Lipid treatment guidelines and cardiovascular risk for Aboriginal people in Central Australia

Objective: To evaluate the extent to which the current Pharmaceutical Benefits Scheme (PBS) guidelines for patient eligibility for lipid-lowering medication are applicable to Aboriginal people in Central Australia. Design, setting and participants: A 10-year cohort study of 659 Aboriginal people who participated in population-based cardiovascular disease (CVD) risk factor surveys in 1995 and who were free of CVD at baseline, for the period from 1995 to 2004-2005 or until first CVD event. Evidence of atherosclerotic CVD (ischaemic heart disease, ischaemic stroke, and peripheral vascular disease) was sought from hospital, primary health care and death records. PBS eligibility was assigned according to the current PBS criteria, which were amended in 2006 to include Aboriginal-specific criteria, using participants' baseline (1995) and 10-year follow-up data. Main outcome measures: Proportions of PBS-eligible and PBS-ineligible participants who had CVD events during the study period; sensitivity and specificity of the criteria. Results: Of 42 participants who had CVD events during the study period, 35 were PBS-eligible (incidence, 1130/100 000 person-years; relative risk compared with PBS-ineligible population, 4.87 [95% CI, 2.19-10.80]) and seven were PBS-ineligible. PBS eligibility was associated with older mean age (37 v 32 years) and male sex (48% v 37%), with 50.7% of participants (334/659) meeting eligibility criteria. The mean high-density lipoprotein cholesterol level at baseline was very low in both groups (0.81 v 0.87mmol/L). The current PBS guidelines have low specificity (52%) in this population, which was found to improve (to 71%-82%) by incorporating additional non-lipid criteria (age and multiple non-lipid risk factors). Conclusion: The current PBS lipid treatment criteria, which include any Aboriginal person with diabetes and less stringent cholesterol thresholds than the previous version, identify a group at very high risk of CVD. Global risk assessment may better identify those at risk.