Figure 2  .

Questions added to the SF-36 questionnaire to measure the effect of permanent anticoagulation on quality of life. Scoring was on a five point scale. Questions 11a and 12a: "definitely false" (1 point) to "definitely true" (5 points); the remaining questions were scored in reverse order: "definitely true" (1 point) to "definitely false" (5 points). The cumulative score for question 11 was calculated as: (a+b+c+d+e+f+g—7)/28 × 100, and for question 12 as: (a+b+c+d—4)/16 × 100. The cumulative score ranged from worst effect (0 points) to no adverse effect (100 points) on quality of life.