Table 3

 Effect of various factors on the median time (years) for patients to reach MRC grade 3 dyspnoea from onset of symptoms

YesNoHazard ratio(95% CI)
n (censored)Median(95% CI)n (censored)Median(95% CI)
OCP, oral contraceptive pill.
Censored identifies patients who had not achieved grade 3 dyspnoea by end of follow up.
*Value of zero is due to one patient presenting with grade 3 dyspnoea.
Pregnancy since diagnosis7 (1)7.8 (0.0* to 20.4)38 (14)12.4 (7.4 to 17.5)2.7 (1.0 to 7.4)
Ever taken OCP34 (11)9.0 (8.3 to 9.7)13 (4)12.5 (2.9 to 13.75)1.2 (0.5 to 2.6)
Age at onset under 3325 (6)9.3 (7.7 to 10.8)21 (8)8.8 (4.7 to 12.9)1.0 (0.5 to 2.0)
Ever had progesterone treatment29 (6)9.0 (5.5 to 12.5)18 (9)13.6 (6.3 to 20.9)2.2 (1.0 to 4.9)
Ever smoked15 (4)7.8 (1.8 to 13.7)30 (10)12.5 (7.7 to 17.4)2.0 (0.9 to 4.3)