Pneumonia in the elderly - diagnosis and treatment in general practice

Pneumonia is common in the elderly and clinical manifestations are frequently atypical. Pneumonia should be considered in any older person presenting with falls, confusion, incontinence, worsening comorbidities or a deterioration in functional status. The respiratory rate is the most reliable sign to alert the health carer to the presence of pneumonia. Therapy should follow the recommendations of the South African Pneumonia Guidelines. Prevention strategies include the prevention and management of aspiration, reduction in the use of neuroleptic medication, influenza vaccination, maintenance of oral hygiene, smoking cessation and possibly the use of the newer antiviral preparations

The burden and risk factors for adverse drug events in older patients - a prospective cross-sectional study

Objective: To determine the burden and risk factors for adverse drug events (ADEs) in older patients. Design: A prospective cross-sectional study. Methods: Patients (65 years and older) presenting to the tertiary Emergency Unit of Groote Schuur Hospital, Cape Town, between February and May 2005, were assessed for well established ADEs, as defined by the South African Medicines Formulary. Logistic regression models were fitted to determine drugs and other factors associated with the likelihood of developing ADEs. Results: ADEs were identified in 104 of the 517 (20%) presentations. The most frequently involved drug classes were cardiovascular (34%), anticoagulant (27%), analgesic (19%) and antidiabetic (9%). Patients who developed ADEs were more likely to have five or more prescription drugs (p < 0.0001), more than three clinical problems (p = 0.001), require admission (p = 0.04), and report compliance with medication (p = 0.02) than those who did not. Drugs shown to independently confer increased risk of ADEs were angiotensin-converting enzyme inhibitors (RR = 2.6, 95% CI: 1.3 - 5.2, p = 0.009), non-steroidal anti-inflammatory drugs (RR = 4.1, 95% CI: 2.1 - 8.0, p < 0.0001) and warfarin (RR = 3.1, 95% CI: 1.6 - 6.3, p = 0.0014). Conclusion: ADEs contribute significantly to the burden of elderly care in the Emergency Unit. In a setting such as ours, increased pill burden and certain drug classes are likely to result in increased risk of ADEs in the older population group.South African Medical Journal Vol. 96 (12) 2006: pp. 1255-125

Atypical femoral fractures

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Recommendations for the acute and long-term medical management of low-trauma hip fractures

Hip fractures are the most serious complication of osteoporosis and are associated with high morbidity and mortality. Generally, patients who sustain osteoporotic hip fractures are older adults who have a number of comorbiddiseases which predispose them to perioperative complications, disability and death. Furthermore, patients who survive a hip fracture are at higher risk of a subsequent fracture. The morbidity and mortality of hip fractures can be substantially reduced by a structured multidisciplinary approach to pre- and postoperative management. This review will focus on the epidemiology of hip fractures, predictors of mortality and the acute and long-term management of hip fractures

Active Sampling-based Binary Verification of Dynamical Systems

Nonlinear, adaptive, or otherwise complex control techniques are increasingly relied upon to ensure the safety of systems operating in uncertain environments. However, the nonlinearity of the resulting closed-loop system complicates verification that the system does in fact satisfy those requirements at all possible operating conditions. While analytical proof-based techniques and finite abstractions can be used to provably verify the closed-loop system's response at different operating conditions, they often produce conservative approximations due to restrictive assumptions and are difficult to construct in many applications. In contrast, popular statistical verification techniques relax the restrictions and instead rely upon simulations to construct statistical or probabilistic guarantees. This work presents a data-driven statistical verification procedure that instead constructs statistical learning models from simulated training data to separate the set of possible perturbations into "safe" and "unsafe" subsets. Binary evaluations of closed-loop system requirement satisfaction at various realizations of the uncertainties are obtained through temporal logic robustness metrics, which are then used to construct predictive models of requirement satisfaction over the full set of possible uncertainties. As the accuracy of these predictive statistical models is inherently coupled to the quality of the training data, an active learning algorithm selects additional sample points in order to maximize the expected change in the data-driven model and thus, indirectly, minimize the prediction error. Various case studies demonstrate the closed-loop verification procedure and highlight improvements in prediction error over both existing analytical and statistical verification techniques.Comment: 23 page

The effect of mode and context on survey results: Analysis of data from the Health Survey for England 2006 and the Boost Survey for London

Background: Health-related data at local level could be provided by supplementing national health surveys with local boosts. Self-completion surveys are less costly than interviews, enabling larger samples to be achieved for a given cost. However, even when the same questions are asked with the same wording, responses to survey questions may vary by mode of data collection. These measurement differences need to be investigated further.Methods: The Health Survey for England in London ('Core') and a London Boost survey ('Boost') used identical sampling strategies but different modes of data collection. Some data were collected by face-to-face interview in the Core and by self-completion in the Boost; other data were collected by self-completion questionnaire in both, but the context differed.Results were compared by mode of data collection using two approaches. The first examined differences in results that remained after adjusting the samples for differences in response. The second compared results after using propensity score matching to reduce any differences in sample composition. Results: There were no significant differences between the two samples for prevalence of some variables including long-term illness, limiting long-term illness, current rates of smoking, whether participants drank alcohol, and how often they usually drank. However, there were a number of differences, some quite large, between some key measures including: general health, GHQ12 score, portions of fruit and vegetables consumed, levels of physical activity, and, to a lesser extent, smoking consumption, the number of alcohol units reported consumed on the heaviest day of drinking in the last week and perceived social support (among women only).Conclusion: Survey mode and context can both affect the responses given. The effect is largest for complex question modules but was also seen for identical self-completion questions. Some data collected by interview and self-completion can be safely combined

The effect of survey method on survey participation: Analysis of data from the Health Survey for England 2006 and the Boost Survey for London

Background: There is a need for local level health data for local government and health bodies, for health surveillance and planning and monitoring of policies and interventions. The Health Survey for England (HSE) is a nationally-representative survey of the English population living in private households, but sub-national analyses can be performed only at a regional level because of sample size. A boost of the HSE was commissioned to address the need for local level data in London but a different mode of data collection was used to maximise participant numbers for a given cost. This study examines the effects on survey and item response of the different survey modes.Methods: Household and individual level data are collected in HSE primarily through interviews plus individual measures through a nurse visit. For the London Boost, brief household level data were collected through interviews and individual level data through a longer self-completion questionnaire left by the interviewer and collected later. Sampling and recruitment methods were identical, and both surveys were conducted by the same organisation. There was no nurse visit in the London Boost. Data were analysed to assess the effects of differential response rates, item non-response, and characteristics of respondents.Results: Household response rates were higher in the 'Boost' (61%) than 'Core' (HSE participants in London) sample (58%), but the individual response rate was considerably higher in the Core (85%) than Boost (65%). There were few differences in participant characteristics between the Core and Boost samples, with the exception of ethnicity and educational qualifications. Item non-response was similar for both samples, except for educational level. Differences in ethnicity were corrected with non-response weights, but differences in educational qualifications persisted after non-response weights were applied. When item non-response was added to those reporting no qualification, participants' educational levels were similar in the two samples.Conclusion: Although household response rates were similar, individual response rates were lower using the London Boost method. This may be due to features of London that are particularly associated with lower response rates for the self-completion element of the Boost method, such as the multi-lingual population. Nevertheless, statistical adjustments can overcome most of the demographic differences for analysis. Care must be taken when designing self-completion questionnaires to minimise item non-response

HoloCam: A subsea holographic camera for recording marine organisms and particles

The HoloCam system is a major component of a multi-national multi-discipline project known as HoloMar (funded by the European Commission under the MAST III initiative). The project is concerned with the development of pulsed laser holography to analyse and monitor the populations of living organisms and inanimate particles within the world's oceans. We describe here the development, construction and evaluation of a prototype underwater camera, the purpose of which is to record marine organisms and particles, in-situ. Recording using holography provides several advantages over conventional sampling methods in that it allows non-intrusive, non-destructive, high-resolution imaging of large volumes (up to 10^5 cm^3) in three dimensions. The camera incorporates both in-line and off-axis holographic techniques, which allows particles from a few micrometres to tens of centimetres to be captured. In tandem with development of the HoloCam, a dedicated holographic replay system and an automated data extraction and image processing facility are being developed. These will allow, optimisation of the images recorded by the camera, identification of species and particle concentration plotting

Proton binding by groundwater fulvic acids of different age, origins, and structure modeled with the model V and NICA-Donnan model

The proton binding properties of four fulvic acids from pristine groundwater and leachate-polluted groundwater were measured at four different ionic strengths (0.005−0.12 M) and modeled by the Model V and the NICA−Donnan model in order to evaluate the necessity of detailed proton binding parameters for groundwater fulvic acids. The proton binding parameters derived from the various fulvic acids were very similar, and on the basis of these parameters, it was not possible to distinguish between pristine and polluted groundwater. Normalization of the proton charge density by the proton charge density at pH 7 for each fulvic acid made all four fulvic acids regress to the same curve. The effects of varying the proton binding parameters were evaluated by simulating cadmium complexation using sets of proton binding parameters for the four fulvic acids and default sets of proton binding parameters available in the models WHAM (based on Model V) and Ecosat (based on NICA−Donnan). The Model V was rather indifferent with respect to specific characteristics of fulvic acids proton binding, and for most practical uses, the default values available in the model can be used. The NICA−Donnan model resulted in larger deviations between simulations based on default values and specific parameters. However, the NICA−Donnan database is still rather limited, and specific proton binding parameters should be used until the database providing default values has been extended