Browsing by Author "Bakan, E"

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    A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers
    (WALTER DE GRUYTER GMBH) Ozarda, Y; Ichihara, K; Aslan, D; Aybek, H; Ari, Z; Taneli, F; Coker, C; Akan, P; Sisman, AR; Bahceci, O; Sezgin, N; Demir, M; Yucel, G; Akbas, H; Ozdem, S; Polat, G; Erbagci, AB; Orkmez, M; Mete, N; Evliyaoglu, O; Kiyici, A; Vatansev, H; Ozturk, B; Yucel, D; Kayaalp, D; Dogan, K; Pinar, A; Gurbilek, M; Cetinkaya, CD; Akin, O; Serdar, M; Kurt, I; Erdinc, S; Kadicesme, O; Ilhan, N; Atali, DS; Bakan, E; Polat, H; Noyan, T; Can, M; Bedir, A; Okuyucu, A; Deger, O; Agac, S; Ademoglu, E; Kaya, A; Nogay, T; Eren, N; Dirican, M; Tuncer, G; Aykus, M; Gunes, Y; Ozmen, SU; Kawano, R; Tezcan, S; Demirpence, O; Degirmen, E
    Background: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. Methods: Blood samples were collected nationwide in 28 laboratories from the seven regions (>= 400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). Results: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and.-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m(2). Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. Conclusions: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population.
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    A nationwide multicentre study in Turkey for establishing reference intervals of haematological parameters with novel use of a panel of whole blood
    (CROATIAN SOC MEDICAL BIOCHEMISTRY & LABORATORY MEDICINE) Ozarda, Y; Ichihara, K; Bakan, E; Polat, H; Ozturk, N; Baygutalp, NK; Taneli, F; Guvenc, Y; Ormen, M; Erbayraktar, Z; Aksoy, N; Sezen, H; Demir, M; Eskandari, G; Polat, G; Mete, N; Yuksel, H; Vatansev, H; Gun, F; Akin, O; Ceylan, O; Noyan, T; Gozlukaya, O; Aliyazicioglu, Y; Kahraman, S; Dirican, M; Tuncer, GO; Kimura, S; Eker, P
    Introduction: A nationwide multicentre study was conducted to establish well-defined reference intervals (Rls) of haematological parameters for the Turkish population in consideration of sources of variation in reference values (RVs). Materials and methods: K2-EDTA whole blood samples (total of 3363) were collected from 12 laboratories. Sera were also collected for measurements of iron, UIBC, TIBC, and ferritin for use in the latent abnormal values exclusion (LAVE) method. The blood samples were analysed within 2 hours in each laboratory using Cell Dyn and Ruby (Abbott), LH780 (Beckman Coulter), or XT-2000i (Sysmex). A panel of freshly prepared blood from 40 healthy volunteers was measured in common to assess any analyser-dependent bias in the measurements. The SD ratio (SDR) based on ANOVA was used to judge the need for partitioning RVs. Rls were computed by the parametric method with/without applying the LAVE method. Results: Analyser-dependent bias was found for basophils (Bas), MCHC, RDW and MPV from the panel test results and thus those Rls were derived for each manufacturer. Rls were determined from all volunteers' results for WBC, neutrophils, lymphocytes, monocytes, eosinophils, MCV, MCH and platelets. Gender-specific Rls were required for RBC, haemoglobin, haematocrit, iron, UIBC and ferritin. Region-specific Rls were required for RBC, haemoglobin, haematocrit, UIBC, and TIBC. Conclusions: With the novel use of a freshly prepared blood panel, manufacturer-specific Rls' were derived for Bas, Bas%, MCHC, RDW and MPV. Regional differences in Rls were observed among the 7 regions of Turkey, which may be attributed to nutritional or environmental factors, including altitude.