Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Quebec”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1983

Methyl mercury exposure in northern Quebec. I. Neurologic findings in adults.

Cree Indians of northern Quebec were exposed to methyl mercury through contamination of local fish. The relationship between measures of exposure and neurologic abnormalities was studied in two communities in 1978 by comparing the exposure of 41 "cases" with selected neurologic abnormalities with that of 179 normal "controls." In the community of Mistassini, a significant positive association was found between neurologic abnormalities and methyl mercury exposure; in Great Whale, the association, although also positive, was not statistically significant. However, although allowance was made for confounding variables, it remains possible that the effects are not entirely attributable to methyl mercury. Further, the data do not permit estimation of a threshold level of exposure above which excess neurologic abnormalities might occur, because recent levels of exposure do not reflect those of the past. Whether the abnormalities observed in this study will remain stable, regress, or progress can only be determined by continued surveillance.

Adult↗
PubMed1994

Occupational risk factors for bladder cancer: results from a case-control study in Montreal, Quebec, Canada.

A population-based case-control study of the associations between various cancers and occupational exposures was carried out in Montreal, Quebec, Canada. Between 1979 and 1986, 484 persons with pathologically confirmed cases of bladder cancer and 1,879 controls with cancers at other sites were interviewed, as was a series of 533 population controls. The job histories of these subjects were evaluated by a team of chemist/hygienists for evidence of exposure to a list of 294 workplace chemicals, and information on relevant non-occupational confounders was obtained. On the basis of results of preliminary analyses and literature review, 19 occupations, 11 industries, and 23 substances were selected for in-depth multivariate analysis. Logistic regression analyses were carried out to estimate the odds ratio between each of these occupational circumstances and bladder cancer. There was weak evidence that the following substances may be risk factors for bladder cancer: natural gas combustion products, aromatic amines, cadmium compounds, photographic products, acrylic fibers, polyethylene, titanium dioxide, and chlorine. Among the substances evaluated which showed no evidence of an association were benzo(a)pyrene, leather dust, and formaldehyde. Several occupations and industries were associated with bladder cancer, including motor vehicle drivers and textile dyers.

Adult↗
PubMed2003

Persistency of use of COX-2-specific inhibitors and non-specific non-steroidal anti-inflammatory drugs (NSAIDs) in Quebec.

The effectiveness of pharmacological therapies is dependent in part on patient persistency with the prescribed therapeutic regimen. In the case of non-specific non-steroidal anti-inflammatory drugs (NSAIDs), effectiveness is often compromised by undesirable side-effects, poor compliance or discontinuation of therapy. While patterns of utilization of non-specific NSAIDs have been investigated, few data are available on the patterns of persistency for cyclooxygenase (COX)-2-specific inhibitors. This study used a provincial health-care system database in Quebec, Canada, to determine the duration of treatment in new users of COX-2-specific inhibitors and non-specific NSAIDs over the first 3 months of treatment, and to characterize the factors associated with treatment persistency. Results demonstrate that the median duration of treatment was longer among patients initially prescribed COX-2-specific inhibitors (30 days and 23 days for celecoxib and rofecoxib respectively) than in those prescribed non-selective NSAIDs (10 days). Although the percentage of patients remaining on COX-2-specific drugs declined over the course of treatment, few patients on either celecoxib or rofecoxib switched drugs, either to the other COX-2-specific inhibitor or to non-specific NSAIDs. Factors associated with persistent drug use were: COX-2-specific inhibitors, age, and the use of gastroprotective agents either at treatment initiation or during follow-up. Dosage, chronic disease score and prescriber's specialty were only marginally associated with persistency. Prior use of gastroprotective agents was associated with lower persistency. Although the limitations of this study, which included lack of information on the indication for the prescription and the reason for switch or discontinuation, preclude definite conclusions regarding patterns of use of these drugs, the data suggest that the use of COX-2-specific inhibitors may result in increased persistency with treatment.

Adolescent↗
PubMed2006

Therapy switching and associated costs in elderly patients receiving COX-2 selective inhibitors or non-selective non-steroidal anti-inflammatory drugs in Quebec, Canada.

OBJECTIVES: Lack of efficacy or tolerability of some non-steroidal anti-inflammatory drugs (NSAIDs) may lead to switching between non-selective NSAIDs (nsNSAIDs) and cyclooxygenase-2 (COX-2) selective inhibitors (coxibs), potentially increasing treatment costs due to additional physician visits and wastage of medication. This study assessed drug switching and associated costs among elderly chronic NSAID users. METHODS: Data for patients who filled their first prescription for a coxib or nsNSAID in 2001 were obtained from the Quebec Health Insurance Agency. Follow-up was terminated at the earliest of: 1 yr, the first day without NSAID exposure following the index filling date, or death. Patients could switch NSAIDs several times during follow-up. Person-days of exposure were categorized by the NSAID most recently dispensed: rofecoxib, celecoxib, Arthrotec(R) or non-Arthrotec (nA) nsNSAID. Cox regression models compared time to switch between groups, adjusting for patient baseline characteristics. Upon a switch, pills remaining from the previous prescription were considered wasted. The costs of wasted pills and switch-associated physician visits were estimated. RESULTS: Throughout follow-up, patients filled 38 267 prescriptions for rofecoxib, 31 282 for celecoxib, 1108 for Arthrotec and 4388 for nA-nsNSAIDs. Adjusted hazard ratios (95% confidence interval) for switching versus nA-nsNSAIDs were: rofecoxib, 0.39 (0.35-0.44); celecoxib, 0.43 (0.38-0.48). Compared with nA-nsNSAID prescriptions, adjusted switching-related healthcare costs were 53 and 47% lower on average for rofecoxib and celecoxib prescriptions, respectively. These costs were 34% higher for Arthrotec prescriptions than for nA-nsNSAIDs. CONCLUSIONS: Compared with recipients of nsNSAIDs, coxib recipients were less likely to switch medications and had approximately half the adjusted costs for switching-related wasted resources per prescription.

Aged↗
PubMed1998

Diagnostic Interview Schedule for Children (DISC-2.25) in Quebec: reliability findings in light of the MECA study.

OBJECTIVE: To examine the reliability of the French Diagnostic Interview Schedule for Children (DISC-2.25) in Quebec in light of other DISC-2 studies conducted in the National Institute of Mental Health's Methods for the Epidemiology of Child and Adolescent Mental Disorders Study. METHOD: Reliability was assessed for DSM-III-R disorders in a community sample comprising 260 parents of youths aged 6 to 14 years and 145 adolescents aged 12 to 14 years. The DISC was completed at home. The mean test-retest interval was 13.8 days for parents and 12.8 days for adolescents. RESULTS: Parents' reports: Internal consistency was acceptable for a majority of disorders. The kappa coefficients were in the fair or good ranges except for depressive disorders and were higher for children than for adolescents, and intraclass correlations were higher than kappa coefficients. Adolescents' reports: Internal consistency was acceptable or nearly acceptable for a majority of disorders. The kappa coefficients were in the fair range, and intraclass correlations were higher than kappa coefficients. The kappa coefficients were significantly higher for the test-retest interval of 7 to 14 days than for 14 to 21 days for adolescents' reports of anxious disorders and internalizing disorders. CONCLUSION: The French DISC-2.25 shows acceptable internal consistency and fair to good test-retest reliability. Across DISC-2 studies, test-retest reliability of the parents' reports improved for anxiety and depressive disorders. Among sources of variation, studies on attributes of questions would be meaningful.

Adolescent↗
PubMed2002

Impact of deferred treatment of blunt diaphragmatic rupture: a 15-year experience in six trauma centers in Quebec.

BACKGROUND: The purpose of this study was to show that blunt diaphragmatic rupture does not require immediate emergency operation in the absence of other indications. METHODS: We reviewed all patients with blunt diaphragmatic rupture admitted within 24 hours of injury to one of six university trauma centers providing trauma care for the province of Quebec from April 1, 1984, to March 31, 1999. Multivariate analysis of demographic profiles, severity indices, indications for operation, and preoperative delays was performed. RESULTS: There were 160 patients (91 men and 69 women) with blunt diaphragmatic rupture. Mean age was 40.1 +/- 16.2 years. Mean Injury Severity Score was 26.9 +/- 11.5 and mortality was 14.4%. Patients undergoing emergency surgery for indications other than diaphragmatic rupture had a significantly higher Injury Severity Score than those undergoing surgery for repair of diaphragmatic rupture alone (34.7 +/- 10.7 vs. 22.0 +/- 9.0, p < 0.001). In patients undergoing surgery for diaphragmatic rupture alone, delay before repair of the diaphragmatic hernia did not lead to an increased mortality compared with patients undergoing immediate surgery (3.4% vs. 5.0%, p = NS). CONCLUSION: Blunt diaphragmatic rupture in the absence of other surgical injuries carries low mortality. Operative repair of diaphragmatic rupture can be deferred without appreciable increased mortality if no other indication mandates immediate surgery.

Adult↗
PubMed1978

Hospital admission before and after Medicare in Quebec.

A 1 in 60 random sample of Quebec hospital admission records ("separations") for the years 1966 through 1974 was studied for evidence of change associated with the introduction in 1970 of universal health insurance. Non-surgical separation rates continued to decline in Montreal and remained steady in the rest of the province. In contrast, separations following surgical operation did not decline in Montreal and have increased substantially since 1970 in the rest of the province. Ten operative procedures accounting for 41 per cent of all surgical admissions were selected for separate study: of these, cholecystectomy, hysterectomy and hernia repairs conformed most closely to the new pattern. Directly or indirectly, Medicare may have contributed to these changes but more study is required to confirm or explain this.

Bed Occupancy↗
PubMed1978

Hospital emergency room utilization in Montreal before and after Medicare: the Quebec experience.

The impact of the introduction of Medicare in Quebec on hospital emergency room services was examined in Metropolitan Montreal. After Medicare, the emergency room visit rate increased 14 per cent per year compared to a 7 per cent per year increase in the five years preceding Medicare. The outpatient clinic visit rate continued an upward trend (4 per cent per year). In six of the hospitals selected for more detailed studies, patient interviews revealed that before Medicare 33 per cent of emergency room attenders attempted to contact a physician before reporting to the emergency room and 63 per cent were successful in speaking to the physician. After Medicare, 39 per cent attempted but only 38 per cent were successful. Before Medicare, 47 per cent of patients said that their usual source of care was a private physician, and only 17 per cent usually sought care in the emergency room. After Medicare 58 per cent reported a private physician and 31 per cent the emergency room. These findings together with the increased population density of physicians and increased annual number of physician visits per person suggest that there has been a substantial rise in demand from the public for medical care of which one important early manifestation is an increased reliance on emergency rooms.

Attitude to Health↗
PubMed1998

Does practice make perfect? Examining the relationship between hospital surgical volume and outcomes for hip fracture patients in Quebec.

OBJECTIVES: Most tests of the practice-makes-perfect hypothesis have used cross-sectional data, which reveal that patients receiving surgery in high-volume hospitals tend to experience better postsurgery outcomes. This study uses longitudinal data to explicitly examine whether any given hospital's patient outcomes change as its surgery volume varies with time. METHODS: Longitudinal data from all hospitals conducting hip fracture surgery in Quebec between 1990 and 1993 were used to examine the relationship between surgery volume and outcomes. The longitudinal data allowed volume to be measured using the actual number of surgeries performed by the admitting hospital in the 12 months before a patient's surgery. Determinants of postsurgery length of stay were assessed using ordinary least squares regression, and the explanators of inpatient mortality were identified using logistic regression. The regressions included fixed effects (hospital-specific dummy variables) to control for systematic differences in outcomes across hospitals that persist with time. Therefore, the coefficient on hip fracture surgery volume in the regression models captured differences in outcomes that were attributable to changes in surgery volume within hospitals with time. RESULTS: The fixed effects were significant explanators of both postsurgery length of stay and inpatient mortality, indicating that there were significant differences in outcomes across hospitals that persisted with time. In regressions that excluded the fixed effects, the coefficient on surgery volume was significant. In contrast, the coefficient on surgery volume was insignificant when the fixed effects were included. CONCLUSIONS: Longitudinal data revealed that after controlling for differences in hospital outcomes that were fixed with time, hospitals performing more surgeries in one period than in another experienced no significant improvement in outcomes. These results do not support the "practice makes perfect" hypothesis. The volume-outcome relationship for hip fracture patients thus appears to reflect fixed differences in quality between high-volume and low-volume hospitals.

Comorbidity↗
PubMed1999

Factors associated with hepatitis B vaccination among men having sexual relations with men in Montreal, Quebec, Canada. Omega Study Group.

OBJECTIVE: To determine factors associated with hepatitis B virus (HBV) vaccination status among HIV-uninfected men who have affective and sexual relations with men (MASM) in Montreal, Quebec, Canada. METHODS: The Omega Cohort is a study of the incidence and psychosocial determinants of HIV infection among MASM in Montreal. Participants complete a questionnaire and are HIV-tested every 6 months. At baseline, we also performed testing for HBV markers and collected data on HBV vaccination history. RESULTS: Forty-six percent of 653 participants had received at least one dose of HBV vaccination, whereas 28% were completely vaccinated. Lack of vaccination was associated with injection drug use, having > or =20 regular lifetime partners, living outside Montreal, not having sex in bathhouses, and not having consulted a physician aware of the participant's sexual orientation. Among vaccinated MASM, incomplete vaccination was associated with having <20 lifetime casual partners, trading sex for drugs, having given goods for sex, having had unprotected anal sex with regular partners, and having no history of a previous sexually transmitted disease. CONCLUSION: A significant proportion of Montreal's MASM, some of whom are at risk of contracting HBV through sexual and parenteral transmission, have not been vaccinated for HBV. Men who have affective and sexual relations with men should be educated about the risk of HBV transmission and the seriousness of the disease.

Adolescent↗
PubMed2001

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among at-risk women, young sex workers, and street youth attending community organizations in Quebec City, Canada.

BACKGROUND: Despite a relatively recent decline in the global incidence of Chlamydia trachomatis and Neisseria gonorrhoeae it seems that some segments of the population such as street youth, sex workers, and individuals with social problems or delinquent behavior could be part of a core group for STDs. These persons may be reluctant to undergo STD diagnosis in traditional medical settings. GOALS: To determine the prevalence of C trachomatis and N gonorrhoeae infection using polymerase chain reaction on urine samples among subjects attending an anonymous HIV testing clinic and four community organizations in Quebec City, and to identify associated risk factors. STUDY DESIGN: A cross-sectional study of 626 street youth, sex workers, and women with social problems or delinquent behavior was conducted. RESULTS: The prevalences of N gonorrhoeae and C trachomatis were, respectively, 1.1% (95% CI, 0.5%--2.3%) and 5.8% (95% CI, 4.1%--7.9%). No significant difference was found between men and women, but the sexually transmitted disease (STD) prevalence was much higher in subjects younger than 20 years: 11.4% versus 3.6% (P < 0.01). In a logistic regression model, factors independently associated with STD infection were age younger than 20 years (OR, 2.6; P = 0.007), occasional sex partners (OR, 2.9; P = 0.007), and injection of drugs (OR, 2.8; P = 0.002) in the preceding 6 months. CONCLUSIONS: A moderate STD prevalence was found in the study population. The prevalence, however, can be considered high (>10%) among street youth and young sex workers. Providing community-based STD screening and treatment services appear to be an efficient method for reaching these high-risk groups.

Adolescent↗
PubMed2005

Plasminogen-activator inhibitor-1 polymorphisms are associated with obesity and fat distribution in the Quebec Family Study: evidence of interactions with menopause.

OBJECTIVE: Obesity is associated with increased plasma levels of plasminogen-activator inhibitor-1 (PAI1), the major fibrinolysis inhibitor. PAI1 levels are also increased at menopause, a condition that is associated with fat mass gain, especially in the abdominal area. DESIGN: We hypothesized that genetic variations within PAI1 gene are related to the amount of body fat and its regional distribution. We genotyped 666 subjects of the Quebec Family Study for five PAI1 gene polymorphisms. Stratified analyses were performed with analysis of covariance in men (n = 280) and women (n = 386) separately. RESULTS: PAI1-675 4G/5G polymorphism was strongly associated with body mass index (P < or = 0.01) and fat mass (P < or = 0.05) in women. The PAI1-675 4G/5G promoter polymorphism and the c.43G<A (p.A15T, rs6092) variant within the exon 1 were associated with abdominal visceral fat but only in postmenopausal women (P < or = 0.05). More specifically, homozygotes for the -675 5G and the 43A alleles had about 50% more visceral fat compared to carriers of the -675 4G allele as well as carriers of the 43G allele. No association was observed in men. CONCLUSION: Taken together, these results suggest that the PAI1 gene is associated with obesity and may modulate the changes in adipose tissue distribution generally observed at menopause.

Adipose Tissue↗
PubMed1998

Effects of the intensity and timing of asbestos exposure on lung cancer risk at two mining areas in Quebec.

Mortality data from 9609 workers at two asbestos mining areas in Quebec were analyzed to assess the effects of the intensity and timing of exposure on lung cancer risk. Summary exposure measures based on differing assumption were computed for lung cancer cases and matched controls and were fitted to the data using conditional logistic regression. A non-linear relationship between intensity and risk fit both mining areas, but risk was greater at one area than the other. At the mine with lower risk, exposure occurring more than 30 years prior to death had little effect, while at the other mine risk did not vary with time since exposure and men starting employment before 1924 were at elevated risk. The results point to differences in dust composition at the two areas and illustrate the difficulties in estimating risk.

Adult↗
PubMed2004

Injuries among skiers and snowboarders in Quebec.

BACKGROUND: Snow sports such as skiing and snowboarding are recognized as hazardous, but population-based injury rates or specific risk factors have been difficult to estimate as a result of a lack of complete data for both numerator and denominator. METHODS: We used data from 3 surveys to estimate the number of participants and annual number of outings in Quebec by age, sex, activity, and calendar year. Injuries reported by ski patrollers were used to estimate injury rates among skiers and snowboarders for the head and neck, trunk, upper extremity, and lower extremity. RESULTS: Head-neck and trunk injury rates increased over time from 1995-1996 to 1999-2000. There was a steady increase in the rate of injury with younger age for all body regions. The rate of head-neck injury was 50% higher in snowboarders than in skiers (adjusted rate ratio [ARR] = 1.5; 95% confidence interval = 1.3-1.8). Women and girls had a lower rate of head-neck injury (0.73; 0.62-0.87). Snowboarders were twice as likely as skiers to have injuries of the trunk (2.1; 1.7-2.6), and more than 3 times as likely to have injuries of the upper extremities (3.4; 2.9-4.1). Snowboarders had a lower rate of injury only of the lower extremities (0.79; 0.66-0.95). Snowboarder collision-related injury rates increased substantially over time. CONCLUSIONS: Except for lower extremity injuries, snowboarders have a higher rate of injuries than skiers. Furthermore, collision-related injury rates have increased over time for snowboarders. Targeted injury prevention strategies in this group seem justified.

Adolescent↗
PubMed2003

Factors associated with pattern of care before surgery for breast cancer in Quebec between 1992 and 1997.

BACKGROUND: Practice guidelines for breast cancer emphasize the importance of establishing an accurate diagnosis using a minimum number of procedures and selecting optimal treatment regimens. Understanding the determinants of waiting time is essential to develop optimum interventions to reduce delay. OBJECTIVES: The purpose of this study is to estimate the extent to which variability in 1) the number of procedures before surgery and 2) waiting time from initial procedure to surgery are explainable by factors related to the woman, to the provider, and to the care setting. RESEARCH DESIGN: Records of physicians' fee-for-service claims were obtained for 23,370 women undergoing breast cancer surgery in Quebec between 1992 and 1997. Multilevel logistic regression was used to determine predictors of having multiple procedures before surgery. Hierarchical linear regression models were used to identify predictors of waiting time, separately for women with lymph node involvement and without this involvement. RESULTS: Overall, 23% of the women had 3 or more procedures before surgery with significant variation found across hospitals and surgeons. Number of procedures was a strong predictor of waiting time. Waiting time also varied by stage, age, comorbidity, a history of benign disease, surgical setting, calendar time, month of initial procedure, and hospital teaching status. CONCLUSION: Although variability in waiting time was more strongly influenced by the characteristics of the women rather than by physician- or hospital-related factors, most variation remained unexplained by the factors included in this study. To reduce overall waiting time, strategies would need to be systemically applied.

Adult↗
PubMed2004

Risks of adverse pregnancy outcomes among Inuit and North American Indian women in Quebec, 1985-97.

We used Statistics Canada's linked stillbirth, live birth and infant death files to assess the risks of adverse pregnancy outcomes among Inuit and North American Indian vs. other ethnic women in Quebec, 1985-97 (1 125 462 singleton births). Mother tongue was used to define ethnicity, with the largest French language group as the reference. Main outcome measures are adjusted odds ratios (AOR) for preterm birth, small-for-gestational-age (SGA), stillbirth, neonatal and postneonatal death controlled for maternal age, education, marital status, parity, infant sex, community size, and community-level random effects using multilevel logit models. Inuit women had higher risks of preterm birth (AOR = 1.49, 95% CI [1.25, 1.78]) and immaturity-related infant mortality (AOR = 3.03 [1.36, 6.74]), while Indian women did not. Infants of Inuit (AOR = 0.39 [0.31, 0.49]) and Indian (AOR = 0.27 [0.24, 0.31]) women had substantially lower risks of SGA. Elevated risks of stillbirth were observed among Indian women [AOR = 1.53 (1.09, 2.15)], and of postneonatal death among both Inuit (AOR = 4.45 [2.74, 7.22]) and Indian (AOR = 1.86 [1.28, 2.70]) infants. Both Inuit and Indian infants had much higher risks of sudden infant death syndrome (SIDS) and infection-related mortality. Although the absolute risks of adverse outcomes declined from 1985-87 to 1995-97, the relative disparities between aboriginal and non-aboriginal women changed little over this period. We conclude that Inuit and Indian women have different risk profiles for adverse pregnancy outcomes, and that prevention of preterm birth among Inuit women, and of SIDS and infection-related infant mortality in both aboriginal groups, are important targets for future research and intervention.

Adult↗
PubMed1991

Genetic epidemiology of cystic fibrosis in Saguenay-Lac-St-Jean (Quebec, Canada).

Cystic fibrosis (CF) is an autosomal recessive disorder with a prevalence at birth estimated at 1/2000-1/2500 livebirths in Caucasian populations. Some 127 CF individuals are known in Saguenay-Lac-St-Jean (SLSJ), a geographically isolated region of Quebec. The prevalence at birth was estimated at 1/902 live borns, and the carrier rate was estimated at 1/15 inhabitants in the SLSJ region. The mean inbreeding coefficient was only slightly elevated in the CF group compared with three control groups, and was due to remote consanguinity. The mean kinship coefficient was 2.4 times higher in the CF group than in the control groups. In SLSJ region, the places of origin of the CF individuals and their parents did not show a clustered nonuniform distribution. Endogamy was not higher in the CF group than in control groups.

Consanguinity↗
PubMed2004

Putative common origin of two MLH1 mutations in Italian-Quebec hereditary non-polyposis colorectal cancer families.

Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common inherited cancer syndromes, accounting for 3-5% of all cases of colorectal cancer. In most HNPCC families, the disease is caused by a germline mutation in MLH1 or MSH2. In some populations, founder mutations appear to explain a substantial fraction of HNPCC. We report here the identification and preliminary characterization of two putative MLH1 founder mutations. The mutation MLH1c.1831delAT was shown to segregate in two Quebec families of Italian origin who fulfilled the Amsterdam criteria for HNPCC. Haplotype analysis using five intragenic microsatellite/single nucleotide polymorphism markers spanning MLH1 on chromosome 3 showed that these two unrelated families share an identical haplotype. In addition, two other Italian kindred whose affected members carry MLH1g.IVS6 + 3A>G also share a common haplotype, suggesting that, similarly, the latter mutation has a common origin. These mutations are the first putative founder MLH1 mutations to be identified in HNPCC kindred of Italian origin.

Adaptor Proteins, Signal Transducing↗