Evaluation and optimization of pre-pregnancy and pregnancy thalassaemia screening programmes in Hainan Province / 中国热带医学

@#Abstract: Objective　To evaluate the free thalassaemia screening programme for preconception and pregnancy in Hainan Province, and to provide a theoretical basis for optimizing the screening process for thalassaemia. Methods From November 2020 to July 2021, a survey was conducted on 10 396 adults with Hainan household registration who participated in the Epidemiological Survey of Thalassemia in Hainan Residents in 19 cities and counties of Hainan Province. All of them underwent routine blood tests, haemoglobin electrophoresis tests and genetic tests for thalassaemia. The optimal diagnostic cut-off values for mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and haemoglobin adult type 2 (HbA2) were determined using screening test indexes such as receiver operating characteristic curve and sensitivity. The diagnostic effectiveness of different primary screening programs for thalassemia gene carriers was evaluated. Results Using the existing MCV single-indicator thalassemia primary screening protocol in Hainan Province, where individuals with MCV<82 fL undergo thalassemia gene testing, resulted in a high missed diagnosis rate (34.06%) and low sensitivity (65.94%). The optimal cut-off values for MCV screening for alpha-and beta-thalassaemia were 84.45 fL and 79.05 fL, respectively; the optimal cut-off values for MCH screening for alpha-and beta-thalassaemia were 27.95 pg and 25.15 pg, respectively. The optimal cut-off value for HbA2 screening for alpha-thalassaemia was less than 2.55% and greater than 3.35% for beta-thalassaemia. The "combined HbA2 or MCH or MCV screening protocol" with the cut-off values recommended in this study had a better performance in primary screening for thalassemia, with the highest sensitivity (92.96%) and negative predictive value (92.67%) and the lowest underdiagnosis rate (7.04%), statistically significant differences compared with the existing protocol (P<0.05). Conclusions The current process of screening for thalassemia in Hainan Province may lead to missed diagnoses. The combined use of MCV, MCH and HbA2 for thalassemia screening, adopting locally suitable cutoff values for primary screening indicators, can improve the incidence of missed reporting of thalassemia and enhance diagnostic effectiveness.

Comparative analysis of IDF, ATPIII and CDS in the diagnosis of metabolic syndrome among adult inhabitants in Jiangxi Province, China.

BACKGROUND: Currently, the prevalence of metabolic syndrome (MS) has attracted widespread public attention. However, there is a war regarding the applicability of the diagnosis in different populations regarding the distinct criteria for the diagnosis of MS. Data about the prevalence rate of MS and its components in Jiangxi Province are limited. Thus, our goals were to compare the consistency rates and applicability of three criteria, i.e., those of the International Diabetes Federation (IDF), the National Cholesterol Education Program Adult Treatment PanelⅢ (ATPⅢ), and the Chinese Diabetes Society (CDS). METHODS: From September 2013 to March 2014, 5959 residents (age≥18 years) from Jiangxi Province were selected by multistage stratified cluster random sampling methods. The prevalence rate of MS and its components were calculated according to the IDF, ATPⅢ and CDS criteria, and the protocols of the different criteria were measured in terms of consistency with the kappa statistic and Youden's index. Receiver operator characteristic (ROC) curve analysis was used to explore the optimal cut-off points of body mass index (BMI) and waist circumference (WC). RESULTS: The mean age of the participants was 50.52±13.92 years among the total of 5959 individuals (2451 male and 3508 female). The standardized prevalence rate of MS was 19.85%, 24.77% and 9.95% according to the IDF, ATPⅢ and CDS criteria, respectively. The order of the prevalence rates of the different components of MS according to the IDF or ATPⅢ criteria from high to low were as follows: elevated blood pressure, central obesity, reduced high density lipoprotein cholesterol (HDL-C), hyperglycemia, and hypertriglyceridemia. The most prevalent component of MS, according to the CDS criterion, was being overweight or obese, followed by elevated blood pressure, dyslipidemia and hyperglycemia. The Youden's index in IDF criterion was higher than which in CDS criterion (0.79 for IDF vs. 0.38 for CDS) referring to the ATPⅢ criterion. The agreement between the IDF and ATPⅢ criteria was good (kappa = 0.85), whereas the agreement of the CDS with the IDF and ATPⅢ criteria was moderate (kappa = 0.46 and 0.46, respectively). The ability to predict MS risk factors clusters was superior when the BMI cut-off point was 24/24kg/m2 (male/female), and the WC cut-off point was 87/80cm (male/female). Among the 18~59 years old male group, BMI was superior to WC in predicting clusters of risk factors for MS; while in the 60 years and above male group and all-age female group, WC was superior to BMI. CONCLUSION: Our results revealed that the prevalence rate of metabolic syndrome among adults was high in Jiangxi Province. BMI and WC had different ability to predict clusters of risk factors for MS in different age groups and gender. Among the three criteria for MS, there was bigger difference in applicability for the adults of Jiangxi Province. The choice of the appropriate criteria should be based on the actual conditions of the site.