Cost effectiveness analysis of larval therapy for leg ulcers

Objective: To assess the cost effectiveness of larval therapy compared with hydrogel in the management of leg ulcers. Design: Cost effectiveness and cost utility analyses carried out alongside a pragmatic multicentre, randomised, open trial with equal randomisation. Population: Intention to treat population comprising 267 patients with a venous or mixed venous and arterial ulcers with at least 25% coverage of slough or necrotic tissue. Interventions: Patients were randomly allocated to debridement with bagged larvae, loose larvae, or hydrogel. Main outcome measure: The time horizon was 12 months and costs were estimated from the UK National Health Service perspective. Cost effectiveness outcomes are expressed in terms of incremental costs per ulcer-free day (cost effectiveness analysis) and incremental costs per quality adjusted life years (cost utility analysis). Results: The larvae arms were pooled for the main analysis. Treatment with larval therapy cost, on average, 96.70 pound ((sic)109.61; $140.57) more per participant per year (95% confidence interval -491.9 pound to 685.8) pound than treatment with hydrogel. Participants treated with larval therapy healed, on average, 2.42 days before those in the hydrogel arm (95% confidence interval -0.95 to 31. 91 days) and had a slightly better health related quality of life, as the annual difference in QALYs was 0.011 (95% confidence interval -0.067 to 0.071). However, none of these differences was statistically significant. The incremental cost effectiveness ratio for the base case analysis was estimated at 8826 pound per QALY gained and 40 pound per ulcer-free day. Considerable uncertainty surrounds the outcome estimates. Conclusions: Debridement of sloughy or necrotic leg ulcers with larval therapy is likely to produce similar health benefits and have similar costs to treatment with hydrogel. Trial registration: Current Controlled Trials ISRCTN55114812 and National Research Register N0484123692

Respiratory health and immunological profile of poultry workers

No Abstrac

A rapid motor task-based screening tool for parkinsonism in community-based studies

The prevalence of parkinsonism in developing countries is largely unknown due to difficulty in ascertainment because access to neurologists is often limited. Develop and validate a parkinsonism screening tool using objective motor task-based tests that can be administered by non-clinicians. In a cross-sectional population-based sample from South Africa, we evaluated 315 adults, age \u3e40, from an Mn-exposed (smelter) community, using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3), Purdue grooved pegboard, and kinematic-UPDRS3-based motor tasks. In 275 participants (training dataset), we constructed a linear regression model to predict UPDRS3. We selected motor task summary measures independently associated with UPDRS3 ( \u3c 0.05). We validated the model internally in the remaining 40 participants from the manganese-exposed community (test dataset) using the area under the receiver operating characteristic curve (AUC), and externally in another population-based sample of 90 participants from another South African community with only background levels of environmental Mn exposure. The mean UPDRS3 score in participants from the Mn-exposed community was 9.1 in both the training and test datasets (standard deviation = 6.4 and 6.1, respectively). Together, 57 (18.1%) participants in this community had a UPDRS3 ≥ 15, including three with Parkinson\u27s disease. In the non-exposed community, the mean UPDRS3 was 3.9 (standard deviation = 4.3). Three (3.3%) had a UPDRS3 ≥ 15. Grooved pegboard time and mean velocity for hand rotation and finger tapping tasks were strongly associated with UPDRS3. Using these motor task summary measures and age, the UPDRS3 predictive model performed very well. In the test dataset, AUCs were 0.81 (95% CI 0.68, 0.94) and 0.91 (95% CI 0.81, 1.00) for cut points for neurologist-assessed UPDRS3 ≥ 10 and UPDRS3 ≥ 15, respectively. In the external validation dataset, the AUC was 0.85 (95% CI 0.73, 0.97) for UPDRS3 ≥ 10. AUCs were 0.76-0.82 when excluding age. A predictive model based on a series of objective motor tasks performs very well in assessing severity of parkinsonism in both Mn-exposed and non-exposed population-based cohorts

Larval therapy for leg ulcers (VenUS II) : randomised controlled trial

Objective To compare the clinical effectiveness of larval therapy with a standard debridement technique (hydrogel) for sloughy or necrotic leg ulcers. Design Pragmatic, three armed randomised controlled trial. Setting Community nurse led services, hospital wards, and hospital outpatient leg ulcer clinics in urban and rural settings, United Kingdom. Participants 267 patients with at least one venous or mixed venous and arterial ulcer with at least 25% coverage of slough or necrotic tissue, and an ankle brachial pressure index of 0.6 or more. Interventions Loose larvae, bagged larvae, and hydrogel. Main outcome measures The primary outcome was time to healing of the largest eligible ulcer. Secondary outcomes were time to debridement, health related quality of life (SF-12), bacterial load, presence of meticillin resistant Staphylococcus aureus, adverse events, and ulcer related pain (visual analogue scale, from 0 mm for no pain to 150 mm for worst pain imaginable). Results Time to healing was not significantly different between the loose or bagged larvae group and the hydrogel group (hazard ratio for healing using larvae v hydrogel 1.13, 95% confidence interval 0.76 to 1.68; P=0.54). Larval therapy significantly reduced the time to debridement (2.31, 1.65 to 3.2; P<0.001). Health related quality of life and change in bacterial load over time were not significantly different between the groups. 6.7% of participants had MRSA at baseline. No difference was found between larval therapy and hydrogel in their ability to eradicate MRSA by the end of the debridement phase (75% (9/12) v 50% (3/6); P=0.34), although this comparison was underpowered. Mean ulcer related pain scores were higher in either larvae group compared with hydrogel (mean difference in pain score: loose larvae v hydrogel 46.74 (95% confidence interval 32.44 to 61.04), P<0.001; bagged larvae v hydrogel 38.58 (23.46 to 53.70), P<0.001). Conclusions Larval therapy did not improve the rate of healing of sloughy or necrotic leg ulcers or reduce bacterial load compared with hydrogel but did significantly reduce the time to debridement and increase ulcer pain. Trial registration Current Controlled Trials ISRCTN55114812 and National Research Register N0484123692

The impact of confounding on the associations of different adiposity measures with the incidence of cardiovascular disease: a cohort study of 296 535 adults of white European descent

Aims: The data regarding the associations of body mass index (BMI) with cardiovascular (CVD) risk, especially for those at the low categories of BMI, are conflicting. The aim of our study was to examine the associations of body composition (assessed by five different measures) with incident CVD outcomes in healthy individuals. Methods and results: A total of 296 535 participants (57.8% women) of white European descent without CVD at baseline from the UK biobank were included. Exposures were five different measures of adiposity. Fatal and non-fatal CVD events were the primary outcome. Low BMI (≤18.5 kg m−2) was associated with higher incidence of CVD and the lowest CVD risk was exhibited at BMI of 22–23 kg m−2 beyond, which the risk of CVD increased. This J-shaped association attenuated substantially in subgroup analyses, when we excluded participants with comorbidities. In contrast, the associations for the remaining adiposity measures were more linear; 1 SD increase in waist circumference was associated with a hazard ratio of 1.16 [95% confidence interval (CI) 1.13–1.19] for women and 1.10 (95% CI 1.08–1.13) for men with similar magnitude of associations for 1 SD increase in waist-to-hip ratio, waist-to-height ratio, and percentage body fat mass. Conclusion: Increasing adiposity has a detrimental association with CVD health in middle-aged men and women. The association of BMI with CVD appears more susceptible to confounding due to pre-existing comorbidities when compared with other adiposity measures. Any public misconception of a potential ‘protective’ effect of fat on CVD risk should be challenged

Validation of Parkinson\u27s disease-related questionnaires in South Africa

Background: There are very few epidemiological studies investigating Parkinson\u27s disease (PD) in Africa. The hundreds of local languages and dialects make traditional screening and clinical evaluation tools difficult to use. Objective: The objective of the study was to validate two commonly used PD questionnaires in an African population. Methods: The PD Screening Questionnaire (PDSQ) and Parkinson\u27s Disease Questionnaire (PDQ-39) were modified and translated into Afrikaans, Setswana, and isiZulu and administered to a sample of healthy local residents. We assessed the internal consistencies and cluster characteristics of the questionnaires, using a Cronbach\u27s alpha test and exploratory factor analysis. The questionnaires were then administered to a population-based sample of 416 research participants. We evaluated the correlations between the questionnaires and both a timed motor task and the Unified Parkinson\u27s Disease Rating Scale motor subsection 3 (UPDRS3), using locally weighted scatterplot smoothing (LOWESS) regression analysis and Spearman\u27s rank correlation. Results: Both questionnaires had high overall internal consistency (Cronbach\u27s alpha = 0.86 and 0.95, respectively). The modified PDQ-39 had evidence of five subscales, with Factor 1 explaining 57% and Factor 2 explaining 14%, of the variance in responses. The PDSQ and PDQ-39 scores were correlated with the UPDRS3 score ( Conclusion: The translated PDSQ and PDQ-39 questionnaires demonstrated high internal consistency and correlations with clinical severity of parkinsonism and a timed motor task, suggesting that they are valid tools for field-based epidemiological studies

The effect of HIV infection on time off work in a large cohort of gold miners with known dates of seroconversion

Objectives To estimate the effect of HIV infection on time off work. To provide baseline estimates for economic and actuarial models, and for evaluations of ART and other workplace interventions.Methods A retrospective cohort study of gold miners with known dates of seroconversion to HIV, and an HIV-negative comparison group, used routinely collected data to estimate the proportion of time off work by calendar period (1992-2002, prior to the introduction of ART), age, time since seroconversion and period before death. The authors calculated ORs for overall time off work and RR ratios (RRR, using multinomial logistic regression) for reasons off work relative to being at work.Results 1703 HIV-positive and 4859 HIV-negative men were followed for 34 424 person-years. HIV-positive miners spent a higher proportion of time off work than negative miners (20.7% vs 16.1%) due to greater medical and unauthorised absence. Compared with HIV-negative miners, overall time off work increased in the first 2 years after seroconversion (adjusted OR 1.40 (95% CI 1.36 to 1.45)) and then remained broadly stable for a number years, reaching 38.8% in the final year before death (adjusted OR 3.27, 95% CI 2.95 to 3.63). Absence for medical reasons showed the strongest link to HIV infection, increasing from an adjusted RRR of 2.66 (95% CI 2.45 to 2.90) for the first 2 years since seroconversion to 13.6 (95% CI 11.8 to 15.6) in the year prior to death.Conclusions Time off work provides a quantifiable measure of the effect of HIV on overall morbidity. HIV/AIDS affects both labour supply (increased time off work) and demand for health services (increased medical absence). The effects occur soon after seroconversion and stabilise before reaching very high levels in the period prior to death. Occupational health services are an important setting to identify HIV-infected men early

Focus on the Role of D-serine and D-amino Acid Oxidase in Amyotrophic Lateral Sclerosis/Motor Neuron Disease (ALS)

Highly pathogenic avian influenza (HPAI) H5N1 virus has been circulating in Vietnam since 2003, while outbreaks of HPAI H5N6 virus are more recent, having only been reported since 2014. Although the spatial distribution of H5N1 outbreaks and risk factors for virus occurrence have been extensively studied, there have been no comparative studies for H5N6. Data collected through active surveillance of Vietnamese live-bird markets (LBMs) between 2011 and 2015 were used to explore and compare the spatio-temporal distributions of H5N1- and H5N6-positive LBMs. Conditional autoregressive models were developed to quantify spatio-temporal associations between agro-ecological factors and the two HPAI strains using the same set of predictor variables. Unlike H5N1, which exhibited a strong north-south divide, with repeated occurrence in the extreme south of a cluster of high-risk provinces, H5N6 was homogeneously distributed throughout Vietnam. Similarly, different agro-ecological factors were associated with each strain. Sample collection in the months of January and February and higher average maximum temperature were associated with higher likelihood of H5N1 positive market-day status. The likelihood of market-days being positive for H5N6 increased with decreased river density, and with successive Rounds of data collection. This study highlights marked differences in spatial patterns and risk factors for H5N1 and H5N6 in Vietnam, suggesting the need for tailored surveillance and control approaches

A review of wildland fire spread modelling, 1990-present 2: Empirical and quasi-empirical models

In recent years, advances in computational power and spatial data analysis (GIS, remote sensing, etc) have led to an increase in attempts to model the spread and behaviour of wildland fires across the landscape. This series of review papers endeavours to critically and comprehensively review all types of surface fire spread models developed since 1990. This paper reviews models of an empirical or quasi-empirical nature. These models are based solely on the statistical analysis of experimentally obtained data with or without some physical framework for the basis of the relations. Other papers in the series review models of a physical or quasi-physical nature, and mathematical analogues and simulation models. The main relations of empirical models are that of wind speed and fuel moisture content with rate of forward spread. Comparisons are made of the different functional relationships selected by various authors for these variables.Comment: 22 pages + 7 pages references + 2 pages tables + 2 pages figures. Submitted to International Journal of Wildland Fir