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.

Objective: To develop the environment scale of unintentional injury in the home for children aged 0-6 years living in urban area of China, and test its validity and reliability. Methods: The content of the environment scale was established through the literature review, expert consultation and pilot study. A total of 1 104 children aged 0-6 years in urban area of Changsha were enrolled in this study by using a multi-stage stratified cluster random sampling method. The questionnaire was used to collect the basic information of children, the incidence of unintentional injury and the status of home environment. The reliability of the scale was tested by using Cronbach′s α coefficient and split-half reliability coefficient. The content validity and construct validity were tested by using Pearson correlation analysis and factor analysis. All children were divided into two groups according to the incidence of unintentional injury in the home and the discrimination validity of the scale was tested by using t-test. Results: The scale had 54 items in 6 dimensions. The number of eligible questionnaires was 1 074, including 554 (51.6%) from boys and 519 (48.3%) from children under 3 years old. The incidence rate of unintentional injury and in-home injury was 18.34% (197 children) and 10.71% (115 children). The internal consistency reliability (Cronbach′s α) coefficient for the scale was 0.87 and the split-efficacy reliability coefficient was 0.82, both meeting the standard of reliability above 0.70. The Pearson correlation coefficient between each dimension and the whole scale ranged from 0.53 to 0.84 (all P values <0.001). The common factor cumulative variance contribution rate of the scale was 58.34%. There were 54 items with factor loadings greater than 0.30. The root mean square error of approximation, comparative fit index and goodness-of-fit index were 0.07, 0.61 and 0.71, respectively. The score of scale in children with injury was significantly higher than that in children without injury (P=0.022). Conclusion The validity and reliability of the environment scale for unintentional injury in the home for children aged 0-6 years old in the urban area of China are good.