Albumin and calcium reference interval using healthy individuals and a data-mining approach.

BACKGROUND: Harmonization of reference intervals for analytes that have a sound calibration and metrological traceability is a widely recommended practice. The UK Pathology Harmony has recently harmonized reference intervals for calcium and albumin. In this study, we have determined the reference intervals for calcium and albumin on the UK's most commonly used analytical platforms. METHOD: A prospective reference population of healthy individuals was recruited according to the IFCC CRIDL criteria. A second indirect population was collected from 14 primary care setting and measured in laboratories using various analytical platforms and methods (Roche, Abbott, Beckman and Siemens analytical platforms). RESULTS: In total, 299 subjects were recruited; the central 95th centile values for calcium for three out of four analytical platforms were in a close agreement with UK Pathology Harmony reference intervals of 2.2-2.6 mmol/L. Reference intervals of BCG methods from both cohorts and irrespective of analytical platforms were higher for both lower and upper reference limits than those for BCP. In comparison, the indirect study showed an age-related variation. The younger population reference intervals varied by up to 5.7% at the lower reference limit and up to 12% at the upper reference limit compared with Pathology Harmony reference intervals, and the older population showed a variation of up to 14% at both limits. CONCLUSION: While calcium reference intervals can be a subject for harmonization, albumin reference intervals studied showed large variation which is unsupportive of embracing a common reference interval for albumin.

The effect of different analytical platforms and methods on the performance of population-specific adjusted calcium equation.

BACKGROUND: A recent attempt to improve the diagnostic value of adjusted calcium addressed a primary care-specific adjusted calcium equation, but validated the new equation for Roche Cobas, BCG and NM-BAPTA methods only. In this study, we aim to validate a population-specific equation for other methods and platforms. METHOD: We collected retrospective patient data-sets from 15 hospital laboratories using a range of commercially available analytical platforms and methods for calcium and albumin measurements. Raw data-sets were collected and filtered according to Payne's criteria, and separate adjusted calcium equations were derived for hospitalized and primary care patients. RESULTS: Mean albumin and calcium results were significantly higher in primary care populations (P < 0.0001). The prevalence of hypocalcaemia using adjusted calcium ranged between 6% and 44% for inpatient data-sets and was higher in users of BCG methods. The application of community-specific adjustment equation to primary care data-sets reduced the prevalence of hypocalcaemia (mean 1.7%, range 0.8-3.7%). CONCLUSION: We demonstrated that the use of a community-specific calcium adjustment equation to a primary care population reduces both the percentage and the variation of hypocalcaemia between different laboratories.

Do we need post-pregnancy screening with human chorionic gonadotrophin after previous hydatidiform mole to identify patients with recurrent gestational trophoblastic disease?

OBJECTIVE: To determine whether post-pregnancy human chorionic gonadotrophin screening after previous hydatidiform mole identifies patients with recurrent gestational trophoblastic disease. STUDY DESIGN: A retrospective evaluation of 9315 patients who underwent post-pregnancy screening from 2000 to 2009, as part of the National Gestational Trophoblastic Disease Service in the UK. RESULTS: Patients with previous hydatidiform mole, who had human chorionic gonadotrophin screening after one or more subsequent pregnancies, were identified (n = 9315). Of these, 8630 patients had an initial hydatidiform mole that did not require chemotherapy. In 12,329 subsequent pregnancy events, screening with human chorionic gonadotrophin identified 3 cases of gestational trophoblastic neoplasm. The remaining 685 patients developed gestational trophoblastic neoplasm, following their initial hydatidiform mole and required chemotherapy. In this group there were 1012 further pregnancy events, human chorionic gonadotrophin screening identified 3 patients with gestational trophoblastic neoplasm. The overall recurrence rate was 6 in 13,341 events (risk 1: 2227). The rate was 3 in 12,329 (risk 1:4110) for HM that did not require chemotherapy and 3 in 1012 (1:337) for previously treated gestational trophoblastic neoplasm. All 6 patients with recurrent disease were successfully treated with chemotherapy. CONCLUSION: Routine post-pregnancy human chorionic gonadotrophin screening may be safely discontinued in patients with one previous uncomplicated hydatidiform mole.

A model QA program in radiation oncology.

This article presents a detailed and comprehensive technically oriented quality assurance (QA) program for radiation oncology. The primary aspects of care that relate to all departments are included and may serve as a guide for development of criteria and indicators for specialty areas, such as hyperthermia and interoperative radiation. The Joint Commission on Accreditation of Healthcare Organization's (JCAHO) step-by-step process for QA program development is also summarized to clarify the process.