Table 3.

Per cent prevalence of persistently positive lupus anticoagulant based on different strategies for identifying patients

	Persistent positivity identified by the first two clinical assessments	Persistent positivity identified by annual assessments with reassessment of positives	Persistent positivity identified by two or more positives among 16 assessments
All patients	4.3 (2.9 to 5.7)	6.6 (4.8 to 8.3)	10.5 (8.3 to 12.7)
Sex
Female	3.7 (2.3 to 5.1)	5.7 (4.0 to 7.4)	9.7 (7.5 to 11.9)
Male	12.3 (3.5 to 21.1)*	17.5 (7.4 to 27.7)‡	20.7 (9.8 to 31.6)¶
Race
Caucasian-American	6.5 (4.1 to 8.9)	8.1 (5.4 to 10.8)	12.2 (9.0 to 15.4)
African-American	1.7 (0.3 to 3.2)†	4.3 (2.0 to 6.7)§	8.6 (5.4 to 11.8)**
Other	3.2 (0.0 to 7.6)	7.9 (1.0 to 14.8)	9.5 (2.1 to 17.0)
Age group
<30	8.1 (2.6 to 13.5)	9.1 (3.3 to 14.9)	11.0 (4.7 to 17.4)
30–44	3.4 (1.3 to 5.5)	7.1 (4.1 to 10.1)	10.6 (7.0 to 14.3)
45–59	4.4 (2.0 to 6.8)	5.8 (3.0 to 8.6)	11.2 (7.5 to 14.9)
60+	2.9 (0.0 to 6.2)	4.9 (0.6 to 9.1)	7.8 (2.5 to 13.0)

*P=0.051 comparing men with women.

†P=0.0011 comparing African-Americans with Caucasians.

‡P=0.021 comparing men with women.

§P=0.038 comparing African-Americans with Caucasians.

¶P=0.053 comparing men with women.

**P=0.12 comparing African-Americans with Caucasians.