title: Some heterogeneity factors affecting the B-type natriuretic peptides outcome: a meta-analysis.
abstract: BACKGROUND
  Cardiac B-type natriuretic peptides (NPs) are products of a complex neuro-hormonal equilibrium also involving heart and kidneys; they should be carefully handled as heart failure (HF) markers. Meta-analysis of variance (ANOVA) could extrapolate heterogeneity factors (HeFs) in an attempt to reliably evaluate the outcome.
  
  
  METHODS
  A total of 98 samples from 67 studies were considered - 52 samples from 41 studies evaluating brain natriuretic peptide (BNP), 46 from 24 evaluating N-terminal pro-brain natriuretic peptide (NT-proBNP). Case-control apparently unbiased studies linking NP values to a specific degree of HF clinical severity (HFd), and considering marker sensitivity and specificity, were selected. As an outcome measurement, the natural logarithm of [(true positives/false negatives)/(false positives/true negatives)] was considered. On data negative to the distribution normality and to the publication bias tests, the random-effect heterogeneity test was applied; heterogeneous data - adjusted for the candidate HeFs - were tested using the one-way meta-ANOVA. Afterwards, contrast tests among level means were carried out on the HeFs significant to the one-way meta-ANOVA and not significant to the interaction two-way meta-ANOVA tests. A sensitivity analysis was carried out on the data without the outlier results.
  
  
  CONCLUSIONS
  Reference method (RM), disease prevalence (DP) and HFd resulted in significant BNP HeFs, RM and DP being responsible for, respectively, reference and spectrum biases. No significant NT-proBNP HeFs were found.
authors.affiliation: Department of Laboratory Medicine, Azienda Ospedaliera Moscati, Avellino, Mercato S. Severino, Salerno, Italy. mastandreapaolo@yahoo.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Mastandrea
mesh_terms: D006333:Heart Failure / Q000175:diagnosis; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain