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Journal of Clinical Laboratory Analysis Dec 2020A common problem in clinical laboratories is maintaining the stability of analytes during pre-analytical processes. The aim of this study was to systematically summarize...
OBJECTIVE
A common problem in clinical laboratories is maintaining the stability of analytes during pre-analytical processes. The aim of this study was to systematically summarize the results of a set of studies about the biochemical analytes stability.
METHODS
A literature search was performed on the Advanced search field of PubMed using the keywords: "(stability) AND (analytes OR laboratory analytes OR laboratory tests OR biochemical analytes OR biochemical tests OR biochemical laboratory tests)." A total of 56 entries were obtained. After applying the selection criteria, 20 articles were included in the study.
RESULTS
In the 20 included references, up to 123 different analytes were assessed. The 34 analytes in order of the most frequently studied analytes were evaluated: Alanine aminotransferase, aspartate aminotransferase, potassium, triglyceride, alkaline phosphatase, creatinine, total cholesterol, albumin, lactate dehydrogenase, sodium, calcium, γ-glutamyltransferase, total bilirubin, urea, creatine kinase, inorganic phosphate, total protein, uric acid, amylase, chloride, high-density lipoprotein, magnesium, glucose, C-reactive protein, bicarbonate, ferritin, iron, lipase, transferrin, cobalamin, cortisol, folate, free thyroxine, and thyroid-stimulating hormone. Stable test results could be varied between 2 hours and 1 week according to the type of samples and/or type of blood collection tubes on a basic classification set as refrigerated or room temperature.
CONCLUSIONS
Biochemical analytes stability could be improved if the best pre-analytical approaches are used.
Topics: Biomarkers; Blood Chemical Analysis; Blood Specimen Collection; Humans; Sample Size; Time Factors
PubMed: 32869910
DOI: 10.1002/jcla.23551 -
European Journal of Clinical... Dec 2019To describe methodological and reporting issues in non-randomised comparative drug safety studies pooled in meta-analyses, with focus on confounding by indication.
PURPOSE
To describe methodological and reporting issues in non-randomised comparative drug safety studies pooled in meta-analyses, with focus on confounding by indication.
METHODS
All studies included in statistically significant meta-analyses in a recent publication investigating fall risk properties of cardiovascular drugs were reviewed. Study characteristics were extracted and assessed.
RESULTS
Nine studies, including between 498 and 321,995 individuals, contributed data to the significant meta-analyses in which loop diuretics and beta-blockers were associated with falls, five published in 2015. Five individual studies reported a statistically significant association. In the five cohort studies, characteristics of exposed vs unexposed individuals were either not reported (n = 3) or differed substantially regarding morbidity (n = 2). Drug treatment was determined at baseline, and data on falls were collected for up to 2 years thereafter. Out of the four case-control studies, the cases and controls in only one study were matched for morbidity. Morbidity characteristics of fallers compared with non-fallers were either not reported (n = 2) or they differed (n = 1) or were reported according to the matched-for diseases (n = 1). Confounding by indication was explicitly discussed in two studies. None of the abstract conclusions considered causality issues or the possibility of confounding by indication.
CONCLUSIONS
Confounding by indication is a major issue in non-randomised comparative drug safety studies, a problem which may be concealed in meta-analyses. To enhance such research, compared groups need to be balanced regarding relevant factors including morbidities and characteristics adequately reported. Confounding by indication needs to be explicitly discussed and highlighted in the abstract conclusion.
Topics: Accidental Falls; Adrenergic beta-Antagonists; Humans; Meta-Analysis as Topic; Risk Factors; Sodium Potassium Chloride Symporter Inhibitors
PubMed: 31599346
DOI: 10.1007/s00228-019-02754-6