Application of Naïve Bayesian sequential analysis to primary care optometry

The objective of this study was to investigate the effects of circularity, comorbidity, prevalence and presentation variation on the accuracy of differential diagnoses made in optometric primary care using a modified form of naïve Bayesian sequential analysis. No such investigation has ever been reported before. Data were collected for 1422 cases seen over one year. Positive test outcomes were recorded for case history (ethnicity, age, symptoms and ocular and medical history) and clinical signs in relation to each diagnosis. For this reason only positive likelihood ratios were used for this modified form of Bayesian analysis that was carried out with Laplacian correction and Chi-square filtration. Accuracy was expressed as the percentage of cases for which the diagnoses made by the clinician appeared at the top of a list generated by Bayesian analysis. Preliminary analyses were carried out on 10 diagnoses and 15 test outcomes. Accuracy of 100% was achieved in the absence of presentation variation but dropped by 6% when variation existed. Circularity artificially elevated accuracy by 0.5%. Surprisingly, removal of Chi-square filtering increased accuracy by 0.4%. Decision tree analysis showed that accuracy was influenced primarily by prevalence followed by presentation variation and comorbidity. Analysis of 35 diagnoses and 105 test outcomes followed. This explored the use of positive likelihood ratios, derived from the case history, to recommend signs to look for. Accuracy of 72% was achieved when all clinical signs were entered. The drop in accuracy, compared to the preliminary analysis, was attributed to the fact that some diagnoses lacked strong diagnostic signs; the accuracy increased by 1% when only recommended signs were entered. Chi-square filtering improved recommended test selection. Decision tree analysis showed that accuracy again influenced primarily by prevalence, followed by comorbidity and presentation variation. Future work will explore the use of likelihood ratios based on positive and negative test findings prior to considering naïve Bayesian analysis as a form of artificial intelligence in optometric practice.

Improving the description of the retinal vasculature and patient history taking for monitoring systemic hypertension

Systemic hypertension is an important public health concern. If optometrists are to perform a more active role in the detection and monitoring of high blood pressure (BP), there is a need to improve the consistency of describing the retinal vasculature and to assess patient's ability to correctly report the diagnosis of hypertension, its control and medication. One hundred and one patients aged >40 years were dilated and had fundus photography performed. BP was measured and a self-reported history of general health and current medication was compared with the records of their general practitioner (GP). The status of the retinal vasculature was quantified using a numeric scale by five clinicians and this was compared to the same evaluation performed with the aid of a basic pictorial grading scale. Image analysis was used to objectively measure the artery-to-vein (A/V) ratio and arterial reflex. Arteriolar tortuosity and calibre changes were found to be the most sensitive retinal signs of high BP. Using the grading scale to describe the retinal vasculature significantly improved inter- and intra-observer repeatability. Almost half the patients examined were on medication for high BP or cardiovascular disease. Patients' ability to give their complete medical history was poor, as was their ability to recall what medication they had been prescribed. GPs indicated it was useful to receive details of their patient's BP when it was >140/90 mmHg. The use of improved description of the retinal vasculature and stronger links between optometrists and GPs may enhance future patient care. © 2001 The College of Optometrists. Published by Elsevier Science Ltd. All rights reserved.

Watermarking biomedical time series data

This thesis addresses the problem of information hiding in low dimensional digital data focussing on issues of privacy and security in Electronic Patient Health Records (EPHRs). The thesis proposes a new security protocol based on data hiding techniques for EPHRs. This thesis contends that embedding of sensitive patient information inside the EPHR is the most appropriate solution currently available to resolve the issues of security in EPHRs. Watermarking techniques are applied to one-dimensional time series data such as the electroencephalogram (EEG) to show that they add a level of confidence (in terms of privacy and security) in an individual’s diverse bio-profile (the digital fingerprint of an individual’s medical history), ensure belief that the data being analysed does indeed belong to the correct person, and also that it is not being accessed by unauthorised personnel. Embedding information inside single channel biomedical time series data is more difficult than the standard application for images due to the reduced redundancy. A data hiding approach which has an in built capability to protect against illegal data snooping is developed. The capability of this secure method is enhanced by embedding not just a single message but multiple messages into an example one-dimensional EEG signal. Embedding multiple messages of similar characteristics, for example identities of clinicians accessing the medical record helps in creating a log of access while embedding multiple messages of dissimilar characteristics into an EPHR enhances confidence in the use of the EPHR. The novel method of embedding multiple messages of both similar and dissimilar characteristics into a single channel EEG demonstrated in this thesis shows how this embedding of data boosts the implementation and use of the EPHR securely.

Provision of primary care to patients with chronic cough in the community pharmacy setting

BACKGROUND: Community pharmacies are at the forefront of primary care providers and have an important role in the referral of patients to a medical practitioner for review when necessary. Chronic cough is a common disorder in the community and requires medical assessment. The proficiency of community pharmacy staff to refer patients with chronic cough is currently unknown. OBJECTIVE: To assess the ability of community pharmacy staff to recognize and medically refer patients with a chronic nonproductive cough. METHODS: Following ethics approval, a simulated patient study of 156 community pharmacies in Perth, Western Australia, was conducted over a 3-month period. Simulated patients presented to the pharmacy requesting treatment for a cough. The simulated patient required a referral based on a designated scenario. Demographic details, assessment questions, and advice provided were recorded by the simulated patient immediately postvisit. A logistic regression analysis was performed, with referral for medical assessment as the dependent variable. RESULTS: Of the 155 community pharmacies included in the analysis, 38% provided appropriate medical referral. Cough suppressants were provided as therapy in 72% of all visits. Predictors of medical referral were assessment of symptom duration, medical history, current medications being taken, frequency of reliever use, and the position of the pharmacy staff member conducting the consultation. A third of community pharmacies provided appropriate primary care by recommending medical referral advice to patients with chronic cough. The majority of pharmacy staff members acquired information from the patient that suggested a need for medical referral, yet did not provide referral advice. CONCLUSIONS: Appropriate medical referral is more likely when adequate assessment is undertaken and when a pharmacist is directly involved in the consultation. This highlights the need for pharmacies to ensure that processes are in place for patients to access the pharmacist.

Health promotion for chronic obstructive pulmonary disease

Peter, a 45 year old male, enters the pharmacy and asks, 'do you have something to stop a cough?' On questioning you find out that Peter has an irritating cough that has been off and on for the past few weeks since winter started. He coughs up phlegm every now and then, mostly upon waking. He has tried some cough mixture that he bought at the supermarket but is looking for something stronger. He states that he does not have any medical history or allergies and does not take any medication. He does feel that he can't exercise as much as he used to as he gets more breathless these days.

A review of the information-gathering process for the provision of medicines for self-medication via community pharmacies in developing countries

Background: Currently, no review has been completed regarding the information-gathering process for the provision of medicines for self-medication in community pharmacies in developing countries. Objective: To review the rate of information gathering and the types of information gathered when patients present for self-medication requests. Methods: Six databases were searched for studies that described the rate of information gathering and/or the types of information gathered in the provision of medicines for self-medication in community pharmacies in developing countries. The types of information reported were classified as: signs and symptoms, patient identity, action taken, medications, medical history, and others. Results: Twenty-two studies met the inclusion criteria. Variations in the study populations, types of scenarios, research methods, and data reporting were observed. The reported rate of information gathering varied from 18% to 97%, depending on the research methods used. Information on signs and symptoms and patient identity was more frequently reported to be gathered compared with information on action taken, medications, and medical history. Conclusion: Evidence showed that the information-gathering process for the provision of medicines for self-medication via community pharmacies in developing countries is inconsistent. There is a need to determine the barriers to appropriate information-gathering practice as well as to develop strategies to implement effective information-gathering processes. It is also recommended that international and national pharmacy organizations, including pharmacy academics and pharmacy researchers, develop a consensus on the types of information that should be reported in the original studies. This will facilitate comparison across studies so that areas that need improvement can be identified. © 2013 Elsevier Inc.

Multiple component patient safety intervention in English hospitals:controlled evaluation of second phase

Objective: To independently evaluate the impact of the second phase of the Health Foundation's Safer Patients Initiative (SPI2) on a range of patient safety measures. Design: A controlled before and after design. Five substudies: survey of staff attitudes; review of case notes from high risk (respiratory) patients in medical wards; review of case notes from surgical patients; indirect evaluation of hand hygiene by measuring hospital use of handwashing materials; measurement of outcomes (adverse events, mortality among high risk patients admitted to medical wards, patients' satisfaction, mortality in intensive care, rates of hospital acquired infection). Setting: NHS hospitals in England. Participants: Nine hospitals participating in SPI2 and nine matched control hospitals. Intervention The SPI2 intervention was similar to the SPI1, with somewhat modified goals, a slightly longer intervention period, and a smaller budget per hospital. Results: One of the scores (organisational climate) showed a significant (P=0.009) difference in rate of change over time, which favoured the control hospitals, though the difference was only 0.07 points on a five point scale. Results of the explicit case note reviews of high risk medical patients showed that certain practices improved over time in both control and SPI2 hospitals (and none deteriorated), but there were no significant differences between control and SPI2 hospitals. Monitoring of vital signs improved across control and SPI2 sites. This temporal effect was significant for monitoring the respiratory rate at both the six hour (adjusted odds ratio 2.1, 99% confidence interval 1.0 to 4.3; P=0.010) and 12 hour (2.4, 1.1 to 5.0; P=0.002) periods after admission. There was no significant effect of SPI for any of the measures of vital signs. Use of a recommended system for scoring the severity of pneumonia improved from 1.9% (1/52) to 21.4% (12/56) of control and from 2.0% (1/50) to 41.7% (25/60) of SPI2 patients. This temporal change was significant (7.3, 1.4 to 37.7; P=0.002), but the difference in difference was not significant (2.1, 0.4 to 11.1; P=0.236). There were no notable or significant changes in the pattern of prescribing errors, either over time or between control and SPI2 hospitals. Two items of medical history taking (exercise tolerance and occupation) showed significant improvement over time, across both control and SPI2 hospitals, but no additional SPI2 effect. The holistic review showed no significant changes in error rates either over time or between control and SPI2 hospitals. The explicit case note review of perioperative care showed that adherence rates for two of the four perioperative standards targeted by SPI2 were already good at baseline, exceeding 94% for antibiotic prophylaxis and 98% for deep vein thrombosis prophylaxis. Intraoperative monitoring of temperature improved over time in both groups, but this was not significant (1.8, 0.4 to 7.6; P=0.279), and there were no additional effects of SPI2. A dramatic rise in consumption of soap and alcohol hand rub was similar in control and SPI2 hospitals (P=0.760 and P=0.889, respectively), as was the corresponding decrease in rates of Clostridium difficile and meticillin resistant Staphylococcus aureus infection (P=0.652 and P=0.693, respectively). Mortality rates of medical patients included in the case note reviews in control hospitals increased from 17.3% (42/243) to 21.4% (24/112), while in SPI2 hospitals they fell from 10.3% (24/233) to 6.1% (7/114) (P=0.043). Fewer than 8% of deaths were classed as avoidable; changes in proportions could not explain the divergence of overall death rates between control and SPI2 hospitals. There was no significant difference in the rate of change in mortality in intensive care. Patients' satisfaction improved in both control and SPI2 hospitals on all dimensions, but again there were no significant changes between the two groups of hospitals. Conclusions: Many aspects of care are already good or improving across the NHS in England, suggesting considerable improvements in quality across the board. These improvements are probably due to contemporaneous policy activities relating to patient safety, including those with features similar to the SPI, and the emergence of professional consensus on some clinical processes. This phenomenon might have attenuated the incremental effect of the SPI, making it difficult to detect. Alternatively, the full impact of the SPI might be observable only in the longer term. The conclusion of this study could have been different if concurrent controls had not been used.

Large scale organisational intervention to improve patient safety in four UK hospitals:mixed method evaluation

Objectives: To conduct an independent evaluation of the first phase of the Health Foundation's Safer Patients Initiative (SPI), and to identify the net additional effect of SPI and any differences in changes in participating and non-participating NHS hospitals. Design: Mixed method evaluation involving five substudies, before and after design. Setting: NHS hospitals in United Kingdom. Participants: Four hospitals (one in each country in the UK) participating in the first phase of the SPI (SPI1); 18 control hospitals. Intervention: The SPI1 was a compound (multicomponent) organisational intervention delivered over 18 months that focused on improving the reliability of specific frontline care processes in designated clinical specialties and promoting organisational and cultural change. Results: Senior staff members were knowledgeable and enthusiastic about SPI1. There was a small (0.08 points on a 5 point scale) but significant (P<0.01) effect in favour of the SPI1 hospitals in one of 11 dimensions of the staff questionnaire (organisational climate). Qualitative evidence showed only modest penetration of SPI1 at medical ward level. Although SPI1 was designed to engage staff from the bottom up, it did not usually feel like this to those working on the wards, and questions about legitimacy of some aspects of SPI1 were raised. Of the five components to identify patients at risk of deterioration - monitoring of vital signs (14 items); routine tests (three items); evidence based standards specific to certain diseases (three items); prescribing errors (multiple items from the British National Formulary); and medical history taking (11 items) - there was little net difference between control and SPI1 hospitals, except in relation to quality of monitoring of acute medical patients, which improved on average over time across all hospitals. Recording of respiratory rate increased to a greater degree in SPI1 than in control hospitals; in the second six hours after admission recording increased from 40% (93) to 69% (165) in control hospitals and from 37% (141) to 78% (296) in SPI1 hospitals (odds ratio for "difference in difference" 2.1, 99% confidence interval 1.0 to 4.3; P=0.008). Use of a formal scoring system for patients with pneumonia also increased over time (from 2% (102) to 23% (111) in control hospitals and from 2% (170) to 9% (189) in SPI1 hospitals), which favoured controls and was not significant (0.3, 0.02 to 3.4; P=0.173). There were no improvements in the proportion of prescription errors and no effects that could be attributed to SPI1 in non-targeted generic areas (such as enhanced safety culture). On some measures, the lack of effect could be because compliance was already high at baseline (such as use of steroids in over 85% of cases where indicated), but even when there was more room for improvement (such as in quality of medical history taking), there was no significant additional net effect of SPI1. There were no changes over time or between control and SPI1 hospitals in errors or rates of adverse events in patients in medical wards. Mortality increased from 11% (27) to 16% (39) among controls and decreased from17%(63) to13%(49) among SPI1 hospitals, but the risk adjusted difference was not significant (0.5, 0.2 to 1.4; P=0.085). Poor care was a contributing factor in four of the 178 deaths identified by review of case notes. The survey of patients showed no significant differences apart from an increase in perception of cleanliness in favour of SPI1 hospitals. Conclusions The introduction of SPI1 was associated with improvements in one of the types of clinical process studied (monitoring of vital signs) and one measure of staff perceptions of organisational climate. There was no additional effect of SPI1 on other targeted issues nor on other measures of generic organisational strengthening.

Prevalence and risk factors for mild and high-frequency bilateral sensorineural hearing loss at age 11 years old:a UK prospective cohort study

OBJECTIVE: This study aimed to assess prevalence and risk factors for mild/high-frequency bilateral sensorineural hearing loss within a UK population of children at age 11 years. DESIGN: Prospective birth cohort study. STUDY SAMPLE: Repeat hearing thresholds were measured in 5032 children, as part of the Avon Longitudinal Study of Parents and Children (ALSPAC) at age 7, 9, and 11 years. Pregnancy, birth, and early medical history were obtained prospectively through parental questionnaires and medical records. RESULTS: Twenty children had mild and seven had high-frequency bilateral sensorineural hearing loss, giving a combined prevalence of 0.5% (95% CI 0.4-0.8%). These children were more likely than the rest of the study sample to have been admitted to hospital at 6-18 months (OR 2.7, 95% CI 1.00-7.30). Parents of these children were more likely to have suspected a hearing problem when the children were 3 years old (OR 2.4, 95% CI 1.05-5.60). CONCLUSIONS: This is the first UK prospective cohort study to investigate the prevalence of mild and high-frequency hearing loss. This study, which has the advantage of a large sample size and repeat hearing measures over a four year period, reports lower prevalence values than US cross-sectional studies.

(Re)inventing the past: the politics of 'national' history in the Ukrainian classroom

This article examines how the Ukrainian state has used, and continues to use, history to forge collective identities in Ukraine. It assesses how history textbooks are utilised by the state as ‘tools’ to introduce schoolchildren to key historical episodes around which a modern Ukrainian national identity can be shaped. Attempts to ‘historicise’ Ukrainian national identity must answer fundamental questions such as: Who are we? Where have we come from? Where are we going? Who are we not? The final question is vital in understanding ‘who we are’ in comparison to the ‘other’. Thus, emphasis is placed on how the Ukrainian state is attempting to form an all-encompassing Ukrainian identity by distancing itself from Russia. The article argues that while a ‘national’ history is being espoused, a ‘regional politics of the textbook’ is subtly being allowed by the state to develop. This stands at odds with state attempts to create one universal, all-encompassing Ukrainian history.

'Animal electricity' in the long eighteenth century with special reference to the Edinburgh medical school

Coleridge, looking back at the end of the ‘long eighteenth century’, remarked that the whole of natural philosophy had been ‘electrified’ by advances in the understanding of electrical phenomena. In this paper I trace the way in which these advances affected contemporary ‘neurophysiology.’ At the beginning of the long eighteenth century, neurophysiology (in spite of Swammerdam’s and Glisson’s demonstrations to the contrary) was still understood largely in terms of hollow nerves and animal spirits. At the end of that period the researches of microscopists and electricians had convinced most medical men that the old understanding had to be replaced. Walsh, Patterson, John Hunter and others had described the electric organs of electric fish. Gray and Nollet had demonstrated that electricity was not merely static, but flowed. Franklin had alerted the world to atmospheric electricity. Galvani’s frog experiments were widely known. Volta had invented his ‘pile.’ But did ‘animal electricity’ exist and was it identical to the electricity physicists studied in the inanimate world? Was the brain a gland, as Malpighi’s researches seemed to confirm., and did it secrete electricity into the nervous system? The Monros (primus and secundus), William Cullen, Luigi Galvani, Alessandro Volta, Erasmus Darwin, Luigi Rolando and François Baillarger all had their own ideas. This paper reviews these ‘long-eighteenth century’ controversies with special reference to the Edinburgh medical school and the interaction between neurophysiology and physics.

The unnatural history of the lichen Rhizocarpon geographicum

One of the most widely distributed species of crustose lichen is Rhizocarpon geographicum. This unusual organism comprises yellow-green 'areolae' growing on the surface of a non-lichenised hypothallus that extends beyond the margin of the areolae to form a ring. This article describes the general structure of R. geographicum, how the areolae and hypothallus are formed, why the species grows so slowly, and whether it can inhibit its neighbours by releasing allelochemicals.

Do ‘passive’ medical titanium surfaces deteriorate in service in the absence of wear?

Globally, more than 1000 tonnes of titanium (Ti) is implanted into patients in the form of biomedical devices on an annual basis. Ti is perceived to be ‘biocompatible’ owing to the presence of a robust passive oxide film (approx. 4 nm thick) at the metal surface. However, surface deterioration can lead to the release of Ti ions, and particles can arise as the result of wear and/or corrosion processes. This surface deterioration can result in peri-implant inflammation, leading to the premature loss of the implanted device or the requirement for surgical revision. Soft tissues surrounding commercially pure cranial anchorage devices (bone-anchored hearing aid) were investigated using synchrotron X-ray micro-fluorescence spectroscopy and X-ray absorption near edge structure. Here, we present the first experimental evidence that minimal load-bearing Ti implants, which are not subjected to macroscopic wear processes, can release Ti debris into the surrounding soft tissue. As such debris has been shown to be pro-inflammatory, we propose that such distributions of Ti are likely to effect to the service life of the device.

Discovering the preferences of physicians with regards to rank-ordered medical documents

The practice of evidence-based medicine involves consulting documents from repositories such as Scopus, PubMed, or the Cochrane Library. The most common approach for presenting retrieved documents is in the form of a list, with the assumption that the higher a document is on a list, the more relevant it is. Despite this list-based presentation, it is seldom studied how physicians perceive the importance of the order of documents presented in a list. This paper describes an empirical study that elicited and modeled physicians' preferences with regard to list-based results. Preferences were analyzed using a GRIP method that relies on pairwise comparisons of selected subsets of possible rank-ordered lists composed of 3 documents. The results allow us to draw conclusions regarding physicians' attitudes towards the importance of having documents ranked correctly on a result list, versus the importance of retrieving relevant but misplaced documents. Our findings should help developers of clinical information retrieval applications when deciding how retrieved documents should be presented and how performance of the application should be assessed. © 2012 Springer-Verlag Berlin Heidelberg.

Hospital accounting and the history of health-care rationing

Focussing on the period from 1948 to 1997, this paper examines the history of rationing in the British National Health Service (NHS), with special reference to the role of hospital accounting in this context. The paper suggests that concerns regarding rationing first emerged in the 1960s and 1970s in response to the application of economic theories to the health services, and that rationing only became an issue of wider concern when the NHS increasingly came to resemble economic models of health services in the early 1990s. The paper moreover argues that, unlike in the USA, hospital accounting did not play a significant role in allocating or withholding health resources in Britain. Rudimentary information systems as well as resistance from medical professionals are identified as significant factors in this context.