Social support moderates the relationship between D-dimer and SRSA in PWH and older adults. Within PWH, at high levels of social support (obtaining a score of 11.24 or more on the Duke Social Support Index, DSSI), D-dimer and SRSA have a positive relationship (interaction p= .05). Within older adults (age 56–65), at high levels of social support (obtaining a score of 9.62 or more on the DSSI), D-dimer and SRSA have a positive relationship and at low levels of social support (obtaining a score of 6.68 or less on the DSSI), D-dimer and SRSA have a negative relationship (interaction p< .001). The within level analysis was corrected for age and number of visits.