Family factors, emotional functioning, and functional impairment in juvenile fibromyalgia syndrome
Family factors and emotional functioning can play an important role in the ability of adolescents with juvenile primary fibromyalgia syndrome (JPFS) to cope with their condition and function in their everyday lives. The primary objectives of this study were to determine 1) whether adolescents with JPFS and their caregivers differed from healthy age-matched comparison peers and their caregivers in terms of emotional distress and functional impairment; 2) whether there were any differences in the family environment of adolescents with JPFS compared with healthy comparison peers; and 3) which individual-, caregiver-, and family-level variables were associated with functional impairment in adolescents with JPFS.
Participants were 47 adolescents with JPFS recruited from a pediatric rheumatology clinic and 46 comparison peers without chronic illness matched for age, sex, and race. Participants and their caregivers (all mothers) completed a battery of standardized measures administered in their homes.
Adolescents with JPFS had greater internalizing and externalizing symptoms than healthy comparison peers. Mothers of adolescents with JPFS reported twice as many pain conditions and significantly greater depressive symptoms than mothers of comparison peers. The JPFS group also had poorer overall family functioning and more conflicted family relationships. In adolescents with JPFS, maternal pain history was associated with significantly higher functional impairment.
Increased distress and chronic pain are evident in families of adolescents with JPFS, and family relationships are also impacted. Implications for child functional impairment and the need for inclusion of caregivers in treatment are discussed.
Juvenile primary fibromyalgia syndrome (JPFS) is a chronic pain syndrome that occurs in children and adolescents, primarily adolescent girls. JPFS is characterized by generalized musculoskeletal pain, multiple painful tender points, sleep difficulty, fatigue, and other symptoms such as emotional distress and irritable bowel symptoms (1). It is estimated that JPFS represents 7–40% of new referrals to pediatric rheumatology clinics (2, 3). Many adolescent patients with JPFS have high levels of disability, difficulty attending regular school, difficulty with peer relationships, and increased emotional distress (4–7). Increased emotional distress and greater pain sensitivity are also found among parents of adolescents with JPFS (4), and more research is needed concerning how familial factors, including parental pain history and emotional distress, affect the child's functioning.
Two lines of research underscore the importance of the role of the family in children and adolescents with JPFS. One line of research emphasizes potential genetic factors and another suggests environmental influences. Strong familial aggregation of fibromyalgia symptoms and coaggregation of mood and anxiety disorders in adults with fibromyalgia indicate a potential genetic component (8–10). However, the familial environment has also been proposed as being extremely important in understanding pediatric pain and associated disability (11). Parental solicitousness, family conflict, cohesiveness, parental pain history, and coping have all been associated with children's adaptation to chronic pain (11–14), but further research into the familial context in JPFS and implications for disability in patients with JPFS is needed. Involvement of family members is a necessary component of managing any chronic condition of childhood, and it is important to identify which aspects of the familial environment are important to consider when planning for intervention in adolescents with JPFS.
The current study was the second phase of a larger investigation of the psychosocial functioning of adolescents with JPFS. The objective of the larger study was to collect the most ecologically valid information about peer and family relationships of adolescents with JPFS using a matched case–control design. Data were gathered in the classrooms and homes of participants rather than the clinic setting to minimize the disease focus of the study and assess functioning in the adolescents' usual environment. In phase 1, data on peer relationships were collected in the classrooms of 55 adolescents with JPFS (ages 12–18 years) and 55 age-, sex-, and race-matched comparison peers without chronic illness. Each child in the classroom rated all others in the classroom on a number of dimensions of peer reputation and peer acceptance. Results showed that adolescents with JPFS had significantly more social difficulties, including problems with peer relationships and social isolation, than their matched comparison peers (7).
We report the results of phase 2, in which we conducted home visits to assess emotional and family functioning in the same cohort of participants from the peer study (JPFS and matched healthy comparison peers). We hypothesized that 1) adolescents with JPFS would be significantly more distressed and have greater functional impairment than comparison peers; 2) caregivers (mothers) of adolescents with JPFS would have significantly more depressive and anxiety symptoms, and a greater number of pain conditions compared with mothers of comparison peers; and 3) the family environment of adolescents with JPFS would be less supportive and more conflictual than families of comparison peers. Finally, we sought to determine which individual-, caregiver-, and family-level variables were associated with functional impairment in JPFS.
PARTICIPANTS AND METHODS
Participants in the initial phase of the study were 55 adolescents with JPFS recruited from a pediatric rheumatology clinic and 55 matched comparison peers selected from the classroom of each target adolescent with JPFS. To be eligible, JPFS patients had to meet the Yunus and Masi criteria (1), not have any other rheumatic disease (i.e., juvenile idiopathic arthritis, lupus), and be enrolled in regular school (i.e., no full-time special education or home-bound instruction). Enrollment in school was necessary, even if the child was not attending regularly, for selection of matched healthy comparison peers for phase 1 and phase 2 of this study. Of the 99 JPFS patients screened, 13 patients were ineligible due to home schooling/special education, and 5 could not be contacted. Of the 81 families approached, 59 (72.8%) agreed to participate, and we were able to obtain permission from 55 schools to conduct classroom data collection. Comparison peers were the most closely matched classroom peers based on date of birth, same sex and race, and no chronic illness. Of the 55 JPFS patients and 55 peers who participated in phase 1, 47 JPFS patients and 46 peers agreed to participate in the current study (84.5% of the original sample). Detailed methodology of the peer relationship study is described in a previous article (7).
Data were collected at the family's home at a time that was convenient for the family. Participation of both parents was requested, but most often mothers (99% mothers) agreed to participate. Therefore, this study focused only on data provided by adolescents and their mothers. Written consent from the parent and verbal and written assent from the adolescent was obtained. The child and mother completed measures independently. The study was carried out in compliance with current ethical standards for research with human subjects and was approved by the hospital institutional review board.
The Demographic Background Questionnaire included information about basic background characteristics, including the parents' marital status, education, income, and occupation. Familial socioeconomic status was determined using the revised Duncan Socioeconomic Index of Occupations 2 (15), a revised occupation-based measure of socioeconomic status (16).
The following measures were used to assess depressive symptoms, behavior problems, self-esteem, and impact of JPFS on daily functioning of adolescents.
Children's Depression Inventory.
The Children's Depression Inventory (CDI) is a validated and widely used measure of depressive symptoms in children and adolescents (17, 18) and is frequently used to assess depressive symptoms in pediatric pain populations (4, 5, 19). For each item, adolescents choose 1 of 3 responses, representing varying symptom levels that best describe their symptoms for the past 2 weeks. The CDI total T-score was used as an indicator of level of depressive symptoms.
Child Behavior Checklist.
The Child Behavior Checklist (CBCL) is a parent-report measure evaluating common behavioral problems for children age 6–18 years. The instrument has strong psychometric properties (20). It contains 120 questions about emotional and behavioral problems rated on a 3-point Likert scale (where 0 = not true and 2 = often true). Scores on the 2 primary higher-order scales of emotional and behavioral problems obtained from the CBCL (internalizing and externalizing) were used in this study.
Self-Perception Profile for Adolescents.
The Self-Perception Profile for Adolescents (21) measures adolescents' perceived competence in scholastic, athletic, social acceptance, physical appearance, behavioral conduct, and global self-worth domains. Six items compose each subscale, and subscales are summed to produce a Global Self-Worth score. The reliability and validity of these scales are acceptable, and this measure has been used in studies of adolescents with pediatric pain (22–24). The Global Self-Worth score was used as an overall indicator of adolescents' self-esteem in this study.
Modified Fibromyalgia Impact Scale for Children.
The Modified Fibromyalgia Impact Scale for Children (MFIQ) assesses the impact of fibromyalgia symptoms on the child's functioning and includes the following domains: general functioning, mood (anxiety and depression), pain, stiffness, fatigue, and sleep disturbance. The MFIQ was modified by Schanberg et al (12) from the Fibromyalgia Impact Questionnaire designed for adults (25) to make items developmentally appropriate for children and adolescents (e.g., by changing questions about employment to questions about school). The MFIQ has been used in juvenile fibromyalgia research (12, 26). Domain scores are summed to create a composite score. The total impairment score and pain intensity rating were used in this study.
Maternal pain history, maternal distress, and family environment were assessed using the following measures.
Parent Pain History Questionnaire.
The Parent Pain History Questionnaire assesses parental history of a variety of pain conditions. Twelve pain conditions are identified (e.g., migraine headaches, shoulder/neck pain, fibromyalgia, lower back pain), and parents indicate whether or not they have experienced each type of pain, and whether they sought medical treatment for each. The total number of pain conditions for which treatment was sought was used in this study as a measure of maternal pain history. This type of pain history questionnaire has been used in prior studies of pain history in parents of young adults and children with JPFS (12, 27).
The Symptom Checklist-90-Revised (SCL-90-R) is designed to assess emotional symptoms and psychopathology in adults (28). Items are rated on a 5-point Likert scale regarding the degree to which each symptom distressed the individual in the past week (0 = not at all, 4 = extremely). Scores on the anxiety and depression subscales were used in this study based upon past research indicating a higher prevalence of anxiety and mood symptoms in fibromyalgia patients and family members (8). The SCL-90-R has demonstrated adequate reliability (28) and has been previously used to assess distress in parents of children with chronic illness (29, 30).
The Family Environment Scale (FES) assesses the parent's perception of the family climate (31). The FES contains 10 subscales: cohesion, expressiveness, conflict, independence, achievement orientation, intellectual-cultural orientation, active-recreational orientation, moral-religious orientation, organization, and control (32). The internal consistency of some of the individual subscales has been found to be low, but a 3-factor model consisting of 3 higher-order scales (supportive, conflicted, and controlling) that are derived by combining individual subscales and an overall Family Relationship Index (FRI) has robust psychometric properties (33). The FRI and 3 higher-order subscales were used to test the hypotheses of this study.
All data were entered using SPSS software, version 14.0 (SPSS, Chicago, IL). Data were double entered by 2 research assistants and converted to SAS PROC COMPARE (SAS Institute, Cary, NC) to run a check for accuracy. After any errors in data entry were corrected and reconciled, data analysis was conducted using SPSS version 14.0. The first step was to compute descriptive information on demographic characteristics (Table 1) and measures of emotional and family functioning (Tables 2 and 3). A one-way, between-groups, multivariate analysis of variance (MANOVA) was conducted to examine differences between adolescents with JPFS and comparison peers on measures of emotional distress and functional impairment; differences between mothers of adolescents with JPFS and peers in terms of maternal pain history, anxiety, and depressive symptoms; and differences in family environment between adolescents with JPFS and peers. Holm's correction (a modified Bonferroni procedure) was applied to correct for multiple comparisons (34).
Table 1. Demographic characteristics of families and adolescents with JPFS (n = 47) and comparison peers (n = 46)*
|Family SES†||42.97 ± 20.85||49.70 ± 23.34|
|Father education, no. of years||13.79 ± 2.64||14.53 ± 2.85|
|Mother education, no. of years||14.09 ± 2.41||14.20 ± 2.47|
|Total number of children living at home||2.06 ± 1.07||2.31 ± 1.24|
|Adolescent's age||14.85 ± 1.67||15.02 ± 1.77|
|Mother's marital status: currently married||33 (70.2)||33 (71.7)|
|Adolescent's sex|| || |
| Boy||5 (10.6)||4 (8.7)|
| Girl||42 (89.4)||42 (91.3)|
|Adolescent's race|| || |
| African American||6 (12.8)||6 (13.0)|
| White||41 (87.2)||40 (87.0)|
Table 2. Descriptive data on adolescent functioning*
|Mother Report|| || || || |
| CBCL internalizing total score||61.04 ± 11.56||45.98 ± 8.53||58.71||0.000†|
| CBCL externalizing total score||53.28 ± 11.51||46.78 ± 10.27||10.65||0.002†|
|Child Report|| || || || |
| CDI total T-score||52.85 ± 12.18||48.13 ± 10.30||3.29||0.074|
| MFIQ|| || || || |
| Pain rating over past week (0–10)||5.35 ± 2.27||2.85 ± 2.83||16.08||0.000†|
| Total score||40.11 ± 14.07||27.27 ± 14.10||12.82||0.001†|
| Harter Self-Perception Profile|| || || || |
| Global-Self Worth||3.07 ± 0.67||3.28 ± 0.52||3.91||0.052|
Table 3. Descriptive data on maternal functioning and family environment*
|SCL-90-R|| || || || |
| Depression total T-score||57.00 ± 9.86||50.67 ± 8.71||7.97||0.006†|
| Anxiety total T-score||53.61 ± 10.97||47.56 ± 9.90||5.61||0.021|
|Parent pain history (0–12)|| || || || |
| Number of conditions treated||5.00 ± 2.56||2.51 ± 2.52||16.92||0.000†|
|Family environment|| || || || |
| Higher-order scales‡|| || || || |
| Supportive (0–45)||29.97 ± 6.48||32.51 ± 4.48||5.82||0.018|
| Conflicted (−18–9)||−8.02 ± 5.97||−10.71 ± 3.26||10.46||0.002†|
| Controlling (−9–27)||9.43 ± 4.13||10.31 ± 4.46||0.94||0.336|
|Family Relationship Index (−9–18)‡||9.21 ± 5.37||11.63 ± 2.99||9.86||0.002†|
Based on the results of the MANOVA, variables that significantly distinguished the JPFS sample from comparison peers were selected to be used as predictors in a hierarchical regression analysis. The purpose was to determine which individual-, caregiver-, and family-level variables were most strongly associated with functional impairment in the sample of adolescents with JPFS after controlling for pain intensity. The hierarchical regression was conducted in 3 steps. In step 1, the effects of pain intensity were entered; in step 2, the block of child variables was entered; and in step 3, the block of maternal and family variables was entered.
Our primary aim was to examine large and clinically meaningful differences between the 2 groups (JPFS and comparison peers). From the results of our previous peer relationship phase of the study, a large effect size (effect size = 1) difference between the 2 groups was expected. For the MANOVA analysis, a sample size of 46 in each group yielded 92% power to detect an effect size of 1.00, representing the difference between the group means of the 13 response variables of adolescent, maternal, and family functioning (Hotelling's T2; α = 0.05).
For the hierarchical regression analysis, we assumed that pain intensity would account for 25% of the variance (R2 = 0.25) in functional impairment, and the group of 6 child, maternal, and family variables (found to be significant in the MANOVA analysis) together would account for another 25% of the variance in functional impairment (F test; α = 0.05). Based upon these assumptions, we had a power of 93% to detect significant effects.
As shown in Table 1, the majority of adolescents with JPFS were white females (89.4%). The JPFS and comparison peer groups were similar in terms of age, sex, and race, as planned in the study design. On average, parents had a high school diploma and 2 years of college (or technical school). The average family socioeconomic status based upon the Duncan Index corresponded to occupational attainment at the technical, sales, or administrative support job levels.
Adolescent, maternal, and family functioning.
As hypothesized, the results of the MANOVA showed a statistically significant difference between the JPFS group and comparison peers on the combined dependent variables of adolescent functioning, maternal pain and distress, and family environment (F = 6.14, P = 0.000; Hotelling's T2 = 1.43; partial eta2 = 0.59). When the results for the dependent variables were considered separately, the following differences were found to be significant after correction for multiple comparisons: adolescents' pain intensity, functional impairment, internalizing and externalizing symptoms, maternal pain history, maternal depression, family relationship index, and the conflicted dimension of family environment. Adolescents with JPFS had significantly higher levels of pain, overall impairment, and internalizing and externalizing symptoms compared with their healthy comparison peers (Table 2). Mothers of adolescents with JPFS had significantly more pain conditions and depressive symptoms than mothers of healthy peers, and the JPFS group had poorer overall family relationships with significantly higher scores on the conflicted dimension of the FES (Table 3). Higher scores on the conflicted dimension indicated greater conflict, lower levels of cohesion, and lower organizational structure in the family. In addition, there was a trend (i.e., did not reach significance after Holm's correction) toward adolescents with JPFS reporting poorer self-esteem and mothers reporting greater anxiety and lower levels of family support.
In addition to the MANOVA analysis, data on maternal pain history were specifically examined for presence of fibromyalgia. We found that 24.3% of mothers of adolescents with JPFS reported having fibromyalgia. Only 5.7% of mothers of comparison peers had fibromyalgia, which is consistent with the prevalence of fibromyalgia syndrome in women in the general population (35).
Factors associated with functional impairment in adolescents with JPFS.
The dependent measure of interest in the hierarchical regression analysis was the level of functional impairment of the adolescents with JPFS (MFIQ total score). To examine factors that were associated with impairment after controlling for pain intensity, we entered pain intensity in the first step of the analysis, and then entered the 6 adolescent, maternal, and family environment variables from the MANOVA analysis that significantly distinguished between the JPFS and comparison peer groups in steps 2 and 3. The 6 variables were internalizing and externalizing symptoms (step 2), maternal pain history, maternal depressive symptoms, family relationship index, and conflicted dimension of the family environment (step 3). Results showed a significant overall model that explained 48.1% of the variance in functional impairment (Table 4). Not surprisingly, pain intensity was significantly associated with the level of overall impairment, explaining 37.0% of the variance. After pain intensity was accounted for, the remaining variables explained 11.4% of the variance, with maternal pain history being the only other significant predictor in the model.
Table 4. Results of hierarchical regression analysis on factors associated with functional impairment in adolescents with juvenile primary fibromyalgia syndrome*
|Step 1|| || || || |
| Pain intensity||0.629||0.000†||0.370||0.370|
|Step 2|| || || || |
| CBCL internalizing||0.103||0.584|| || |
| CBCL externalizing||−0.109||0.552||0.367||−0.003|
|Step 3|| || || || |
| SCL-90-R (mother) depression||0.204||0.219|| || |
| Mother: no. of pain conditions treated||0.597||0.007‡|| || |
| FES: Family Relationship Index||0.371||0.187|| || |
| FES: conflicted||0.317||0.277||0.481||0.114|
The findings of this study showed significant differences in the emotional functioning of adolescents with JPFS and their primary caregivers (mothers), as well as differences in the family environment of adolescents with JPFS, compared with healthy comparison peers. As hypothesized, adolescents with JPFS showed greater emotional and behavioral difficulties, but only as reported by their mothers. Mothers of adolescents in the JPFS group reported that their child had significantly greater internalizing symptoms (such as anxiety and depression) and greater externalizing symptoms (such as difficulties with attention and conduct problems). Interestingly, adolescents with JPFS did not rate themselves as having significantly greater depression or lower self-esteem than their healthy peers on self-report measures. This finding replicates findings from studies of other pediatric chronic pain samples in which adolescents' self-report of their own emotional and social functioning did not appear to suggest significant difficulties (22, 36). In contrast, studies utilizing standardized clinical interviews, in which both the parent and child provided information to a trained interviewer, demonstrated a high prevalence of anxiety disorders in patients with JPFS (37). While the discrepancy between parent or clinician reports and adolescents' own self-report may seem puzzling, it might suggest that children and adolescents with chronic pain do not have a sufficiently sophisticated understanding of their own emotional functioning to accurately respond to self-report questionnaires. In addition, they may be more focused on their pain symptoms and activity limitations, and less on their emotional responses. Gathering data from multiple sources is therefore highly desirable when assessing children and adolescents with chronic pain.
The findings of the present study, which used an unusually precise matched control group design, confirmed the results of past research indicating that mood difficulties and pain sensitivity tend to cluster in families (8), and that parents of adolescents with JPFS have a higher likelihood of experiencing chronic pain themselves (12). Mothers of adolescents with JPFS in this study reported significantly greater depressive symptoms than mothers of comparison peers. They also reported having twice as many pain conditions for which they received treatment, and they were more than 4 times as likely to have fibromyalgia compared with mothers of comparison peers. This clustering of symptoms may have a genetic basis, as past research has suggested. However, a familial environment in which a primary caregiver experiences chronic pain and depressive symptoms could also influence children's ability to cope with chronic pain and function in their everyday lives. In this study, we found that after adolescents' pain levels were taken into account, maternal pain history was the only variable that was significantly associated with level of impairment in adolescents with JPFS. These findings are consistent with findings from prior studies that demonstrated that parental history of chronic pain was associated with greater disability in children and adolescents with JPFS (13), as well as those with chronic back pain (14). This area of research is worthy of further study because it underscores the need for parent or caregiver involvement in behavioral treatment programs for adolescents with JPFS or other chronic pain conditions. Although some multidisciplinary pain programs already have a parent training component (38), there is converging evidence to suggest that a specific area requires special consideration, i.e., support or intervention for parents who experience chronic pain themselves.
As anticipated, significant differences in family environment were found in the JPFS group compared with healthy peers, with poorer overall family functioning in JPFS families. More specifically, JPFS family relationships tended to be characterized by higher levels of conflict, lower levels of cohesion, and less organizational structure than comparison families. Although this study did not find that the family environment was significantly associated with impairment in adolescents with JPFS, prior research has found that family factors affect impairment in adolescents with JPFS (12). Poorer family functioning may be a consequence of pain-related impairment or emotional distress in adolescents, and potentially their parents. Unfortunately, a more conflictual environment with less organizational structure has the potential to further exacerbate adjustment problems in adolescents with chronic pain. For example, this type of family environment may be less conducive to adherence with medical and behavioral treatment, and may contribute to inconsistent implementation of treatment recommendations.
We caution that the results of this study can be generalized only to adolescents with JPFS who seek subspecialty care and may represent those with more severe symptoms. We did not include home-schooled/special education children who may be the most severely impaired, but the results can be said to be applicable to most adolescents with JPFS typically seen in pediatric rheumatology clinics. Another limitation of this study was that it was cross-sectional in nature, precluding any determination of causality. Finally, the sample size was relatively modest, with sufficient power to only detect large differences. Therefore, more subtle effects of emotional factors and family environment may not have been detected. Longitudinal family studies with larger sample sizes are necessary to examine causal relationships between pain, impairment, and emotional functioning in family members, but this study lays the initial groundwork for further research.
In summary, the findings of this study provide increased insight into the multifaceted nature of the impact of JPFS on adolescents and families and the need for further attention to family issues in young patients with JPFS. At this time, there is no known cure for fibromyalgia. Many individuals do not benefit from currently available treatments, especially those patients with greater psychiatric comorbidity and interpersonal distress (39). Cognitive–behavioral therapy (CBT) has been shown to be a promising intervention for reducing pain, disability, and depressive symptoms in patients with JPFS (40). However, even for adolescents who receive CBT to address coping, it is not currently known whether CBT treatment effects in adolescents are maintained over time. Recent research has shown that dysfunctional parent–child interactions are related to impairments in social and role functioning in adolescents with chronic pain (36). Therefore, the family environment and emotional functioning of family members might impact whether CBT effects are supported or eroded over time, and must be considered an important aspect of intervention to prevent a long-term cycle of increasing disability and distress in patients with JPFS.
Dr. Kashikar-Zuck had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study design. Kashikar-Zuck, Graham, Noll.
Acquisition of data. Kashikar-Zuck, Lynch, Graham, Swain, Noll.
Analysis and interpretation of data. Kashikar-Zuck, Noll.
Manuscript preparation. Kashikar-Zuck, Lynch, Slater, Noll.
Statistical analysis. Kashikar-Zuck.