Evaluating performance in sweat testing in medical biochemistry laboratories in Croatia

Abstract

IntroductionSweat test has a diagnostic role in evaluation of cystic fibrosis. Its performance includes sweat stimulation, collection and analysis. All listed may be sources of inconsistencies in everyday practice. The aim of this study was an evaluation of external quality assessment (EQA) of sweat chloride measurement including sweat test performance in medical biochemistry laboratories in Croatia.Materials and methodsEQA for sweat chloride measurement was provided by Croatian Centre for Quality Assessment in Laboratory Medicine (CROQALM) in five consecutive exercises to medical biochemistry laboratories (MBL) that offered sweat testing. A questionnaire regarding all phases of testing was mailed to involved MBL (N = 10). Survey results were compared to current guidelines for sweat test performance.ResultsReported results of EQA in 2015 exercises showed coefficients of variation (CV) from 28.9%, 29.0% to 35.3%, respectively. An introduction of uniform sweat chloride measurement protocol resulted in CV of 15.5% and 14.7% reported in following two exercises in 2016. All MBL included in this study replied to the questionnaire. Results reported by MBL indicated: lack of patient information policy (7/10), use of unacceptable electrodes (6/9), misuse of minimum of acceptable sweat weight (6/9), lack of internal quality assessment (5/9) and recommended reference ranges (5/9 and 4/9). Agreements to guidelines were found in approach to unsuitable patients (9/10) and sweat collection (8/9).ConclusionPresented results indicate major weak points of current practice in sweat test performance in Croatian MBL and stress the need for its standardization on a national level.

National Guidelines for the Performance of the Sweat Test in Diagnosis of Cystic Fibrosis on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine and the Cystic Fibrosis Centre - Paediatrics and adults, University Hospital Centre Zagreb

“…A survey demonstrated the need for standardising the ST at the national level because of suboptimal practices at medical biochemical laboratories (MBLs) in Croatia ( 19 ). This survey therefore laid a solid foundation for developing the NGPST.…”

“…The NGPST were developed using questionnaires in survey conducted in 2018. The first was an update of a previously published survey covering all ST procedures ( 19 ). The second questionnaire examined the use of electrodes for PI and quality indicators, while the third investigated current power supply instruments.…”

“…PI may be performed using a commercial system or the original or modified method of Gibson and Cooke ( 17 ). Before commercial PI systems became available, laboratories or paediatric outpatient clinics would typically use in-house equipment and materials adapted for the Gibson and Cooke method ( 18 , 19 ).…”

Indicações clínicas, variações com a idade e proporção entre os eletrólitos do teste de suor para o diagnóstico de fibrose cística

“…Finally, it is necessary but not sufficient to organize and publish CF diagnosis consensus processes. In addition, monitoring implementation efforts and practices seem essential as recommended in the literature (41)(42)(43).…”