Socioeconomic status and health in women with systemic lupus erythematosus.
OBJECTIVE
Health outcomes of patients with chronic illnesses are commonly worse in people of lower socioeconomic status (SES). We investigated psychosocial factors that may mediate the relationship between SES and measures of morbidity in women with systemic lupus erythematosus (SLE).


METHODS
We collected information on SES, psychosocial factors, and health status in a cross sectional survey of 100 women with SLE. SES was rated using the Hollingshead Two-Factor Index, a weighted average of years of formal education and occupational prestige (higher Hollingshead Index=lower SES). Health status measures included the Health Assessment Questionnaire Disability Index (HAQ), the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR), the Systemic Lupus Activity Measure (SLAM), and the SLE Disease Activity Index (SLEDAI). Potential mediators consisted of 18 environmental, medical care, social, psychological, and behavioral factors.


RESULTS
Patients with higher Hollingshead Indexes (lower SES) had more functional disability as measured by the HAQ (r=0.22: p=0.03) and more cumulative organ damage as measured by the SLICC/ACR Damage Index (r = 0.19; p=0.06). SES was not related to either the SLAM or SLEDAI. Significant univariate associations were present between the Hollingshead Index and 10 potential mediating variables: household crowding, insurance status, organizational barriers to medical care, depression, health locus of control by powerful others, SLE knowledge, social support, marital status, body mass index, and regular alcohol use. However, in multiple linear regression analyses, only 3 of these variables modified the relationship between Hollingshead Index and the HAQ: more severe depression scores, higher body mass index, and more restricted access to medical care. More severe depression and greater locus of control by powerful others tended to mediate the relationship between low SES and greater organ damage.


CONCLUSIONS
SES is related to morbidity in women with SLE. There are identifiable and potentially modifiable mediators of this relationship.
Lotstein
D S
DS
Department of Medicine, Stanford University School of Medicine, California, USA.
Ward
M M
MM
Bush
T M
TM
Lambert
R E
RE
van Vollenhoven
R
R
Neuwelt
C M
CM
D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000503:physiopathology* / Q000523:psychology; D008875:Middle Aged; D009017:Morbidity; D012923:Social Class; D016387:Women's Health