A comparison of participants with non-participants in a population-based epidemiologic study: the Melbourne Visual Impairment Project

PURPOSE: Adequate participation in population-based studies in essential to ensure that the sample is representative of the population under investigation. Participants may differ from non-participants on important variables such as age, sex socioeconomic status, and general health factors. The Melbourne Visual Impairment Project (Melbourne VIP) is a population-based study designed to increase understanding of the prevalence and severity of common ocular disorders affecting people 40 years of age and over. AIM: The aim of this study was to determine the potential for any non-response bias by comparing data from participants and non-participants of the Melbourne VIP. METHODS: Specific demographic and general variables were compared between the two groups. The variables included age, sex, education level, and social status. The reason for non-attendance was also recorded. RESULTS: A total of 3271 (83%) eligible residents from the 9 sample areas were screened; 46% males and 54% females. Language spoken at home was significantly associated with participation. Residents whose main language at home was not English were less likely to attend the screening centre. (OR: 0.60; CI: 0.44-0.81). The main reasons given for non-attendance by eligible residents were lack of interest (6%), too busy to attend (4%), personal illness (2%), and attend own eye specialist (2%). CONCLUSION: We believe these results will not impact significantly on the interpretation of gender and age-specific data from the Melbourne VIP

Superhard Phases of Simple Substances and Binary Compounds of the B-C-N-O System: from Diamond to the Latest Results (a Review)

The basic known and hypothetic one- and two-element phases of the B-C-N-O system (both superhard phases having diamond and boron structures and precursors to synthesize them) are described. The attention has been given to the structure, basic mechanical properties, and methods to identify and characterize the materials. For some phases that have been recently described in the literature the synthesis conditions at high pressures and temperatures are indicated.Comment: Review on superhard B-C-N-O phase

Transmission of Carbapenem-Resistant Klebsiella pneumoniae in US Hospitals

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is the most prevalent carbapenem-resistant Enterobacterales in the United States. We evaluated CRKp clustering in patients in US hospitals. Methods: From April 2016 to August 2017, 350 patients with clonal group 258 CRKp were enrolled in the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae, a prospective, multicenter, cohort study. A maximum likelihood tree was constructed using RAxML. Static clusters shared ≤21 single-nucleotide polymorphisms (SNP) and a most recent common ancestor. Dynamic clusters incorporated SNP distance, culture timing, and rates of SNP accumulation and transmission using the R program TransCluster. Results: Most patients were admitted from home (n = 150, 43%) or long-term care facilities (n = 115, 33%). Urine (n = 149, 43%) was the most common isolation site. Overall, 55 static and 47 dynamics clusters were identified involving 210 of 350 (60%) and 194 of 350 (55%) patients, respectively. Approximately half of static clusters were identical to dynamic clusters. Static clusters consisted of 33 (60%) intrasystem and 22 (40%) intersystem clusters. Dynamic clusters consisted of 32 (68%) intrasystem and 15 (32%) intersystem clusters and had fewer SNP differences than static clusters (8 vs 9; P =. 045; 95% confidence interval [CI]: -4 to 0). Dynamic intersystem clusters contained more patients than dynamic intrasystem clusters (median [interquartile range], 4 [2, 7] vs 2 [2, 2]; P =. 007; 95% CI: -3 to 0). Conclusions: Widespread intrasystem and intersystem transmission of CRKp was identified in hospitalized US patients. Use of different methods for assessing genetic similarity resulted in only minor differences in interpretation

Meta-analysis of type 2 Diabetes in African Americans Consortium

Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR)  = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe

Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: Pooled individual data analysis of 17 prospective studies

Background: Insulin-like growth factor 1 (IGF1) stimulates mitosis and inhibits apoptosis. Some published results have shown an association between circulating IGF1 and breast-cancer risk, but it has been unclear whether this relationship is consistent or whether it is modified by IGF binding protein 3 (IGFBP3), menopausal status, oestrogen receptor status or other factors. The relationship of IGF1 (and IGFBP3) with breast-cancer risk factors is also unclear. The Endogenous Hormones and Breast Cancer Collaborative Group was established to analyse pooled individual data from prospective studies to increase the precision of the estimated associations of endogenous hormones with breast-cancer risk. Methods: Individual data on prediagnostic IGF1 and IGFBP3 concentrations were obtained from 17 prospective studies in 12 countries. The associations of IGF1 with risk factors for breast cancer in controls were examined by calculating geometric mean concentrations in categories of these factors. The odds ratios (ORs) with 95% CIs of breast cancer associated with increasing IGF1 concentrations were estimated by conditional logistic regression in 4790 cases and 9428 matched controls, with stratification by study, age at baseline, and date of baseline. All statistical tests were two-sided, and a p value of less than 0\ub705 was considered significant. Findings: IGF1 concentrations, adjusted for age, were positively associated with height and age at first pregnancy, inversely associated with age at menarche and years since menopause, and were higher in moderately overweight women and moderate alcohol consumers than in other women. The OR for breast cancer for women in the highest versus the lowest fifth of IGF1 concentration was 1\ub728 (95% CI 1\ub714-1\ub744; p&lt;0\ub70001). This association was not altered by adjusting for IGFBP3, and did not vary significantly by menopausal status at blood collection. The ORs for a difference in IGF1 concentration between the highest and lowest fifth were 1\ub738 (95% CI 1\ub714-1\ub768) for oestrogen-receptor-positive tumours and 0\ub780 (0\ub757-1\ub713) for oestrogen-receptor-negative tumours (p for heterogeneity=0\ub7007). Interpretation: Circulating IGF1 is positively associated with breast-cancer risk. The association is not substantially modified by IGFBP3, and does not differ markedly by menopausal status, but seems to be confined to oestrogen-receptor-positive tumours

Risk Factors for Cataract: A Case Study at National University of Malaysia Hospital

The purpose of this study was to identify the most common forms of age-related Cataracts ant to estimate possible risk factors for age-related cataracts in a sample of cataract patients at the National University of Malaysia Hospital. Thirty five patients (17 males and 18 female) with cataract were recruited from the ophthalmology ward and clinic at the hospital. The age range of the patients was between 39 to 93 years (mean 64.9 ± 11.5 years). The Lens Opacities Classification System (LOCS) III was used to grade nuclear, cortical and posterior subcapsular lens opacities. Grading of the cataract was carried out and the following information was collected: initial visual acuity and best-corrected visual acuity, demographic details, health history, dietary intake of antioxidants and lifetime ocular ultraviolet B exposure. Analyses were conducted using a standard case-control design. T-tests were used to assess the significance of continuous variable and chi-squared test were used for categorical variables. The overall prevalence of cortical cataract was 34.4% (12 patients), nuclear cataract was 60.0% (21 patients), and posterior subcapsular cataract was 57.1% (20 patients). No significant potential risk factor was found for nuclear cataracts. In the case of posterior subcapsular cataract, hypertension was the only potential significant risk factor (x² = 4.38, p = 0.036), and in the case of corticalcataract, cigarette smoking was the only significant risk factor. Although lifetime effective ocular UV-B exposure was found to be not a significant potential risk factor, but it was seen that for cortical cataracts, the mean difference of lifetime effective ocular UV-B exposure between those with cortical and those without cortical cataract was larger compared to others with nuclear and posterior subcapsular cataracts. Hypertension was found to be a potential significant risk factor for posterior subcapsular cataract whereas cigarette smoking was a potentially significant risk factor for cortical cataract. Although not statistically significant, lifetime effective ocular UV-B exposure maybe a potential risk factor for cortical cataract

Compliance with recommendations from a screening programme for diabetic retinopathy

METHODS: General practitioner compliance with recommendations for patient follow-up after participation in a screening programme for diabetic retinopathy was assessed. Six months after screening with non-mydriatic retinal photography in four areas of Victoria, the genera practitioner of each participant was surveyed if the participant reported no examination for diabetic retinopathy in the past 2 years and if the results of the screening indicated the need for further assessment. RESULTS: Overall, 208 of 253 (82%) completed questionnaires were analysed. A total of 123 (59%) patients were referred by their doctors for further assessment and 97 (79%) of those referred were reported to have complied with the referral. Of the 85 (41%) patients who were not referred for further assessment, 31 (36%) were reported by their doctors to be already under regular review by an ophthalmologist. CONCLUSIONS: Compliance with genera practitioner referrals suggests that this screening programme was effective and a useful means by which to remind general practitioners of the importance of regular eye examinations for people with diabetes

Recruitment methods for community-based screening for diabetic retinopathy

Regular screening of all people with diabetes is the most efficient and cost-effective way to detect early stages of diabetic retinopathy so that laser treatment can be performed at the optimal time. A major aim of the Program for the Early Detection of Diabetic Retinopathy was to increase compliance with guidelines for screening for diabetic retinopathy. This community-based screening program used non-mydriatic retinal photography and was initiated in four areas of Victoria, Australia from 1996-1998. Recruitment strategies included targeted mail-outs, provision of the program brochure in English and the main languages spoken in the areas and media promotion in ethnic newspapers and on ethnic radio stations. In Victoria, only 55% of the population with diabetes currently access eye care services at the recommended intervals. This program was able to increase compliance with guidelines to 70% among people with diabetes that had not had a recent eye examination. A total of 1,197 people with diabetes were screened for diabetic retinopathy. Of the 1,197 people who were screened, 620 (15% of the estimated number of people with diabetes) had not had their eyes examined in the past two years. This pilot study identified strategies to encourage people with diabetes to have their eyes examined at the recommended intervals