Table 3.

Exposure to non-steroidal anti-inflammatory drugs (NSAIDs) in the control and risk periods. For each length of the risk periods (one, three, and six days, respectively), the cumulative duration of the control periods was 60 days (see fig 1 ▶)

	Length of the risk period
	1 day	3 days	6 days
No of control periods	60	20	10
Total No of subjects	285	285	285
No of subjects having taken NSAIDs  within the risk period	7	8	11
No of subjects having taken NSAIDs at  least once within the control periods	22	22	22
Mean proportion of control periods  during which a subject has taken NSAIDs (min-max)	0.14 (0.05–0.43)	0.17 (0.05–0.55)	0.24 (0.10–0.60)
RR (95% CI)	2.9 (1.4–6.1)	2.7 (1.4–5.1)	3.3 (2.0–5.4)

RR, relative risk; CI, confidence interval.