Population screening and intervention for vascular disease in Danish men (VIVA): a randomised controlled trial.

BACKGROUND

Abdominal aortic aneurysm is the only cardiovascular disease targeted by population screening. In this study, we test the effect of screening and subsequent intervention for abdominal aortic aneurysm, peripheral arterial disease, and hypertension combined.

METHODS

In this randomised controlled trial, we randomly allocated (1:1) all men aged 65-74 years living in the Central Denmark Region to screening for abdominal aortic aneurysm, peripheral arterial disease, and hypertension, or to no screening. We based allocation on computer-generated random numbers from 1 to 100 in blocks of 1067 to 4392, stratified by 19 municipalities. Only the non-screening group and the investigator assessing outcomes were masked. We invited participants who were found to have abdominal aortic aneurysm or peripheral arterial disease back for confirmation and eventual initiation of relevant pharmacological therapy. We further offered participants with abdominal aortic aneurysm annual control or surgical repair. We referred participants with suspected hypertension to their general practitioner. The primary outcome was all-cause mortality, assessed 5 years after randomisation, analysed in all randomly allocated participants except for those who had incorrect person identification numbers. This trial is registered at ClinicalTrials.gov, number NCT00662480.

FINDINGS

Between Oct 8, 2008, and Jan 11, 2011, we randomly allocated 50 156 participants, with 25 078 (50%) each in the screening and non-screening groups. Four (<1%) participants in the screening group were lost to follow-up. After a median follow-up of 4·4 years (IQR 3·9-4·8), 2566 (10·2%) of 25 074 participants in the screening group and 2715 (10·8%) of 25 078 in the non-screening group had died. This finding resulted in a significant hazard ratio of 0·93 (95% CI 0·88-0·98; p=0·01), an absolute risk reduction of 0·006 (0·001-0·011), and a number needed to invite of 169 (89-1811). Incidences of diabetes (3995 per 100 000 person-years in the screening group vs 4129 per 100 000 person-years in the non-screening group), intracerebral haemorrhage (146 vs 140), renal failure (612 vs 649), cancer (3578 vs 3719), or 30 day mortality after cardiovascular surgery (44·57 vs 39·33) did not differ between groups.

INTERPRETATION

The observed reduction of mortality risk from abdominal aortic aneurysm, peripheral arterial disease, and hypertension has never been seen before in the population screening literature and can be linked primarily to initiation of pharmacological therapy. Health policy makers should consider implementing combined screening whether no screening or isolated abdominal aortic aneurysm screening is currently offered.

FUNDING

The 7th European Framework Programme, Central Denmark Region, Viborg Hospital, and the Danish Council for Independent Research.