RT Journal Article SR Electronic T1 Lipid re-screening: what is the best measure and interval? JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 448 OP 452 DO 10.1136/hrt.2009.172619 VO 96 IS 6 A1 Osamu Takahashi A1 Paul P Glasziou A1 Rafael Perera A1 Takuro Shimbo A1 Jiro Suwa A1 Sonoe Hiramatsu A1 Tsuguya Fukui YR 2010 UL http://heart.bmj.com/content/96/6/448.abstract AB Objectives To estimate the long-term true change variation (‘signal’) and short-term within-person variation (‘noise’) of the different lipid measures and evaluate the best measure and the optimal interval for lipid re-screening.Design Retrospective cohort study from 2005 to 2008.Setting A medical health check-up programme at a centre for preventive medicine in a teaching hospital in Tokyo, Japan.Participants 15 810 apparently healthy Japanese adults not taking cholesterol-lowering drugs at baseline, with a mean body mass index of 22.5 kg/m2 (SD 3.2).Main outcome measures Annual measurement of the serum total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and calculation of the ratio of TC/HDL and LDL/HDL. Measurement of the ratio of long-term true change variation (‘signal’) to the short-term within-person variation (‘noise’) for each measure.Results At baseline, participants (53% male) with a mean age of 49 years (range 21–92) and a mean TC level of 5.3 mmol/l (SD 0.9 mmol/l) had annual check-ups over 4 years. Short-term within-person variations of TC, LDL, HDL, TC/HDL, and LDL/HDL were 0.12 (coefficient of variation (CV) 6.4%), 0.08 (CV 9.4%), 0.02 (CV 8.0%) mmol2/l2, 0.08 (CV 7.9%) and 0.05 (CV 10.6%), respectively. The ratio of signal-to-noise at 3 years was largest for TC/HDL (1.6), followed by LDL/HDL (1.5), LDL (0.99), TC (0.8) and HDL (0.7), suggesting that cholesterol ratios are more sensitive re-screening measures.Conclusion The signal-to-noise ratios of standard single lipid measures (TC, LDL and HDL) are weak over 3 years and decisions based on these measures are potentially misleading. The ratios, TC/HDL and LDL/HDL, seem to be better measures for monitoring assessments. The lipid re-screening interval should be >3 years for those not taking cholesterol-lowering drugs.