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1.  Closing Open Medicine 
Open Medicine  2014;8(4):e147-e149.
PMCID: PMC4242792  PMID: 25426183
2.  Use of mental health care for nonpsychotic conditions by immigrants in different admission classes and by refugees in Ontario, Canada 
Open Medicine  2014;8(4):e136-e146.
Background:
Most Canadian newcomers are admitted in the economic, family, or refugee class, each of which has its own selection criteria and experiences. Evidence has shown various risks for mental health disorders across admission classes, but the respective service-use patterns for people in these classes are unknown. In this study, we compared service use for nonpsychotic mental health disorders by newcomers in various admission classes with that of long-term residents (i.e., Canadian-born persons or immigrants before 1985) in urban Ontario.
Methods:
In this population-based matched cross-sectional study, we linked health service databases to the Ontario portion of the Citizenship and Immigration Canada database. Outcomes were mental health visits to primary care physicians, mental health visits to psychiatrists, and emergency department visits or hospital admissions. We measured service use for recent immigrants (those who arrived in Ontario between 2002 and 2007; n = 359 673). We compared service use by immigrants in each admission class during the first 5 years in Canada with use by age- and sex-matched long-term residents. We measured likelihood of access to each service and intensity of use of each service using conditional logistic regression and negative binomial models.
Results:
Economic and family class newcomers were less likely than long-term residents to use primary mental health care. The use of primary mental health care by female refugees did not differ from that of matched long-term residents, but use of such care by male refugees was higher (odds ratio 1.14, 95% confidence interval 1.09–1.19). Immigrants in all admission classes were less likely to use psychiatric services and hospital services for mental health care. Exceptions were men in the economic and family classes, whose intensity of hospital visits was similar to that of matched long-term residents.
Interpretation:
Immigrants in all admission classes generally used less care for nonpsychotic disorders than longterm residents, although male refugees used more primary care. Future research should examine how mental health needs align with service use, particularly for more vulnerable groups such as refugees.
PMCID: PMC4242791  PMID: 25426182
3.  Comparison of sampling methods for hard-to-reach francophone populations: yield and adequacy of advertisement and respondent-driven sampling 
Open Medicine  2014;8(4):e120-e129.
Background:
Francophones who live outside the primarily French-speaking province of Quebec, Canada, risk being excluded from research by lack of a sampling frame. We examined the adequacy of random sampling, advertising, and respondent-driven sampling for recruitment of francophones for survey research.
Methods:
We recruited francophones residing in the city of Calgary, Alberta, through advertising and respondentdriven sampling. These 2 samples were then compared with a random subsample of Calgary francophones derived from the 2006 Canadian Community Health Survey (CCHS). We assessed the effectiveness of advertising and respondent-driven sampling in relation to the CCHS sample by comparing demographic characteristics and selected items from the CCHS (specifically self-reported general health status, perceived weight, and having a family doctor).
Results:
We recruited 120 francophones through advertising and 145 through respondent-driven sampling; the random sample from the CCHS consisted of 259 records. The samples derived from advertising and respondentdriven sampling differed from the CCHS in terms of age (mean ages 41.0, 37.6, and 42.5 years, respectively), sex (proportion of males 26.1%, 40.6%, and 56.6%, respectively), education (college or higher 86.7% , 77.9% , and 59.1%, respectively), place of birth (immigrants accounting for 45.8%, 55.2%, and 3.7%, respectively), and not having a regular medical doctor (16.7%, 34.5%, and 16.6%, respectively). Differences were not tested statistically because of limitations on the analysis of CCHS data imposed by Statistics Canada.
Interpretation:
The samples generated exclusively through advertising and respondent-driven sampling were not representative of the gold standard sample from the CCHS. Use of such biased samples for research studies could generate misleading results.
PMCID: PMC4242789  PMID: 25426180
5.  Dengue fever: a Wikipedia clinical review 
Open Medicine  2014;8(4):e105-e115.
Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treatment of acute dengue fever is supportive, with either oral or intravenous rehydration for mild or moderate disease and use of intravenous fluids and blood transfusion for more severe cases. Along with attempts to eliminate the mosquito vector, work is ongoing to develop a vaccine and medications targeted directly at the virus.
PMCID: PMC4242787  PMID: 25426178
6.  Modern medicine comes online 
Open Medicine  2014;8(4):e116-e119.
PMCID: PMC4242788  PMID: 25426179
9.  Universal coverage without universal access: a study of psychiatrist supply and practice patterns in Ontario 
Open Medicine  2014;8(3):e87-e99.
Background:
We studied the relationships among psychiatrist supply, practice patterns, and access to psychiatrists in Ontario Local Health Integration Networks (LHINs) with differing levels of psychiatrist supply.
Methods:
We analyzed practice patterns of full-time psychiatrists (n = 1379) and postdischarge care to patients who had been admitted to hospital for psychiatric care, according to LHIN psychiatrist supply in 2009. We measured the characteristics of psychiatrists' patient panels, including sociodemographic characteristics, outpatient panel size, number of new patients, inpatient and outpatient visits per psychiatrist, and percentages of psychiatrists seeing fewer than 40 and fewer than 100 unique patients. Among patients admitted to hospital with schizophrenia, bipolar disorder, or major depression (n = 21,123), we measured rates of psychiatrist visits, readmissions, and visits to the emergency department within 30 and 180 days after discharge.
Results:
Psychiatrist supply varied from 7.2 per 100 000 residents in LHINs with below-average supply to 62.7 per 100 000 in the Toronto Central LHIN. Population-based outpatient and inpatient visit rates and psychiatric admission rates increased with LHIN psychiatrist supply. However, as the supply of psychiatrists increased, outpatient panel size for full-time psychiatrists decreased, with Toronto psychiatrists having 58% smaller outpatient panels and seeing 57% fewer new outpatients relative to LHINs with the lowest psychiatrist supply. Similar patterns were found for inpatient practice. Moreover, as supply increased, annual outpatient visit frequency increased: the average visit frequency was 7 visits per outpatient for Toronto psychiatrists and 3.9 visits per outpatient in low-supply LHINs. One-quarter of Toronto psychiatrists and 2% of psychiatrists in the lowest-supply LHINs saw their outpatients more than 16 times per year. Of full-time psychiatrists in Toronto, 10% saw fewer than 40 unique patients and 40% saw fewer than 100 unique patients annually; the corresponding proportions were 4% and 10%, respectively, in the lowest-supply LHINs. Overall, follow-up visits after psychiatric discharge were low, with slightly higher rates in LHINs with a high psychiatrist supply.
Interpretation:
Full-time psychiatrists who practised in Ontario LHINs with high psychiatrist supply saw fewer patients, but they saw those patients more frequently than was the case for psychiatrists in low-supply LHINs. Increasing the supply of psychiatrists while funding unlimited frequency and duration of psychotherapy care may not improve access for patients who need psychiatric services.
PMCID: PMC4242254  PMID: 25426177
10.  Elevator buttons as unrecognized sources of bacterial colonization in hospitals 
Open Medicine  2014;8(3):e81-e86.
Background:
Elevators are ubiquitous and active inside hospitals, potentially facilitating bacterial transmission. The objective of this study was to estimate the prevalence of bacterial colonization on elevator buttons in large urban teaching hospitals.
Methods:
A total of 120 elevator buttons and 96 toilet surfaces were swabbed over separate intervals at 3 tertiary care hospitals on weekdays and weekends in Toronto, Ontario. For the elevators, swabs were taken from 2 interior buttons (buttons for the ground floor and one randomly selected upper-level floor) and 2 exterior buttons (the "up" button from the ground floor and the "down" button from the upper-level floor). For the toilet surfaces, swabs were taken from the exterior and interior handles of the entry door, the privacy latch, and the toilet flusher. Samples were obtained using standard bacterial collection techniques, followed by plating, culture, and species identification by a technician blind to sample source.
Results:
The prevalence of colonization of elevator buttons was 61% (95% confidence interval 52%–70%). No significant differences in colonization prevalence were apparent in relation to location of the buttons, day of the week, or panel position within the elevator. Coagulase-negative staphylococci were the most common organisms cultured, whereas Enterococcus and Pseudomonas species were infrequent. Elevator buttons had a higher prevalence of colonization than toilet surfaces (61% v. 43%, p = 0.008).
Conclusions:
Hospital elevator buttons were commonly colonized by bacteria, although most pathogens were not clinically relevant. The risk of pathogen transmission might be reduced by simple countermeasures.
PMCID: PMC4242253  PMID: 25426176
12.  A clinician's guide to the assessment and interpretation of noninferiority trials for novel therapies 
Open Medicine  2014;8(2):e67-e72.
A noninferiority trial is designed to demonstrate that an experimental therapy is not worse than an active control. Although noninferiority trials are superficially similar to conventional superiority trials, there are fundamental differences. In particular, aspects of a study that make the therapies appear more similar than they actually are can falsely bias the study toward demonstrating noninferiority. This has important implications for methodologic techniques such as blinding and statistical analysis based on the intention-to-treat principle. When applying the results of noninferiority trials, clinicians should be judicious in determining whether the degree of noninferiority demonstrated is clinically acceptable and whether the ancillary benefits of the treatment justify its use.
PMCID: PMC4085087  PMID: 25009686
13.  Decision-making about complementary and alternative medicine by cancer patients: integrative literature review 
Open Medicine  2014;8(2):e54-e66.
Background:
Patients with cancer consistently report conflict and anxiety when making decisions about complementary and alternative medicine (CAM) treatment. To design evidence-informed decision-support strategies, a better understanding is needed of how the decision-making process unfolds for these patients during their experience with cancer. We undertook this study to review the research literature regarding CAM-related decisionmaking by patients with cancer within the context of treatment, survivorship, and palliation. We also aimed to summarize emergent concepts within a preliminary conceptual framework.
Methods:
We conducted an integrative literature review, searching 12 electronic databases for articles published in English that described studies of the process, context, or outcomes of CAM-related decision-making. We summarized descriptive data using frequencies and used a descriptive constant comparative method to analyze statements about original qualitative results, with the goal of identifying distinct concepts pertaining to CAM-related decision-making by patients with cancer and the relationships among these concepts.
Results:
Of 425 articles initially identified, 35 met our inclusion criteria. Seven unique concepts related to CAM and cancer decision-making emerged: decision-making phases, information-seeking and evaluation, decision-making roles, beliefs, contextual factors, decision-making outcomes, and the relationship between CAM and conventional medical decision-making. CAM decision-making begins with the diagnosis of cancer and encompasses 3 distinct phases (early, mid, and late), each marked by unique aims for CAM treatment and distinct patterns of informationseeking and evaluation. Phase transitions correspond to changes in health status or other milestones within the cancer trajectory. An emergent conceptual framework illustrating relationships among the 7 central concepts is presented.
Interpretation:
CAM-related decision-making by patients with cancer occurs as a nonlinear, complex, dynamic process. The conceptual framework presented here identifies influential factors within that process, as well as patients' unique needs during different phases. The framework can guide the development and evaluation of theorybased decision-support programs that are responsive to patients' beliefs and preferences.
PMCID: PMC4085086  PMID: 25009685
14.  Health system capacity and infrastructure for adopting innovations to care for patients with venous thromboembolic disease 
Open Medicine  2014;8(2):e46-e53.
Background:
Diagnosis and treatment for venous thromboembolic disease (VTE) have evolved considerably through diagnostic and therapeutic innovations. Despite their considerable potential for enhancing care, however, the extent to which these innovations are being adopted in usual practice is unknown. We documented the infrastructure available in hospitals and health regions across Canada for provision of optimal diagnosis and therapy for VTE disease.
Methods:
Over the period January 2008 through October 2009, we studied health system infrastructure for care of VTE disease in Canada's 10 provinces and 3 territories and all 94 health regions therein. We interviewed health system managers and/or clinical leaders from all 658 acute care hospitals in Canada and documented key elements of health system infrastructure at the hospital level for these institutions.
Results:
There was considerable variation across Canada in the availability of key infrastructure for the diagnosis and management of VTE disease. Provinces with higher populations tended to have a large proportion of hospitals with capability to measure d-dimer levels, whereas less populated provinces were more likely to send samples to centralized analysis facilities for d-dimer testing. All provinces and territories had some facilities offering advanced diagnostic imaging, but the number of institutions and the availability of imaging were highly variable (with the proportion offering at least limited availability ranging from 0% to 90%). Only 6 provinces had regions with availability of dedicated early and/or long-term outpatient clinics for VTE disease.
Conclusions:
Infrastructure in Canada for optimal care of patients with VTE disease was suboptimal during the study period and was not entirely in step with the evidence. Such shortfalls in health system infrastructure limit the extent to which health care providers can deliver optimal, evidence-based care to their patients. Nationwide evaluations of health system infrastructure such as this one should be undertaken internationally to better characterize quality of care and potential for improvement.
PMCID: PMC4085085  PMID: 25009684
15.  High rates of hospital admission among older residents in assisted living facilities: opportunities for intervention and impact on acute care 
Open Medicine  2014;8(1):e33-e45.
Background:
Little is known about health or service use outcomes for residents of Canadian assisted living facilities. Our objectives were to estimate the incidence of admission to hospital over 1 year for residents of designated (i.e., publicly funded) assisted living (DAL) facilities in Alberta, to compare this rate with the rate among residents of long-term care facilities, and to identify individual and facility predictors of hospital admission for DAL residents.
Methods:
Participants were 1066 DAL residents (mean age ± standard deviation 84.9 ± 7.3 years) and 976 longterm care residents (85.4 ± 7.6 years) from the Alberta Continuing Care Epidemiological Studies (ACCES). Research nurses completed a standardized comprehensive assessment for each resident and interviewed family caregivers at baseline (2006 to 2008) and 1 year later. We used standardized interviews with administrators to generate facility- level data. We determined hospital admissions through linkage with the Alberta Inpatient Discharge Abstract Database. We used multivariable Cox proportional hazards models to identify predictors of hospital admission.
Results:
The cumulative annual incidence of hospital admission was 38.9% (95% confidence interval [CI] 35.9%– 41.9%) for DAL residents and 13.7% (95% CI 11.5%–15.8%) for long-term care residents. The risk of hospital admission was significantly greater for DAL residents with greater health instability, fatigue, medication use (11 or more medications), and 2 or more hospital admissions in the preceding year. The risk of hospital admission was also significantly higher for residents from DAL facilities with a smaller number of spaces, no licensed practical and/ or registered nurses on site (or on site less than 24 hours a day, 7 days a week), no chain affiliation, and from select health regions.
Interpretation:
The incidence of hospital admission was about 3 times higher among DAL residents than among long-term care residents, and the risk of hospital admission was associated with a number of potentially modifiable factors. These findings raise questions about the complement of services and staffing required within assisted living facilities and the potential impact on acute care of the shift from long-term care to assisted living for the facility-based care of vulnerable older people.
PMCID: PMC4085093  PMID: 25009683
16.  Travel-acquired infections and illnesses in Canadians: surveillance report from CanTravNet surveillance data, 2009–2011 
Open Medicine  2014;8(1):e20-e32.
Background:
Important knowledge gaps exist in our understanding of migration medicine practice and the impact of pathogens imported by Canadian travellers. We present here a comprehensive, Canada-specific surveillance summary of illness in a cohort of returned Canadian travellers and new immigrants.
Methods:
We extracted and analyzed (using standard parametric and nonparametric techniques) data from the Canadian Travel Medicine Network (CanTravNet) database for ill returned Canadian travellers and new immigrants who presented to a Canadian GeoSentinel Surveillance Network site between September 2009 and September 2011.
Results:
During the study period, 4365 travellers and immigrants presented to a CanTravNet site, 3943 (90.3%) of whom were assigned a travel-related diagnosis. Among the 3115 non-immigrant travellers with a definitive travel-related diagnosis, arthropod bite (n = 127 [4.1%]), giardiasis (n = 91 [2.9%]), malaria (n = 77 [2.5%]), latent tuberculosis (n = 73 [2.3%]), and strongyloidiasis (n = 66 [2.1%]) were the most common specific etiologic diagnoses. Among the 828 immigrants with definitive travel-related diagnoses, the most frequent etiologies were latent tuberculosis (n = 229 [27.7%]), chronic hepatitis B (n = 182 [22.0%]), active tuberculosis (n = 97 [11.7%]), chronic hepatitis C (n = 89 [10.7%]), and strongyloidiasis (n = 41 [5.0%]). Potentially serious infections, such as dengue fever (61 cases) and enteric fever due to Salmonella enterica serotype Typhi or Paratyphi (36 cases), were common. Individuals travelling for the purpose of visiting friends and relatives (n = 500 [11.6% of those with known reason for travel]) were over-represented among those diagnosed with malaria and enteric fever, compared with other illnesses (for malaria 34/94 [36.2%] v. 466/4221 [11.0%]; for enteric fever, 17/36 [47.2%] v. 483/4279 [11.3%]) (both p < 0.001). For cases of malaria, there was also overrepresentation (compared with other illnesses) from business travellers (22/94 [23.4%] v. 337/4221 [8.0%]) and males (62/94 [66.0%] v. 1964/4269 [46.0%]) (both p < 0.001). Malaria was more likely than other illnesses to be acquired in sub-Saharan Africa (p < 0.001), whereas dengue was more likely than other illnesses to be imported from the Caribbean and South East Asia (both p = 0.003) and enteric fever from South Central Asia (24/36 [66.7%]) (p < 0.001).
Interpretation:
This analysis of surveillance data on ill returned Canadian travellers has detailed the spectrum of imported illness within this cohort. It provides an epidemiologic framework for Canadian practitioners encountering ill returned travellers. We have confirmed that travel to visit friends and relatives confers particularly high risks, which underscores the need to improve pretravel intervention for a population that is unlikely to seek specific pretravel advice. Potentially serious and fatal illnesses such as malaria and enteric fever were common, as were illnesses of public health importance, such as tuberculosis and hepatitis B.
PMCID: PMC4085092  PMID: 25009682
17.  How safe are new drugs? Market withdrawal of drugs approved in Canada between 1990 and 2009 
Open Medicine  2014;8(1):e14-e19.
Background:
Studying drugs withdrawn from the market for safety reasons can help in evaluating the strengths and weaknesses of the pre- and post-market safety evaluation systems. This study considered 2 questions: Has there been a change over time in the percentage of new drugs that are eventually withdrawn because of safety reasons? How long are new drugs on the market before their serious safety problems are recognized?
Methods:
All drugs approved between 1 January 1990 and 31 December 2009 and subsequently withdrawn for safety reasons (until 1 October 2013) were identified, and the generic name, date of approval, and date of withdrawal were recorded. The total number of drugs approved over the same period was obtained from annual Health Canada reports. The percentages of new active substances approved in the 5-year periods 1990–1994, 1995–1999, 2000–2004, and 2005–2009 and eventually withdrawn were compared using the χ2 test. The time between approval and withdrawal was calculated in days.
Results:
Of the 528 new drugs approved over the period of interest, a total of 22 (4.2%) were eventually withdrawn. Between 3.9% and 4.4% of the drugs approved in each 5-year period were eventually withdrawn (χ2 = 0.04, p = 0.99 for difference among 5-year periods). The median time between approval and withdrawal was 1271 days (interquartile range 706–2876).
Interpretation:
One explanation for the finding of no difference in the percentage of drugs approved in the four 5-year periods that were eventually withdrawn is the lack of any change in the rigour of the premarket evaluation system and the postmarket surveillance systems. The 1271-day median time between Notice of Compliance and withdrawal emphasizes the need to be particularly cautious in prescribing new drugs early in their life cycle.
PMCID: PMC4085091  PMID: 25009681
19.  Gestational diabetes and risk of cardiovascular disease: a scoping review 
Open Medicine  2014;8(1):e1-e9.
Background:
Gestational diabetes mellitus is associated with an increased risk of incident type 2 diabetes and has deleterious effects on other cardiovascular risk factors. However, the effect of gestational diabetes on the risk of cardiovascular disease remains unclear. We conducted a scoping review of the literature to examine the association between these 2 conditions.
Methods:
We systematically searched the PubMed and Embase databases for studies examining the association between gestational diabetes and cardiovascular disease. We restricted our search to studies involving humans that were published in English or French. Outcomes of interest included acute coronary syndromes, angina, arrhythmia, coronary artery disease, heart failure, myocardial infarction, stroke, and composite end points with these outcomes.
Results:
A total of 11 publications (3 cohort studies [1 published as an abstract], 2 cross-sectional studies, 1 case–control study [published as an abstract], 4 narrative reviews, and 1 editorial) met our inclusion criteria. The 2 cohort studies published as full manuscripts were conducted in overlapping populations. The included studies reported a range of adjusted relative risks for incident cardiovascular disease, from not significant to 1.85 (95% confidence interval [CI] 1.21 to 2.82). Adjustment for subsequent type 2 diabetes mellitus attenuated the effects but with wide 95% CIs that spanned unity (range 1.13 [95% CI 0.67 to 1.89] to 1.56 [95% CI 1.00 to 2.43]).
Interpretation:
Available data suggest that gestational diabetes is associated with an increased risk of cardiovascular disease. However, these data are limited, and evidence regarding this association independent of the increased risk due to subsequent type 2 diabetes and other risk factors for cardiovascular disease remains inconclusive.
PMCID: PMC4085089  PMID: 25009679
21.  Trends in HIV prevalence, new HIV diagnoses, and mortality among adults with HIV who entered care in Ontario, 1996/1997 to 2009/2010: a population-based study 
Open Medicine  2013;7(4):e98-e106.
Background:
Population-based estimates of HIV prevalence, rates of new HIV diagnoses, and mortality rates among persons with HIV who have entered care are needed to optimize health service delivery and to improve the health outcomes of these individuals. However, these data have been lacking for Ontario.
Methods:
Using a validated case-finding algorithm and linked administrative health care databases, we conducted a population-based study to determine the prevalence of HIV and rates of new HIV diagnoses among adults aged 18 years or older in Ontario between fiscal year 1996/1997 and fiscal year 2009/2010, as well as all-cause mortality rates among persons with HIV over the same period.
Results:
Between 1996/1997 and 2009/2010, the number of adults living with HIV increased by 98.6% (from 7608 to 15 107), and the age- and sex-standardized prevalence of HIV increased by 52.8% (from 92.8 to 141.8 per 100 000 population; p < 0.001). Women and individuals 50 years of age or older accounted for increasing proportions of persons with HIV, rising from 12.8% to 19.7% (p < 0.001) and from 10.4% to 29.9% (p < 0.001), respectively, over the study period. During the study period, age- and sex-standardized rates of new HIV diagnoses decreased by 32.5% (from 12.3 to 8.3 per 100 000 population; p < 0.001) and mortality rates among adults with HIV decreased by 71.9% (from 5.7 to 1.6 per 100 adults with HIV; p < 0.001).
Interpretation:
The prevalence of HIV infection in Ontario increased considerably between 1996/1997 and 2009/2010, with a greater relative burden falling on women and individuals aged 50 years of age or older. These trends may be due to the decreased rate of new diagnoses among younger men. All-cause mortality rates declined among persons with HIV who entered care.
PMCID: PMC4161501  PMID: 25237406
23.  Classification of Canadian immigrants into visible minority groups using country of birth and mother tongue 
Open Medicine  2013;7(4):e85-e93.
Background:
The Permanent Resident Database of Citizenship and Immigration Canada (CIC) contains sociodemographic information on immigrants but lacks ethnic group classifications. To enhance its usability for ethnicityrelated research, we categorized immigrants in the CIC database into one of Canada's official visible minority groups or a white category using their country of birth and mother tongue.
Methods:
Using public data sources, we classified each of 267 country names and 245 mother tongues in the CIC data into 1 of 10 visible minority groups (South Asian, Chinese, black, Latin American, Filipino, West Asian, Arab, Southeast Asian, Korean, and Japanese) or a white group. We then used country of birth alone (method A) or country of birth plus mother tongue (method B) to classify 2.5 million people in the CIC database who immigrated to Ontario between 1985 and 2010 and who had a valid encrypted health card number. We validated the ethnic categorizations using linked selfreported ethnicity data for 6499 people who responded to the Canadian Community Health Survey (CCHS).
Results:
Among immigrants listed in the CIC database, the 4 most frequent visible minority groups as classified by method B were South Asian (n = 582 812), Chinese (n = 400 771), black (n = 254 189), and Latin American (n = 179 118). Methods A and B agreed in 94% of the categorizations (kappa coefficient 0.94, 95% confidence interval [CI] 0.93–0.94). Both methods A and B agreed with self-reported CCHS ethnicity in 86% of all categorizations (for both comparisons, kappa coefficient 0.83, 95% CI 0.82–0.84). Both methods A and B had high sensitivity and specificity for most visible minority groups when validated using self-reported ethnicity from the CCHS (e.g., with method B, sensitivity and specificity were, respectively, 0.85 and 0.97 for South Asians, 0.93 and 0.99 for Chinese, and 0.90 and 0.97 for blacks).
Interpretation:
The use of country of birth and mother tongue is a validated and practical method for classifying immigrants to Canada into ethnic categories.
PMCID: PMC4161499  PMID: 25237404
24.  Defining hospitalist physicians using clinical practice data: a systems-level pilot study of Ontario physicians 
Open Medicine  2013;7(3):e74-e84.
Background:
Hospitalists have become dominant providers of inpatient care in many North American hospitals. Despite the global growth of hospital medicine, no objective method has been proposed for defining the hospitalist discipline and delineating among inpatient practices on the basis of physicians' clinical volumes. We propose a functional method of identifying hospital-based physicians using aggregated measures of inpatient volume and apply this method to a retrospective, population-based cohort to describe the growth of the hospitalist movement, as well as the prevalence and practice characteristics of hospital-based generalists in one Canadian province.
Methods:
We used human resource databases and financial insurance claims to identify all active fee-for-service physicians working in Ontario, Canada, between fiscal year 1996/1997 and fiscal year 2010/2011. We constructed 3 measures of inpatient volume from the insurance claims to reflect the time that physicians spent delivering inpatient care in each fiscal year. We then examined how inpatient volumes have changed for Ontario physicians over time and described the prevalence of full-time and part-time hospital-based generalists working in acute care hospitals in fiscal year 2010/2011.
Results:
Our analyses showed a significant increase since fiscal year 2000/2001 in the number of high-volume hospital-based family physicians practising in Ontario (p < 0.001) and associated decreases in the numbers of high-volume internists and specialists (p = 0.03), where high volume was defined as ≥ 2000 inpatient services/ year. We estimated that 620 full-time and 520 part-time hospital-based physicians were working in Ontario hospitals in 2010/2011, accounting for 4.5% of the active physician workforce (n = 25 434). Hospital-based generalists, consisting of 207 family physicians and 130 general internists, were prevalent in all geographic regions and hospital types and collectively delivered 10% of all inpatient evaluation and care coordination for Ontario residents who had been admitted to hospital.
Interpretation:
These analyses confirmed a substantial increase in the prevalence of general hospitalists in Ontario from 1996 to 2011. Systems-level analyses of clinical practice data represent a practical and valid method for defining and identifying hospital-based physicians.
PMCID: PMC4161497  PMID: 25237402
25.  Herpes zoster as a marker of underlying malignancy 
Open Medicine  2013;7(2):e68-e73.
Background
Both herpes zoster and malignancy are associated with immunosuppression. However, the association between herpes zoster and the subsequent diagnosis of malignancy is unclear. We undertook this study to assess whether a diagnosis of herpes zoster is a risk factor for subsequent malignancy.
Methods
For this matched retrospective cohort study, a physician billing database was used to identify individuals 18 years of age or older with a diagnosis of herpes zoster and no prior diagnosis of cancer or HIV infection. Individuals with a herpes zoster diagnosis were matched one-to-one to individuals without a herpes zoster diagnosis, and both groups were examined for up to 5 years for diagnosis of cancer.
Results
A total of 542 575 individuals with a diagnosis of herpes zoster were identified. Compared with matched controls, these patients were more likely (p < 0.001) to have a history of myocardial infarction, asthma, congestive heart failure, chronic obstructive pulmonary disease, diabetes mellitus, and hypertension. The incidence of cancer was significantly greater among individuals with herpes zoster than among those without herpes zoster, for both men and women and across all time intervals studied (up to 5 years). The greatest adjusted hazard ratio was seen 180 days after a herpes zoster diagnosis (1.19, 95% confidence interval 1.12–1.25); the hazard ratio decreased as the time from herpes zoster diagnosis increased. Lymphoma was the type of cancer with the greatest relative increase in incidence following diagnosis of herpes zoster.
Interpretation
There is a risk of malignancy following an episode of herpes zoster in both men and women and in all age groups 18 years and over. The risk is greatest during the first 180 days following the diagnosis of herpes zoster.
PMCID: PMC3863753  PMID: 24348886

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