Concordance of apolipoprotein B concentration with the Friedewald,Martin-Hopkins,and Sampson formulas for calculating LDL cholesterol

IntroductionTwo new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles.Materials and methodsIn a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared.ResultsThe Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula.ConclusionThe Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula.     

Detecting potential hucksterism in meta-analysis using a follow-up fail-safe test

Meta-analysis is an analysis of analyses. It is a technique widely used by researchers and practitioners to aggregate and summarize statistically reported empirical educational research. In 10 years, meta-analysis appeared more than 600 times in research journals and dissertation abstracts. Although most meta-analyses were reported as significant, few of the findings determined how many unpublished “no-effect” studies, if sampled, would have invalidated significance. If significant meta-analysis results are over represented through selective sampling, hucksterism in the form of sampling bias exists. An explanation for using a follow-up test called the fail-safe N is provided with tables constructed to assist researchers and practitioners to estimate, without calculation, the relative stability of meta-analysis results. The implication is that failsafe N should routinely be used and reported in meta-analysis research.     

Social skills interventions across school settings: Case study reviews of students with mild disabilities

This study investigates the efficacy of a social skills training program with seven mildly handicapped students across three school settings: regular classroom, special education resource room, and recess. It was found that social skills training generated improvement on both pre-post measures and behavior ratings. Improvements were maintained 2 weeks after treatment was discontinued for seven students. All students' performance generalized from resource room to regular classroom settings; only four students' performance generalized to the recess setting.