A note on Youden's J and its cost ratio

<p>Abstract</p> <p>Background</p> <p>The Youden index, the sum of sensitivity and specificity minus one, is an index used for setting optimal thresholds on medical tests.</p> <p>Discussion</p> <p>When using this index, one implicitly uses decision theory with a ratio of misclassification costs which is equal to one minus the prevalence proportion of the disease. It is doubtful whether this cost ratio truly represents the decision maker's preferences. Moreover, in populations with a different prevalence, a selected threshold is optimal with reference to a different cost ratio.</p> <p>Summary</p> <p>The Youden index is not a truly optimal decision rule for setting thresholds because its cost ratio varies with prevalence. Researchers should look into their cost ratio and employ it in a decision theoretic framework to obtain genuinely optimal thresholds.</p

Health care expenditure for hospital-based delivery care in Lao PDR

<p>Abstract</p> <p>Background</p> <p>Delivery by a skilled birth attendant (SBA) in a hospital is advocated to improve maternal health; however, hospital expenses for delivery care services are a concern for women and their families, particularly for women who pay out-of-pocket. Although health insurance is now implemented in Lao PDR, it is not universal throughout the country. The objectives of this study are to estimate the total health care expenses for vaginal delivery and caesarean section, to determine the association between health insurance and family income with health care expenditure and assess the effect of health insurance from the perspectives of the women and the skilled birth attendants (SBAs) in Lao PDR.</p> <p>Methods</p> <p>A cross-sectional study was carried out in two provincial hospitals in Lao PDR, from June to October 2010. Face to face interviews of 581 women who gave birth in hospital and 27 SBAs was carried out. Both medical and non-medical expenses were considered. A linear regression model was used to assess influencing factors on health care expenditure and trends of medical and non-medical expenditure by monthly family income stratified by mode of delivery were assessed.</p> <p>Results</p> <p>Of 581 women, 25% had health care insurance. Health care expenses for delivery care services were significantly higher for caesarean section (270 USD) than for vaginal delivery (59 USD). After adjusting for the effect of hospital, family income was significantly associated with all types of expenditure in caesarean section, while it was associated with non-medical and total expenditures in vaginal delivery. Both delivering women and health providers thought that health insurance increased the utilisation of delivery care.</p> <p>Conclusions</p> <p>Substantially higher delivery care expenses were incurred for caesarean section compared to vaginal delivery. Three-fourths of the women who were not insured needed to be responsible for their own health care payment. Women who had higher family incomes were able to pay for more non-medical care expenses. The effect of health insurance on service utilization was noted by women and SBAs. To achieve the goal of utilizing delivery care in the hospitals, coverage of health insurance needs to be expanded.</p

Diagnosis of oesophageal cancer by detection of minichromosome maintenance 5 protein in gastric aspirates

Symptomatic oesophageal cancer is usually advanced and the prognosis poor. Lethality of symptomatic oesophageal cancer has motivated screening for these diseases earlier in their evolution, but reliable methods for early diagnosis remain elusive. We have demonstrated that dysregulated expression of minichromosome maintenance (MCM) proteins 2–7 is characteristic of early epithelial carcinogenesis, and that these key DNA replication initiation factors can be used as diagnostic markers for cervical and genito-urinary tract cancer. In this study, we investigated whether minichromosome maintenance protein 5 (Mcm5) can be used to detect oesophageal cancer cells in gastric aspirates. Two monoclonal antibodies raised against His-tagged human Mcm5 were used in a time-resolved immunofluorometric assay to measure Mcm5 levels in cells isolated from gastric aspirates of 40 patients undergoing gastroscopy for suspected or known oesophageal carcinoma or symptoms of dyspepsia. The test discriminated with high specificity and sensitivity between patients with and without oesophageal cancer (85% sensitivity (95% confidence interval (CI)=62–97%), 85% specificity (CI=66–96%)), as demonstrated by the large area under the receiver operating characteristics curve (0.93 (95% CI=0.85–0.99)). Elevated levels of Mcm5 in gastric aspirates are highly predictive of oesophageal cancer. This simple test for oesophageal cancer is readily automated with potential applications in primary diagnosis, surveillance and screening

Heritable patterns of tooth decay in the permanent dentition: principal components and factor analyses

<p>Abstract</p> <p>Background</p> <p>Dental caries is the result of a complex interplay among environmental, behavioral, and genetic factors, with distinct patterns of decay likely due to specific etiologies. Therefore, global measures of decay, such as the DMFS index, may not be optimal for identifying risk factors that manifest as specific decay patterns, especially if the risk factors such as genetic susceptibility loci have small individual effects. We used two methods to extract patterns of decay from surface-level caries data in order to generate novel phenotypes with which to explore the genetic regulation of caries.</p> <p>Methods</p> <p>The 128 tooth surfaces of the permanent dentition were scored as carious or not by intra-oral examination for 1,068 participants aged 18 to 75 years from 664 biological families. Principal components analysis (PCA) and factor analysis (FA), two methods of identifying underlying patterns without <it>a priori </it>surface classifications, were applied to our data.</p> <p>Results</p> <p>The three strongest caries patterns identified by PCA recaptured variation represented by DMFS index (correlation, r = 0.97), pit and fissure surface caries (r = 0.95), and smooth surface caries (r = 0.89). However, together, these three patterns explained only 37% of the variability in the data, indicating that <it>a priori </it>caries measures are insufficient for fully quantifying caries variation. In comparison, the first pattern identified by FA was strongly correlated with pit and fissure surface caries (r = 0.81), but other identified patterns, including a second pattern representing caries of the maxillary incisors, were not representative of any previously defined caries indices. Some patterns identified by PCA and FA were heritable (h²= 30-65%, p = 0.043-0.006), whereas other patterns were not, indicating both genetic and non-genetic etiologies of individual decay patterns.</p> <p>Conclusions</p> <p>This study demonstrates the use of decay patterns as novel phenotypes to assist in understanding the multifactorial nature of dental caries.</p

Adverse Drug Reactions Related Hospital Admissions in Persons Aged 60 Years and over, The Netherlands, 1981–2007: Less Rapid Increase, Different Drugs

Background: Epidemiologic information on time trends of Adverse Drug Reactions (ADR) and ADR-related hospitalizations is scarce. Over time, pharmacotherapy has become increasingly complex. Because of raised awareness of ADR, a decrease in ADR might be expected. The aim of this study was to determine trends in ADR-related hospitalizations in the older Dutch population. Methodology and Principal Findings: Secular trend analysis of ADR-related hospital admissions in patients ≥60 years between 1981 and 2007, using the National Hospital Discharge Registry of the Netherlands. Numbers, age-specific and age-adjusted incidence rates (per 10,000 persons) of ADR-related hospital admissions were used as outcome measures in each year of the study. Between 1981 and 2007, ADR-related hospital admissions in persons ≥60 years increased by 143%. The overall standardized incidence rate increased from 23.3 to 38.3 per 10,000 older persons. The increase was larger in males than in females. Since 1997, the increase in incidence rates of ADR-related hospitalizations flattened (percentage annual change 0.65%), compared to the period 1981-1996 (percentage annual change 2.56%). Conclusion/Significance: ADR-related hospital admissions in older persons have shown a rapidly increasing trend in the Netherlands over the last three decades with a temporization since 1997. Although an encouraging flattening in the increasing trend of ADR-related admissions was found around 1997, the incidence is still rising, which warrants sustained attention to this problem

A Population-Based Evaluation of a Publicly Funded, School-Based HPV Vaccine Program in British Columbia, Canada: Parental Factors Associated with HPV Vaccine Receipt

Analysis of a telephone survey by Gina Ogilvie and colleagues identifies the parental factors associated with HPV vaccine uptake in a school-based program in Canada

Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV

A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed events are consistent with the expectations from Standard Model background processes. A lower limit of 65.5 GeV on the charged Higgs mass is derived at 95 % confidence level, independent of the decay branching ratio Br(H^{+/-} -> tau nu)

emm gene diversity, superantigen gene profiles and presence of SlaA among clinical isolates of group A, C and G streptococci from western Norway

In order to investigate molecular characteristics of beta-hemolytic streptococcal isolates from western Norway, we analysed the entire emm gene sequences, obtained superantigen gene profiles and determined the prevalence of the gene encoding streptococcal phospholipase A2 (SlaA) of 165 non-invasive and 34 contemporary invasive group A, C and G streptococci (GAS, GCS and GGS). Among the 25 GAS and 26 GCS/GGS emm subtypes identified, only emm3.1 was significantly associated with invasive disease. M protein size variation within GAS and GCS/GGS emm types was frequently identified. Two non-invasive and one invasive GGS possessed emm genes that translated to truncated M proteins as a result of frameshift mutations. Results suggestive of recombinations between emm or emm-like gene segments were found in isolates of emm4 and stG485 types. One non-invasive GGS possessed speC, speG, speH, speI and smeZ, and another non-invasive GGS harboured SlaA. speA and SlaA were over-represented among invasive GAS, probably because they were associated with emm3. speGdys was identified in 83% of invasive and 63% of non-invasive GCS/GGS and correlated with certain emm subtypes. Our results indicate the invasive potential of isolates belonging to emm3, and show substantial emm gene diversity and possible lateral gene transfers in our streptococcal population

General practitioners' views and experiences of counselling for physical activity through the New Zealand Green Prescription program

Background: Regular physical activity is beneficial in both the prevention and management of chronic health conditions. A large proportion of adult New Zealanders, however, are insufficiently active. To help increase population levels of physical activity in New Zealand the Green Prescription, a primary care physical activity scripting program, was developed. The primary aim of this study was to identify why general practitioners (GPs) counsel for physical activity and administer Green Prescriptions. A secondary aim was to examine GPs' views and experiences of Green Prescription counselling for the management of depression. Methods. Individual face-to-face interviews were conducted with 15 GPs. All interviews were audio-taped and transcribed. Data were analysed using an inductive thematic approach. Results: Several themes and sub-themes emerged from the data. Notably, GPs counselled for physical activity and prescribed Green Prescriptions for both primary preventive (e.g., weight control) and secondary management (e.g., diabetes management) purposes. GPs reported the benefits of the Green Prescription centred around two main themes: (i) a non-medication approach to a healthier lifestyle and (ii) the support benefits of physical activity. Time constraints within the consultation was the only main theme that emerged regarding the barriers GPs perceived to Green Prescription use. Physical activity in general, and physical activity prescribed through the Green Prescription, were also viewed by GPs as beneficial for the management of depression. Conclusions: The results of this study suggest that New Zealand GPs view the Green Prescription program as beneficial for their patients with pre-existing conditions and/or weight problems. While this is encouraging, the Green Prescription may also be used to promote physical activity in currently healthy but low-active and sedentary individuals. Such individuals are currently disease free, but are at risk for future health-related problems because of their inactive lifestyle. It is recommended that time constraints of the consultation in regard to administering Green Prescriptions could be dealt with by delegating the more time consuming tasks to the patient support counsellors that support the Green Prescription program, and having practice nurses assist in the administration of Green Prescriptions. Green Prescription counselling in conjunction with antidepressant medication may be beneficial for the management of depression and warrants further research