Table 3.

Prevalence and demographic correlates of disease burden and treatment burden

	Disease burden		Treatment burden
	Pain interference T-scorea	Morning stiffness	Serious medication side effect	Intolerance to methotrexateb
	Mean (SD)	% >15 mins	% Yes	% Intolerant
Total (N = 180)	50.1 (11.1)	17.8%	26.7%	42.2%
Disease duration
> 8 years	50.3 (11.8)	24.0%	32.0%	41.9%
≤ 8 years	49.9 (10.6)	13.3%	22.9%	42.4%
p-value	0.8676	0.0650	0.1715	0.9682
Age group
≥ 13 years	51.3 (11.7)	25.3%	39.2%	40.0%
< 13 years	49.1 (10.5)	11.9%	16.8%	43.6%
p-value	0.1481	0.0193	0.0007	0.7335
Sex
Female	50.3 (11.1)	18.1%	26.1%	48.5%
Male	49.3 (11.1)	16.7%	28.6%	22.7%
p-value	0.5835	0.8297	0.7499	0.0332
Race/Ethnicity
White non-Hispanic	49.2 (10.7)	19.2%	26.7%	40.6%
Other	53.8 (12.0)	11.8%	26.5%	47.6%
p-value	0.0266	0.3086	0.9771	0.5674
Highest parental education
≤ High school graduate	50.2 (10.6)	22.9%	27.1%	42.9%
Any college	50.0 (11.3)	15.9%	26.5%	42.0%
p-value	0.7779	0.2768	0.9392	0.9464

Data are presented as mean and standard deviation (SD) for pain interference and as row percentages for other outcomes

P-values derived from the chi-squared (χ²) or Wilcoxon tests

Disease duration was dichotomized using the sample mean rounded to the nearest integer as the cut point

^aRaw pain interference scores were transformed into a ‘T-score’ for each participant. The T-score rescales the raw score into a standardized score with a mean of 50, standard deviation of 10, and possible range of 38–78

^bIntolerance to methotrexate was assessed only among those who were on methotrexate (N= 90)