A Monte Carlo method for calculation of the characteristic limits decision threshold and detection limit in low-level radioactivity measurements.

In this study, calculation of decision threshold and detection limit expressed in counts for low-level radioactivity measurements were evaluated and compared to a Monte Carlo method for the case of paired Poisson-distributed observations, i.e. for discrete variables. The calculated characteristic limits obtained from Monte Carlo calculations were compared with analytical expressions given in literature. The results in this study show that the equations given by Currie are in good agreement with the results from the Monte Carlo calculations simulating nuclear counting applications with a low number of observed counts. An exception is observed for a background corresponding to zero counts. This study also shows that at a low number of counts, the specific boundary conditions of the interval that represents counts corresponding to the presence of the analyte (>or ≥), have an impact on the false positives and negatives rates as defined by the parameters α and ß.

Calculation of decision threshold and detection limit in radiometric measurements using a Monte Carlo Method.

Calculation of the decision threshold and detection limit of a measurement, or measurement method, are crucial in order to decide if an analyte is present or not and with what confidence it can be quantified. That decision is important in view of possible actions if something would be detected. In this work, a method for calculating these limits using a Monte Carlo method is presented. In the Monte Carlo method any a priori distribution (e.g. normal distribution, rectangular distribution, triangular distribution) of an input quantity can be selected. Differences between the Monte Carlo calculated characteristic limits and the ones calculated according to ISO 11929:2010 is presented. Moreover, suggestions how to calculate the detection limit when it can not be calculated according to the ISO 11929:2010 are given.

Daily Assessment of Stressful events and Coping in early post-operative recovery after colorectal cancer surgery.

This study describes the most stressful events and coping strategies used by patients with colorectal cancer 4-6 weeks after surgery and whether the coping strategies were considered helpful or not. For the investigation of situational coping, an exploratory design was used. One hundred and five patients from three Swedish hospitals were included to fill in the Daily Coping Assessment. Most stressful event, number and types of pre-defined coping strategies used, and if the coping strategy used was considered helpful or not, were measured for 5 days. Of 523 diary entries, 180 reported no stressful events. The most stressful event, also with worst level of control and expectation, was "Pain," followed by "Nausea/vomiting." The areas causing most stressful events were "Bowel-related" and "Surgery and treatment-related problems." Acceptance and Direct action were the most frequently used coping strategies. There was a wide range of perceived helpfulness if coping strategies were placed in relation to specific areas of events. The conclusion was that patients revealed several strategies for coping with stressful events but needed a higher level of preparedness for what might come and therefore need to be given appropriate support to cope during the early recovery phase. Such support is suggested to be person-centred and oriented towards individually adapting standardised regimens, given the variety of situations to which the stressful events reported in the study were related.

Some inequalities for Cesàro means of double Vilenkin-Fourier series.

In this paper, we state and prove some new inequalities related to the rate of L p approximation by Cesàro means of the quadratic partial sums of double Vilenkin-Fourier series of functions from L p .

RADIATION PROTECTION MEASUREMENTS WITH THE VARIANCE-COVARIANCE METHOD IN THE STRAY RADIATION FIELDS FROM PHOTON AND PROTON THERAPY FACILITIES.

The microdosimetric variance-covariance method was used to study the stray radiation fields from the photon therapy facility at the Technical University of Denmark and the scanned proton therapy beam at the Skandion Clinic in Uppsala, Sweden. Two TEPCs were used to determine the absorbed dose, the dose-average lineal energy, the dose-average quality factor and the dose equivalent. The neutron component measured by the detectors at the proton beam was studied through Monte Carlo simulations using the code MCNP6. In the photon beam the stray absorbed dose ranged between 0.3 and 2.4 µGy per monitor unit, and the dose equivalent between 0.4 and 9 µSv per monitor unit, depending on beam energy and measurement position. In the proton beam the stray absorbed dose ranged between 3 and 135 µGy per prescribed Gy, depending on detector position and primary proton energy.

FACTORS INFLUENCING CONDOM USE AMONG NIGERIAN UNDERGRADUATES: A MIXED METHOD STUDY.

OBJECTIVE: This study's objective was to explore and assess the factors influencing condom use among Nigerian undergraduates within the age group 16-34 years. SETTING: The University of Lagos, a federal University in the commercial capital of Nigeria. STUDY DESIGN: Both qualitative (focus group discussions) and quantitative (cross-sectional survey) methods were utilised for this study. SUBJECTS: A total of 101 subjects were recruited with age range 18 to 34 years as against 100 years, with a mean age of 21 years. Data collection was conducted in July and August 2011 at the University of Lagos. SUBJECTS: A total of 820 students from University of Lagos in four faculties participated in the cross-sectional survey, and we organised four focus group discussions with six students each. RESULTS: Students were of the perception that various socio-economic and environmental factors influenced condom use during sexual intercourse. Factors identified as having great influence on condom use include: "adequate sex education" and "unplanned/ unanticipated sexual intercourse". Conversely, the influence of alcohol/social drugs on condom use was ranked low. CONCLUSION: The study showed that students had the perception that various factors influenced condom use but these perceptions varied between young men and women. It may therefore be rewarding to have customised messages based on specific needs when reaching out to different groups stratified based on gender.

Household food security is associated with early childhood language development: results from a longitudinal study in rural Bangladesh.

BACKGROUND: Although household food security (HHFS) has been linked to academic performance in school children, its association with early childhood development has received less attention, particularly in low-income countries. We investigated the association of HHFS with subsequent language development of children at 18 months of age in rural Bangladesh. METHODS: We followed 1439 infants born in 2002-2003 to the mothers in Maternal and Infant Nutrition Intervention in Matlab study, a large intervention trial conducted in rural Bangladesh. A HHFS scale was created from data collected from mothers during pregnancy. At 18 months, children's language (expression and comprehension) development was assessed using a Bengali adaptation of MacArthur's Communicative Development Inventory which was based on mothers' report of their children's ability to comprehend and express words in different categories. General linear regression models were used to examine the association between HHFS and language development at 18 months of age adjusting for potential confounders. RESULTS: Household food security was associated with language comprehension (B = 0.19, 95% CI = 0.09, 0.30, P < 0.001) and expression (B = 1.01, 95% CI = 1.00, 1.02, P < 0.01) at 18 months of age. Mean language comprehension and expression at 18 months of the children in higher quartiles of HHFS were higher (P < 0.05) than those of the children in lower quartiles. CONCLUSIONS: Household food security is positively associated with subsequent language development of rural Bangladeshi children. Early language development has been reported to predict later child development. Therefore, strategies to ensure HHFS status in Bangladesh and similar settings should be considered for optimum child development.

Daily assessment of stressful events and coping among post-menopausal women with breast cancer treated with adjuvant chemotherapy.

The purpose of the study was twofold: to examine what type of daily stressful events post-menopausal woman with breast cancer experience during adjuvant chemotherapy and how bothersome these are and to identify coping strategies used by these women used to manage such stressful events. The patient group comprised 75 consecutively invited women (>or=55 years of age) at two university hospitals and one county hospital in Sweden. The Daily Coping Assessment was used to collect data over time. Data were analysed both qualitatively and quantitatively. Six categories of stressful events were identified: 'nausea and vomiting', 'fatigue', 'other symptoms', 'isolation and alienation', 'fear of the unknown' and 'being controlled by the treatment'. The first three categories were subsumed under the domain physical problems and the latter three under psychosocial problems. Almost 30% of the diary entries recorded no stressful event. Physical problems were three times as frequent as psychosocial problems. 'Nausea/vomiting' was the most frequently observed stressful event (21.6%). 'Isolation and alienation' and 'fear of the unknown' were less frequent, but when they occurred they were rated as the most distressing. Several coping strategies were used to manage each stressful event. The most common strategies were acceptance, relaxation and distraction. Religion was rarely used as a coping strategy.

Point-of-care testing has a limited effect on time to clinical decision in primary health care.

OBJECTIVE: To investigate the clinical logistics of laboratory routines at primary health care centres (PHCs). DESIGN AND METHODS: Prospective registration was carried out for each PHC using questionnaires during 2-week intervals between the end of November 2001 and mid-January 2002. The study included 9 PHCs in the county of Ostergötland and 4 in the county of Jönköping, Sweden, with different numbers of blood tests analysed using point-of-care testing (POCT). Data for B-glucose, HbA1c, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), thyroid-stimulating hormone (TSH), T4, cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides were collected. Main outcome measures were median time from sampling to available test result (TATa) and median time from sampling to clinical decision (TATd), and the proportion of patients informed of the outcome of the blood test in question during the sampling occasion. RESULTS: A total of 3542 samples were collected. The median TATa showed that B-glucose, ESR and CRP were immediately analysed at all 13 PHCs. For the other tests, TATa varied from immediately to about two days. The median TATd varied from immediately to about a week. When POCT was used, 30% of the patients were informed about the outcome of the test during the sampling occasion. CONCLUSION: POCT has a limited effect on the clinical logistics in PHCs.

Public health services use in a mountainous area, Vietnam: implications for health for policy.

AIMS: The aim of this study is to describe the use of public health services in different social and ethnic groups and to explore the implementation of user fee exemption in a mountainous area in Vietnam. METHODS: A cross-sectional household survey with a structured questionnaire and a four-week diary were used to collect information on illnesses, health seeking behaviour and socioeconomic factors. Three communes in a mountainous district in Northern Vietnam were selected and a random sample of 1,452 individuals in 300 households was drawn. RESULTS: Self-medication was most common (57%) while 30% used public health services when suffering from a health problem. Persons living far from health services attended public health services less frequently than the others (adjusted OR = 0.28; 95% CI 0.15-0.51). This was especially the case for ethnic minorities who were less likely to use public health services than the others were (adjusted OR = 0.47; 95% CI 0.25-0.87). Persons with mild conditions tended to use public health services less than those with more severe conditions (OR = 0.19; 95% CI 0.10-0.37). Health services use was similar among women and men, but the total expenditure per visit was higher for men. Almost no patients supposed to get free attendance had been exempted from user fees. CONCLUSIONS: It was found that there was a geographical inequity in use of public health services while there was relatively equal use of these services between social, gender, and ethnic groups. Long distance in combination with failure of the fee exemption may increase inequity in use of health services in remote and isolated areas. These observations contribute to the basis for implementation of the Vietnamese health policy, emphasizing efficiency and equity.

Health-related quality of life in COPD: why both disease-specific and generic measures should be used.

Although research has consistently demonstrated that chronic obstructive pulmonary disease (COPD) impairs health-related quality of life (HRQL), little agreement has been evidenced regarding the factors identified as contributing to impaired HRQL. The aim was to study such factors using well established generic and specific HRQL instruments. The patients (n=68) were stratified by forced expiratory volume in one second (FEV1) to represent a wide range of disease severity. Pulmonary function, blood gases and 6-min walking distance test (6MWD) were assessed. HRQL instruments included: St George's Respiratory Questionnaire (SGRQ), Sickness Impact Profile (SIP), Hospital Anxiety and Depression Scale and Mood Adjective Check List. The strength of the impact of COPD on HRQL was represented along a continuum ranging from lung function, functional status (physical and psychosocial) to wellbeing. Although correlations between FEV1 versus SGRQ total and SIP overall scores (r=-0.42 and -0.32) were stronger than previously reported, multiple regression analyses showed that lung function contributed little to the variance when dyspnoea-related limitation, depression scores and 6MWD were included in the models. These three factors were important to varying degrees along the whole range of HRQL. Physiological, functional and psychosocial consequences of chronic obstructive pulmonary disease are only poorly to moderately related to each other. The present study concludes that a comprehensive assessment of the effects of chronic obstructive pulmonary disease requires a battery of instruments that not only tap the disease-specific effects, but also the overall burden of the disease on everyday functioning and emotional wellbeing.

The effect of poverty, social inequity, and maternal education on infant mortality in Nicaragua, 1988-1993.

OBJECTIVES: This study assessed the effect of poverty and social inequity on infant mortality risks in Nicaragua from 1988 to 1993 and the preventive role of maternal education. METHODS: A cohort analysis of infant survival, based on reproductive histories of a representative sample of 10,867 women aged 15 to 49 years in León, Nicaragua, was conducted. A total of 7073 infants were studied; 342 deaths occurred during 6394 infant-years of follow-up. Outcome measures were infant mortality rate (IMR) and relative mortality risks for different groups. RESULTS: IMR was 50 per 1000 live births. Poverty, expressed as unsatisfied basic needs (UBN) of the household, increased the risk of infant death (adjusted relative risk [RR] = 1.49; 95% confidence interval [CI] = 1.15, 1.92). Social inequity, expressed as the contrast between the household UBN and the predominant UBN of the neighborhood, further increased the risk (adjusted RR = 1.74; 95% CI = 1.12, 2.71). A protective effect of the mother's educational level was seen only in poor households. CONCLUSIONS: Apart from absolute level of poverty, social inequity may be an independent risk factor for infant mortality in a low-income country. In poor households, female education may contribute to preventing infant mortality.

Fertility and infant mortality trends in Nicaragua 1964-1993. The role of women's education.

OBJECTIVES: To assess trends in fertility and infant mortality rates (IMR) in León, Nicaragua, and to examine the effect of women's education on these trends during 1964-1993, a period of rapid social change. DESIGN: Cross sectional survey, based on random cluster sampling. A retrospective questionnaire on reproductive events was used. SETTING: The municipality of León, which is the second largest city in Nicaragua, with a total population of 195,000 inhabitants. SUBJECTS: 10,867 women aged 15-49 years, corresponding to 176,281 person years of reproductive life. Their children contributed 22,899 person years under 12 months of age to the IMR analysis. MAIN OUTCOME MEASURES: Fertility rate (number of pregnancies per 1000 person years) for specific age groups and calendar periods, total fertility rate, and IMR. RESULTS: Fertility rates and IMR declined in parallel, especially during the 1980s. However, education specific fertility rates did not decline, but the proportion of educated young women increased from 20% to 46%. This had also an impact on the overall IMR decline, although IMR reduction mainly took place among infants of women without formal education, decreasing from 118 to 69 per 1000 during the observation period. CONCLUSIONS: In this demographic transition over three decades, fertility and IMR declined simultaneously. The decreasing trend in fertility was mainly explained by an increase in women's education, while the IMR decline seemed to be the result of health interventions, specially targeted to poorer groups of women and their infants. Thus, social differences in fertility rates remained unchanged, while equity in chances of child survival increased.

Testing an oral assessment guide during chemotherapy treatment in a Swedish care setting: a pilot study.

Oral complications are common in patients with haematological malignancies who undergo chemotherapy treatment. A pilot study including 16 haematological patients was carried out to evaluate the oral status using an Oral Assessment Guide (OAG) and to test the reliability of the OAG. The oral assessments were made daily by registered nurses at a Department of Internal Medicine in Sweden. Once a week a dental hygienist made the oral assessments independent of the registered nurses in order to provide data for calculations of inter-rater reliability. All patients had varying degrees of alterations in the oral cavity, especially in the mucous membranes, teeth/dentures and gums. The inter-rater agreement between the nurses and the dental hygienist was good for saliva and swallow, and moderate for voice and gums. Assessments to detect alterations in the oral cavity afford the opportunity for early and individualized interventions and may decrease the risk of oral infections. It is necessary to train the nurses to ensure high levels of reliability in the oral assessments. The OAG seems to be a reliable and clinical useful tool for assessing the oral cavity status and determining changes.

Assessment of Soil Suppressiveness to Aphanomyces Root Rot of Pea.

The ability of field soils to suppress pea root rot caused by Aphanomyces euteiches was assessed in field soil samples in a greenhouse bioassay and in field experiments sown with pea in monoculture for four years. In the bioassay, an inoculum of oospores in talcum powder was added to the test soils 1 week prior to sowing of pea seeds. The rate of infection was assessed 4 weeks after sowing. The field experiments were placed in six localities with varying degrees of soil suppressiveness to pea root rot and the pea yield and number of oospores of A. euteiches in root tissue were measured each year. A large variation in disease suppression was found in 24 arbitrarily chosen soils, sampled in the vining pea growing area in southern Sweden, and some soils were found to be strongly disease suppressive. The pea root rot development was also clearly different between the field experiments, depending on the soil. In an experiment on a soil showing low disease suppressiveness in the greenhouse bioassay, the crop failed in the second year, the number of oospores in root tissue increased rapidly over time, and no yield at all could be taken the fourth year. In contrast, on a soil with a high disease suppressiveness in the bioassay, the pea monoculture led to a slow build-up of oospores in root tissue and a steady high yield of 5,300 kg/ha the fourth year.

The Swedish SF-36 Health Survey II. Evaluation of clinical validity: results from population studies of elderly and women in Gothenborg.

The validity of the Swedish SF-36 Health Survey was examined, replicating techniques used in the U.S. validation. Principal components analysis was used to test the internal structure of the eight SF-36 scales in relation to hypothesized associations with the two major dimensions of health--physical and mental. Hypothesized relationships between scales and external criteria were also examined by means of clinical group contrasts. Both the principal components analysis and clinical group contrasts largely replicated U.S. findings, which supported the cross-cultural stability of the SF-36 in Sweden. As expected, the Physical Functioning and Mental Health scales were most sensitive to clinical manifestations of medical and mental health, respectively. The General Health scale was associated more with physical than mental health. However, the Social Functioning scale and particularly the Vitality scale were more related to mental health in Sweden than in the corresponding U.S. study. Cultural differences and variation in study samples and selection criteria were suggested as possible explanatory factors for these differences.

Are there social inequities in child morbidity and mortality in rural Vietnam.

This study was conducted to investigate the relationship between various socio-economic factors, and child morbidity and mortality during a period of rapid social change in Vietnam. One-thousand-one-hundred-and-thirty-two rural mothers with children under 5 years of age were interviewed regarding their reproductive history, survival of their children, and morbidity of their children under 5 years of age. Causes of child death were established by a verbal autopsy technique. Fifty-seven per cent of the children were reported to have suffered from some illness during the preceding 2 weeks. Acute respiratory infection (ARI) (46 per cent of all children) was most common. Two-thirds of the sick children had been treated with antibiotics. Eighty-one children under 5 years of age had died during the 10-year period 1982-1992. Two-thirds of these deaths occurred in infancy, most of them were related to prematurity, asphyxia or tetanus. ARI was more common in poor families while neither education nor occupation were associated with ARI occurrence. No significant relationship between education or occupation of the mother and mortality was found. The low under-5 mortality (U5MR) in spite of the high morbidity may be related to good child health care both by families and by the health care system.

Ethical issues in radiation protection.

In this note the authors survey existing international radiation-protection recommendations of the ICRP, the IAEA, and the ILO. After outlining previous work on the ethics of radiation protection and risk assessment/management, the authors review ethical thinking on five key issues related to radiation protection and ethics. They formulate each of these five issues in terms of alternative ethical stances: (1) Equity vs. Efficiency, (2) Health vs. Economics, (3) Individual Rights vs. Societal Benefits, (4) Due Process vs. Necessary Sacrifice, and (5) Stakeholder Consent vs. Management Decisions.

Gender and social differences in adolescent sexuality and reproduction in Nicaragua.

PURPOSE: The aim of this research was to study gender and social differences in adolescent sexuality and reproduction, as reflected in age at first intercourse and age at first pregnancy, as a basis for future interventions in the municipality of León, Nicaragua. METHODS: In a community-based cross-sectional study including 7789 households, all women aged 15-49 years (n = 10,867) were interviewed about socioeconomic, sexual, and reproductive issues. A random subsample of men (n = 388) and women (n = 413) aged 15-49 years was interviewed in more detail about sexual patterns and reproduction. RESULTS: The median age at first intercourse for women and men was 17.8 and 16.2 years, respectively. Women's average latency period to end of first pregnancy was 22 months. There was a significant tendency to start active sexual life later among today's girls aged 15-20 years, compared to the groups 21-27, 28-35, and 36-49 years old. A similar trend was found in age at first pregnancy. These secular trends were not found among men. Age at first pregnancy for current adolescents was lower among those having less formal education. CONCLUSIONS: The short latency period between first sexual intercourse and end of first pregnancy, probably reflecting lack of access to counseling and contraception, is worrying in light of the growing sexually transmitted disease/human immunodeficiency virus threat. The secular trend of later start of reproduction, however, is a positive sign which partly may be an effect of increasing education in the Nicaraguan society.

PIP: This study sought to uncover gender and social differences in adolescent sexuality and reproduction in Nicaragua through an investigation of age at first coitus and first pregnancy. Data were gathered through a 1993 cross-sectional, community-based survey of a representative sample of 7789 households in the municipality of Leon. Interviews were held with 10,867 women aged 15-49, and more detailed information was elicited from a random subsample of 388 men and 413 women. It was found that median age at first coitus was 17.8 for women and 16.2 for men, with 25% of the population engaging in coitus before age 15. Women delivered their first child at a median age of 19.6 years, whereas men became fathers at 21.2 years. Lack of formal education increased risk of earlier pregnancy for women by 2.5 times, but no increased risk occurred for rural versus urban residence. Earlier pregnancy occurred in women who did not live with their biological fathers during childhood and adolescence (living with a stepfather increased risk of early coitus and delivery even more). Men without a formal education became fathers at an earlier age in both urban and rural areas. The period between first coitus and delivery for women was 21.5 months (20 months for women with primary education or less and 27 months for those who completed ninth-grader or higher). Age groups comparisons (15-20, 21-27, 28-35, and 36-49) showed that the current adolescents were experiencing first coitus and first pregnancy significantly later than the older groups but that the 28-35 age group showed significantly earlier onset of each event. These results point to the need to improve gender equity and women's status and to develop a health care policy that responds to the special needs of adolescents (counseling, access to contraceptives, and availability of safe abortion). Sex education programs must begin at the primary levels in schools because of high drop-out rates.

Excess female mortality in rural Somalia--is inequality in the household a risk factor?

Gender differences in mortality risks in rural Somali communities were studied to assess their relation to literacy, marital status and family economy between January 1987 and December 1989. In all, 6947 person-years form the basis for the demographic analysis and estimations of mortality rates and survival. Both sexes showed similar mortality risks in infancy and early childhood, but females demonstrated a greater risk of dying during their reproductive life than males. Respiratory symptoms, diarrhoea, fever and jaundice dominated the symptoms prior to death Illiteracy in women considerably increased the risk of dying from 15 years and onwards particularly when living with literate men. The life expectancy from 15 years was 58 for a literate male but only 42 years for an illiterate woman living with a literate head of household. Multivariate analyses showed after adjustment for marital status and literacy that an excess female mortality from 15 years, but especially from 45 years, was associated to a household situation, where the woman did not subside on farming but on other, mainly commercial, activities. This vulnerability of females was associated to the recession of the economy in the pre-war situation in Somalia, a backlash hitting women trying to earn their living. To conclude, gender differences in a number of factors in the household-literacy, marital status and especially source of income-were disadvantageous for the women, increasing the mortality risk in this setting.