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Biomedical subjects

M L Russell

Publications and source records attributed to M L Russell.

At least 19 recordsLinked to original sources
PubMed2007

Duration and distance of exposure are important predictors of transmission among community contacts of Ontario SARS cases.

We report attack rates and contact-related predictors among community contacts of severe acute respiratory syndrome (SARS) cases from the 2003 Toronto-area outbreak. Community contact data was extracted from public health records for single, well-defined exposures to a SARS case. In total, 8662 community-acquired exposures resulted in 61 probable cases; a crude attack rate of 0.70% [95% confidence interval (CI) 0.54-0.90]. Persons aged 55-69 years were at higher risk of acquiring SARS (1.14%) than those either younger (0.60%) or older (0.70%). In multivariable analysis exposures for at least 30 min at a distance of <or=1 m increased the likelihood of becoming a SARS case 20.4-fold (95% CI 11.8-35.1). Risk related to duration of illness in the source case at time of exposure was greatest for illness duration of 7-10 days (rate ratio 3.4, 95% CI 1.9-6.1). Longer and closer proximity exposures incurred the highest rate of disease. Separate measures of time and distance from source cases should be added to minimum datasets for the assessment of interventions for SARS and other emerging diseases.

Adolescent↗
PubMed2005

The changing epidemiology of chickenpox in Alberta.

BACKGROUND: Varicella vaccine was licensed in Canada in 1998. The province of Alberta introduced a universal publicly funded varicella vaccination program in 2001. PURPOSE: To describe the epidemiology of non-fatal cases of chickenpox for which publicly funded health services were utilized for the period 1986-2002. METHODS: We used the records of Alberta's universal, publicly funded health care insurance system to identify cases of chickenpox for the period 1986-2002. The earliest dated utilization of a health service for which there was an ICD9-CM code of 052.xx or an IC10-CA code of B01.xx was used as the date of illness onset. Denominators for rates were estimated using mid-year population estimates from the Alberta Health Care Insurance Registry. Age-specific rates were estimated for each year. RESULTS: The crude incidence of chickenpox significantly declined over the period 1994-2002, most steeply after the year 2000. The incidence of chickenpox varied by age group and year and there was evidence of age-group-year interaction. Among those aged 5-19 years, chickenpox incidence began to decline prior to vaccine licensure in Canada. Among those aged less than one year and those aged 1-4 years, the incidence increased until 1999 when a decline began. Over the period 0.8% of cases were hospitalized. CONCLUSION: Chickenpox rates began to decline prior to the introduction of the publicly funded vaccination program; however the declines in rates among the youngest age-groups are consistent with a vaccination program effect.

Adolescent↗
PubMed2004

Response rates for surveys of chiropractors.

BACKGROUND: Survey response rates may vary by type of practitioner studied and may have declined over time. Response rates for surveys of complementary practitioners have not been studied. OBJECTIVE: To describe the response rates in published surveys of chiropractors and explore for secular trends in response rates and for methodologic and geographic correlates of response rates. METHODS: Secondary analysis of data extracted from published English language reports of surveys of chiropractors. Response rates were calculated as the total number of persons from whom a questionnaire was returned divided by the total number of persons who were sent a questionnaire. RESULTS: Sixty-two surveys represented by 79 articles published in the interval 1980 to 2000 met inclusion criteria for analysis. We were able to calculate a response rate for 46 postal surveys. The mean response rate was 52.7%. There was no significant association between geographic setting and response rate, and there was no evidence of secular trend in response rates. None of the studies employed incentives. The strongest predictor of response rate was number of contacts with the target population. CONCLUSION: Response rates for surveys of chiropractors are similar to those observed for surveys of medical doctors. The key to obtaining high response rates is the use of evidence-based methods in design and conduct of the surveys.

Attitude of Health Personnel↗
PubMed2004

Doctors, patients and influenza-like illness: clinicians or patients at risk?

BACKGROUND: Healthcare providers can transmit influenza and influenza-like illness (ILI) to patients and vice versa. However, the magnitude of this problem in the healthcare system as a whole is unknown. Using population-based administrative health data, we tested the hypothesis of a temporal association of ILI diagnosis among clinicians and their patients. METHODS: Healthcare providers under study included physicians (85%) and a variety of other medical professionals (such as chiropractors, dentists and optometrists). Cases of ILI were defined as having an ICD-9 code of influenza (487), pneumonia (480-486) or bronchitis (466 and 490) in a province-wide healthcare-provider billing system. Rates of ILI among persons who saw a sick (case) and non-sick (control) doctor were calculated and compared. RESULTS: The rate of ILI was lower among providers than among patients for every year of the study. The mean number of exposures to patients diagnosed with ILI was higher among case providers than among control providers (P = 0.044). However, exposure to case providers did not significantly increase the risk of ILI diagnosis among patients (OR=1.11; 95% confidence intervals 0.85-1.36). INTERPRETATION: Our findings are consistent with the hypothesis of patient-to-provider transmission. However, we may have underestimated the association and magnitude of this effect. Our results do not support the hypothesis that infectious doctors transmit disease to their patients, although this may be partly accounted for by the lower rates of ILI among the provider population in general.

Canada↗
PubMed2001

Influenza vaccination in Alberta long-term care facilities.

BACKGROUND: Canada's National Advisory Committee on Immunization recommends that both staff and residents of long-term care facilities be vaccinated against influenza. This paper describes the influenza vaccination policies and programs, as well as vaccination rates, for staff and residents of long-term care institutions in Alberta. Such data have not previously been reported. METHODS: Data were collected by means of an anonymous mail survey (with 2 reminders) sent to Alberta nursing homes and auxiliary hospitals in spring 1999. RESULTS: Of 160 facilities providing long-term care during the study period, 136 responded to the survey (85%). Of these, only 85 provided data on staff vaccination rates, whereas 118 provided data on resident vaccination rates. For institutions reporting this information, the median proportion of staff vaccinated was 29.9% and the median proportion of residents vaccinated was 91.0%. Only 2 facilities reported that staff vaccination was mandatory; however, only one of these had a written policy consistent with the self-report period. Using a travelling vaccination cart, offering vaccination on night shift, and monitoring and providing feedback about staff vaccination rates were infrequently employed as elements of staff vaccination programs, although all were positively correlated with staff vaccination rates. Standing orders for resident vaccination were reported by only 84 facilities. Fourteen institutions required written consent for vaccination from the resident or a relative. Facility requirements for consent to vaccinate from the resident or a relative were significantly associated with mean vaccine coverage: 90.5% coverage for institutions requiring verbal consent, 86.5% coverage for institutions requiring written consent and 95.0% for institutions not requiring written or verbal consent. INTERPRETATION: Staff vaccination rates in Alberta long-term care facilities are unacceptably low. Changes in staff vaccination programs may improve the situation even in the absence of mandatory vaccination or work exclusion rules. Requirements for written consent for vaccination of residents of long-term care facilities may be a barrier to immunization.

Aged↗
PubMed2001

Using epidemiology to target staff influenza vaccination programs.

We examined staff influenza vaccination rates in rural hospitals that had both acute- and long-term-care (LTC) units. After controlling for hospital, acute-care staff were less likely to be vaccinated than LTC staff. There was no consistent association between type of worker and vaccination after controlling for both hospital and type of care.

Canada↗
PubMed2001

Alternative medicine use by individuals with major depression.

OBJECTIVE: To describe the use of alternative medicine (AM) by persons with major depression and to examine the factors associated with AM use among these individuals. METHODS: We used data from the 1994-1995 and 1996-1997 National Population Health Surveys. We selected subjects who had major depression according to the Composite International Diagnostic Interview Short Form for Major Depression (CIDI-SFMD). The prevalence of AM and conventional health service use by the subjects was calculated for each survey and was stratified by province. We employed logistic regression to examine the factors associated with AM use. RESULTS: There was a temporal trend toward increasing use of AM among persons with major depression. The prevalence of AM use among subjects with major depression was 7.8% in 1994-1995 and 12.9% in 1996-1997. Female sex, having more than 12 years' education, and having 1 or more long-term medical conditions were associated with an increased likelihood of using AM. The sex difference in AM use depended on subjects' age in 1996-1997. CONCLUSION: General practitioners, mental health specialists, and AM providers should be aware of their patients' use of both conventional medical services and AM because there may be interactions between conventional and alternative treatments. Communication and, if possible, cooperation may lead to improved outcomes in the management of depressive disorders.

Adolescent↗
PubMed2001

Major depression: prevalence, treatment utilization and age in Canada.

OBJECTIVE: To determine the relationships between age, prevalence of major depression and antidepressant treatment in Canadian populations by using data from three health surveys. BACKGROUND: Major depression is an important disorder, and there is a concern that treatment for it may be underutilized. Age may have an impact on treatment use. METHODS: Two of the surveys incorporated into the present analysis were random digit dial telephone surveys, with sample sizes of 2542 subjects and 796 subjects, respectively. The third data source was the National Population Health Survey (n=73,402), which used some face to face and some telephone-based data collection methods. In each of these studies, major depression was evaluated using a short form version of the Composite International Diagnostic Interview for Major Depression. Diagnostic status was evaluated in relation to current use of antidepressant medications, age and other relevant factors. All analyses accounted for unequal selection probabilities and clustering inherent in the sampling procedures. RESULTS: The prevalence of major depression was consistently found to be highest in subjects under the age of 45 years. However, older subjects were more likely to report having depression diagnosed. Antidepressant treatment was found to be less frequent in young subjects, despite these subjects being in the group with the highest prevalence of depression. Younger respondents were less likely to see a physician about their depressive symptoms, and when they did they were less likely to be told that they had a depressive disorder. CONCLUSIONS: The data presented indicate that antidepressant medications tend to be used less frequently in younger than older age groups in Canada. Additional studies are needed to confirm optimal use rates in relation to age.

Adolescent↗
PubMed2000

The incidence of pulmonary embolism in unexplained sudden cardiac arrest with pulseless electrical activity.

PURPOSE: The cause of many cases of sudden cardiac arrest from pulseless electrical activity is unknown. We hypothesized that pulmonary embolism was responsible for a substantial proportion of these cases and used transesophageal echocardiography to identify pulmonary embolism among patients with sudden cardiac arrest. SUBJECTS AND METHODS: We performed a prospective study at a tertiary care, university-operated county hospital, with a level 1 trauma center. Consecutive patients (n = 36) who were admitted with (n = 20) or unexpectedly developed (n = 16) sudden cardiac arrest of unknown cause were studied with transesophageal echocardiography during cardiopulmonary resuscitation. We determined the presence of central pulmonary embolism, right ventricular enlargement, and other causes of sudden cardiac arrest (such as myocardial infarction and aortic dissection) using prospectively defined criteria. RESULTS: Of the 25 patients with pulseless electrical activity as the initial event, 9 (36%) had pulmonary emboli (8 seen with transesophageal echocardiography and 1 diagnosed at autopsy) compared with none of the 11 patients with other rhythms, such as asystole or ventricular tachycardia or fibrillation (P = 0.02). Of the 8 patients who had pulmonary embolism diagnosed by transesophageal echocardiography, 2 survived to hospital discharge. CONCLUSIONS: Mortality from massive pulmonary embolism is high, particularly if patients present with sudden cardiac arrest. Earlier diagnosis of pulmonary embolus may permit wider use of thrombolytic agents or other interventions and may potentially increase survival.

Aged↗
PubMed2000

Crystallographic, X-ray absorption, and IR studies of solid- and solution-state structures of tris(nitrato) N,N,N',N'-tetraethylmalonamide complexes of lanthanides. Comparison with the Americium complex.

To fine-tune the design of optimized donor ligands for nuclear waste actinide selective extraction, both electronic and molecular structures of the actinide complexes that are formed must be investigated. In particular, to achieve the selective complexation of transplutonium 3+ ions versus lanthanide 3+ ions is one of the major challenges, given the chemical similarities between these two f-element families. In this work, the structure of solvent-phase M(NO3)3(TEMA)2 complexes (Ln = Nd, Eu, Ho, Yb, Lu, Am; TEMA = N,N,N',N'-tetraethylmalonamide) was investigated by liquid-phase spectroscopic methods among which extended X-ray absorption fine structure played a major role. In addition, the crystal structures of the species Nd(NO3)3(TEMA)2 and Yb(NO3)3(TEMA)2 have been determined by X-ray diffraction. Nd(NO3)3(C11N2O2H22)2 crystallizes in the monoclinic system (P2(1) space group; a = 11.2627(4) A, b = 20.5992(8) A, c = 22.2126(8) A; alpha = gamma = 90 degrees, beta = 102.572(1) degrees; Z = 6), and Yb(NO3)3(C11N2O2H22)2 crystallizes in the orthorhombic system (P2(1)2(1)2(1) space group; a = 9.3542(1) A, b = 18.1148(2) A, c = 19.7675(2) A; alpha = beta = gamma = 90 degrees; Z = 4). In the solvent phase, the metal polyhedron was found to be similar to that of the solid-state complex Nd(NO3)3(TEMA)2 for M = Nd to Ho. For M = Yb and Lu, a significant elongation of one nitrate oxygen bond was observed. Comparison with measurements on the Am(NO3)3(TEMA)2 complex in ethanol has shown the similarities between the Nd3+ and Am3+ coordination spheres.

Journal Article↗
PubMed2000

Paying research subjects: participants' perspectives.

OBJECTIVE: To explore the opinions of unpaid healthy volunteers on the payment of research subjects. DESIGN: Prospective cohort. SETTING: Southern Alberta, Canada. PARTICIPANTS: Medically eligible persons responding to recruiting advertisements for a randomised vaccine trial were invited to take part in a study of informed consent at the point at which they formally consented or refused trial participation. Of 72 invited, 67 (62 trial consenters, 5 trial refusers) returned questionnaires at baseline and 54 at follow-up. OUTCOME MEASURES: Proportions of persons who agreed or disagreed with three close-ended statements on the payment of research subjects; themes and categories identified by content analysis of responses to an open-ended question. RESULTS: A minority (43.3%) agreed with paying either patient or healthy volunteer participants. Opinions did not change over time. Participants' comments addressed: benefits and drawbacks to research participation; benefits and drawbacks to paying research participants; conditions under which payment of research subjects would be acceptable, and the nature of acceptable recognition. Acceptable conditions were to improve problematic recruitment, to reimburse costs, and to recognise participants, particularly for their time investment. Both non-monetary and monetary recognition of volunteers were thought to be appropriate. CONCLUSIONS: Most unpaid volunteers disagreed with paying research participants. The themes arising from their comments are similar to those that have been raised by ethicists and suggest that recognising the time and effort of participants should receive greater emphasis than presently occurs.

Adult↗
PubMed1999

Cellular and connective tissue changes in alveolar septal walls in emphysema.

Emphysema is commonly defined as enlargement of airspaces distal to terminal bronchioles accompanied by destruction of alveolar walls, but without obvious fibrosis. Morphometric techniques were used to correlate changes in components of the alveolar septa surrounding enlarged airspaces in human emphysema with the mean linear intercept (Lm) of those airspaces. Alveolar and capillary surface density decreased with increased Lm, but the ratio of these surface densities to each other remained close to normal for mild to moderate increases in Lm. This suggests that the decreased gas exchange observed in emphysema is initiated by a total loss of septa and not by selective pathological changes of the microvasculature. Increases in septal wall thickness directly correlated with increases in Lm. For the mild to moderate emphysema lesions included in this study, an increase of 100% in Lm correlated with a 130% increase in the relative volume of the alveolar septal interstitium. Significant increases occurred in both elastin (0.14 to 0.56 microm(3)/microm(2) basement membrane [BM]) and collagen (0.49 to 1. 63 microm(3)/microm(2) BM). The increase in elastin and collagen raises the possibility of a remodeling process in the connective matrix in alveolar walls. Whether or not the new connective tissue represents a disordered, nonfunctional regional response needs to be determined.

Aged↗
PubMed1999

A disease severity scale for systemic sclerosis: development and testing.

OBJECTIVE: To develop and test a severity scale for individual organ involvements in systemic sclerosis (SSc, scleroderma). METHODS: An international study group completed the following tasks: (1) developed a glossary of terms including all pertinent variables for 9 potentially affected organ systems; (2) collected prospective data to determine the feasibility and practicality of each proposed variable; (3) revised the initial list of variables; (4) determined the association of each variable with mortality (a proxy for morbidity) using 579 patients in an existing comprehensive longitudinal scleroderma databank; (5) developed a severity grading scale for each organ system by discussion and consensus; and (6) externally validated the scale using an independent group of 680 patients from the same databank. RESULTS: Nine organ-specific severity scales were developed from 0 (no documented involvement) to 4 (endstage disease). The data required for scale completion are relatively easy and practical for all physicians to obtain. CONCLUSION: This preliminary severity scale will be useful for assessing disease severity status in individual patients both at one point in time and longitudinally. The severity scale will assist in the design and conduct of clinical trials and the comparison of study populations with one another. The scale will serve as a framework for developing a scleroderma disease activity index.

Humans↗
PubMed1998

Physician specialty is associated with differences in warfarin use for atrial fibrillation.

OBJECTIVE: To determine whether physician specialty is associated with prescription of warfarin to elderly persons with atrial fibrillation. DESIGN: Cross-sectional survey. SETTING: One hundred and thirty-eight randomly selected general practitioners--all 58 internists and all 27 cardiologists in southern Alberta were surveyed by mail. INTERVENTION: Physicians identified their preferred drug for stroke prevention generally and in response to two hypothetical cases. MAIN RESULTS: Response rates were 66% (general practitioners), 76% (internists) and 89% (cardiologists). Specialists (92%) were more likely than general practitioners (76%) to choose warfarin (P = 0.007). Findings were similar for questions related to case scenarios; however, the magnitude of differences between specialists and general practitioners was less pronounced. Specialists were more likely (77%) to prescribe warfarin for elderly females than were general practitioners (62%, P = 0.08). Similar proportions of specialists (77%) and general practitioners (67%) would prescribe warfarin to elderly males. CONCLUSION: Physician specialty is associated with warfarin prescription for elderly persons with atrial fibrillation.

Aged↗
PubMed1997

A strategy to improve communication between health care professionals and people living with cancer: II. Follow-up of a workshop on the teaching and assessment of communication skills in Canadian Medical Schools.

BACKGROUND AND METHODS: Follow-up questionnaires were sent to all Canadian medical schools in 1994 and 1996 in order to evaluate changes that had taken place in the teaching of physician-patient communication skills since recommendations were made by a national "Workshop on the Teaching and Assessment of Communication Skills in Canadian Medical Schools" in 1992. RESULTS AND CONCLUSIONS: Fifteen of 16 schools responded. All 15 reported major changes in the teaching of physician-patient communication over the preceding four years or planned changes in the very near future. However, barriers to improving the communications curriculum still existed. The most frequently cited barrier was the lack of trained faculty to teach communication skills; this was followed in frequency by poor coordination over the four years of medical school with lack of scheduled time in the clerkship years. There were identified needs to train faculty to teach communication skills and to extend formal teaching of the subject into the clerkship. Concurrent with these changes, the accreditation process for Canadian medical schools now requires the teaching and evaluation of communication skills.

Canada↗
PubMed1997

Influenza and tetanus immunization. Are adults up-to-date in rural Alberta?

PURPOSE: To discover what proportion of adults residing within the boundaries of a rural health district were up-to-date with influenza and tetanus vaccinations. METHODS: A directory-seeded, random digit dial telephone survey of health knowledge, attitudes, and practices was conducted in summer 1993. Eligible subjects were aged 16 or older, lived within health district boundaries, and spoke English. RESULTS: Just over half (57.5%) of people aged 65 and older had received influenza vaccine in the previous 12 months, and 55.4% of people 16 years and older had received tetanus vaccine in the last 10 years (93% of people aged 16 to 24 were covered, but only 20.5% of people aged 65 or older). Most (89.8%) of those 65 and older knew that influenza vaccine was recommended for people their age. Only 59% of respondents knew that influenza vaccine was recommended for people with chronic health conditions, regardless of age. CONCLUSION: Among adults, coverage with influenza and tetanus vaccines varies with age, but is generally unsatisfactory. Rates in this rural area of Alberta were similar to Canadian rates for tetanus vaccine coverage but higher for influenza vaccine coverage.

Adolescent↗