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Keywords:

  • Systemic lupus erythematosus;
  • Health-related quality of life;
  • Disease activity;
  • Organ damage

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

Objective

To assess the health-related quality of life (HRQL) of patients with juvenile-onset systemic lupus erythematosus (JSLE) and its relationship with disease activity and accumulated damage.

Methods

In this cross-sectional study, HRQL was assessed using the Child Health Questionnaire (CHQ), disease activity using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and accumulated damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI).

Results

A total of 297 patients were included. The mean ± SD physical and psychosocial summary scores of the CHQ were 40.2 ± 15.0 and 44.8 ± 10.7, respectively. The most impaired CHQ subscales were global health, general health perceptions, and parent impact–emotional. The SLEDAI score was significantly correlated with both the physical summary score (r = −0.29, P < 0.0001) and psychosocial summary score (r = −0.25, P < 0.0001), whereas the SDI score was significantly correlated only with the physical summary score (r = −0.23, P = 0.0001).

Conclusion

We found that patients with JSLE have significant impairment of their HRQL, particularly in the physical domain. HRQL may be affected by both disease activity and accumulated damage, particularly in the renal, central nervous, and musculoskeletal systems.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

The survival of patients with juvenile-onset systemic lupus erythematosus (JSLE) has increased considerably over the past 2 decades, partly due to earlier diagnosis, recognition of mild disease, and better approaches to treatment (1). In parallel with the significant improvement in life expectancy, patients with JSLE are now exposed to a considerable risk of morbidity, which can be due to the sequelae of disease activity, side effects of medications, and comorbid conditions (2, 3). Because this morbidity may raise problems related to physical and psychological adaptation to chronic illness, pediatric rheumatologists are becoming more aware of the need to measure health-related quality of life (HRQL) of children and adolescents with lupus.

Health status, disease activity, and accumulated damage are regarded as important independent outcome measures of SLE (4) and are recommended for use in longitudinal followup studies (5). However, little information exists on the relationship among these 3 outcome domains in lupus patients with disease onset during the pediatric or adolescent years.

In this study, we assessed the HRQL of patients with JSLE and evaluated the relationship between the level of HRQL in the different health areas and presence of disease activity and accumulated damage in the organ systems that can be affected by lupus.

METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

Study design and patient population.

Patients included in this study were part of a cross-sectional multicenter survey aimed at investigating the frequency of accumulated damage and its risk factors in JSLE (3). The eligibility criteria of the survey were the following: 1) at least 4 American College of Rheumatology (ACR) criteria for SLE (6); 2) age <18 years at disease onset; 3) disease duration ≥12 months at study entry; 4) informed consent. To be included in the present study, patients had to have an assessment of HRQL and a simultaneous assessment of disease activity or accumulated damage.

Control groups.

The results of HRQL assessment in JSLE patients were compared with those reported in the literature for 649 patients with juvenile idiopathic arthritis (JIA) and 1,333 healthy children from Italy (7), Greece (8), US (9), and Mexico (10). Age range was 5–18 years in both JIA patients and healthy children. No control group was available from Japan.

Measuring instruments.

HRQL was evaluated through Italian (7), Greek (8), American English (9), and Mexican (10) parent versions of the Child Health Questionnaire (CHQ). Because the CHQ has not yet been validated in Japan, the questionnaire was completed by Japanese parents after verbal translation of each item from the American English version by the physician. Briefly, the CHQ (9) is a generic instrument that is modeled after the adult Short Form 36 and is designed to capture the physical, emotional, and social components of health status of children of at least 5 years of age. The CHQ comprises 15 subscales: global health (GGH); physical functioning (PF); role/social limitations–emotional/behavioral (REB); role/social limitations–physical (RP); bodily pain/discomfort (BP); behavior (BE); general behavior (GBE); mental health (MH); self esteem (SE); general health perceptions (GH); change in health (CH); parent impact–emotional (PE); parent impact–time (PT); family activities (FA); and family cohesion (FC). The questionnaire is completed by a parent, who is asked to recall the preceding 4-week period for all subscales except for the GGH, GH, CH, and FC scales. The recall stem for CH is “compared to last year.” Because the GGH, GH, and FC subscales ask about health and family relationships “in general,” no recall period is used. Scores for each subscale range from 0 to 100, with higher scores reflecting better health status. In addition, 2 summary measures have been created through the aggregation of 10 of the 15 subscales (PF, RP, BP, GH, REB, PT, PE, SE, MH, BE): the physical summary score (PhS) and the psychosocial summary score (PsS). These have been standardized to have a mean of 50 and a standard deviation of 10. Higher scores in the scales indicate better HRQL.

Disease activity was assessed using the SLE Disease Activity Index (SLEDAI) (11). The version covering the last 10 days was used. It is a validated disease activity measure that contains 24 descriptors in 9 organ systems, including clinical and laboratory measures of SLE activity, and is weighted to reflect the degree of activity. The total SLEDAI score can range from 0 (no activity) to 105 (maximum activity).

Accumulated damage was measured using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) (12, 13). It is a validated physician-rated index that consists of 41 items in 12 organ systems/domains. Damage is defined as any nonreversible change not related to active inflammation occurring since onset of SLE, ascertained by clinical assessment and present for at least 6 months. Damage may be due to the disease itself, its treatment, or comorbid illnesses. The damage index score can only increase over time, theoretically to a maximum of 49.

Disease onset was defined as the time the patient fulfilled the ACR criteria for SLE (6). Disease duration was defined as the period from disease onset to the time of the study assessment.

Statistics.

Descriptive statistics were reported as absolute frequencies and percentages for qualitative data, and as means, medians, and standard deviations (SDs) for quantitative data. Spearman's rank correlation coefficient was used to evaluate the relationship between the SLEDAI or SDI scores and the CHQ PhS or PsS. The Student's t-test was used to compare the mean values of the CHQ subscales in patients with or without each item of the SLEDAI or SDI. Whenever the assumption of homoscedasticity was not fulfilled or the number of cases was very low, the Mann-Whitney U test was used to perform the comparisons, and the median values were reported instead of the mean values. The one-way nonparametric analysis of variance (Kruskal Wallis test) was conducted to compare the values of the CHQ subscales for the SDI items with 3 possible categories (0 = absent, 1 = present, 2 = repeated episodes) and when the relationship between the CHQ summary scores and the SLEDAI and SDI scores was evaluated after categorization of the 2 latter scores in 4 severity levels. All statistical tests were 2 sided; a P value < 0.05 was considered statistically significant. The statistical package Statistica for Windows (release 6; StatSoft, Tulsa, OK) was used to perform all analyses.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

Of the 387 JSLE patients included in the cross-sectional survey (3), 297 had an assessment of HRQL and a simultaneous evaluation of disease activity or accumulated damage and were thus eligible for this study. The main clinical and demographic features of these patients are reported in Table 1. The 90 noneligible patients were comparable to the 297 enrolled patients with regard to sex, ethnicity, age at diagnosis, and SLEDAI and SDI scores, but were older (mean ± SD 19.8 ± 5.8 years versus 16.2 ± 4.9 years; P < 0.001) and had a longer disease duration (mean ± SD 7.1 ± 5.0 years versus 4.3 ± 4.3 years; P < 0.001) at study entry.

Table 1. Demographic and clinical characteristics of 297 patients with juvenile-onset systemic lupus erythematosus*
 No. (%)Mean ± SDMedian
  • *

    SLEDAI = Systemic Lupus Erythematosus Disease Activity Index; SDI = Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

Sex (M/F)45/252  
Race   
 Caucasian104 (35.0)  
 Hispanic96 (32.3)  
 Japanese49 (16.5)  
 African American27 (9.1)  
 Asian13 (4.4)  
 Others8 (2.7)  
Age at diagnosis, years 11.9 ± 3.312.3
Age at study entry, years 16.2 ± 4.915.9
Disease duration at study entry, years 4.3 ± 4.32.9
SLEDAI score 7.2 ± 6.95
SDI score 1.1 ± 1.51

Table 2 shows the results of the HRQL assessment in patients with JSLE and in the 2 control groups. HRQL in JSLE patients was not significantly different across the 4 national cohorts, although patients from Mexico tended to have a worse HRQL in both the physical and psychosocial domains (data not shown). The mean ± SD PhS score was 40.2 ± 15.0 and for PsS, it was 44.8 ± 10.7. These results are in the low range of those observed in JIA patients (who also had a greater impairment in the physical health domain), but much lower than those reported in healthy children. The most impaired CHQ subscales were GGH, GH, and PE. As compared with healthy children, JSLE patients had lower values in all subscales of the CHQ, with the exception of BE and CH, which were in the range of those observed in healthy subjects. As compared with children with JIA, patients with JSLE tended to have a greater reduction of SE and GH, and to a lesser degree of BP.

Table 2. Mean ± SD values of the 15 subscales and 2 summary scores of the CHQ in patients with JSLE, patients with JIA, and in healthy children*
 JSLEJIA (n = 649) MeanHealthy children (n = 1,333) Mean
No. patientsMean ± SD
  • *

    CHQ = Child Health Questionnaire; JSLE = juvenile-onset systemic lupus erythematosus; JIA = juvenile idiopathic arthritis.

  • CHQ values from patients with JIA and healthy controls were available only in Italy, Greece, US, and Mexico (data from references 7–10). For each scale, the minimum and maximum of the mean reported values are indicated.

  • Not available for the US.

CHQ subscales    
 Global health (GGH)29352.2 ± 25.946.1–65.483.6–94.6
 Physical functioning (PF)29376.5 ± 28.265.4–79.796.1–97.7
 Role/social limitations–emotional/behavioral (REB)29080.6 ± 29.170.0–92.092.5–96.8
 Role/social limitations–physical (RP)28877.9 ± 31.969.5–87.793.6–98.9
 Bodily pain/discomfort (BP)29371.3 ± 27.458.3–70.481.7–94.9
 Behavior (BE)29374.0 ± 18.871.4–78.173.9–94.8
 General behavior (GBE)28666.4 ± 23.958.4–75.369.5–86.4
 Mental health (MH)29368.7 ± 20.065.5–78.174.9–83.1
 Self esteem (SE)29264.9 ± 20.365.1–80.478.0–90.7
 General health perceptions (GH)29446.2 ± 16.347.9–59.569.0–79.8
 Change in health (CH)27567.7 ± 31.255.7–78.359.1–74.5
 Parent impact–emotional (PE)28951.3 ± 30.145.6–72.062.7–80.3
 Parent impact–time (PT)28876.2 ± 28.971.3–86.587.8–94.1
 Family activities (FA)28877.0 ± 24.475.1–77.488.0–91.8
 Family cohesion (FC)28963.8 ± 27.060.0–75.270.5–83.1
Summary scores    
 Physical score (PhS)27440.2 ± 15.042.1–49.253.0–55.3
 Psychosocial score (PsS)27444.8 ± 10.744.6–53.449.2–55.2

The SLEDAI score was significantly correlated with both the PhS score (r = −0.29, P < 0.0001) and the PsS score (r = −0.25, P < 0.0001), whereas the SDI score was significantly correlated only with the PhS score (r = −0.23, P = 0.0001). These relationships were confirmed after categorization of the SLEDAI and SDI scores in 4 different severity levels, as shown in Figures 1 and 2. Both curves confirmed a progressive decline of HRQL with increasing disease activity and accumulated damage, with the effect being more pronounced in both instances on the physical than on the psychosocial health domain.

thumbnail image

Figure 1. Relationship between the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score and the 2 summary scores of the Child Health Questionnaire (physical summary score [PhS] and the psychosocial summary score [PsS]).

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thumbnail image

Figure 2. Relationship between the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC) score and the 2 summary scores of the Child Health Questionnaire (physical summary score [PhS] and the psychosocial summary score [PsS]).

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The analysis of the relationship between the single items of the CHQ and the SLEDAI descriptors is reported in Table 3. Overall, the greater impairment of HRQL occurred in patients with active disease in the central nervous, renal, and musculoskeletal systems. Looking at more specific associations, the presence of active nephritis and seizure most significantly affected family life (PE, PT, and FA); lupus headache was the only disease manifestation that impaired MH; and pleurisy and fever had a more significant impact, respectively, on BP and CH. It is worth noting the marked reduction of SE associated with renal disease. As compared with arthritis, myositis had a greater influence on the physical health and FA. In general, HRQL abnormalities were more associated with clinical features than with laboratory abnormalities. The BE, MH, and FC were the CHQ subscales least affected by active lupus manifestations.

Table 3. Comparison of the mean or median values of the CHQ subscales in patients who had or did not have each descriptor of the SLEDAI (n = 297); only significant comparisons are reported*
SLEDAI descriptorNo. with attributeCHQ subscale
Score for those with attribute/score for those without attribute
GGHPFREBRPBPBEGBEMHSEGHCHPEPTFAFC
  • *

    Only Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) descriptors that were observed in at least 4 patients were considered. Figures refer to mean values whenever the Student's t-test was performed and to median values whenever the Mann-Whitney U test was performed. For abbreviations, see Table 2.

  • P < 0.05 by Mann-Whitney U test.

  • P < 0.01 by Mann-Whitney U test.

  • §

    P < 0.05 by Student's t-test.

  • P < 0.01 by Student's t-test.

  • #

    P < 0.001 by Student's t-test.

Seizure40/600/880/100     33/6717/470/750/5011/8921/88 
Psychosis40/60   30/80    17/4713/75    
Lupus headache9   57/79§52/72§59/75§ 49/70  44/69§    
Vasculitis14           31/53*   
Arthritis25   65/80§56/73     49/69    
Myositis415/606/8917/10017/10025/80   44/67 25/75  31/88 
Urinary casts31  89/100     56/66  39/54   
Hematuria6244/5570/79§ 83/10062/74 59/70 56/68# 50/7541/55#   
Proteinuria5943/5565/80#89/10067/10060/80 62/69§ 62/6739/4850/7541/5578/8975/88 
Pyuria14 57/78 55/8051/73   53/66§  37/53§   
New rash5246/54§              
Alopecia21               
Mucosal ulcers9           30/53*48/77**  
Pleurisy415/60 56/10050/10030/80   42/67 38/7529/50   
Pericarditis730/53§     46/68§        
Low complement15849/58       63/69§ 64/73§    
Increased DNA binding16050/57§74/81§78/85§   65/72§ 62/69§ 64/74§48/57§   
Fever2930/60§     58/69§ 57/66§ 50/70    
Thrombocytopenia19        56/66§     53/66§
Leukopenia32      57/69        

Table 4 reports the relationship between damage in the more frequently affected SDI items and the diverse health domains of the CHQ. The presence of renal damage had the greater negative impact on the patients' HRQL and was more associated with general health (GGH, GH), physical health (PF, RP, BP), and family life (PE, PT, FA). The second most common cause of HRQL impairment was musculoskeletal damage, which mostly affected physical health (PF, RP, and BP) and family life (FA, PT). Other noteworthy associations were that of retinal change/optic atrophy with SE, of cognitive impairment/major psychosis and seizures with behavioral items, and of cerebral vascular accidents with PT. Among the family life items, PT and FA were more affected by the presence of accumulated damage than PE and FC. Damage did not affect MH and CH.

Table 4. Comparison of the mean or median values of the CHAQ subscales in patients who had or did not have each item of the SDI (n = 297); only significant comparisons are reported*
DescriptorNo. with attributeCHQ subscale
Score for those with attribute/score for those without attribute
GGHPFREBRPBPBEGBEMHSEGHCHPEPTFAFC
  • *

    Only SDI items that were observed in at least 5 patients were considered. Figures refer to mean values whenever the Student's t test was performed and to median values whenever the Mann-Whitney U test was performed. CHAQ = Childhood Health Assessment Questionnaire; SDI = Systemic Lupus Erythematosus International Collaborating Clinics/American College of Rheumatology Damage Index; CI = cognitive impairment; GFR = glomerular filtration rate; for other abbreviations, see Table 2.

  • P < 0.05 by Student's t-test.

  • P < 0.01 by Student's t-test.

  • §

    P < 0.01 by Mann-Whitney U test.

  • P < 0.001 by Mann-Whitney U test.

  • #

    P < 0.001 by Student's t-test.

Cataract1941/53              
Retinal change/optic atrophy7        41/66     42/64
CI or major psychosis27     67/75   40/47     
Seizures19     64/7556/67  38/47  64/77 50/65
Cerebral vascular accident1135/5360/77          53/77  
GFR < 50%2039/5361/7867/100§56/7956/73    38/47 37/5359/7864/88§ 
Proteinuria 24 hour ≥ 3.5 gm5746/5467/79 83/100§63/73    42/47  67/8971/88§ 
Minor tissue loss8               
Muscle atrophy or weakness14 61/77          59/7759/78 
Deforming/erosive arthritis5   47/7842/72        49/78 
Avascular necrosis16 56/78  47/73#    34/47   65/78 
Chronic scarring alopecia12  56/8257/79           
Skin scarring11               
Skin ulceration15            60/77  
Gonadal failure11               

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

In recent years, it has been increasingly recognized that a complete assessment of pediatric patients with chronic rheumatic diseases requires an understanding of the impact of the disease and the prescribed therapies on their lives (14, 15). Our study is the first to provide a comprehensive assessment of the HRQL of patients with JSLE and a comparison with pediatric patients with another chronic rheumatic condition (JIA) and healthy controls. We selected the CHQ because it was the sole instrument validated in the countries that participated in the study (with the exception of Japan) and for which published data for patients with JIA and healthy children and adolescents were available.

Our results indicate that, on average, patients with JSLE have a poorer HRQL as compared with healthy controls in both physical and psychosocial domains, with physical health being more affected. The areas of HRQL most affected by JSLE were global health, general health perceptions, and parent impact–emotional. This would suggest that parents of JSLE patients are mostly concerned with their child's overall health and resistance/susceptibility to sickness and they are emotionally distressed about their child's physical, emotional, mental, and social functioning. Behavior and change in health subscales were the only CHQ subscales that were in the range of the control group. This may indicate that the patients had no behavioral problems, had an unimpaired ability to get along with others, and were not perceived by their parents as having had significant health deterioration in the year preceding the study visit. As compared with JIA patients, JSLE patients revealed a very similar HRQL, although they tended to have a lower intensity and frequency of bodily pain and discomfort, a more compromised self esteem, and a worse parents' subjective assessment of overall health and illness.

We found that the scores registered on the SLEDAI were highly correlated with both CHQ summary scores, although to a greater degree with the PhS. SDI scores were significantly correlated with the PhS but not with the PsS. The latter finding may lead one to postulate that once irreversible damage has occurred, its effect on physical function will be long lasting, whereas social, mental, emotional, and behavioral health may adapt and improve over time. It should be taken into account, however, that the more marked effect of disease activity versus damage on HRQL may be partially due to the fact the study patients had a relatively higher degree of activity as compared with damage.

The analysis of the relationship between the single descriptors of the SLEDAI and items of the SDI with the 15 subscales of the CHQ (Tables 3 and 4) revealed that the presence of active clinical/laboratory manifestations tended to exert a generalized influence on the HRQL domains, whereas the presence of damage in the diverse systems affected physical health and family life functioning more. Within family life, ongoing disease activity had a greater impact on the parents' emotional distress, whereas accumulated damage led more commonly to limitations in the parents' time and to disruption in the usual family activities. Both disease activity and damage modestly affected family cohesion, indicating that the severity of the illness and its consequences may not significantly alter the ability of family members to get along with one another. Overall, the more profound impairment of HRQL occurred in patients with active disease or accumulated damage in the renal, central nervous, and musculoskeletal systems. The relationship of HRQL with renal and central nervous system manifestations, which are generally associated with a worse clinical course and prognosis (1), may reflect, as suggested in adult-onset SLE (16), a tendency for patients with a progressive and potentially life-threatening disease to report lower HRQL, even if their actual symptomatology is relatively benign. However, because patients with renal or central nervous system disease are commonly treated with the more aggressive corticosteroid and immunosuppressive drug regimens, their poorer HRQL, particularly the impairment of self esteem in adolescents, can also be related to the changes in body image due to the side effects of medications. As expected, the presence of either active disease or damage in the musculoskeletal system led to worse physical functioning, caused more bodily pain and discomfort, and significantly disrupted family activities. The accumulation of damage in any organ or system did not impair mental health and did not lead parents to perceive any significant change in their child's health over the previous year.

We must acknowledge the study limitation due to its cross-sectional nature. Because JSLE is a long-lasting disease characterized by periods of exacerbation and remission, there can be remission phases in which patients feel well and exacerbation phases in which they can be acutely ill. It is therefore difficult to determine a causal relationship in a cross-sectional study, since there is doubt about the timing of the relationship.

In summary, we found that patients with JSLE have significant impairment of their HRQL, particularly in the physical domain. HRQL may be affected by both disease activity and accumulated damage, particularly in the renal, central nervous, and musculoskeletal systems. Longitudinal prospective studies are needed to examine the relative change in health status, disease activity, and damage over time and to search for disease variables that predict changes in these disease domains at followup.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES
  • 1
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