Compared to the general population, APS patients experienced a lower HRQoL. In these patients, a history of arterial thrombosis significantly impaired HRQoL. Therefore, measurements of HRQoL should be included in APS patient management to assess the burden of the disease from a patient's perspective and to provide patients with the support they need.

(RPE) and percentage of 1RM while performing resisted knee extension, and (2) to examine test-retest reliability of RPE in a general population of adults. Methods: Following determination of 1RM, participants performed 1-3 repetitions of knee extension at ten equal increments of the determined 1RM (10%-100% of 1RM) in random order. Participants stated perceived exertion rating for each level of resistance. This protocol was repeated 5-10 days later to determine test-retest reliability. Spearman rho correlations were calculated to assess correlation between 1RM and RPE, as well as test-retest reliability. Sensitivity, specificity, Youden's index, and likelihood ratios were calculated to determine optimal RPE cutoff values for use in dosage of resistive exercise. Results: 14 female and 12 male participants completed the study (mean age 45.3, SD 18.4, range 21.0-81.4). 27% of participants selfreported knee OA, and 19% reported a history of unilateral lower extremity surgery. A good-to-excellent correlation was found between 1RM and RPE (Spearman rho, 0.787, p < .001; see Figure 1 for Bland-Altman plot). In addition to the overall relationship between the two dosage methods, moderate correlations were determined to exist between percentage of 1RM and RPE at each resistance interval (see Table 1). Test-retest reliability was excellent (Spearman rho, 0.830, p < .001, see Figure 2 for Bland-Altman plot). Area under the curve was high at each resistance interval (0.83-0.92), indicating that RPE strongly predicted percentage of 1RM at each interval from 20% through 90% of 1RM. Table 2 represents these data and suggested RPE cutoff values to approximate each percentage of 1RM for use in dosage of strengthening exercises.