Personality traits, including explanatory style, are linked to a patient’s risk of developing rheumatoid arthritis (RA) and risk of elevated mortality in patients with existing RA, according to research published in the Journal of Rheumatology.
Aaron Crowson, MS, of the Department of Health Sciences Research and the Division of Rheumatology at the Mayo Clinic, and colleagues conducted a retrospective study of residents of Olmstead County, Minnesota, with incident diagnoses of RA between 1955 and 2007.
Researchers studied 148 patients with RA and 135 matched, non-RA comparison subjects. All patients completed the Minnesota Multiphasic Personality Index (MMPI) — composed of 550 true/false questions focusing on physical and emotional symptoms, attitudes, feelings, thoughts, and life experiences — at least once prior to their RA incidence/index date; 86 RA and non-RA participants completed the MMPI multiple times — in which case, the earliest MMPI was used.
High Yield Data Summary
- Patients with rheumatoid factor positive (RF+) or rheumatoid factor negative (RF-) RA were more likely to be pessimistic than patients without RA.
On average, the MMPI was completed 13.7 years and 14.2 years before incidence and index date in the RA and non-RA cohorts, respectively. Only 9 patients in the RA cohort completed the MMPI after symptom onset but before RA diagnosis.
Mr Crowson and colleagues found that pessimism was slightly more common among patients with RA vs non-RA (39% vs 31%; P =.19). Pessimism was more common in RA patients who had rheumatoid factor-positive (RF+) RA vs non-RA (44% vs 31%; P =.049). The difference in pessimism was negligible between RF negative (RF-) RA and non-RA populations (29% vs 31%; P =.76). Adjustment for known RA risk factors, including age, sex, smoking status, and obesity, showed that pessimism was persistent in those with RF+ RA (odds ratio [OR]: 1.74; 95% confidence interval [CI], 0.99 to 3.04; P =.053).
Multivariable models adjusted for age, sex, calendar year, smoking status, obesity, and Charlson comorbidity index found that patients with RF+ RA had twice the mortality risk than patients with RF- RA (hazard ratio [HR]: 2.28; 95% CI, 1.10 to 4.73); pessimism increased patients’ mortality risk 3-fold (HR: 2.88; 95% CI, 1.02 to 8.14).
Over 10 years, survival was highest for RF- RA non-pessimists (93%), followed by RF+ RA pessimists (84%), RA- RA pessimists (77%), and RF+ RA non-pessimists (73%).
Summary and Clinical Applicability
“This increased mortality in patients with RA is consistent with that from other studies of chronic diseases, demonstrating that pessimism is associated with an increase in all-cause mortality,” the researchers wrote, noting that although pessimism can be linked to a number of poor health outcomes, the effect of biology and pessimism — particularly in RA — is poorly studied.
“Our results suggest that personality traits may influence how patients perceive and manage illness, as well as their global outcomes,” the researchers concluded. “Patients who learn and have techniques to counter consequences of pessimistic explanatory style may be able to achieve better outcomes of RA.”
- The MMPI was not administered to all possible candidates, indicating potential selection bias
- Small sample size limited statistical power to detect differences
- Olmsted County, Minnesota, is predominantly white, meaning that results may not be generalizable to more diverse populations
Crowson AD, Colligan RC, Matteson El, Davis JM III, Crowson CS. Explanatory style in patients with rheumatoid arthritis: an unrecognized predictor of mortality. J Rheum. 2016 Oct 14. doi:10.3899/jrheum.160026 [Epub ahead of print]