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Variation among cardiovascular risk calculators in relative risk increases with identical risk factor increases.

Allan GM, Nouri F, Korownyk C, Kolber MR, Vandermeer B, McCormack J - BMC Res Notes (2015)

Bottom Line: Relative risk increases due to specific risk factors were determined and compared.Similar results were found among diabetic patients.It also limits the use of risk calculators in estimating the benefits of therapy.

View Article: PubMed Central - PubMed

Affiliation: Evidence-Based Medicine, Department of Family Medicine-Research Program, University of Alberta, 6-10 University Terrace, Edmonton, AB, T6G 2T4, Canada. michael.allan@ualberta.ca.

ABSTRACT

Background: Risk estimates for the same patient can vary substantially among cardiovascular risk calculators and the reasons are not fully explained. We compared the relative risk increases for consistent risk factors changes across different cardiovascular risk calculators.

Methods: Five clinicians independently selected 16 calculators providing absolute risk estimations. Hypothetical patients were generated using a combination of seven risk factors [age, gender, smoking, blood pressure, high-density lipoprotein (HDL), total cholesterol and diabetes] dichotomized to high and low risk, generating 2(7) patients (128 total). Relative risk increases due to specific risk factors were determined and compared.

Results: The 16 selected calculators were from six countries, used 5- and 10-year predictions, and estimated CVD or coronary heart disease risk. Across the different calculators for non-diabetic patients, changing age from 50 to 70 produced average relative risk increases from 82 to 395%, gender (female to male) 35-225%, smoking status 31-118%, systolic blood pressure (120-160 mmHg) 16-124%, total cholesterol (4-7 mmol/L) 51-302% and HDL (1.3-0.8 mmol/L) 27-133%. Similar results were found among diabetic patients. Some calculators appeared to have consistently higher relative risk increases over multiple risk factors.

Conclusions: Cardiovascular risk calculators weigh the same risk factors differently. For each risk factor, the relative risk increase from the calculator with the highest increase was generally three to eight times greater than the relative risk increase from the calculator with lowest increase. This likely contributes to some of the inconsistency in risk calculator estimation. It also limits the use of risk calculators in estimating the benefits of therapy.

No MeSH data available.


Related in: MedlinePlus

Flow of identification and selection of cardiovascular risk calculators for inclusion
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Related In: Results  -  Collection

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Fig1: Flow of identification and selection of cardiovascular risk calculators for inclusion

Mentions: We searched for and then independently selected a broad range of CVD and coronary heart disease (CHD) risk calculators. Our goal was to identify representative sample of calculators from different countries, were or were not associated with guidelines, used different data sources (Framingham and others), used different formats (internet, paper and pencil, other) and calculated different outcomes durations (5 or 10 years). Originally, 20 calculators were selected and 4 more were added to enhance diversity. In this sub-study, absolute risk estimates are needed to compare the relative risk increases that result from risk factor changes. Therefore, we excluded seven calculators that did not provide absolute numbers. We also excluded the SCORE calculator as it only provided CVD mortality risk. Calculator inclusion and exclusion flow are presented in Fig. 1.Fig. 1


Variation among cardiovascular risk calculators in relative risk increases with identical risk factor increases.

Allan GM, Nouri F, Korownyk C, Kolber MR, Vandermeer B, McCormack J - BMC Res Notes (2015)

Flow of identification and selection of cardiovascular risk calculators for inclusion
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4561470&req=5

Fig1: Flow of identification and selection of cardiovascular risk calculators for inclusion
Mentions: We searched for and then independently selected a broad range of CVD and coronary heart disease (CHD) risk calculators. Our goal was to identify representative sample of calculators from different countries, were or were not associated with guidelines, used different data sources (Framingham and others), used different formats (internet, paper and pencil, other) and calculated different outcomes durations (5 or 10 years). Originally, 20 calculators were selected and 4 more were added to enhance diversity. In this sub-study, absolute risk estimates are needed to compare the relative risk increases that result from risk factor changes. Therefore, we excluded seven calculators that did not provide absolute numbers. We also excluded the SCORE calculator as it only provided CVD mortality risk. Calculator inclusion and exclusion flow are presented in Fig. 1.Fig. 1

Bottom Line: Relative risk increases due to specific risk factors were determined and compared.Similar results were found among diabetic patients.It also limits the use of risk calculators in estimating the benefits of therapy.

View Article: PubMed Central - PubMed

Affiliation: Evidence-Based Medicine, Department of Family Medicine-Research Program, University of Alberta, 6-10 University Terrace, Edmonton, AB, T6G 2T4, Canada. michael.allan@ualberta.ca.

ABSTRACT

Background: Risk estimates for the same patient can vary substantially among cardiovascular risk calculators and the reasons are not fully explained. We compared the relative risk increases for consistent risk factors changes across different cardiovascular risk calculators.

Methods: Five clinicians independently selected 16 calculators providing absolute risk estimations. Hypothetical patients were generated using a combination of seven risk factors [age, gender, smoking, blood pressure, high-density lipoprotein (HDL), total cholesterol and diabetes] dichotomized to high and low risk, generating 2(7) patients (128 total). Relative risk increases due to specific risk factors were determined and compared.

Results: The 16 selected calculators were from six countries, used 5- and 10-year predictions, and estimated CVD or coronary heart disease risk. Across the different calculators for non-diabetic patients, changing age from 50 to 70 produced average relative risk increases from 82 to 395%, gender (female to male) 35-225%, smoking status 31-118%, systolic blood pressure (120-160 mmHg) 16-124%, total cholesterol (4-7 mmol/L) 51-302% and HDL (1.3-0.8 mmol/L) 27-133%. Similar results were found among diabetic patients. Some calculators appeared to have consistently higher relative risk increases over multiple risk factors.

Conclusions: Cardiovascular risk calculators weigh the same risk factors differently. For each risk factor, the relative risk increase from the calculator with the highest increase was generally three to eight times greater than the relative risk increase from the calculator with lowest increase. This likely contributes to some of the inconsistency in risk calculator estimation. It also limits the use of risk calculators in estimating the benefits of therapy.

No MeSH data available.


Related in: MedlinePlus