Ethnic inequalities in cardiovascular disease: incidence, prognosis, and health care use

Abstract

This thesis investigates ethnic inequalities in the incidence and prognosis of cardiovascular disease (CVD) and cardiovascular health care use, by linking several Dutch nationwide registers (Population Register, Hospital Discharge Register, Cause of Death Register, and the Regional Income Survey) and data from the Achmea health insurance company (Achmea Health Database). Results of this thesis show that there are clear ethnic inequalities in the incidence of acute myocardial infarction (AMI) and stroke, and that the direction and extent of these inequalities depend on the country of origin. Especially Surinamese minorities have a substantially higher incidence of AMI and stroke compared with their ethnic Dutch counterparts, whereas Moroccan minorities have a substantially lower incidence. However, Moroccan minorities seem to lose this beneficial position regarding cardiovascular disease rapidly over time. Furthermore, the found ethnic inequalities are mostly present among first generation ethnic minorities (born abroad), and are less clear or absent among second generation ethnic minorities (born in the Netherlands with at least one of the parents born abroad). This thesis also demonstrates that after the first AMI hospitalisation, mortality rates as well as readmission rates for AMI and congestive heart failure (CHF) are higher in the majority of ethnic minority groups compared with ethnic Dutch. After the first CHF hospitalisation, ethnic inequalities in prognosis are more diverse. This thesis reveals that ethnic minority groups without CVD are more likely to quit their prescribed cardiovascular drug therapy (blood-pressure lowering and lipid lowering drugs) compared with the ethnic Dutch population without CVD. The same phenomenon occurs in those known with CVD. Although ethnic minority groups were just as likely as ethnic Dutch to collect their cardiovascular drugs (blood-pressure lowering, lipid lowering, and antithrombotic drugs) at the pharmacy after an AMI event, they were more likely to quit their therapy over time. This thesis did not find ethnic inequalities in revascularisation rate (percutaneous coronary intervention and coronary artery bypass grafting) after an ST-elevation myocardial infarction, suggesting equity in acute in-hospital care in the Netherlands. In conclusion, health care professionals should be aware of the substantial inequalities in the incidence and prognosis of cardiovascular disease between ethnic minority groups and the ethnic Dutch population, and of ethnic inequalities in cardiovascular health care use, especially cardiovascular drug use. The higher quitting rates with cardiovascular drugs in ethnic minority groups compared with the ethnic Dutch population could partially underlie the higher AMI and stroke incidence found in some ethnic minority groups, and the worse prognosis after a first AMI hospitalisationin most ethnic minority groups. Health care professionals should take the findings of this thesis into account when developing primary and secondary preventive strategies, and when treating ethnic minority groups in the primary as well as specialised care setting.