Figure 1
Retrospective survival analysis of Raynaud's phenomenon in relation to exposure (hours · value (m/s2 ). Hand-arm vibration exposure dose was defined as the product of exposure hours and the hand-arm vibration exposure value according to ISO 5349-1 [10], unit hours · m/s2 (h · m/s2). Non-exposed = 0–1600 h · m/s2, class 1 was 1601 to 7578 h · m/s2, exposure class 2 was 7579–16787 h · m/s2, class 3 was 16788–39699 h · m/s2, and exposure class 4 was>39699 h · m/s2.