An optimal design for screening trials

Yao, Begg, and Livingston (1996, Biometrics 52, 992-1001) considered the optimal group size for testing a series of potentially therapeutic agents to identify a promising one as soon as possible for given error rates. The number of patients to be tested with each agent was fixed as the group size. We consider a sequential design that allows early acceptance and rejection, and we provide an optimal strategy to minimize the sample sizes (patients) required using Markov decision processes. The minimization is under the constraints of the two types (false positive and false negative) of error probabilities, with the Lagrangian multipliers corresponding to the cost parameters for the two types of errors. Numerical studies indicate that there can be a substantial reduction in the number of patients required.

Is there a relationship between screening for diabetes related foot complications and limb amputation?

Background From the conservative estimates of registrants with the National Diabetes Supply Scheme, we will be soon passing 1.1 Million Australians affected by all types of diabetes. The diabetes complications of foot ulceration and amputation are costly to all. These costs can be reduced with appropriate prevention strategies, starting with identifying people at risk through primary care diabetic foot screening. Yet levels of diabetic foot screening in Australia are difficult to quantify. This presentation aims to report on foot screening rates as recorded in existing academic literature, national health surveys and national database reports. Methods Literature searches included diabetic foot screening that occurred in the primary care setting for populations over 2000 people from 2002 to 2014. Searches were performed using Medline and CINAHL as well as internet searches of Organisations for Economic Co-operation and Development (OECD) countries health databases. The focus is on type 1 and type 2 diabetes in adults, and not gestational diabetes or children. The two primary outcome measures were foot -screening rates as a percentage of adult diabetic population and major lower limb amputation incidence rates from standardised OECD data. Results The most recent and accurate level for Australian population review was in the AUSDIAB (Australian Diabetes and lifestyle survey) from 2004. This survey reported screening in primary care to be as low as 50%. Countries such as the United Kingdom and United States of America have much higher reported rates of foot screening (67-86%) recorded using national databases and web based initiatives that involve patients and clinicians. By comparison major amputation rates for Australia were similar to the United Kingdom at 6.5 versus 5.1 per 100,000 population, but dis-similar to the United States of America at 17 per 100,000 population. Conclusions Australian rates of diabetic foot screening in primary care centres is ambiguous. There is no direct relationship between foot screening levels in a primary care environment and major lower limb amputation, based on national health survey's and OECD data. Uptake of national registers, incentives and web-based systems improve levels of diabetic foot assessment, which are the first steps to a healthier diabetic population.

Inconsistent Transmission of Banana Bunchy Top Virus in Micropropagated Bananas and its Implication for Germplasm Screening

Banana bunchy top virus (BBTV) was readily transmitted through tissue culture in banana (Mum sp.) cv. Lady finger (AAB) and Cavendish cv. Williams (AAA). Lines derived from infected and healthy field plants had similar in vitro multiplication rates. BBTV infected in vitro cultures displayed symptoms of stunting, leaf curling, chlorotic and green flecks, and poor root growth. Symptoms became milder with time, and were often difficult to discern in older, rapidly multiplying cultures. A triple antibody sandwich ELISA using polyclonal and monoclonal antibodies was very efficient for detecting BBTV in vitro. Symptomless, ELISA-negative plants arose in 10 out of 11 lines derived from BBTV-infected field plants and first appeared after 9 months continuous in vitro culture at a constant 28OC. Meristem tip culture or heat therapy was not used. These plants remained symptomless and ELISA-negative after planting out in the glasshouse (individual plants checked for up to 16 months). The implications of this inconsistent transmission of BBTV for germplasm indexing and exchange are discussed.

Neonatal screening for cystic fibrosis

Two groups of patients with cystic fibrosis were compared. The screened group, detected with an improved neonatal screening assay for immunoreactive trypsin, developed fewer chest infections requiring treatment and gained more weight than the unscreened group. Early diagnosis by screening seems to affect early morbidity.

Rapid and efficient screening of a Representational Difference Analysis library using reverse Southern hybridisation: Identification of genetic differences between Haemophilus parasuis isolates

Representational Difference Analysis (RDA) is an established technique used for isolation of specific genetic differences between or within bacterial species. This method was used to investigate the genetic basis of serovar-specificity and the relationship between serovar and virulence in Haemophilus parasuis. An RDA clone library of 96 isolates was constructed using H. parasuis strains H425(P) (serovar 12) and HS1967 (serovar 4). To screen such a large clone library to determine which clones are strain-specific would typically involved separately labelling each clone for use in Southern hybridisation against genomic DNA from each of the strains. In this study, a novel application of reverse Southern hybridisation was used to screen the RDA library: genomic DNA from each strain was labelled and used to probe the library to identify strain-specific clones. This novel approach represents a significant improvement in methodology that is rapid and efficient.

Women's views of ultrasonography: A comparison of women's experiences of antenatal ultrasound screening with cerebral ultrasound of their newborn infant

Ultrasound screening is now a routine procedure which forms part of antenatal care provision. Within this routine context ultrasound technology has been found to be generally acceptable and indeed is positively demanded by many women. This paper raises the question whether the routine presentation of ultrasound implicitly conveys the message that is use in antenatal care is both valuable and safe. It examines women's views of ultrasound technology beyond a routine context. In a study designed to examine women's reactions to cerebral ultrasound on their normal term infants mothers were asked their views and knowledge of ultrasound and a comparison with their antenatal experience of ultrasound was elicited. A generalized concern about ultrasound techniques was found to underlie many of the women's comments. This raised questions concerning the current practice in the presentation of ultrasound to women attending for antenatal care.

Effect of Ethanol Extract of Whole Plant of Trichosanthes cucumerina var. cucumerina L. on Gonadotropins, Ovarian Follicular Kinetics and Estrous Cycle for Screening of Antifertility Activity in Albino Rats

Ethanol extract of whole plant of Trichosanthes cucumerina L. var. cucumerina was evaluated for antiovulatory activity in adult rats. The ethanol extract at the doses 200 and 400mg/kg body weight (orally) affected the normal estrous cycle showing a significant increase in estrus and metestrus phases and decrease in diestrus and proestrus phases. The extract also significantly reduced the number of healthy follicles (Class I-Class VI) and corpora lutea and increased the number of regressing follicles (Stage IA, Stage IB, Stage IIA, and Stage IIB). The protein and glycogen content in the ovaries were significantly reduced in treated rats. The cholesterol level was significantly increased, whereas, the enzyme activities like 3b-HSD and 17b-HSD were significantly inhibited in the ovary of treated rats. Serum FSH and LH levels were significantly reduced in the treated groups were measured by RIA. In acute toxicity test, neither mortality nor change in the behavior or any other physiological activities in mice were observed in the treated groups. In chronic toxicity studies, no mortality was recorded and there were no significant differences in the body and organ weights were observed between controls and treated rats. Hematological analysis showed no significant differences in any of the parameters examined (RBC, WBC count and Hemoglobin estimation). These observations showed the antiovulatory activity of ethanol extract of whole plant of Trichosanthes cucumerina L. var. cucumerina in female albino rats.

Screening selected myrtaceous tree species for production of essential oils in northern Queensland

Trials to identify alternative cropping options to Melaleuca alternifolia for northern Queensland essential oil growers were established at Dimbulah and Innot Hot Springs in 2001. Seed sources of Asteromyrtus symphyocarpa (1,8-cineole form), Eucalyptus staigeriana (citral), Melaleuca cajuputi subsp. cajuputi (trans-nerolidol), M. ericifolia (d-linalool), M. quinquenervia (trans-nerolidol and viridiflorol forms) and M. viridiflora (methyl cinnamate) with potential to produce commercial foliar oils were evaluated. Information was gathered on their adaptability, growth and oil yields over 49 months and 52 months (two harvests) from planting at Dimbulah and Innot Hot Springs, respectively. Of the species and chemotypes evaluated, M. quinquenervia showed potential for commercial production of trans-nerolidol, a compound used in perfumery. It had a very high survival rate (96%) and yields could be expected to improve dramatically from the average 100 kg/ha per harvest achieved in these trials with further research into selection of seed source, control of insect damage and breeding for genetic improvement. M. cajuputi subsp. cajuputi gave a similar performance to M. quinquenervia. The rarity of the trans-nerolidol form of this species and remoteness of its natural occurrence are impediments to further planting and research. E. staigeriana, with second harvest yields of ~600 kg/ha, performed exceptionally well on both sites but potential for development is limited by the ready availability of competitively priced E. staigeriana oil produced in South America. Survival of M. ericifolia ranged from 62% to 82% at 32 months (second harvest) at Innot Hot Springs and was deemed a failure at Dimbulah with poor growth and low survival, raising a major question about the suitability of this species for cultivation in the seasonally dry tropics. Planting of this species on a wider scale in northern Queensland cannot be recommended until more is known about factors affecting its survival. A. symphyocarpa and M. viridiflora were too slow-growing to warrant further consideration as potential oil-producing species at this time.

Development and evaluation of training in culturally specific screening and brief intervention for hospital patients with alcohol-related injuries

Objective To evaluate health practitioners’ confidence and knowledge of alcohol screening, brief intervention and referral after training in a culturally adapted intervention on alcohol misuse and well-being issues for trauma patients. Design Mixed methods, involving semi-structured interviews at baseline and a post-workshop questionnaire. Setting: Targeted acute care within a remote area major tertiary referral hospital. Participants Ten key informants and 69 questionnaire respondents from relevant community services and hospital-based health care professionals. Intervention Screening and brief intervention training workshops and resources for 59 hospital staff. Main outcome measures Self-reported staff knowledge of alcohol screening, brief intervention and referral, and satisfaction with workshop content and format. Results After training, 44% of participants reported being motivated to implement alcohol screening and intervention. Satisfaction with training was high, and most participants reported that their knowledge of screening and brief intervention was improved. Conclusion Targeted educational interventions can improve the knowledge and confidence of inpatient staff who manage patients at high risk of alcohol use disorder. Further research is needed to determine the duration of the effect and influence on practice behaviour. Ongoing integrated training, linked with systemic support and established quality improvement processes, is required to facilitate sustained change and widespread dissemination.

Guaiac versus immunochemical tests: Faecal occult blood test screening for colorectal cancer in a rural community

Objective: To describe patient participation and clinical performance in a colorectal cancer (CRC) screening program utilising faecal occult blood test (FOBT). Methods: A community-based intervention was conducted in a small, rural community in north Queensland, 2000/01. One of two FOBT kits – guaiac (Hemoccult-ll) or immunochemical (Inform) – was assigned by general practice and mailed to participants (3,358 patients aged 50–74 years listed with the local practices). Results: Overall participation in FOBT screening was 36.3%. Participation was higher with the immunochemical kit than the guaiac kit (OR=1.9, 95% Cl 1.6-2.2). Women were more likely to comply with testing than men (OR=1.4, 95% Cl 1.2-1.7), and people in their 60s were less likely to participate than those 70–74 years (OR=0.8, 95% Cl 0.6-0.9). The positivity rate was higher for the immunochemical (9.5%) than the guaiac (3.9%) test (χ2=9.2, p=0.002), with positive predictive values for cancer or adenoma of advanced pathology of 37.8% (95% Cl 28.1–48.6) for !nform and 40.0% (95% Cl 16.8–68.7) for Hemoccult-ll. Colonoscopy follow-up was 94.8% with a medical complication rate of 2–3%. Conclusions: An immunochemical FOBT enhanced participation. Higher positivity rates for this kit did not translate into higher false-positive rates, and both test types resulted in a high yield of neoplasia. Implications: In addition to type of FOBT, the ultimate success of a population-based screening program for CRC using FOBT will depend on appropriate education of health professionals and the public as well as significant investment in medical infrastructure for colonoscopy follow-up.

Retinal photography screening programs to prevent vision loss from diabetic retinopathy in rural and urban Australia: A review

Purpose This review assessed the effectiveness of diabetic retinopathy (DR) screening programs, using retinal photography in Australian urban and rural settings, and considered implications for public health strategy and policy. Methods An electronic search of MEDLINE, PubMed, and Embase for studies published between 1 January 1996 and the 30 June 2013 was undertaken. Key search terms were “diabetic retinopathy,” “screening,” “retinal photography” and “Australia.” Results Twelve peer-reviewed publications were identified. The 14 DR screening programs identified from the 12 publications were successfully undertaken in urban, rural and remote communities across Australia. Locations included a pathology collection center, and Indigenous primary health care and Aboriginal community controlled organizations. Each intervention using retinal photography was highly effective at increasing the number of people who underwent screening for DR. The review identified that prior to commencement of the screening programs a median of 48% (range 16–85%) of those screened had not undergone a retinal examination within the recommended time frame (every year for Indigenous people and every 2 years for non-Indigenous people in Australia). A median of 16% (range 0–45%) of study participants had evidence of DR. Conclusions This review has shown there have been many pilot and demonstration projects in rural and urban Australia that confirm the effectiveness of retinal photography-based screening for DR

Associations with low rates of postpartum glucose screening after gestational diabetes among Indigenous and non-Indigenous Australian women

OBJECTIVES To explore factors associated with postpartum glucose screening among women with Gestational Diabetes Mellitus (GDM). METHODS A retrospective study using linked records from women with GDM who gave birth at Cairns Hospital in Far North Queensland, Australia, from 1 January 2004 to 31 December 2010. RESULTS The rates of postpartum Oral Glucose Tolerance Test (OGTT) screening, while having increased significantly among both Indigenous* and non-Indigenous women from 2004 to 2010 (HR 1.15 per year, 95%CI 1.08-1.22, p<0.0001), remain low, particularly among Indigenous women (10% versus 27%, respectively at six months postpartum). Indigenous women in Cairns had a longer time to postpartum OGTT than Indigenous women in remote areas (HR 0.58, 0.38-0.71, p=0.01). Non-Indigenous women had a longer time to postpartum OGTT if they: were born in Australia (HR 0.76, 0.59-1.00, 0.05); were aged <25 years (HR 0.45, 0.23-0.89, p=0.02); had parity >5 (HR 0.33, 0.12-0.90, p=0.03); smoked (HR 0.48, 0.31-0.76, p=0.001); and did not breastfeed (HR 0.09, 0.01-0.64, p=0.02). CONCLUSIONS Postpartum diabetes screening rates following GDM in Far North Queensland are low, particularly among Indigenous women, with lower rates seen in the regional centre; and among non-Indigenous women with indicators of low socioeconomic status. IMPLICATIONS Strategies are urgently needed to improve postpartum diabetes screening after GDM that reach women most at risk.

Screening of new lines of cereal grains for inclusion in Near Infra Red Scan calibrations

The project will provide enough data for a reliable and robust NIRs. It will more fully develop the in vitro method to enable less costly assessment of grains in the future. It will also provide a reliable assessment for DE which is the most expensive component of pig feed.