Estimating the prevalence of breast cancer using a disease model: data problems and trends

BACKGROUND: Health policy and planning depend on quantitative data of disease epidemiology. However, empirical data are often incomplete or are of questionable validity. Disease models describing the relationship between incidence, prevalence and mortality are used to detect data problems or supplement missing data. Because time trends in the data affect their outcome, we compared the extent to which trends and known data problems affected model outcome for breast cancer. METHODS: We calculated breast cancer prevalence from Dutch incidence and mortality data (the Netherlands Cancer Registry and Statistics Netherlands) and compared this to regionally available prevalence data (Eindhoven Cancer Registry, IKZ). Subsequently, we recalculated the model adjusting for 1) limitations of the prevalence data, 2) a trend in incidence, 3) secondary primaries, and 4) excess mortality due to non-breast cancer deaths. RESULTS: There was a large discrepancy between calculated and IKZ prevalence, which could be explained for 60% by the limitations of the prevalence data plus the trend in incidence. Secondary primaries and excess mortality had relatively small effects only (explaining 17% and 6%, respectively), leaving a smaller part of the difference unexplained. CONCLUSION: IPM models can be useful both for checking data inconsistencies and for supplementing incomplete data, but their results should be interpreted with caution. Unknown data problems and trends may affect the outcome and in the absence of additional data, expert opinion is the only available judge

Ethanol reversal of tolerance to the respiratory depressant effects of morphine

Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO(2) in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths

Quantifying Child Mortality Reductions Related to Measles Vaccination

Background: This study characterizes the historical relationship between coverage of measles containing vaccines (MCV) and mortality in children under 5 years, with a view toward ongoing global efforts to reduce child mortality. Methodology/Principal Findings: Using country-level, longitudinal panel data, from 44 countries over the period 1960–2005, we analyzed the relationship between MCV coverage and measles mortality with (1) logistic regressions for no measles deaths in a country-year, and (2) linear regressions for the logarithm of the measles death rate. All regressions allowed a flexible, non-linear relationship between coverage and mortality. Covariates included birth rate, death rates from other causes, percent living in urban areas, population density, per-capita GDP, use of the two-dose MCV, year, and mortality coding system. Regressions used lagged covariates, country fixed effects, and robust standard errors clustered by country. The likelihood of no measles deaths increased nonlinearly with higher MCV coverage (ORs: 13.8 [1.6–122.7] for 80–89% to 40.7 [3.2–517.6] for ≥95%), compared to pre-vaccination risk levels. Measles death rates declined nonlinearly with higher MCV coverage, with benefits accruing more slowly above 90% coverage. Compared to no coverage, predicted average reductions in death rates were −79% at 70% coverage, −93% at 90%, and −95% at 95%. Conclusions/Significance: 40 years of experience with MCV vaccination suggests that extremely high levels of vaccination coverage are needed to produce sharp reductions in measles deaths. Achieving sustainable benefits likely requires a combination of extended vaccine programs and supplementary vaccine efforts

Corneal topographic changes in premenopausal and postmenopausal women

<p>Abstract</p> <p>Background</p> <p>To asses the effect of menopause on the corneal curvature changes using corneal computerized videokeratography (CVK) in premenopausal and postmenopausal healthy women.</p> <p>Methods</p> <p>Thirty-six postmenopausal women with mean ages of 49.2 (range 39 to 57) were enrolled in this randomized, prospective study, comparing with 26 healthy controls with mean ages of 38.5 +/- 4.9 (range 32 to 49). Subjects were determined to be postmenopausal, by the Gynecology and Obstetrics Department, based on blood Follicular Stimulating Hormone (FSH), Luteinizing Hormone (LH), Estradiol, Progesterone levels and clinical complaints. Complete ophthalmic examination and CVK using Haag-Streit System was performed in both premenopausal and postmenopausal women.</p> <p>Results</p> <p>Mean horizontal curvature and vertical curvature of central corneal power in premenopausal women were 43.5 +/- 1.25 Diopter (D), and 44.1 +/- 1.53 D. Mean horizontal curvature and vertical curvature of central corneal power in postmenopausal women were 43.9 +/- 1.4 D, and 44.6 +/- 1.3 D. The mean keratometric astigmatisms of premenopausal and postmenopausal women were 0.81 +/- 0.57 D (4–179 degrees), 0.74 degrees +/- 0.5 D (1–180 degrees) respectively. No significant corneal curvature changes were detected between premenopausal and postmenopausal groups (P > 0.05). On the other hand, we only found negative but significant correlation between horizontal corneal curvature and estrogen level of postmenopausal women (r = -0.346, p = 0.038).</p> <p>Conclusion</p> <p>Menopause is physiologic process and may also affect corneal topographic changes. In postmenopausal women, corneal steeping was observed minimally compared to premenopausal women. The results suggest that changes in estrogen level of women with menopause are associated with slightly alteration of horizontal curvature of cornea.</p

Effectiveness of a web-based self-help smoking cessation intervention: protocol of a randomised controlled trial

BACKGROUND: Cigarette smoking is a major risk factor for many chronic and fatal illnesses. Stopping smoking directly reduces those risks. The aim of this study is to investigate the effectiveness of a web-based interactive self-help programme for smoking cessation, known as the StopSite, by comparing it to an online self-help guide. Both interventions were based on cognitive-behavioural and self-control principles, but the former provided exercises, feedback and interactive features such as one-to-one chatrooms and a user forum, which facilitated mutual support and experience sharing. METHODS AND DESIGN: We conducted a randomised controlled trial to compare the interactive intervention with the self-help guide. The primary outcome measure was prolonged abstinence from smoking. Secondary outcomes were point-prevalence abstinence, number of cigarettes smoked, and incidence of quit attempts reported at follow-up assessments. Follow-up assessments took place three and six months after a one-month grace period for starting the intervention after baseline. Analyses were based on intention-to-treat principles using a conservative imputation method for missing data, whereby non-responders were classified as smokers. DISCUSSION: The trial should add to the body of knowledge on the effectiveness of web-based self-help smoking cessation interventions. Effective web-based programmes can potentially help large numbers of smokers to quit, thus having a major public health impact. TRIAL REGISTRATION: ISRCTN7442376

Explicit and implicit information needs of people with depression: a qualitative investigation of problems reported on an online depression support forum

<p>Abstract</p> <p>Background</p> <p>Health management is impeded when consumers do not possess adequate knowledge about their illness. At a public health level, consumer knowledge about depression is particularly important because depression is highly prevalent and causes substantial disability and burden. However, currently little is known about the information needs of people with depression. This study aimed to investigate the explicit and implicit information needs of users of an online depression support forum.</p> <p>Methods</p> <p>A sample of 2680 posts was systematically selected from three discussion forums on an online depression bulletin board (blueboard.anu.edu.au). Data were examined for evidence of requests for information (reflecting explicit needs) and reports of past or current problems (implicit needs). Thematic analysis was conducted using a data-driven inductive approach with the assistance of NVivo 7, and instances of questions and people reporting particular types of problems were recorded.</p> <p>Results</p> <p>A total of 134 participants with personal experience of depression contributed to the data analysed. Six broad themes represented participant queries and reported problems: Understanding depression; disclosure and stigma; medication; treatment and services; coping with depression; and comorbid health problems. A variety of specific needs were evident within these broad thematic areas. Some people (n = 46) expressed their information needs by asking direct questions (47 queries) but the majority of needs were expressed implicitly (351 problems) by the 134 participants. The most evident need for information related to coping with depression and its consequences, followed by topics associated with medication, treatment and services.</p> <p>Conclusions</p> <p>People with depression have substantial unmet information needs and require strategies to deal with the difficulties they face. They require access to high quality and relevant online resources and professionals; thus, there is a need to rectify current gaps in the provision of information and limitations of dissemination. Greater knowledge about depression and its treatment is also needed at the general community level.</p

Quality of chronic disease care in general practice: the development and validation of a provider interview tool

BACKGROUND: This article describes the development and psychometric evaluation of an interview instrument to assess provider-reported quality of general practice care for patients with diabetes, cardiovascular disease and asthma – the Australian General Practice Clinical Care Interview (GPCCI). METHODS: We administered the GPCCI to 28 general practitioners (family physicians) in 10 general practices. We conducted an item analysis and assessed the internal consistency of the instrument. We next assessed the quality of care recorded in the medical records of 462 of the general practitioners' patients with Type 2 diabetes, ischaemic heart disease/hypertension and/or moderate to severe asthma. This was then compared with results of the GPCCI for each general practice. RESULTS: Good internal consistency was found for the overall GPCCI (Cronbach's alpha = 0.75). As far as the separate sub-scales were concerned, diabetes had good internal consistency (0.76) but the internal consistency of the heart disease and asthma subscales was not strong (0.49 and 0.16 respectively). There was high inter-rater reliability of the adjusted scores of data extracted from patients' medical notes for each of the three conditions. Correlations of the overall GPCCI and patients' medical notes audit, combined across the three conditions and aggregated to practice level, showed that a strong relationship (r = 0.84, p = 0.003) existed between the two indices of clinical care. CONCLUSION: This study suggests that the GPCCI has good internal consistency and concurrent validity with patients' medical records in Australian general practice and warrants further evaluation of its properties, validity and utility

Comparison of non-invasive to invasive oxygenation ratios for diagnosing acute respiratory distress syndrome following coronary artery bypass graft surgery: a prospective derivation-validation cohort study

Objective: To determine if non-invasive oxygenation indices, namely peripheral capillary oxygen saturation (SpO2)/ fraction of inspired oxygen (Fi O2) and partial pressure of alveolar oxygen (PAO2)/Fi O2 may be used as effective surrogates for the partial pressure of arterial oxygen (PaO2)/Fi O2. Also, to determine the SpO2/Fi O2 and PAO2/Fi O2 values that correspond to PaO2/Fi O2 thresholds for identifying acute respiratory distress syndrome (ARDS) in patients following coronary artery bypass graft (CABG) surgery. Methods: A prospective derivation-validation cohort study in the Open-Heart ICU of an academic teaching hospital. Recorded variables included patient demographics, ventilator settings, chest radiograph results, and SPO2, PaO2, PAO2, SaO2, and Fi O2. Linear regression modeling was used to quantify the relationship between indices. Receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of the threshold values. Results: One-hundred seventy-five patients were enrolled in the derivation cohort, and 358 in the validation cohort. The SPO2/Fi O2 and PAO2/Fi O2 ratios could be predicted well from PaO2/Fi O2, described by the linear regression models SPO2/Fi O2 = 71.149 + 0.8PF and PAO2/Fi O2 = 38.098 + 2.312PF, respectively. According to the linear regression equation, a PaO2/Fi O2 ratio of 300 equaled an SPO2/Fi O2 ratio of 311 (R2 0.857, F 1035.742, < 0.0001) and a PAO2/Fi O2 ratio of 732 (R2 0.576, F 234.887, < 0.0001). The SPO2/Fi O2 threshold of 311 had 90% sensitivity, 80% specificity, LR+ 4.50, LR- 0.13, PPV 98, and NPV 42.1 for the diagnosis of mild ARDS. The PAO2/Fi O2 threshold of 732 had 86% sensitivity, 90% specificity, LR+ 8.45, LR- 0.16, PPV 98.9, and NPV 36 for the diagnosis of mild ARDS. SPO2/ Fi O2 had excellent discrimination ability for mild ARDS (AUC ± SE = 0.92 ± 0.017; 95% CI 0.889 to 0.947) as did PAO2/ Fi O2 (AUC ± SE = 0.915 ± 0.018; 95% CI 0.881 to0.942). Conclusions: PaO2 and SaO2 correlated in the diagnosis of ARDS, with a PaO2/Fi O2 of 300 correlating to an SPO2/ Fi O2 of 311 (Sensitivity 90%, Specificity 80%). The SPO2/ Fi O2 ratio may allow for early real-time rapid identification of ARDS, while decreasing the cost, phlebotomy, blood loss, pain, skin breaks, and vascular punctures associated with serial arterial blood gas measurements

Health and economic impact of rotavirus vaccination in GAVI-eligible countries

<p>Abstract</p> <p>Background</p> <p>Rotavirus infection is responsible for about 500,000 deaths annually, and the disease burden is disproportionately borne by children in low-income countries. Recently the World Health Organization (WHO) has released a global recommendation that all countries include infant rotavirus vaccination in their national immunization programs. Our objective was to provide information on the expected health, economic and financial consequences of rotavirus vaccines in the 72 GAVI support-eligible countries.</p> <p>Methods</p> <p>We synthesized population-level data from various sources (primarily from global-level databases) for the 72 countries eligible for the support by the GAVI Alliance (GAVI-eligible countries) in order to estimate the health and economic impact associated with rotavirus vaccination programs. The primary outcome measure was incremental cost (in 2005 international dollars [I$]) per disability-adjusted life year (DALY) averted. We also projected the expected reduction in rotavirus disease burden and financial resources required associated with a variety of scale-up scenarios.</p> <p>Results</p> <p>Under the base-case assumptions (70$25 per vaccinated child (~$5 per dose), the number of countries with the incremental cost per DALY averted less than I$200 was 47. Using the WHO's cost-effectiveness threshold based on per capita GDP, the vaccines were considered cost-effective in 68 of the 72 countries (~94%). A 10-year routine rotavirus vaccination would prevent 0.9-2.8 million rotavirus associated deaths among children under age 5 in the poorest parts of the world, depending on vaccine scale-up scenarios. Over the same intervention period, rotavirus vaccination programs would also prevent 4.5-13.3 million estimated cases of hospitalization and 41-107 million cases of outpatient clinic visits in the same population.</p> <p>Conclusions</p> <p>Our findings suggest that rotavirus vaccination would be considered a worthwhile investment for improving general development as well as childhood health level in most low-income countries, with a favorable cost-effectiveness profile even under a vaccine price ($1.5-$5.0 per dose) higher than those of traditional childhood vaccines.</p