To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Introduction: Vast geography and low population density limit availability of specialized trauma and medical care in many areas of Ontario. As such, patients with severe illnesses often require a higher level of care than local facilities can provide and thus require an interfacility transfer to access tertiary or quaternary care. In Ontario, Ornge, a provincially run air ambulance, serves as the sole provider of air-based medical and critical care transport. Patient outcomes are impacted by the time to definitive care, yet little research about reasons for delay in interfacility transfer within Ontario has been conducted. This study aimed to identify causes of delay in interfacility transport by air ambulance in Ontario. Methods: Causes of delay were identified by manual chart review of electronic patient care records (ePCR). All emergent adult interfacility transfers for patients transported by Ornge between Jan. 1-Dec. 31, 2016 were eligible for inclusion. Patient records were flagged to be manually reviewed if they met one or more of the following criteria: 1) contained a standardized delay code; 2) the ePCR free text contained “delay”, “wait”, “duty-out”, or common misspellings therein; 3) were above the 75th percentile in total transport time; or 4) were above the 90th percentile in time to patient bedside, time spent at the sending hospital, or time to receiving facility. Each trip was categorized as having delays that fall into one or more of the following categories: time-to-sending delays, in-hospital delays, and time-to-receiving/handover delays. Results: Our search strategy identified 1,220 records for manual review and a total of 872 delays were identified. The most common delays cited included aircraft refuelling (234 delays); waiting for land EMS escort (144); and unstable patients requiring advanced care such as intubation, procedures, or transfusion (79). Other delays included handover or delays at the receiving facility (42); mechanical issues (36); dispatch-related issues (53); environmental hazards (43); staffing issues (47); and equipment problems (38). Conclusion: Some common causes of interfacility delay are potentially modifiable: better trip planning around refueling, and improved coordination with local EMS could impact many delayed interfacility trips in Ontario. Our analysis was limited by number and completeness of available records, and documentation quality. To better understand causes for delay, we would benefit from improved documentation and record availability.
Introduction: Timely access to definitive care has been associated with improved outcomes for injured patients. Air ambulance services have become an integral part of Canadian trauma systems to help provide earlier access to a lead trauma centre (LTC). Multiple factors can lead to non-optimal resource utilization resulting in potential transport delays. The goal of this study is to identify patient, institutional and paramedic risk factors for non-optimal resource utilization for interfacility transfers of injured adult patients transported by air ambulance to a LTC. Methods: Ornge is a paramedic-staffed organization that is the sole provider of air ambulance services from a non-trauma centre to a LTC for the province of Ontario, Canada. This is a retrospective cohort study of all Ornge adult emergent interfacility transports over a 5-year period. Data was collected on patient demographics and clinical status, sending facilities, transport details and paramedic qualifications. Optimal resource utilization was determined based on distance and historical times. A logistic regression model was used to explore patient, provider and institutional risk factors for non-optimal resource use. Results: Between January 1, 2013 and December 31, 2017 a total of 1777 injured patients underwent interfacility transport with Ornge. Of these 805 were identified as having non-optimal resource utilization. Patients who had an optimal resource use were found to be older and mechanically ventilated. Risk factors increasing odds of non-optimal transport included patients transported from a nursing station (OR 1.94), transport with primary or advanced care paramedics (OR 6.57 and 1.44, respectively) and transport between both 0800-1700 and 1700-0000 (OR 1.40 and 1.54, respectively). The median delay to arrival to receiving facility if a patient had a non-optimal resource use was 40 minutes Conclusion: We were able to identify several factors resulting in non-optimal resource utilization. We believe that nursing stations as a sending facility and type of paramedics crew transporting patients resulted in non-optimal resource utilization mainly due to these patients being of lower acuity and this affecting their triage. However the timing of day is more likely to be a resource availability issue and something that can be further studied and potentially improved.
HIV-positive individuals are at significantly increased risk of depression. In low- and middle-income countries, depression is frequently under-detected, hampered by a lack of data regarding available screening tools. The 5-item World Health Organization Well-Being Index (WHO-5) is widely used to screen for depression, yet its validity in African adults with HIV has yet to be examined.
In this cross-sectional study, we enrolled HIV-positive adults presenting to an outpatient HIV clinic in Mwanza, Tanzania. Patients were administered the Patient Health Questionnaires (PHQ)-2/9 and WHO-5 questionnaires. The rate of positive screens was calculated. Fisher's exact test and Pearson's correlation coefficients between PHQ-2/9 and WHO-5 scores were calculated.
We enrolled 72 HIV-positive adults: rates of positive depression screen were 62.5%, 77.8%, and 47.2% according to PHQ-2, PHQ-9, and WHO-5, respectively. PHQ and WHO results for depression were significantly associated (Fisher's exact test: PHQ-2 v. WHO-5, p = 0.028; PHQ-9 v. WHO-5, p = 0.002). The level of correlation between PHQ and WHO results for depression was moderate (Pearson's correlation coefficient: PHQ-2 v. WHO-5 −0.3289; PHQ-9 v. WHO-5 −0.4463).Per Mantel–Haenszel analysis, screening results were significantly more concordant among patients in the following strata: men, age >40, Sukuma ethnicity, Christian, unmarried, self-employed, at least primary school education completed, and higher than the median income level.
WHO-5 scores correlated well with those of the PHQ-9, suggesting that the WHO-5 represents a valid screening tool. The concordance of PHQ-9 and WHO-5 results was poorer in marginalized socioeconomic groups. Positive depression screens were exceedingly common among HIV-positive Tanzanian adults according to all three questionnaires.
The present study evaluated the behaviour of the AusBeef model for beef production as part of a 2 × 2 study simulating performance on forage-based and concentrate-based diets from Oceania and North America for four methane (CH4)-relevant outputs of interest. Three sensitivity analysis methods, one local and two global, were conducted. Different patterns of sensitivity were observed between forage-based and concentrate-based diets, but patterns were consistent within diet types. For the local analysis, 36, 196, 47 and 8 out of 305 model parameters had normalized sensitivities of 0, >0, >0·01 and >0·1 across all diets and outputs, respectively. No parameters had a normalized local sensitivity >1 across all diets and outputs. However, daily CH4 production had the greatest number of parameters with normalized local sensitivities >1 for each individual diet. Parameters that were highly sensitive for global and local analyses across the range of diets and outputs examined included terms involved in microbial growth, volatile fatty acid (VFA) yields, maximum absorption rates and their inhibition due to pH effects and particle exit rates. Global sensitivity analysis I showed the high sensitivity of forage-based diets to lipid entering the rumen, which may be a result of the use of a feedlot-optimized model to represent high-forage diets and warrants further investigation. Global sensitivity analysis II showed that when all parameter values were simultaneously varied within ±10% of initial value, >96% of output values were within ±20% of the baseline, which decreased to >50% when parameter value boundaries were expanded to ±25% of their original values, giving a range for robustness of model outputs with regards to potential different ‘true’ parameter values. There were output-specific differences in sensitivity, where outputs that had greater maximum local sensitivities displayed greater degrees of non-linear interaction in global sensitivity analysis I and less variance in output values for global sensitivity analysis II. For outputs with less interaction, such as the acetate : propionate ratio and microbial protein production, the single most sensitive term in global sensitivity analysis I contributed more to the overall total-order sensitivity than for outputs with more interaction, with an average of 49, 33, 15 and 14% of total-order sensitivity for microbial protein production, acetate : propionate ratio, CH4 production and energy from absorbed VFAs, respectively. Future studies should include data collection for highly sensitive parameters reported in the present study to improve overall model accuracy.
There is a growing body of literature describing the characteristics of patients who plan for the end of life, but little research has examined how caregivers influence patients' advance care planning (ACP). The purpose of this study was to examine how patient and caregiver characteristics are associated with advance directive (AD) completion among patients diagnosed with a terminal illness. We defined AD completion as having completed a living will and/or identified a healthcare power of attorney.
A convenience sample of 206 caregiver–patient dyads was included in the study. All patients were diagnosed with an advanced life-limiting illness. Trained research nurses administered surveys to collect information on patient and caregiver demographics (i.e., age, sex, race, education, marital status, and individual annual income) and patients' diagnoses and completion of AD. Multivariate logistic regression was employed to model predictors for patients' AD completion.
Over half of our patient sample (59%) completed an AD. Patients who were older, diagnosed with amyotrophic lateral sclerosis, and with a caregiver who was Caucasian or declined to report an income level were more likely to have an AD in place.
Significance of results:
Our results suggest that both patient and caregiver characteristics may influence patients' decisions to complete an AD at the end of life. When possible, caregivers should be included in advance care planning for patients who are terminally ill.
Introduction: Helicopter emergency medical services (HEMS) have become an engrained component of trauma systems to expedite transportation to a trauma centre. Ornge is a provincially run, paramedic-staffed HEMS that is responsible for all air ambulance service within Ontario, Canada. They provide transportation for trauma patients through one of three ways: scene call, modified scene call or interfacility transfer. In this study we report the characteristics of patients transported by each of these methods to two level 1 trauma centres and assess for any impact on morbidity or mortality. Methods: A local trauma registry was used to identify all patients transported to our two trauma centres by HEMS over a 36-month period. Data surrounding patient demographic, arrival characteristics, transport times and in-hospital course were abstracted from the registry. Statistical analysis will be used to compare methods of transport and characterize any association between mode of transport and mortality. Results: From January 1st, 2012 to December 31st, 2014 HEMS transferred a total of 911 patients to our trauma centers with an overall mortality rate of 11%. Of these patients 139 were scene calls with a mortality rate of 8%, 333 were modified scene calls with a mortality rate of 14% and 439 were interfacility transfers with a mortality rate of 10%. Conclusion: Identifying any association between the type of HEMS transport and morbidity and mortality, we may be able to predict those that need more urgent transfer to a trauma centre and find ways to decrease our overall pre-trauma center time.
Introduction: Smartphones are everywhere. Recent technological advances allow for instantaneous high quality video and audio recordings with the touch of a button. In Canada, physician smartphone use is highly regulated by provincial legislature and multiple policies have been published from provincial physician colleges and the Canadian Medical Protective Association (CMPA). Patients on the other hand have no such laws to observe. We set out to look at what legislation and policies exist to provide guidance to physicians in two potential scenarios: when a patient requests to record a patient-physician interaction and if a patient surreptitiously records a patient-physician interaction without consent of the physician. Methods: A literature review searching for articles on patient video recordings and patient smartphone use was completed on both Medline and PubMed. Further review of each provincial privacy act and communication with each provincial privacy office was performed. Consultation with each provincial physician college and the CMPA was also done to identify any policies or recommendations to guide physicians. Results: Patients making video recordings do not fall under any provincial privacy law and there are no existing policies from any provincial physician college or the CMPA to provide guidance. Therefore, physicians must rely on their own institution’s policy regarding patient video recording in the health care setting. Be familiar with your institution’s policy. If your institution does not have a policy, create one with the input of appropriate stakeholders. Patients may surreptitiously video record medical interactions without physician consent. Although this may not be permitted under an individual institution’s policy, it is not illegal under the Criminal Code. Thus, it is important to behave in a professional manner at all times and assume you may be recorded at any time. Conclusion: The majority of patients’ recordings will be done without litigious intentions, but rather with the goal of understanding more about their own health and medical care. Unfortunately there are those who will undermine the physician-patient relationship. Physicians cannot allow this to cause distrust in future relationships, nor should it force physicians to practice more defensive medicine. Physicians must continue to practice the art of medicine and accept that “performance” is a part of the job.
The influence of feeds containing varying dietary cation–anion differences (DCADs) with and without supplements of 25-hydroxyvitamin D (25(OH)D) on urine pH and excretion of macro minerals was determined in fistulated crossbred steers (mean live weight 315 ± 45 kg). A basal forage diet comprising lucerne hay and wheat chaff was used, to which varying quantities of MgCl2 or K2CO3 were added to achieve four levels of DCAD: −300, 50, 150 or 250 mEq/kg dry matter (DM). Steers were allocated to one of six treatments, one treatment for each diet and a further treatment for both the 50 and 150 mEq/kg DCAD diets, which were supplemented with 25(OH)D at a rate of 3 mg/steer per day. Urine pH from steers offered the diets comprising DCADs of 50, 150 and 250 mEq/kg ranging from 8.3 to 8.8. In treatments not containing 25(OH)D with DCADs of 50 to 250 mEq/kg, there were no significant differences in urine pH or Ca excretion. However, steers offered the diet with a DCAD of −300 mEq/kg DM produced urine with a significantly lower pH (6.5 to 7.5). Daily output of Ca in urine was also significantly higher from steers given this diet. Supplementation with 25(OH)D significantly increased urinary Ca excretion from steers offered diets of DCADs 50 and 150 mEq/kg DM. Estimates of daily urinary Ca excretion, calculated using the ratio of creatinine to Ca in ‘spot’ urine samples, were less variable than those based on total collection (residual mean square of 0.54 and 0.63, respectively).
Background: Suicide rates are higher in the over 65s than in younger adults and there is a strong link between deliberate self harm (DSH) and suicide in older people. The association between personality disorder (PD) and DSH in older adults remains uncertain. Our objective was to describe this association.
Methods: A case control study was conducted in which participants were: (i) those who had undertaken an act of DSH and (ii) a hospital-based control group drawn from a geographical contiguous population. PD was assessed using the Standardised Assessment of Personality (SAP)
Results: Seventy-seven cases of DSH were identified; 61 (79.2%) of these participants were interviewed. There were 171 potential controls identified of whom 140 (81.9%) were included. An SAP was completed in 45/61 (73.8%) of cases and 100/140 (71.4%) of controls. The mean age was 79.8 years (SD = 9, range 65–103). The crude odds ratio for the association between PD and DSH was 5.91 [(95% CI 2.3, 14.9) p<0.0001]. There was a strong interaction with age stratified at 80 years. There was no association between PD and DSH after age 80. The adjusted odds ratio for PD in the group <80 years was 20.5 [(95% CI 3, 141) p = 0.002]. Borderline and impulsive PD traits tended to be associated with an episode of DSH more than other personality types.
Conclusions: PD appears to be a strong and independent risk for an act of DSH in people aged between 65 and 80 years and should be looked for as part of any risk assessment in this population. Access to specialist services may be required to optimally manage this problem and reduce the subsequent risk of suicide.
Several studies have reported high levels of distress in family members who have made health care decisions for loved ones at the end of life. A method is needed to assess the readiness of family members to take on this important role. Therefore, the purpose of this study was to develop and validate a scale to measure family member confidence in making decisions with (conscious patient scenario) and for (unconscious patient scenario) a terminally ill loved one.
On the basis of a survey of family members of patients with amyotrophic lateral sclerosis (ALS) enriched by in-depth interviews guided by Self-Efficacy Theory, we developed six themes within family decision making self-efficacy. We then created items reflecting these themes that were refined by a panel of end-of-life research experts. With 30 family members of patients in an outpatient ALS and a pancreatic cancer clinic, we tested the tool for internal consistency using Cronbach's alpha and for consistency from one administration to another using the test–retest reliability assessment in a subset of 10 family members. Items with item to total scale score correlations of less than .40 were eliminated.
A 26-item scale with two 13-item scenarios resulted, measuring family self-efficacy in decision making for a conscious or unconscious patient with a Cronbach's alphas of .91 and .95, respectively. Test–retest reliability was r = .96, p = .002 in the conscious senario and r = .92, p = .009 in the unconscious scenario.
Significance of results:
The Family Decision-Making Self-Efficacy Scale is valid, reliable, and easily completed in the clinic setting. It may be used in research and clinical care to assess the confidence of family members in their ability to make decisions with or for a terminally ill loved one.
Persons with ALS differ from those with other terminal illnesses in that they commonly retain capacity for decision making close to death. The role patients would opt to have their families play in decision making at the end of life may therefore be unique. This study compared the preferences of patients with ALS for involving family in health care decisions at the end of life with the actual involvement reported by the family after death.
A descriptive correlational design with 16 patient–family member dyads was used. Quantitative findings were enriched with in-depth interviews of a subset of five family members following the patient's death.
Eighty-seven percent of patients had issued an advance directive. Patients who would opt to make health care decisions independently (i.e., according to the patient's preferences alone) were most likely to have their families report that decisions were made in the style that the patient preferred. Those who preferred shared decision making with family or decision making that relied upon the family were more likely to have their families report that decisions were made in a style that was more independent than preferred. When interviewed in depth, some family members described shared decision making although they had reported on the survey that the patient made independent decisions.
Significance of results:
The structure of advance directives may suggest to families that independent decision making is the ideal, causing them to avoid or underreport shared decision making. Fear of family recriminations may also cause family members to avoid or underreport shared decision making. Findings from this study might be used to guide clinicians in their discussions of treatments and health care decision making with persons with ALS and their families.
This study describes the epidemiology of community-acquired pneumonia (CAP) in elderly Australians for the first time. Using a case-cohort design, cases with CAP were in-patients aged ⩾65 years with ICD-10-AM codes J10-J18 admitted over 2 years to two tertiary hospitals. The cohort sample was randomly selected from all hospital discharges, frequency-matched to cases by month. Logistic regression was used to estimate risk ratios for factors predicting CAP or associated mortality. A total of 4772 in-patients were studied. There were 1952 cases with CAP that represented 4% of all elderly admissions: mean length of stay was 9·0 days and 30-day mortality was 18%. Excluding chest radiograph, 520/1864 (28%) cases had no investigations performed. The strongest predictors of CAP were previous pneumonia, history of other respiratory disease, and aspiration. Intensive-care-unit admission, renal disease and increasing age were the strongest predictors of mortality, while influenza vaccination conferred protection. Hospitalization with CAP in the elderly is common, frequently fatal and a considerable burden to the Australian community. Investigation is ad hoc and management empirical. Influenza vaccination is associated with reduced mortality. Patient characteristics can predict risk of CAP and subsequent mortality.
This study examines the validity of using ICD-10 codes to identify hospitalized pneumonia cases. Using a case-cohort design, subjects were randomly selected from monthly cohorts of patients aged ⩾65 years discharged from April 2000 to March 2002 from two large tertiary Australian hospitals. Cases had ICD-10-AM codes J10–J18 (pneumonia); the cohort sample was randomly selected from all discharges, frequency matched to cases by month. Codes were validated against three comparators: medical record notation of pneumonia, chest radiograph (CXR) report and both. Notation of pneumonia was determined for 5098/5101 eligible patients, and CXR reports reviewed for 3349/3464 (97%) patients with a CXR. Coding performed best against notation of pneumonia: kappa 0·95, sensitivity 97·8% (95% CI 97·1–98·3), specificity 96·9% (95% CI 96·2–97·5), positive predictive value (PPV) 96·2% (95% CI 95·4–97·0) and negative predictive value (NPV) 98·2% (95% CI 97·6–98·6). When medical record notation of pneumonia is used as the standard, ICD-10 codes are a valid method for retrospective ascertainment of hospitalized pneumonia cases and appear superior to use of complexes of symptoms and signs, or radiology reports.
The recent upgrade of the Arecibo planetary radar system, combined with the huge increase in the near-Earth asteroid (NEA) discovery rate by large survey programs, has greatly increased our ability to observe these objects with radar. Radar provides size, shape, rotation, and trajectory information, and in most cases is the only ground-based technique that spatially resolves near-Earth objects. While the resolution of radar images (typically 7.5m) is not as high as for the very best spacecraft images, spacecraft can visit only a few such objects, and radar observations greatly increase our understanding of the diversity of near-Earth objects, at orders of magnitude lower cost. The single clearest result of these observations is the great variety of near-Earth objects, with binary systems, very fast and very slow rotations, spheres, “bifurcated” objects, and “shards”, suggesting that a similar variety of production and delivery mechanisms deliver these objects to near-Earth orbit. Spacecraft mission planning should take into account this variety, and concentrate on broad coverage of a wide range of objects.
Nine comets have been detected with either the Arecibo (12.6 cm wavelength) or Goldstone (3.5 cm) radar systems. Included are six nucleus detections and five detections of echoes from coma grains. The radar backscatter cross sections measured for the nuclei correlate well with independent estimates of their sizes and are indicative of surface densities in the range of 0.5 to 1.0 g cm-3. Like most asteroids, comets appear to have surfaces that are very rough at scales much larger than the radar wavelength. Coma echo models can explain the radar cross sections using grain size distributions that include a substantial population of cm-sized grains. A long term goal of the cometary radar program has been the high resolution imaging of a cometary nucleus. Eleven short period comets are potentially detectable over the next two decades a few of which may be suitable for imaging. We are always waiting for the arrival of a new comet with an orbit that brings it within 0.1 AU of the earth.
In an effort to achieve high magnetoresistance ratios at high temperature and low fields, we have fabricated superlattice structures consisting of La0.7MnO3−δ (LMO) and Pr0.65Ba0.05Ca0.3MnO3−δ (PBCMO) systems where La0.7MnO3−δ is believed to act as a ferromagnetic biasing source to Pr0.65Ba0.05Ca0.3MnO3−Δ. LMO and PBCMO individually transform to ferromagnetic states at 240 K and 60 K respectively. A series of samples, in which the thickness of La0.7MnO3−δ is fixed and that of Pr0.65Ba0.05Ca0.3MnO3−δ varied from 1 to 8 unit cells, have been grown in situ on (100) LaAlO3 substrates using a pulsed laser deposition technique. Microstructural characterization carried out on these films show the presence of characteristic intense satellite peaks indicating the chemical modulation of the superlattice structure. The insulator-to-metal transition and the MR ratio, defined as [R(0)-R(H)/R(H)], where R(0) and R(H) are resistances in zero and applied fields, is found to vary with the number of unit cells. The samples with 1, 2, 5 and 8 unit cells of Pr0.65Ba0.05Ca0.3MnO3−δ show a transition temperature of 240 K, 230 K, 150 K and 160 K and MR ratio of 540%, 592%, 3150% and 2875 % respectively. We have observed an enhancement of magnetoresistance ratio in case of superlattices with thickness of PBCMO greater than 5 unit cells. We attribute this enhancement to a ferromagnetic biasing provided by the LMO layers acting as a ferromagnetic film below its transition temperature.
A patterned magnetic medium is the next step to significantly increasing data storage density. To attain extreme density, it is necessary to deal with the smallest granules (each storing a bit of information) admissible from the physical point of view. It is well known that the volume of such granules, and their aspect ratio, have to be large enough to prevent thermally activated magnetization relaxation. However, these requirements are not exhaustive. A patterned recording medium is a set of closely-spaced, aligned magnetic granules, with the random (“up” and “down”) orientations of granules' magnetic moments. Though the exchange interactions between the granules may be neglected, there are long-range intergranular dipole-dipole interactions (DDI) which lead to significant lowering of activation barrier preventing thermal relaxation. Those interactions limit the acceptable density of ferromagnetic granules, and hence, reduce the extreme density of data storage. Our numerical calculations estimate the negative role of DDI for the particular case of a two-dimensional set of ellipsoidal magnetic granules and allow us to determine the extreme density of data storage.