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Childhood adversity and cannabis use are considered independent risk factors for psychosis, but whether different patterns of cannabis use may be acting as mediator between adversity and psychotic disorders has not yet been explored. The aim of this study is to examine whether cannabis use mediates the relationship between childhood adversity and psychosis.
Data were utilised on 881 first-episode psychosis patients and 1231 controls from the European network of national schizophrenia networks studying Gene–Environment Interactions (EU-GEI) study. Detailed history of cannabis use was collected with the Cannabis Experience Questionnaire. The Childhood Experience of Care and Abuse Questionnaire was used to assess exposure to household discord, sexual, physical or emotional abuse and bullying in two periods: early (0–11 years), and late (12–17 years). A path decomposition method was used to analyse whether the association between childhood adversity and psychosis was mediated by (1) lifetime cannabis use, (2) cannabis potency and (3) frequency of use.
The association between household discord and psychosis was partially mediated by lifetime use of cannabis (indirect effect coef. 0.078, s.e. 0.022, 17%), its potency (indirect effect coef. 0.059, s.e. 0.018, 14%) and by frequency (indirect effect coef. 0.117, s.e. 0.038, 29%). Similar findings were obtained when analyses were restricted to early exposure to household discord.
Harmful patterns of cannabis use mediated the association between specific childhood adversities, like household discord, with later psychosis. Children exposed to particularly challenging environments in their household could benefit from psychosocial interventions aimed at preventing cannabis misuse.
While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis.
We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case–control study. 558 first-episode psychosis patients (FEPp) and 567 population controls who had used cannabis and reported their RFUC.
We ran logistic regressions to examine whether RFUC were associated with first-episode psychosis (FEP) case–control status. Path analysis then examined the relationship between RFUC, subsequent patterns of cannabis use, and case–control status.
Controls (86.1%) and FEPp (75.63%) were most likely to report ‘because of friends’ as their most common RFUC. However, 20.1% of FEPp compared to 5.8% of controls reported: ‘to feel better’ as their RFUC (χ2 = 50.97; p < 0.001). RFUC ‘to feel better’ was associated with being a FEPp (OR 1.74; 95% CI 1.03–2.95) while RFUC ‘with friends’ was associated with being a control (OR 0.56; 95% CI 0.37–0.83). The path model indicated an association between RFUC ‘to feel better’ with heavy cannabis use and with FEPp-control status.
Both FEPp and controls usually started using cannabis with their friends, but more patients than controls had begun to use ‘to feel better’. People who reported their reason for first using cannabis to ‘feel better’ were more likely to progress to heavy use and develop a psychotic disorder than those reporting ‘because of friends’.
The concentration of radiocarbon (14C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-average marine record of radiocarbon from 0–55 cal kBP and serves as a baseline for regional oceanic variation. Marine20 is intended for calibration of marine radiocarbon samples from non-polar regions; it is not suitable for calibration in polar regions where variability in sea ice extent, ocean upwelling and air-sea gas exchange may have caused larger changes to concentrations of marine radiocarbon. The Marine20 curve is based upon 500 simulations with an ocean/atmosphere/biosphere box-model of the global carbon cycle that has been forced by posterior realizations of our Northern Hemispheric atmospheric IntCal20 14C curve and reconstructed changes in CO2 obtained from ice core data. These forcings enable us to incorporate carbon cycle dynamics and temporal changes in the atmospheric 14C level. The box-model simulations of the global-average marine radiocarbon reservoir age are similar to those of a more complex three-dimensional ocean general circulation model. However, simplicity and speed of the box model allow us to use a Monte Carlo approach to rigorously propagate the uncertainty in both the historic concentration of atmospheric 14C and other key parameters of the carbon cycle through to our final Marine20 calibration curve. This robust propagation of uncertainty is fundamental to providing reliable precision for the radiocarbon age calibration of marine based samples. We make a first step towards deconvolving the contributions of different processes to the total uncertainty; discuss the main differences of Marine20 from the previous age calibration curve Marine13; and identify the limitations of our approach together with key areas for further work. The updated values for ΔR, the regional marine radiocarbon reservoir age corrections required to calibrate against Marine20, can be found at the data base http://calib.org/marine/.
Women are more likely to be admitted to nursing home after stroke than men. Differences in patient characteristics and outcomes by sex after institutionalization are less understood. We examined sex differences in the characteristics and care needs of patients admitted to nursing home following stroke and their subsequent survival.
We identified patients with stroke newly admitted to nursing home between April 2011 and March 2016 in Ontario, Canada, with follow-up until March 2018 using linked administrative data. We calculated prevalence ratios and 95% confidence intervals (CIs) for the primary outcomes of dependence for activities of daily living, cognitive impairment, frailty, health instability, and symptoms of depression or pain, comparing women to men. The secondary outcome was all-cause mortality.
Among 4831 patients, 60.9% were women. Compared to men, women were older (median age [interquartile range, IQR]: 84 [78, 89] vs. 80 [71, 86]), more likely to be frail (prevalence ratio 1.14, 95% CI [1.08, 1.19]), have unstable health (1.45 [1.28, 1.66]), and experience symptoms of depression (1.25 [1.11, 1.40]) or pain (1.21 [1.13, 1.30]), and less likely to have aggressive behaviors (0.87 [0.80, 0.94]). Overall median survival was 2.9 years. In a propensity-score-matched cohort, women had lower mortality than men (hazard ratio 0.85, 95% CI [0.77, 0.94]), but in the age-stratified survival analysis, the survival advantage in women was limited to those aged 75 years and older.
Despite lower subsequent mortality, women admitted to nursing home after stroke required more care than men. Pain and depression are two treatable symptoms that disproportionately affect women.
Optimal stroke care requires access to resources such as neuroimaging, acute revascularization, rehabilitation, and stroke prevention services, which may not be available in rural areas. We aimed to determine geographic access to stroke care for residents of rural communities in the province of Ontario, Canada.
We used the Ontario Road Network File database linked with the 2016 Ontario Acute Stroke Care Resource Inventory to estimate the proportion of people in rural communities, defined as those with a population size <10,000, who were within 30, 60, and 240 minutes of travel time by car from stroke care services, including brain imaging, thrombolysis treatment centers, stroke units, stroke prevention clinics, inpatient rehabilitation facilities, and endovascular treatment centers.
Of the 1,496,262 people residing in rural communities, the majority resided within 60 minutes of driving time to a center with computed tomography (85%), thrombolysis (81%), a stroke unit (68%), a stroke prevention clinic (74%), or inpatient rehabilitation (77.0%), but a much lower proportion (32%) were within 60 minutes of driving time to a center capable of providing endovascular thrombectomy (EVT).
Most rural Ontario residents have appropriate geographic access to stroke services, with the exception of EVT. This information may be useful for jurisdictions seeking to optimize the regional organization of stroke care services.
Patients with cardiovascular diseases are common in the emergency department (ED), and continuity of care following that visit is needed to ensure that they receive evidence-based diagnostic tests and therapy. We examined the frequency of follow-up care after discharge from an ED with a new diagnosis of one of three cardiovascular diseases.
We performed a retrospective cohort study of patients with a new diagnosis of heart failure, atrial fibrillation, or hypertension, who were discharged from 157 non-pediatric EDs in Ontario, Canada, between April 2007 and March 2014. We determined the frequency of follow-up care with a family physician, cardiologist, or internist within seven and 30 days, and assessed the association of patient, emergency physician, and family physician characteristics with obtaining follow-up care using cause-specific hazard modeling.
There were 41,485 qualifying ED visits. Just under half (47.0%) had follow-up care within seven days, with 78.7% seen by 30 days. Patients with serious comorbidities (renal failure, dementia, COPD, stroke, coronary artery disease, and cancer) had a lower adjusted hazard of obtaining 7-day follow-up care (HRs 0.77-0.95) and 30-day follow-up care (HR 0.76-0.95). The only emergency physician characteristic associated with follow-up care was 5-year emergency medicine specialty training (HR 1.11). Compared to those whose family physician was remunerated via a primarily fee-for-service model, patients were less likely to obtain 7-day follow-up care if their family physician was remunerated via three types of capitation models (HR 0.72, 0.81, 0.85) or via traditional fee-for-service (HR 0.91). Findings were similar for 30-day follow-up care.
Only half of patients discharged from an ED with a new diagnosis of atrial fibrillation, heart failure, and hypertension were seen within a week of being discharged. Patients with significant comorbidities were less likely to obtain follow-up care, as were those with a family physician who was remunerated via primarily capitation methods.
Vertigo is common in the emergency department (ED). Most aetiologies are peripheral and do not require hospitalization, but many patients still fear falling. Some patients may be taking opioid analgesic medications (for other reasons); the risk of falls leading to fractures among patients with vertigo could be potentiated by the simultaneous use of opioids.
To examine the risk of fractures in discharged ED patients with peripheral vertigo who were being prescribed opioids during the same time period.
Linked administrative databases from Ontario were used to compare discharged ED patients aged ≥65 with peripheral vertigo to patients with urinary tract infection (UTI) from 2006 to 2011. We used Cox regression analysis with an interaction term to estimate the modifying effect of an opioid prescription on the hazard of fracture within 90 days.
There were 13,012 patients with a peripheral vertigo syndrome and 76,885 with a UTI. Thirteen percent of the vertigo cohort and 25% of the UTI cohort had access to a filled opioid prescription. Compared to vertigo patients who did not fill an opioid prescription, the adjusted hazard of fracture among vertigo patients who did fill a prescription was 3.59 (95% CI 1.97–6.13). Among UTI patients who filled an opioid prescription the hazard ratio was 1.68 (95% CI 1.43–1.97) compared to UTI patients who did not.
Patients discharged from the ED with peripheral vertigo who were also being prescribed opioids had a higher hazard of subsequent fracture compared to those who were not, and the effect was much greater than among UTI patients. These results suggest that in the acutely vertiginous older patient, opioid analgesic medications should be modified, where possible.
High-quality cost estimates for hospital-acquired Clostridium difficile infection (CDI) are vital evidence for healthcare policy and decision-making.
To evaluate the costs attributable to hospital-acquired CDI from the healthcare payer perspective.
We conducted a population-based propensity-score matched cohort study of incident hospitalized subjects diagnosed with CDI (those with the International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada code A04.7) from January 1, 2003, through December 31, 2010, in Ontario, Canada. Infected subjects were matched to uninfected subjects (those without the code A04.7) on age, sex, comorbidities, geography, and other variables, and followed up through December 31, 2011. We stratified results by elective and nonelective admissions. The main study outcomes were up-to-3-year costs, which were evaluated in 2014 Canadian dollars.
We identified 28,308 infected subjects (mean annual incidence, 27.9 per 100,000 population, 3.3 per 1,000 admissions), with a mean age of 71.5 years (range, 0–107 years), 54.0% female, and 8.0% elective admissions. For elective admission subjects, cumulative mean attributable 1-, 2-, and 3-year costs adjusted for survival (undiscounted) were $32,151 (95% CI, $28,192–$36,005), $34,843 ($29,298–$40,027), and $37,171 ($30,364–$43,415), respectively. For nonelective admission subjects, the corresponding costs were $21,909 ($21,221–$22,609), $26,074 ($25,180–$27,014), and $29,944 ($28,873–$31,086), respectively.
Hospital-acquired CDI is associated with substantial healthcare costs. To the best of our knowledge, this study is the first CDI costing study to present longitudinal costs. New strategies may be warranted to mitigate this costly infectious disease.
Background: Transient ischemic attack (TIA) and minor stroke are associated with
a substantial risk of subsequent stroke; however, there is uncertainty about
whether such patients require admission to hospital for their initial
management. We used data from a clinical stroke registry to determine the
frequency and predictors of hospitalization for TIA or minor stroke across
the province of Ontario, Canada. Methods: The Ontario Stroke Registry collects information on a
population-based sample of all patients seen in the emergency department
with acute stroke or TIA in Ontario. We identified patients with minor
ischemic stroke or TIA included in the registry between April 1, 2008, and
March 31, 2011, and used multivariable analyses to evaluate predictors of
hospitalization. Results: Our study sample included 8540 patients with minor ischemic stroke
or TIA, 47.2% of whom were admitted to hospital, with a range of 37.6% to
70.3% across Ontario’s 14 local health integration network regions. Key
predictors of admission were preadmission disability, vascular risk factors,
presentation with weakness, speech disturbance or prolonged/persistent
symptoms, arrival by ambulance, and presentation on a weekend or during
periods of emergency department overcrowding. Conclusions: More than one-half of patients with minor stroke or TIA were not
admitted to the hospital, and there were wide regional variations in
admission patterns. Additional work is needed to provide guidance to health
care workers around when to admit such patients and to determine whether
discharged patients are receiving appropriate follow-up care.
Many patients are seen in the emergency department (ED) for hypertension, and the numbers will likely increase in the future. Given limited evidence to guide the management of such patients, the practice of one’s peers provides a de facto standard.
A survey was distributed to emergency physicians during academic rounds at three community and four tertiary EDs. The primary outcome measure was the proportion of participants who had a blood pressure (BP) threshold at which they would offer a new antihypertensive prescription to patients they were sending home from the ED. Secondary outcomes included patient- and provider-level factors associated with initiating an antihypertensive based on clinical vignettes of a 69-year-old man with two levels of hypertension (160/100 vs 200/110 mm Hg), as well as the recommended number of days after which to follow up with a primary care provider following ED discharge.
All 81 surveys were completed (100%). Half (51.9%; 95% CI 40.5-63.1) of participants indicated that they had a systolic BP threshold for initiating an antihypertensive, and 55.6% (95% CI 44.1-66.6) had a diastolic threshold: mean systolic threshold was 199 mm Hg (SD 19) while diastolic was 111 mm Hg (SD 8). A higher BP (OR 12.9; 95% CI 7.5-22.2) and more patient comorbidities (OR 3.0; 95% CI 2.1-4.3) were associated with offering an antihypertensive prescription, while physician years of practice, certification type, and hospital type were not. Participants recommended follow-up care within a median 7.0 and 3.0 days for the patient with lower and higher BP levels, respectively.
Half of surveyed emergency physicians report having a BP threshold to start an antihypertensive; BP levels and number of patient comorbidities were associated with a modification of the decision, while physician characteristics were not. Most physicians recommended follow-up care within seven days of ED discharge.
The objective of this study was to investigate whether different staffing models are associated with variation in radiograph use for children seen for bronchiolitis, croup, and asthma and discharged home from emergency departments (EDs) in Ontario.
We surveyed all Ontario EDs regarding physician staffing models and use of clinical protocols. We used a population-based ED database to determine radiograph rates and patient characteristics. Regression techniques that controlled for patient factors and clustering within EDs were applied.
From April 2004 to March 2006, 5,186, 10,408, and 35,150 children were discharged home from an ED with bronchiolitis, croup, and asthma, respectively. Radiograph rates were 42.7% for bronchiolitis, 10.1% for croup, and 25.9% for asthma. Over 50% of children were treated in EDs with nonpediatric front-line care but with consultant pediatricians available. Compared to children in these settings, those seen in EDs with front-line pediatric staff were less likely to have radiographs for all three conditions (adjusted odds ratios [ORs] 0.47 [95% CI 0.24–0.95], 0.47 [95% CI 0.27–0.82], 0.13 [95% CI 0.02–0.66] for bronchiolitis, croup, and asthma, respectively). Children in community hospitals with pediatricians were significantly more likely to have a radiograph if seen by a consultant pediatrician (OR 1.40, 95% CI 1.20–1.63 [bronchiolitis]; OR 2.76, 95% CI 2.16–3.53 [croup]; and OR 1.97, 95% CI 1.64–2.36 [asthma]). We found no association between clinical protocol use and radiograph rates.
High rates of discretionary radiograph use exist for common respiratory problems of children seen across ED settings. Quality improvement efforts should be focused in this area, and radiograph use in EDs staffed by front-line pediatrics-trained staff could serve as an initial benchmark target for other institutions.
The American Heart Association (AHA) recommends a benchmark door-to-electrocardiogram (ECG) time of 10 minutes for acute myocardial infarction patients, but this is based on expert opinion (level of evidence C). We sought to establish an evidence-based benchmark door-to-ECG time.
This retrospective cohort study used a population-based sample of patients who suffered an ST elevation myocardial infarction (STEMI) in Ontario between 1999 and 2001. Using cubic smoothing splines, we described (1) the relationship between door-to-ECG time and ECG-to-needle time and (2) the proportion of STEMI patients who met the benchmark door-to-needle time of 30 minutes based on their door-to-ECG time. We hypothesized nonlinear relationships and sought to identify an inflection point in the latter curve that would define the most efficient (benefit the greatest number of patients) door-to-ECG time.
In 2,961 STEMI patients, the median door-to-ECG and ECG-to-needle times were 8.0 and 27.0 minutes, respectively. There was a linear increase in ECG-to-needle time as the door-to-ECG time increased, up to approximately 30 minutes, after which the ECG-to-needle time remained constant at 53 minutes. The inflection point in the probability of achieving the benchmark door-to-needle time occurred at 4 minutes, after which it decreased linearly, with every minute of door-to-ECG time decreasing the average probability of achievement by 2.2%.
Hospitals that are not meeting benchmark reperfusion times may improve performance by decreasing door-to-ECG times, even if they are meeting the current AHA benchmark door-to-ECG time. The highest probability of meeting the reperfusion target time for fibrinolytic administration is associated with a door-to-ECG time of 4 minutes or less.