However, the risk was higher in NHS II (RR = 1.7, 95% CI 0.8-3.7) than in NHS, and there was a significant trend over duration categories among past users.
1
—
—
However, the risk was higher in NHS II (RR = 1.7, 95% CI 0.8-3.7) than in NHS, and there was a significant trend over duration categories among past users.