Randomised clinical trial of an intensive intervention in the primary care setting of patients with high plasma fibrinogen in the primary prevention of cardiovascular disease

Table 4 Results of the per protocol analysis after two years of follow-up according to type of intervention for the variable 'tobacco consumption'

Proportion of smokers	Intensive intervention	Standard intervention	Difference of proportions	p value^a
Before	31.9%	26.8%	5.1%	0.372
After	19.4%	22.1%	2.7%	0.669
Before-after difference	12.5%	4.7%
95% CI	7. 0-18. 2	1.0-8.4
p value^b	0.016	0.0001

CI confidence interval
a Difference between groups, calculated by means of Χ² (comparison of proportions in independent groups)
b Difference between groups calculated using McNemar test (comparison of proportions with paired data)

ISSN: 1756-0500