SCORE2-OP risk prediction algorithms: estimating incident cardiovascular event risk in older persons in four geographical risk regions

AIMS

The aim of this study was to derive and validate the SCORE2-Older Persons (SCORE2-OP) risk model to estimate 5- and 10-year risk of cardiovascular disease (CVD) in individuals aged over 70 years in four geographical risk regions.

METHODS AND RESULTS

Sex-specific competing risk-adjusted models for estimating CVD risk (CVD mortality, myocardial infarction, or stroke) were derived in individuals aged over 65 without pre-existing atherosclerotic CVD from the Cohort of Norway (28 503 individuals, 10 089 CVD events). Models included age, smoking status, diabetes, systolic blood pressure, and total- and high-density lipoprotein cholesterol. Four geographical risk regions were defined based on country-specific CVD mortality rates. Models were recalibrated to each region using region-specific estimated CVD incidence rates and risk factor distributions. For external validation, we analysed data from 6 additional study populations {338 615 individuals, 33 219 CVD validation cohorts, C-indices ranged between 0.63 [95% confidence interval (CI) 0.61-0.65] and 0.67 (0.64-0.69)}. Regional calibration of expected-vs.-observed risks was satisfactory. For given risk factor profiles, there was substantial variation across the four risk regions in the estimated 10-year CVD event risk.

CONCLUSIONS

The competing risk-adjusted SCORE2-OP model was derived, recalibrated, and externally validated to estimate 5- and 10-year CVD risk in older adults (aged 70 years or older) in four geographical risk regions. These models can be used for communicating the risk of CVD and potential benefit from risk factor treatment and may facilitate shared decision-making between clinicians and patients in CVD risk management in older persons.

Ethnic differences in risk of hip fracture in Norway: a NOREPOS study

Hip fracture is a major public health problem, and the incidence rates vary considerably between countries. Ethnic differences in bone mineral density have been identified as a factor to explain some of the geographical differences in rates of hip fracture. In this Norwegian register-based study, we found that all immigrant groups experienced lower risk of hip fracture than individuals born in Norway.

INTRODUCTION

Norway is among the countries with the highest incidence rates. The aim of this study was to investigate differences in risk of hip fracture between ethnic groups living in Norway.

METHODS

We linked individuals in the Norwegian Population and Housing Census conducted in 2001 and a database consisting of all hip fractures in Norway in the period 2001-2013. Residents (n = 1,392,949) between 50 and 89 years and born in nine different geographical regions of the world were examined, and we computed age-standardized incidence rates for the different geographic regions-denoted ethnic groups in the paper. Gender-stratified Cox regression analysis, adjusted for age, was used to model risk of hip fracture as a function of region of birth.

RESULTS

Age-standardized incidence rates of hip fracture varied considerably between regions of birth living in Norway, in both genders. All immigrant groups had lower risk of hip fracture compared to the Norwegian-born population. Immigrants from Central and Southeast Asia had the lowest risk of hip fracture when compared to individuals born in Norway (HR = 0.2, 95% CI 0.1-0.3 and HR =0.2, 95% CI 0.2-0.4 in men and women, respectively).

CONCLUSION

Lower risk of hip fracture was found in all immigrant groups compared to the Norwegian-born majority population.

Can traditional risk factors explain the higher risk of cardiovascular disease in South Asians compared to Europeans in Norway and New Zealand? Two cohort studies

OBJECTIVES

The objective was to prospectively examine potential differences in the risk of first cardiovascular disease (CVD) events between South Asians and Europeans living in Norway and New Zealand, and to investigate whether traditional risk factors could explain any differences.

METHODS

We included participants (30-74 years) without prior CVD in a Norwegian (n=16 606) and a New Zealand (n=129 449) cohort. Ethnicity and cardiovascular risk factor information was linked with hospital registry data and cause of death registries to identify subsequent CVD events. We used Cox proportional hazards regression to investigate the relationship between risk factors and subsequent CVD for South Asians and Europeans, and to calculate age-adjusted HRs for CVD in South Asians versus Europeans in the two cohorts separately. We sequentially added the major CVD risk factors (blood pressure, lipids, diabetes and smoking) to study their explanatory role in observed ethnic CVD risk differences.

RESULTS

South Asians had higher total cholesterol (TC)/high-density lipoprotein (HDL) ratio and more diabetes at baseline than Europeans, but lower blood pressure and smoking levels. South Asians had increased age-adjusted risk of CVD compared with Europeans (87%-92% higher in the Norwegian cohort and 42%-75% higher in the New Zealand cohort) and remained with significantly increased risk after adjusting for all major CVD risk factors. Adjusted HRs for South Asians versus Europeans in the Norwegian cohort were 1.57 (95% CI 1.19 to 2.07) in men and 1.76 (95% CI 1.09 to 2.82) in women. Corresponding figures for the New Zealand cohort were 1.64 (95% CI 1.43 to 1.88) in men and 1.39 (95% CI 1.11 to 1.73) in women.

CONCLUSION

Differences in TC/HDL ratio and diabetes appear to explain some of the excess risk of CVD in South Asians compared with Europeans. Preventing dyslipidaemia and diabetes in South Asians may therefore help reduce their excess risk of CVD.

Ethnic inequalities in acute myocardial infarction and stroke rates in Norway 1994-2009: a nationwide cohort study (CVDNOR)

Background

Immigrants to Norway from South Asia and Former Yugoslavia have high levels of cardiovascular disease (CVD) risk factors. Yet, the incidence of CVD among immigrants in Norway has never been studied. Our aim was to study the burden of acute myocardial infarction (AMI) and stroke among ethnic groups in Norway.

Methods

We studied the whole Norwegian population (n = 2 637 057) aged 35–64 years during 1994–2009. The Cardiovascular Disease in Norway (CVDNOR) project provided information about all AMI and stroke hospital stays for this period, as well as deaths outside hospital through linkage to the Cause of Death Registry. The direct standardization method was used to estimate age standardized AMI and stroke event rates for immigrants and ethnic Norwegians. Rate ratios (RR) with ethnic Norwegians as reference were calculated using Poisson regression.

Results

The highest risk of AMI was seen in South Asians (men RR = 2.27; 95 % CI 2.08–2.49; women RR = 2.10; 95 % CI 1.76–2.51) while the lowest was seen in East Asians (RR = 0.38 in both men (95 % CI 0.25–0.58) and women (95 % CI 0.18–0.79)). Immigrants from Former Yugoslavia and Central Asia also had increased risk of AMI compared to ethnic Norwegians. South Asians had increased risk of stroke (men RR = 1.26; 95 % CI 1.10–1.44; women RR = 1.58; 95 % CI 1.32–1.90), as did men from Former Yugoslavia, Sub-Saharan Africa and women from Southeast Asia.

Conclusions

Preventive measures should be aimed at reducing the excess numbers of CVD among immigrants from South Asia and Former Yugoslavia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2412-z) contains supplementary material, which is available to authorized users.

Ethnic differences in risk factors and total risk of cardiovascular disease based on the Norwegian CONOR study

BACKGROUND

Risk of cardiovascular disease varies between ethnic groups and the aim of this study was to investigate differences in cardiovascular risk factors, and total cardiovascular risk between ethnic groups in Norway.

DESIGN

Cross-sectional study using data from the Cohort of Norway (CONOR).

METHODS

A sample of 62,145 participants, 40-65 years of age, originating from 11 geographical regions, were included in our study. Self-reported variables, blood samples and physical measurements were used to estimate age- and time-adjusted mean values of cardiovascular risk factors for different ethnic groups. The 10-year risks of cardiovascular mortality and cardiovascular events were calculated using the Framingham and NORRISK risk models.

RESULTS

We observed differences between ethnic groups for cardiovascular risk factors and both Framingham and NORRISK risk scores. NORRISK showed significant differences by ethnicity in women only. Immigrants from the Indian subcontinent had the lowest high-density lipoprotein (HDL) levels, the highest levels of blood glucose, triglycerides, total cholesterol/HDL ratio, waist hip ratio and diabetes prevalence. Immigrants from the former Yugoslavia had the highest Framingham scores, high blood pressure, high total cholesterol/HDL ratio, overweight measures and smoking. Low cardiovascular risk was observed among East Asian immigrants.

CONCLUSION

The previously reported excess cardiovascular risk among immigrants from the Indian subcontinent was supported in this study. We also showed that immigrants from the former Yugoslavian countries had a higher total 10-year risk of cardiovascular events than other ethnic groups. This study adds information about ethnic groups in Norway which needs to be addressed in further research and targeted prevention strategies.