIONS
Juvenile dermatomyositis (DM) is a rare chronic inflammatory disease characterized by inflammation of muscles, skin, and other organs. Before the introduction of corticosteroid in the early 1960s, the mortality rate for patients with juvenile DM was approximately 30%, and many survivors were left with permanent impairment (1). The prognosis of juvenile DM has improved due to enhanced health care and medication. Nevertheless, a number of patients still develop irreversible impairment such as muscular, skeletal, and cutaneous damage, which may affect their health status (2).
A major goal in the treatment of children with juvenile DM is to ensure that the patient can grow up to have the best possible life. Patients' perceptions about their global quality of life (GQOL) and health-related quality of life (HRQOL) can provide important information about the impact of a disease on a patient's life. Such information can guide health care professionals in the care of future patients with juvenile DM and enhance their ability to promote quality of life (QOL) in such patients. Few studies have focused on QOL outcomes in adults with juvenile DM. A previous study from 27 centers in Europe and Latin America reported on 490 patients after a mean of 7.7 years of disease duration. The authors found decreased HRQOL in the physical domain and psychosocial domain in 10.5% and 12.8% of the patients, respectively (3). Another study from 37 countries reported on 272 children after a mean of 1.5 years of disease duration. These authors found children with juvenile DM to have impairment in their HRQOL, particularly in the physical domains (4). Huber et al reported on 65 patients after a median of 7.2 years of followup. They found that patients with juvenile DM had a favorable physical functional outcome measured by the Childhood Health Assessment Questionnaire, with a median score of 0 (range 0–2.50) (5).
Studies of other childhood rheumatic diseases have found patients to be at risk of unsuccessful social development, with a consequent impact on educational and vocational achievement (6–8). In patients with juvenile DM, little knowledge exists of long-term outcome in such areas (9).
The relationship between health and QOL is complex. Perceived health and QOL are not necessarily correlated. In chronic illness, perceived health can have an influence on patients' perceived QOL. This necessitates the use of GQOL and HRQOL measures in this study. GQOL reflects an individual's satisfaction with life (10, 11) and HRQOL reflects the individual's experience of their general health, such as physical, mental, and social well-being (12).
The primary objective of this study was to collect information regarding these issues from the perspective of the adult patient with juvenile DM. The following research questions are raised in this respect: 1) Does the QOL of the adult patient with juvenile DM differ from the general population? 2) Is there a relationship between HRQOL and GQOL in adult patients and the controls? 3) Is there a relationship between disease activity and GQOL and HRQOL in adults with juvenile DM? and 4) Do demographic characteristics such as education, employment, and income differ between adults with juvenile DM and the general population?
Significance & Innovations
Patients' perceptions about their global and health-related quality of life can provide important information about the impact of a disease on a patient's life.
Patients with juvenile-onset dermatomyositis have, after a median of 22.2 years from disease onset, reduced health-related quality of life in general health compared with the control group; however, mental health-related quality of life and global quality of life were comparable.
Reduced health-related quality of life in physical domains was associated with disease activity and damage.
- Top of page
- SUBJECTS AND METHODS
- AUTHOR CONTRIBUTIONS
In our case–control study, adult patients with juvenile-onset DM assessed a median of 22.2 years after diagnosis had comparable overall GQOL (measured by the QOLS-N) compared to the general population. They had poorer HRQOL (measured by the SF-36) in general health, but the other subscales were comparable. No significant relationships were found between HRQOL and GQOL. A correlation was found between HRQOL and disease activity, physical disability, and disease damage, but disease-related characteristics had no impact on GQOL. Patients had lower levels of income compared to the controls despite similar levels of education and occupational status.
The majority of the patients in this cohort were recruited from OUH, a referral-based center for children with rheumatic diseases in Norway. The number of patients in this cohort is relatively small, which is a limitation. However, we believe this cohort contains the majority of Norwegian adult patients with juvenile DM diagnosed between 1970 and 2006 (2). Patient characteristics in this cohort are comparable to other cohorts regarding age at diagnosis and duration from disease onset to diagnosis (2, 9). However, it cannot be ruled out that there may be patients who have not been included due to lack of contact with the departments of pediatrics and rheumatology. This could make the study biased toward more severe cases, which could have an influence on the results. Still, our study shows patients with juvenile DM to have favorable outcomes regarding QOL, despite the possibility of patients with milder cases of juvenile DM not being included.
It has been increasingly recognized that GQOL and HRQOL are important issues in order to provide a comprehensive understanding of the impact of a disease on a patient's life. We found that patients have poorer HRQOL measured by the SF-36 in general health, with a difference of 15 compared to controls. Differences in SF-36 subscales of more than 10 have been proposed to be of clinical difference when comparing normative numbers to groups with different conditions (24). It is not surprising that HRQOL of patients with juvenile DM can be affected by the disease, and the subgroups of the SF-36 enable us to evaluate which aspects of QOL are affected. General health quantifies patients' perceptions of their health (21).
Poorer physical functioning was associated with increasing age among patients with juvenile DM. An explanation for this could be that recent improvements in care and treatment have had a favorable outcome in younger patients. Another explanation could be that accumulations of damage due to years of persistent disease activity have resulted in decline of physical functioning, an explanation supported by the moderate correlation found between the MDI and physical functioning. A recent article has shown that patients in this cohort were treated less aggressively before 1990, which had a detrimental effect on other long-term outcome scores (2). The number of patients in this cohort is relatively small, and larger studies may be necessary to obtain further information regarding this finding.
Data from a Norwegian SF-36 health survey from the general Norwegian population have shown that physical health scores were reduced with increasing age (24); however, there was no correlation between age and physical functioning in the control group. An explanation for this could be that this cohort is relatively young. The median age of the control group was 32.5 years, and there was only 1 patient and 1 control age >50 years. A relatively young cohort could mean the effect of age would not yet be apparent in the healthy control group.
Results from our study indicate that a majority of the patients still have some disease activity or sequelae from the disease measured by the DAS, HAQ, and MDI. This has influenced their HRQOL, with an impact on physical functioning, role physical, general health, and social functioning. A previous article based on children and adults with juvenile DM in Norway found many patients to have muscle weakness (31–42%) and magnetic resonance imaging–detected muscle damage (51%) (29), which further support these findings. Despite this, adults with juvenile DM had similar scores to the controls in the physical functioning, role physical, bodily pain, vitality, role emotional, and mental health subscales and the summary scores of the SF-36. The patients and the controls also had similar total scores on GQOL measured by the QOLS-N, indicating that the impact of the disease on the mental health domains and GQOL is limited or it has no impact at all. Even though we found that GQOL was similar between the patients and controls, the patients were less satisfied with their health and personal safety. They were, however, more satisfied with their relationships with parents and close relatives. A study based on face-to-face interviews with adult patients with juvenile idiopathic arthritis (JIA) found the patients to have strong emotional bonds toward their parents based on the parents' involvement in the disease followup (30). Many of the patients in this study may have had similar experiences, which could explain this finding.
Several factors may contribute to good outcomes in satisfaction with life and mental health. Individuals may adapt to their situation over time and this response shift can play an important role in their perception of QOL (31, 32). Measurement of GQOL and mental health can, however, be difficult and arbitrary since individuals do not have the same frame of reference when answering a given question. Some studies have found chronic illness or health to have an impact on QOL (8, 33), whereas other studies have found that people with severe chronic illnesses have reported QOL equal or superior to healthy people (34, 35). This study has found adults with juvenile DM to be as content with their QOL measured by the QOLS-N and mental health measured by the SF-36 as healthy controls. The significant factors contributing to this finding are, however, not apparent.
This study showed weak correlations between the sum score of the QOLS-N and the SF-36 subscores among the patients, but some moderate correlations existed among the controls. Patients' adaptation to their situation could offer an explanation for this finding. Adaptation to a situation regarding health would imply that satisfaction with QOL may be less affected by health. The DAS, HAQ, and MDI scores were not associated with GQOL, indicating that poor outcome on disease activity and physical disability should not necessarily be equated with poor QOL. Findings similar to this were found in a study of patients with cystic fibrosis who, despite symptoms from a serious disease, reported having better QOL than controls (35).
Patients in this study have a similar level of education to the control group, but despite similar educational achievement, the annual income level was less for the patients than the controls. It should be noted that the controls answered the questionnaire an average of 1 year later than the patients; however, this is unlikely to account for these differences. The patients and controls were from both urban and rural areas, but were not matched based on residency location. Despite Norway being relatively uniform regarding unemployment rate and income level, we do not know if location of residency has influenced the results.
Lack of a relationship between education and income in patients with chronic illness has been demonstrated in a study of young adults with persisting absence epilepsies (36). Other studies have shown that adults with JIA are comparable to healthy controls in terms of level of education, but results on occupational outcomes have varied in different studies (8, 37). Employment status can play an important role in social integration and can be a good measure of the social consequences of juvenile DM. A study showed that 78% of patients with JIA reported the disease to have influenced their choice of occupation (6). In the present study it is unclear whether the level of education has led to employment appropriate to that level, or if the disease has influenced the choice of education and/or career. In order to help patients facing potential occupational challenges, early career advice with followup into adulthood may be an area to focus on in the future.
A limitation of this study lies within the conceptual framework of QOL and the constraints of the QOLS-N and SF-36. Although used widely, they are generic instruments that may not cover or accurately measure domains significant to adults with juvenile DM. In order to achieve a more comprehensive knowledge about QOL in juvenile DM and the multidimensional aspects that could influence QOL, further research is required.
In summary, we found that juvenile DM can have an impact on the adult patient's QOL. Adult patients with juvenile DM have reduced HRQOL after a median of 22.2 years from disease onset within general health. However, patients reported overall GQOL and mental HRQOL comparable to the control group, suggesting that patients with juvenile DM have good GQOL in adult life without long-term psychosocial effects. Hopefully further improvement in patient care and medical treatment will provide even better long-term outcomes in the future.