• Offer lipid-modification therapy if the person's estimated 10-year risk of developing cardiovascular disease (CVD) is 20% or more:
• If the person is less than 75 years of age and does not have Type 2 diabetes, see the CKS topic on CVD risk assessment and management for information on how to estimate CVD risk.
• If the person has Type 2 diabetes, see the CKS topic on Diabetes type 2.
• If the person is 75 years of age or older, assume they are at increased risk of CVD. The decision to offer lipid-modification therapy should be guided by the likely benefits and risks, comorbidities that may make treatment inappropriate, and informed individual preference.
• Refer people with suspected familial hypercholesterolaemia or other monogenic familial disorders for specialist management.

For people with a 10-year cardiovascular disease (CVD) risk of 20% or greater:

• The recommendation to offer lipid-modification therapy for these people is based on guidance issued by the National Institute for Health and Clinical Excellence (NICE) on lipid modification and an earlier NICE Technology Appraisal of statins for the prevention of cardiovascular events [NICE, 2006; NICE, 2008a].
• Taking into consideration the reductions in the cost of some statins, NICE found statins to be cost effective for all age groups (including people older than 75 years of age) at a 20% or greater 10-year risk of CVD.
• For further information, see First-line therapy.

For people with a 10-year CVD risk of less than 20% (without abnormal lipids profile or genetic lipid disorders):

• NICE does not recommend statins for primary prevention for these people because [NICE, 2006; NICE, 2008a]:
• Although analysis indicates that it might be cost effective to initiate statins in this group, NICE is concerned by the uncertainty of the evidence (most of the clinical trials did not include people at very low risk of a cardiovascular event) and the risk of adverse events associated with lifelong statin treatment in a large population at low risk of CVD.
• Consequently, given these considerations and the need to consider the effective use of NHS resources (considering the potentially large eligible population), NICE concluded that initiation of statins for primary prevention of CVD is most appropriate in people with a 20% or greater 10-year CVD risk.

For people (without genetic lipid disorders) with an elevated total cholesterol to high-density lipoprotein (HDL) cholesterol ratio and a 10-year CVD risk of less than 20%:

• CKS is unable to recommend a specific total cholesterol:HDL ratio threshold for initiating lipid modification therapy due to a lack of evidence and expert consensus. Consequently, the decision to offer treatment will based on clinical judgement and informed individual preference.
• The Joint British Societies (JBS) guideline recommend offering lipid modification therapy to people with a total cholesterol:HDL cholesterol ratio of 6.0 or more [British Cardiac Society et al, 2005]. This is based on expert opinion.
• However, the Scottish Intercollegiate Guidelines Network (SIGN) highlight that this, and other recommendations proposed by JBS for primary prevention, would widen the groups to be prescribed statins, raising a number of clinical and economic concerns (e.g. the lack of supporting evidence which is unlikely to be made available from clinical trials) [SIGN, 2007].
• Neither NICE or SIGN make any recommendation regarding an appropriate total cholesterol:HDL ratio target for initiating lipid modification therapy [SIGN, 2007; NICE, 2008a].
• Feedback from expert reviewers was conflicting.