[21] Frequent testing of lipid profiles may lead to over-diagnosis and an increased number of patients who receive unnecessary treatment. Evidence suggests annual lipid testing, when compared to testing every three years, results in unnecessary treatment in 7 per every 1,000 patients.[22] It is unclear how frequently testing should be conducted to eliminate false positives and false negatives.[23] For primary prevention, Perera et al. (2015) found the true variation from testing exceeds the random variation from repeated testing (signal-to-noise ratio exceeds 1.0) when testing is spaced by 9 10 years.[22] Also, cholesterol is a relatively minor contributor to CV risk scores compared to other patient characteristics, which further supports longer testing intervals. Most of the change in CV risk over time is because of the development or change in risk factors (e.g., DM, blood pressure, age) rather than changes in lipid levels. Individuals who progressed to a higher CVD category over a 10-year timeframe lacked a significant change in their cholesterol.[21] In addition to limiting the number of patients inappropriately placed on therapy, less frequent testing can decrease patient anxiety about lipid levels. The Work Group encourages provider and patient education regarding the limited utility and potential harms of frequent lipid screening. The Work Group recognizes there may be situations where patients and providers wish to repeat testing more frequently. For example, a patient may wish to attempt lifestyle changes before starting statin medication. In this case, the change in lipids may provide the information on which to base shared decision making. The common use of this technique is tempered by the limited effect of lipid levels on risk. 