The politics of disease surveillance

The capacity to conduct international disease outbreak surveillance and share information about outbreaks quickly has empowered both State and Non-State Actors to take an active role in stopping the spread of disease by generating new technical means to identify potential pandemics through the creation of shared reporting platforms. Despite all the rhetoric about the importance of infectious disease surveillance, the concept itself has received relatively little critical attention from academics, practitioners, and policymakers. This book asks leading contributors in the field to engage with five key issues attached to international disease outbreak surveillance - transparency, local engagement, practical needs, integration, and appeal - to illuminate the political effect of these technologies on those who use surveillance, those who respond to surveillance, and those being monitored.

Making the most of spatial information in health: A tutorial in Bayesian disease mapping for areal data

Disease maps are effective tools for explaining and predicting patterns of disease outcomes across geographical space, identifying areas of potentially elevated risk, and formulating and validating aetiological hypotheses for a disease. Bayesian models have become a standard approach to disease mapping in recent decades. This article aims to provide a basic understanding of the key concepts involved in Bayesian disease mapping methods for areal data. It is anticipated that this will help in interpretation of published maps, and provide a useful starting point for anyone interested in running disease mapping methods for areal data. The article provides detailed motivation and descriptions on disease mapping methods by explaining the concepts, defining the technical terms, and illustrating the utility of disease mapping for epidemiological research by demonstrating various ways of visualising model outputs using a case study. The target audience includes spatial scientists in health and other fields, policy or decision makers, health geographers, spatial analysts, public health professionals, and epidemiologists.

A randomized controlled trial protocol testing a decision support intervention for older patients with advanced kidney disease

Aim To assess the effectiveness of a decision support intervention using a pragmatic single blind Randomized Controlled Trial. Background Worldwide the proportion of older people (aged 65 years and over) is rising. This population is known to have a higher prevalence of chronic diseases including chronic kidney disease. The resultant effect of the changing health landscape is seen in the increase in older patients (aged ≥65 years) commencing on dialysis. Emerging evidence suggests that for some older patients dialysis may provide minimal benefit. In a majority of renal units non-dialysis management is offered as an alternative to undertaking dialysis. Research regarding decision-making support that is required to assist this population in choosing between dialysis or non-dialysis management is limited. Design. A multisite single blinded pragmatic randomized controlled trial is proposed. Methods Patients will be recruited from four Queensland public hospitals and randomizd into either the control or intervention group. The decision support intervention is multimodal and includes counselling provided by a trained nurse. The comparator is standard decision-making support. The primary outcomes are decisional regret and decisional conflict. Secondary outcomes are improved knowledge and quality of life. Ethics approval obtained November 2014. Conclusion This is one of the first randomized controlled trials assessing a decision support intervention in older people with advance chronic kidney disease. The results may provide guidance for clinicians in future approaches to assist this population in decision-making to ensure reduced decisional regret and decisional conflict.

Factors influencing hospital readmission and length of stay of Vietnamese patients with type 2 diabetes and cardiac disease

Background: Increased hospital readmission and longer stays in the hospital for patients with type 2 diabetes and cardiac disease can result in higher healthcare costs and heavier individual burden. Thus, knowledge of the characteristics and predictive factors for Vietnamese patients with type 2 diabetes and cardiac disease, at high risk of hospital readmission and longer stays in the hospital, could provide a better understanding on how to develop an effective care plan aimed at improving patient outcomes. However, information about factors influencing hospital readmission and length of stay of patients with type 2 diabetes and cardiac disease in Vietnam is limited. Aim: This study examined factors influencing hospital readmission and length of stay of Vietnamese patients with both type 2 diabetes and cardiac disease. Methods: An exploratory prospective study design was conducted on 209 patients with type 2 diabetes and cardiac disease in Vietnam. Data were collected from patient charts and patients' responses to self-administered questionnaires. Descriptive statistics, bivariate correlation, logistic and multiple regression were used to analyse the data. Results: The hospital readmission rate was 12.0% among patients with both type 2 diabetes and cardiac disease. The average length of stay in the hospital was 9.37 days. Older age (OR= 1.11, p< .05), increased duration of type 2 diabetes (OR= 1.22, p< .05), less engagement in stretching/strengthening exercise behaviours (OR= .93, p< .001) and in communication with physician (OR= .21, p< .001) were significant predictors of 30-dayhospital readmission. Increased number of additional co-morbidities (β= .33, p< .001) was a significant predictor of longer stays in the hospital. High levels of cognitive symptom management (β= .40, p< .001) significantly predicted longer stays in the hospital, indicating that the more patients practiced cognitive symptom management, the longer the stay in hospital. Conclusions: This study provides some evidence of factors influencing hospital readmission and length of stay and argues that this information may have significant implications for clinical practice in order to improve patients' health outcomes. However, the findings of this study related to the targeted hospital only. Additionally, the investigation of environmental factors is recommended for future research as these factors are important components contributing to the research model.

Diagnostic values for skin temperature assessment to detect diabetes-related foot complications

Background Skin temperature assessment is a promising modality for early detection of diabetic foot problems, but its diagnostic value has not been studied. Our aims were to investigate the diagnostic value of different cutoff skin temperature values for detecting diabetes-related foot complications such as ulceration, infection, and Charcot foot and to determine urgency of treatment in case of diagnosed infection or a red-hot swollen foot. Materials and Methods The plantar foot surfaces of 54 patients with diabetes visiting the outpatient foot clinic were imaged with an infrared camera. Nine patients had complications requiring immediate treatment, 25 patients had complications requiring non-immediate treatment, and 20 patients had no complications requiring treatment. Average pixel temperature was calculated for six predefined spots and for the whole foot. We calculated the area under the receiver operating characteristic curve for different cutoff skin temperature values using clinical assessment as reference and defined the sensitivity and specificity for the most optimal cutoff temperature value. Mean temperature difference between feet was analyzed using the Kruskal–Wallis tests. Results The most optimal cutoff skin temperature value for detection of diabetes-related foot complications was a 2.2°C difference between contralateral spots (sensitivity, 76%; specificity, 40%). The most optimal cutoff skin temperature value for determining urgency of treatment was a 1.35°C difference between the mean temperature of the left and right foot (sensitivity, 89%; specificity, 78%). Conclusions Detection of diabetes-related foot complications based on local skin temperature assessment is hindered by low diagnostic values. Mean temperature difference between two feet may be an adequate marker for determining urgency of treatment.

Prevention of foot ulcers in the at-risk patient with diabetes: A systematic review

Background Prevention of foot ulcers in patients with diabetes is extremely important to help reduce the enormous burden of foot ulceration on both patient and health resources. A comprehensive analysis of reported interventions is not currently available, but is needed to better inform caregivers about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at risk for ulceration. Methods The available medical scientific literature in PubMed, EMBASE, CINAHL and the Cochrane database was searched for original research studies on preventative interventions. Both controlled and non-controlled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers. Results From the identified records, a total of 30 controlled studies (of which 19 RCTs) and another 44 non-controlled studies were assessed and described. Few controlled studies, of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, multiple RCTs with low risk of bias show the benefit for the use of daily foot skin temperature measurements and consequent preventative actions, as well as for therapeutic footwear that demonstrates to relieve plantar pressure and that is worn by the patient. To prevent recurrence, some evidence exists for integrated foot care when it includes a combination of professional foot treatment, therapeutic footwear and patient education; for just a single session of patient education, no evidence exists. Surgical interventions can be effective in selected patients, but the evidence base is small. Conclusion The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong, but is small for the use of other, sometimes widely applied, interventions and is practically nonexistent for the prevention of a first foot ulcer and non-plantar foot ulcer.

The effect of flexor tenotomy on healing and prevention of neuropathic diabetic foot ulcers on the distal end of the toe

Background Flexor tenotomy is a minimally invasive surgical alternative for the treatment of neuropathic diabetic foot ulcers on the distal end of the toe. The influence of infection on healing and time to heal after flexor tenotomy is unknown. Flexor tenotomy can also be used as a prophylactic treatment. The effectiveness as a prophylactic treatment has not been described before. Methods A retrospective study was performed with the inclusion of all consecutive flexor tenotomies from one hospital between January 2005 and December 2011. Results From 38 ulcers, 35 healed (92%), with a mean time to heal of 22 ± 26 days. The longest duration for healing was found for infected ulcers that were penetrating to bone (35 days; p = .042). Cases of prophylactic flexor tenotomies (n=9) did not result in any ulcer or other complications during follow-up. Conclusions The results of this study suggest that flexor tenotomy may be beneficial for neuropathic diabetic foot ulcers on the distal end of the toe, with a high healing percentage and a short mean time to heal. Infected ulcers that penetrated to bone took a significantly longer time to heal. Prospective research, to confirm the results of this retrospective study, should be performed.

Automatic detection of diabetic foot complications with infrared thermography by asymmetric analysis

Early identification of diabetic foot complications and their precursors is essential in preventing their devastating consequences, such as foot infection and amputation. Frequent, automatic risk assessment by an intelligent telemedicine system might be feasible and cost effective. Infrared thermography is a promising modality for such a system. The temperature differences between corresponding areas on contralateral feet are the clinically significant parameters. This asymmetric analysis is hindered by (1) foot segmentation errors, especially when the foot temperature and the ambient temperature are comparable, and by (2) different shapes and sizes between contralateral feet due to deformities or minor amputations. To circumvent the first problem, we used a color image and a thermal image acquired synchronously. Foot regions, detected in the color image, were rigidly registered to the thermal image. This resulted in 97.8% ± 1.1% sensitivity and 98.4% ± 0.5% specificity over 76 high-risk diabetic patients with manual annotation as a reference. Nonrigid landmark-based registration with Bsplines solved the second problem. Corresponding points in the two feet could be found regardless of the shapes and sizes of the feet. With that, the temperature difference of the left and right feet could be obtained.

Statistical analysis of spectral data: A methodology for designing an intelligent monitoring system for the diabetic foot

Early detection of (pre-)signs of ulceration on a diabetic foot is valuable for clinical practice. Hyperspectral imaging is a promising technique for detection and classification of such (pre-)signs. However, the number of the spectral bands should be limited to avoid overfitting, which is critical for pixel classification with hyperspectral image data. The goal was to design a detector/classifier based on spectral imaging (SI) with a small number of optical bandpass filters. The performance and stability of the design were also investigated. The selection of the bandpass filters boils down to a feature selection problem. A dataset was built, containing reflectance spectra of 227 skin spots from 64 patients, measured with a spectrometer. Each skin spot was annotated manually by clinicians as "healthy" or a specific (pre-)sign of ulceration. Statistical analysis on the data set showed the number of required filters is between 3 and 7, depending on additional constraints on the filter set. The stability analysis revealed that shot noise was the most critical factor affecting the classification performance. It indicated that this impact could be avoided in future SI systems with a camera sensor whose saturation level is higher than 106, or by postimage processing.

Diabetic charcot neuroarthropathy of the knee: Conservative treatment options as alternatives to surgery

In contrast to the well-known Charcot neuroarthropathy (CN) of the foot, CN of the knee is hardly recognized. In a literature search, we only found five articles on total knee arthroplasty for Charcot joints (1–5). We did not find a single article dealing with alternative treatment options or the general clinical course of this disease. We started our study

Lower limb amputation in Northern Netherlands: Unchanged incidence from 1991-1992 to 2003-2004

Background Investigating population changes gives insight into effectiveness and need for prevention and rehabilitation services. Incidence rates of amputation are highly varied, making it difficult to meaningfully compare rates between studies and regions or to compare changes over time. Study Design Historical cohort study of transtibial amputation, knee disarticulation, and transfemoral amputations resulting from vascular disease or infection, with/without diabetes, in 2003-2004, in the three Northern provinces of the Netherlands. Objectives To report the incidence of first transtibial amputation, knee disarticulation, or transfemoral amputation in 2003-2004 and the characteristics of this population, and to compare these outcomes to an earlier reported cohort from 1991 to 1992. Methods Population-based incidence rates were calculated per 100,000 person-years and compared across the two cohorts. Results Incidence of amputation was 8.8 (all age groups) and 23.6 (≥45 years) per 100,000 person-years. This was unchanged from the earlier study of 1991-1992. The relative risk of amputation was 12 times greater for people with diabetes than for people without diabetes. Conclusions Investigation is needed into reasons for the unchanged incidence with respect to the provision of services from a range of disciplines, including vascular surgery, diabetes care, and multidisciplinary foot clinics. Clinical relevance This study shows an unchanged incidence of amputation over time and a high risk of amputation related to diabetes. Given the increased prevalence of diabetes and population aging, both of which present an increase in the population at risk of amputation, finding methods for reducing the rate of amputation is of importance.

A shift in priority in diabetic foot care and research: 75% of foot ulcers are preventable

Diabetic foot ulceration poses a heavy burden on the patient and the healthcare system, but prevention thereof receives little attention. For every euro spent on ulcer prevention, ten are spent on ulcer healing, and for every randomized controlled trial conducted on prevention, ten are conducted on healing. In this article, we argue that a shift in priorities is needed. For the prevention of a first foot ulcer, we need more insight into the effect of interventions and practices already applied globally in many settings. This requires systematic recording of interventions and outcomes, and well-designed randomized controlled trials that include analysis of cost-effectiveness. After healing of a foot ulcer, the risk of recurrence is high. For the prevention of a recurrent foot ulcer, home monitoring of foot temperature, pressure-relieving therapeutic footwear, and certain surgical interventions prove to be effective. The median effect size found in a total of 23 studies on these interventions is large, over 60%, and further increases when patients are adherent to treatment. These interventions should be investigated for efficacy as a state-of-the-art integrated foot care approach, where attempts are made to assure treatment adherence. Effect sizes of 75-80% may be expected. If such state-of-the-art integrated foot care is implemented, the majority of problems with foot ulcer recurrence in diabetes can be resolved. It is therefore time to act and to set a new target in diabetic foot care. This target is to reduce foot ulcer incidence with at least 75%.

Ambient air pollution exposure estimation for the global burden of disease 2013

Exposure to ambient air pollution is a major risk factor for global disease. Assessment of the impacts of air pollution on population health and the evaluation of trends relative to other major risk factors requires regularly updated, accurate, spatially resolved exposure estimates. We combined satellite-based estimates, chemical transport model (CTM) simulations and ground measurements from 79 different countries to produce new global estimates of annual average fine particle (PM2.5) and ozone concentrations at 0.1° × 0.1° spatial resolution for five-year intervals from 1990-2010 and the year 2013. These estimates were then applied to assess population-weighted mean concentrations for 1990 – 2013 for each of 188 countries. In 2013, 87% of the world’s population lived in areas exceeding the World Health Organization (WHO) Air Quality Guideline of 10 μg/m3 PM2.5 (annual average). Between 1990 and 2013, decreases in population-weighted mean concentrations of PM2.5 were evident in most high income countries, in contrast to increases estimated in South Asia, throughout much of Southeast Asia, and in China. Population-weighted mean concentrations of ozone increased in most countries from 1990 - 2013, with modest decreases in North America, parts of Europe, and several countries in Southeast Asia.

Which patients with chronic kidney disease have the greatest symptom burden? A comparative study of advanced CKD stage and dialysis modality

Background Chronic kidney disease (CKD) leads to a range of symptoms, which are often under-recognised and little is known about the multidimensional symptom experience in advanced CKD. Objectives To examine (1) symptom burden at CKD stages 4 and 5, and dialysis modalities, and (2) demographic and renal history correlates of symptom burden. Methods Using a cross-sectional design, a convenience sample of 436 people with CKD was recruited from three hospitals. The CKD Symptom Burden Index (CKD-SBI) was used to measure the prevalence, severity, distress and frequency of 32 symptoms. Demographic and renal history data were also collected. Results Of the sample, 75.5 % were receiving dialysis (haemodialysis, n = 287; peritoneal dialysis, n = 42) and 24.5 % were not undergoing dialysis (stage 4, n = 69; stage 5, n = 38). Participants reported an average of 13.01 ± 7.67 symptoms. Fatigue and pain were common and burdensome across all symptom dimensions. While approximately one-third experienced sexual symptoms, when reported these symptoms were frequent, severe and distressing. Haemodialysis, older age and being female were independently associated with greater symptom burden. Conclusions In CKD, symptom burden is better understood when capturing the multidimensional aspects of a range of physical and psychological symptoms. Fatigue, pain and sexual dysfunction are key contributors to symptom burden, and these symptoms are often under-recognised and warrant routine assessment. The CKD-SBI offers a valuable tool for renal clinicians to assess symptom burden, leading to the commencement of timely and appropriate interventions.

Measuring the multidimensions of symptoms in people with advanced stages of chronic kidney disease

Chronic kidney disease (CKD) is increasing globally and in Saudi Arabia it affects approximately 8% annual increment of dialysis population. It is associated with a high symptom burden. Previous studies have largely reported on the prevalence of symptoms only in the haemodialysis population. This study examined symptom burden across disease stages and treatment groups in advanced CKD, and their correlation with demographic and clinical factors. Using a cross-sectional design, a convenience sample of 436 patients with CKD was recruited from three hospitals in Saudi Arabia. The CKD Symptom Burden Index (CKD-SBI) was used to measure 32 CKD symptoms. Demographic and clinical data were also collected. Of the sample 75.5% were receiving dialysis (haemodialysis, n = 287; peritoneal dialysis, n = 42) and 24.5% were non-dialysis (CKD stage 4, n = 69; CKD stage 5, n = 38). Average symptom reported was 13.01 ± 7.67. Fatigue and pain were common and burdensome across all symptom dimensions.Approximately one-third of participants experienced sexual symptoms. Dialysis patients reported greater symptom burden, especially patients on haemodialysis. Haemodialysis treatment, older age and being female were independently associated with greater total symptom burden. In conclusion, symptom burden is high among advanced stages of CKD, particularly among those receiving dialysis. Although fatigue, pain and sexual dysfunction are key contributors to symptom burden in CKD, these symptoms are often under-recognised and warrant routine assessment. The CKD-SBI offers a valuable tool to assess symptom burden, leading to the commencement of timely and appropriate interventions.