Income, Education May Affect How Patients View Their Capabilities
Among people with systemic scleroderma, education and income are major determinants of perceived functional ability, a new study indicates.
Findings also point to skin involvement and age as substantial determinants of functionality.
“These results may serve to give clinicians novel insight into the predictive factors of patient function and its importance to survival,” the researchers wrote. “Closer monitoring of systemic [scleroderma] patients may be warranted based not only on clinical and laboratory findings, but also on an increased awareness and understanding of socio-economic factors that impact disease progression.”
The study, “Predictors of Perceived Functional Status in Early Systemic Sclerosis: A Prospective Longitudinal Study of the GENISOS Cohort,” was published in Arthritis Care & Research.
Systemic scleroderma, also called systemic sclerosis (SSc), is characterized by the accumulation of scar tissue in the skin and/or other organs. The disease can have a substantial effect on patients’ ability to function daily; however, the factors that influence how patients perceive their own ability to function over time are incompletely understood.
Thus, a team of scientists in Texas conducted an analysis of data from 388 participants in the Genetics Versus Environment in Scleroderma Outcome Study (GENISOS) group, a prospective study of early SSc started in the late 1990s. Among the patients, 52% were white, 18% African American, and 26% Hispanic, and the average disease duration upon study entry was 2.5 years.
At baseline (study start) and regularly over an average follow-up time of nearly four years, participants completed the modified Health Assessment Questionnaire (mHAQ), a self-reported measure of ability to function. Higher scores on the mHAQ indicate greater impairment and, consequently, poorer functionality.
“The mHAQ is a well-established, readily available and easily completed patient-reported outcome measure that is in wide-use in the clinical setting,” the researchers wrote.
At baseline, the team noted that mHAQ scores tended to be higher among African-American and Hispanic patients, as well as in patients who were older, were current smokers, or had more widespread skin involvement. Patients with better lung function tended to have lower mHAQ scores at study entry.
Using statistical models, the researchers looked for factors that were significantly predictive of mHAQ scores over time.
Results revealed four factors that were significantly associated with higher mHAQ scores: lower income, less formal education, older age, and more skin thickness, as assessed by the modified Rodnan skin score (mRSS).
“Higher levels of education and income predicted better functional ability (less disability) whereas higher mRSS and older age predicted worse functional ability (greater disability) over time,” the researchers wrote.
Other analyses showed that a higher score on the mHAQ was significantly associated with an increased risk of mortality.
“This reaffirms the validity and importance of patient-reported outcomes not only as tools for symptom monitoring, but also as predictors of survival,” the researchers wrote.
Overall, the team concluded that the “severity of skin disease and socioeconomic factors such as educational level and income are important predictors of perceived functional disability in SSc,” they wrote, suggesting that the “mHAQ score is a predictor of survival and thus may prove to be a useful routine marker to follow in the clinical setting.”
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