Table 2.

Demographics and RA characteristics in survey responders and nonresponders to the survey among patients with rheumatoid arthritis.

Variable	Responders to the survey (N = 284)	Nonresponders to the survey (N = 209)	P value*
Mean age on the date of response, years (SD)	62.4 (13.4)	61.0 (15.4)	0.16
Female, n (%)	204 (72)	155 (74)	0.57
Mean duration of RA, years (SD)	10.3 (7.2)	9.8 (6.9)	0.55
RF positive, n (%)	188 (67)	141 (68)	0.79

*P value indicates the differences between survey responders and nonresponders to the survey.

Abbreviations: RA: rheumatoid arthritis; SD: standard deviation; RF: rheumatoid factor.