There is a correction factor for erythrocyte sedimentation rate in the elderly. The top normal ESR in the elderly is (age + 10)/2. For example, an 80 yo patients would have a top normal ESR of (80+10)/2 = 45. Most laboratories do not, however, report this correction factor, but simply list < 20 (or thereabouts) as normal.
Be certain to take this correction factor into account when using ESRs for workups for temporal arteritis or other similar conditions.
