title: Systematic versus opportunistic risk assessment for the primary prevention of cardiovascular disease.
abstract: BACKGROUND
  Screening programmes can potentially identify people at high cardiovascular risk and reduce cardiovascular disease (CVD) morbidity and mortality. However, there is currently not enough evidence showing clear clinical or economic benefits of systematic screening-like programmes over the widely practised opportunistic risk assessment of CVD in primary care settings.
  
  
  OBJECTIVE
  The primary objective of this review was to assess the effectiveness, costs and adverse effects of systematic risk assessment compared to opportunistic risk assessment for the primary prevention of CVD.
  
  
  METHODS
  We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE, EMBASE on 30 January 2015, and Web of Science Core Collection and additional databases on the Cochrane Library on 4 December 2014. We also searched two clinical trial registers and checked reference lists of relevant articles. We applied no language restrictions.
  
  
  METHODS
  We selected randomised controlled trials (RCTs) that assessed the effects of systematic risk assessment, defined as a screening-like programme involving a predetermined selection process of people, compared with opportunistic risk assessment which ranged from no risk assessment at all to incentivised case finding of CVD and related risk factors. Participants included healthy adults from the general population, including those who are at risk of CVD.
  
  
  METHODS
  Two review authors independently selected studies. One review author extracted data and assessed them for risk of bias and a second checked them. We assessed evidence quality using the GRADE approach and present this in a 'Summary of findings' table.
  
  
  RESULTS
  Nine completed RCTs met the inclusion criteria, of which four were cluster-randomised. We also identified five ongoing trials. The included studies had a high or unclear risk of bias, and the GRADE ratings of overall quality were low or very low. The length of follow-up varied from one year in four studies, three years in one study, five or six years in two studies, and ten years in two studies. Eight studies recruited participants from the general population, although there were differences in the age ranges targeted. One study recruited family members of cardiac patients (high risk assessment). There were considerable differences between the studies in the interventions received by the intervention and control groups. There was insufficient evidence to stratify by the types of risk assessment approaches.Limited data were available on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.92 to 1.02; 3 studies,103,571 participants, I² = 0%; low-quality evidence) and cardiovascular mortality (RR 1.00, 95% CI 0.90 to 1.11; 2 studies, 43,955 participants, I² = 0%), and suggest that screening has no effect on these outcomes. Data were also limited for combined non-fatal endpoints; overall, evidence indicates no difference in total coronary heart disease (RR 1.01, 95% CI 0.95 to 1.07; 4 studies, 5 comparisons, 110,168 participants, I² = 0%; low-quality evidence), non-fatal coronary heart disease (RR 0.98, 95% CI 0.89 to 1.09; 2 studies, 43,955 participants, I² = 39%), total stroke (RR 0.99, 95% CI 0.90 to 1.10; 2 studies, 79,631 participants, I² = 0%, low-quality evidence), and non-fatal stroke (RR 1.17, 95% CI 0.94 to 1.47; 1 study, 20,015 participants).Overall, systematic risk assessment appears to result in lower total cholesterol levels (mean difference (MD) -0.11 mmol/l, 95% CI -0.17 to -0.04, 6 studies, 7 comparisons, 12,591 participants, I² = 57%; very low-quality evidence), lower systolic blood pressure (MD -3.05 mmHg, 95% CI -4.84 to -1.25, 6 studies, 7 comparisons, 12,591 participants, I² = 82%; very low-quality evidence) and lower diastolic blood pressure (MD -1.34 mmHg, 95% CI -1.76 to -0.93, 6 studies, 7 comparisons, 12,591 participants, I² = 0%; low-quality evidence). One study assessed adverse effects and found no difference in psychological distress at five years (1126 participants).
  
  
  CONCLUSIONS
  The results are limited by the heterogeneity between trials in terms of participants recruited, interventions and duration of follow-up. Limited data suggest that systematic risk assessment for CVD has no statistically significant effects on clinical endpoints. There is limited evidence to suggest that CVD systematic risk assessment may have some favourable effects on cardiovascular risk factors. The completion of the five ongoing trials will add to the evidence base.
authors.affiliation: Division of Health Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Campus, Coventry, Warwickshire, UK, CV4 7AL.
authors.forename: Mariana
authors.initials: M
authors.lastname: Dyakova
authors.forename: Saran
authors.initials: S
authors.lastname: Shantikumar
authors.forename: Jill L
authors.initials: JL
authors.lastname: Colquitt
authors.forename: Christian M
authors.initials: CM
authors.lastname: Drew
authors.forename: Morag
authors.initials: M
authors.lastname: Sime
authors.forename: Joanna
authors.initials: J
authors.lastname: MacIver
authors.forename: Nicola
authors.initials: N
authors.lastname: Wright
authors.forename: Aileen
authors.initials: A
authors.lastname: Clarke
authors.forename: Karen
authors.initials: K
authors.lastname: Rees
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality / Q000517:prevention & control*; D002784:Cholesterol / Q000097:blood; D006801:Humans; D008875:Middle Aged; D011322:Primary Prevention / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D020521:Stroke / Q000401:mortality
chemical_list: D002784:Cholesterol
references.citation: Stat Med. 2012 Nov 10;31(25):2985-97
references.pmid: 22903776
references.citation: Eur Heart J. 1980 Feb;1(1):73-80
references.pmid: 7026247
references.citation: Cochrane Database Syst Rev. 2016 Jan 29;(1):CD010411
references.pmid: 26824223
references.citation: BMJ. 1996 May 18;312(7041):1265-8
references.pmid: 8634616
references.citation: Prev Med. 1973 Jun;2(2):295-301
references.pmid: 4723642
references.citation: Eur Heart J. 1983 Mar;4(3):141-7
references.pmid: 6345161
references.citation: Curr Med Res Opin. 2006 Jun;22(6):1065-73
references.pmid: 16846539
references.citation: BMJ. 2011 Feb 07;342:d442
references.pmid: 21300712
references.citation: Circ Cardiovasc Qual Outcomes. 2008 Nov;1(2):98-106
references.pmid: 20031796
references.citation: Eur Heart J. 1986 Apr;7(4):279-88
references.pmid: 3720755
references.citation: Br J Gen Pract. 1996 Oct;46(411):577-82
references.pmid: 8945794
references.citation: Eur J Cardiovasc Prev Rehabil. 2009 Oct;16(5):541-9
references.pmid: 19773660
references.citation: Scand J Public Health. 2008 Aug;36(6):650-61
references.pmid: 18775821
references.citation: Prev Med. 2008 Jun;46(6):537-44
references.pmid: 18372036
references.citation: BMJ. 2014 Jun 09;348:g3617
references.pmid: 24912589
references.citation: Lancet. 1986 Apr 19;1(8486):869-72
references.pmid: 2870351
references.citation: J Fam Pract. 2002 Jun;51(6):546-52
references.pmid: 12100779
references.citation: Int J Epidemiol. 1977 Dec;6(4):357-63
references.pmid: 608798
references.citation: Br J Gen Pract. 2010 Apr;60(573):e137-43
references.pmid: 20353659
references.citation: Int J Epidemiol. 1972 Spring;1(1):55-60
references.pmid: 4669179
references.citation: BMC Public Health. 2012 Oct 26;12:908
references.pmid: 23101763
references.citation: Implement Sci. 2014 Jun 12;9:73
references.pmid: 24923300
references.citation: BMC Fam Pract. 2013 Nov 20;14:175
references.pmid: 24252125
references.citation: J Chronic Dis. 1986;39(6):453-63
references.pmid: 3711252
references.citation: BMJ. 2009 Jul 14;339:b2613
references.pmid: 19602713
references.citation: BMJ. 2010 Apr 23;340:c1693
references.pmid: 20418545
references.citation: Scand J Public Health. 2007;35(4):365-72
references.pmid: 17786799
references.citation: Br J Gen Pract. 2010 Jan;60(570):40-6
references.pmid: 20040167
references.citation: BMJ. 1997 Sep 13;315(7109):629-34
references.pmid: 9310563
references.citation: Scand J Soc Med. 1977;5(3):137-40
references.pmid: 594708
references.citation: Lancet. 2015 Jan 10;385(9963):117-71
references.pmid: 25530442
references.citation: BMJ. 1996 May 18;312(7041):1269-73
references.pmid: 8634617
references.citation: Scand J Prim Health Care. 2002 Dec;20(4):219-23
references.pmid: 12564573
references.citation: N Engl J Med. 1976 Apr 22;294(17):925-30
references.pmid: 1256483
references.citation: Stroke. 2015 May;46(5):e121-2
references.pmid: 25873596
references.citation: Br J Gen Pract. 1994 Feb;44(379):62-7
references.pmid: 8179948
references.citation: Am Heart J. 2009 Mar;157(3):436-41
references.pmid: 19249412
references.citation: Heart. 2010 Feb;96(3):208-12
references.pmid: 19737737
references.citation: Scand J Soc Med. 1982;10(1):27-32
references.pmid: 7112052
references.citation: Prev Med. 1986 Nov;15(6):661-72
references.pmid: 3797397
references.citation: Am Heart J. 2010 Jul;160(1):49-57.e1
references.pmid: 20598972
references.citation: Int J Epidemiol. 1998 Apr;27(2):194-8
references.pmid: 9602398
references.citation: Prev Med. 1973 Jun;2(2):266-77
references.pmid: 4579345
references.citation: BMJ. 2008 Aug 28;337:a1371
references.pmid: 18755770
references.citation: BMC Fam Pract. 2014 May 09;15:90
references.pmid: 24884779
references.citation: Minn Med. 2003 May;86(5):52-6
references.pmid: 15495678
references.citation: BMJ. 1994 Jan 29;308(6924):313-20
references.pmid: 8124121
references.citation: Lancet. 2004 Sep 11-17;364(9438):937-52
references.pmid: 15364185
references.citation: Am Heart J. 2014 Jan;167(1):28-35
references.pmid: 24332139
references.citation: Cochrane Database Syst Rev. 2012 Oct 17;10:CD009009
references.pmid: 23076952
references.citation: BMJ. 1995 Apr 29;310(6987):1099-104
references.pmid: 7742676
references.citation: BMJ. 1991 May 4;302(6784):1057-60
references.pmid: 2036503
references.citation: Prev Med. 2010 Jan-Feb;50(1-2):35-44
references.pmid: 19944713
references.citation: Br J Gen Pract. 1995 Oct;45(399):542-7
references.pmid: 7492424
references.citation: Eur J Cardiovasc Prev Rehabil. 2004 Jun;11(3):239-43
references.pmid: 15179107