Dataset Information

Should total calcium be adjusted for albumin? A retrospective observational study of laboratory data from central Norway.

ABSTRACT: OBJECTIVES:Albumin-adjusted total calcium is often used as a surrogate marker for free calcium to evaluate hypocalcaemia or hypercalcaemia. Many adjustment formulas based on simple linear regression models have been published, and continue to be used in spite of questionable diagnostic accuracy. In the hope of finding a more pure albumin effect on total calcium, we used multiple linear regression models to adjust for other relevant variables. The regression coefficients of albumin were used to construct local adjustment formulas, and we tested whether the diagnostic accuracy was improved compared with previously published formulas and unadjusted calcium. DESIGN:A retrospective hospital laboratory data study. DATA SOURCES:The local hospital laboratory data system. SETTING:Norway, 2006-2015. PARTICIPANTS:6549 patients above 2 years of age, where free calcium standardised at pH 7.40, total calcium, creatinine, albumin and phosphate had been analysed in a single blood draw, including hospitalised patients and patients from outpatient clinics and general practice. MAIN OUTCOME MEASURES:Diagnostic accuracy by Harrell's c and receiver operating characteristic curve analysis, using free calcium standardised at pH 7.40 as a gold standard, in subgroups with estimated glomerular filtration rate (eGFR) ?60?or <60?mL/min/1.73?m2. RESULTS:In the subgroup with eGFR <60?mL/min/1.73?m2, the Harrell's c of unadjusted total calcium (0.801) was significantly larger than those of the local formulas (0.790, p=0.002) and the best formula taken from literature (0.791, p=0.004). In the subgroup with eGFR ?60?mL/min/1.73?m2, no significant differences were found between these three formulas. CONCLUSIONS:Our study shows that the diagnostic accuracy of unadjusted total calcium is superior to several commonly used adjustment formulas, and we suggest that the use of such formulas should be abandoned in clinical practice. If the clinician does not trust total calcium to reflect the calcium status of the patient, free calcium should be measured.

SUBMITTER: Lian IA

PROVIDER: S-EPMC5892769 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Should total calcium be adjusted for albumin? A retrospective observational study of laboratory data from central Norway.

Lian Ingrid Alsos IA Åsberg Arne A

BMJ open 20180407 4

<h4>Objectives</h4>Albumin-adjusted total calcium is often used as a surrogate marker for free calcium to evaluate hypocalcaemia or hypercalcaemia. Many adjustment formulas based on simple linear regression models have been published, and continue to be used in spite of questionable diagnostic accuracy. In the hope of finding a more pure albumin effect on total calcium, we used multiple linear regression models to adjust for other relevant variables. The regression coefficients of albumin were u ...[more]

PMID: 29627804

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Project description:BackgroundSelection of incidents and accurate identification of patients that require assistance from physician-staffed emergency medical services (P-EMS) remain essential. We aimed to evaluate P-EMS availability, the underlying criteria for dispatch, and the corresponding dispatch accuracy of trauma care in south-east Norway in 2015, to identify areas for improvement.MethodsPre-hospital data from emergency medical coordination centres and P-EMS medical databases were linked with data from the Norwegian Trauma Registry (NTR). Based on a set of conditions (injury severity, interventions performed, level of consciousness, incident category), trauma incidents were defined as complex, warranting P-EMS assistance, or non-complex. Incident complexity and P-EMS involvement were the main determinants when assessing the triage accuracy. Undertriage was adjusted for P-EMS availability and response and transport times.ResultsAmong 19,028 trauma incidents, P-EMS were involved in 2506 (13.2%). The range of overtriage was 74-80% and the range of undertriage was 20-32%. P-EMS readiness in the event of complex incidents ranged from 58 to 70%. The most frequent dispatch criterion was "Police/fire brigade request immediate response" recorded in 4321 (22.7%) of the incidents. Criteria from the groups "Accidents" and "Road traffic accidents" were recorded in 10,875 (57.2%) incidents, and criteria from the groups "Transport reservations" and "Unidentified problem" in 6025 (31,7%) incidents. Among 4916 patient pathways in the NTR, 681 (13.9%) could not be matched with pre-hospital data records.ConclusionsBoth P-EMS availability and dispatch accuracy remain suboptimal in trauma care in south-east Norway. Dispatch criteria are too vague to facilitate accurate P-EMS dispatch, and pre-hospital data is inconsistent and insufficient to provide basic data for scientific research. Future dispatch criteria should focus on the care aspect of P-EMS. Better tools for both dispatch and incident handling for the emergency medical coordination centres are essential. In general, coordination, standardisation, and integration of existing data systems should enhance the quality of trauma care and increase patient safety.

Project description:BackgroundClopidogrel and aspirin are antiplatelet agents that are recommended to reduce the risk of recurrent stroke and other cardiovascular events. Combination therapy of clopidogrel and aspirin has been shown to increase the risk of hemorrhage, but the effects of the drugs on laboratory parameters have not been well studied in patients in routine clinical practice. Therefore, we evaluated and compared the effects of combination therapy with clopidogrel plus aspirin and aspirin monotherapy on laboratory parameters using a clinical database.MethodsWe used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between November 2004 and April 2011, to identify cohorts of new users (n?=?159) of clopidogrel (75 mg/day) plus aspirin (100 mg/day) and new users (n?=?834) of aspirin alone (100 mg/day). We used a multivariable regression model and regression adjustment with the propensity score to adjust for differences in baseline covariates between settings, and compare the mean changes in serum levels of creatinine, aspartate aminotransferase, alanine aminotransferase and hematological parameters, including hemoglobin level, hematocrit, and white blood cell (WBC), red blood cell and platelet counts up to two months after the start of study drug administration.ResultsAfter adjustment, the reduction of WBC count in clopidogrel plus aspirin users was significantly greater than that in aspirin alone users. All other tests showed no statistically significant difference in the mean change from baseline to during the exposure period between clopidogrel plus aspirin users and aspirin alone users. The combination of clopidogrel and aspirin increased the risk of gastrointestinal bleeding compared with aspirin alone, with a relative risk ranging from 2.06 (95% CI, 1.02 to 4.13; p?=?0.043) for the multivariate model and 2.61 (95% CI, 1.18 to 5.80; p?=?0.0184) for propensity adjustment.ConclusionOur findings suggested that hematological adverse effects may be greater with combination therapy of clopidogrel plus aspirin than with aspirin monotherapy.

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Should total calcium be adjusted for albumin? A retrospective observational study of laboratory data from central Norway.

Publications

Should total calcium be adjusted for albumin? A retrospective observational study of laboratory data from central Norway.

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