Biomedical subjects

F Bellavance

Publications and source records attributed to F Bellavance.

At least 37 records · Page 2Linked to original sources

PubMed1999

Low incidence of severe adverse effects after mandibular ridge reconstruction using hydroxylapatite.

The short and long term adverse effects after ridge reconstruction using hydroxylapatite (HA) are presented in this study. The HA was inserted using a modified tunnelling technique, followed by a lowering of the floor of the mouth and a vestibuloplasty using split thickness skin graft, 4-6 weeks later. The study comprised 637 patients followed for a period of 1 to 10 years (mean 6.0+/-2.6 years). Major loss of HA was seen in 17 patients (2.7%). Donor site visibility (skin graft) appeared to improve greatly over the years from 29.2% to 8.8% at the latest follow-up. Neurosurgery deficits also improved from 11.6% (paraesthesia and dysaesthesia) to 4.6%. Long term follow-up revealed a high percentage of patient satisfaction (97%), indicating that the low incidence of severe adverse effects of the procedure does play a significant role in the appreciation of the procedure and prosthetic care.

Adult↗

PubMed1998

The role of the beta-noradrenergic system in cholecystokinin-tetrapeptide-induced panic symptoms.

BACKGROUND: The authors determined whether effective beta-adrenergic blockade could attenuate the panicogenic effects of cholecystokinin-tetrapeptide (CCK-4) in healthy volunteers. METHODS: Subjects were randomly assigned to either a propranolol (n = 14) or placebo (n = 16) infusion. Ten minutes after completion of the infusion subjects received a bolus injection of CCK-4 (50 micrograms). RESULTS: Acute pretreatment with propranolol was more effective than placebo in decreasing behavioral and cardiovascular sensitivity. CONCLUSIONS: These preliminary results suggest that the panicogenic effects of CCK-4 are mediated, in part, through the beta-adrenergic system.

Adult↗

PubMed1998

Mercury levels in the Cree population of James Bay, Quebec, from 1988 to 1993/94.

BACKGROUND: High levels of mercury in the Cree population of James Bay, Que., have been a cause of concern for several years. This study examines changes in mercury levels within the Cree population between 1988 and 1993/94 and identifies potential determinants of high mercury levels. METHODS: Data on mercury levels among the Cree were obtained through a surveillance program undertaken by the Cree Board of Health and Social Services of James Bay. In 1988 and again in 1993/94 surveys were carried out in all 9 Cree communities of northern Quebec. Hair samples were obtained and analysed for mercury content. Analyses were carried out to determine the proportion of people who had mercury levels in excess of established norms. Changes in mercury levels between 1988 and 1993/94 and determinants of high levels were estimated by means of regression methods. RESULTS: The proportion of the Cree population with mercury levels in excess of 15.0 mg/kg declined from 14.2% in 1988 to 2.7% in 1993/94. Wide variations in mercury levels were observed between communities: 0.6% and 8.3% of the Eastmain and Whapmagoostui communities respectively had mercury levels of 15.0 mg/kg or greater in 1993/94. Logistic regression analyses showed that significantly higher levels of mercury were independently associated with male sex, increasing age and trapper status. There was a correlation between the mercury level of the head of the household and that of the spouse. INTERPRETATION: Mercury levels in the Cree of James Bay have decreased in the recent past. Nevertheless, this decrease in mercury levels may not be permanent and does not necessarily imply that the issue is definitively resolved.

Adolescent↗

PubMed1998

Effectiveness of treatments of depression in older ambulatory patients.

OBJECTIVE: To determine the effectiveness of acute-phase pharmacological and psychological treatments of depression in older ambulatory patients by systematically reviewing original research relevant to this topic. METHODS: Searches in MEDLINE and PsycINFO and manual reviews of bibliographies located 233 articles. Of these, 40 (37 different studies) met our 8 inclusion criteria: original research, written in English or French, subjects 55 years and older, diagnosis of depression, outpatient or community setting, prospective controlled study design, acute-phase pharmacological or psychological treatment, and outcome measure of depression. Two independent reviewers assessed the methodological quality of each article using a standard form and a quality score was computed. Quantitative data on levels of depression at the end of treatment were abstracted. Results were grouped by specific treatment comparison (type of treatment and type of control group). For comparisons that used the Hamilton Depression Rating Scale, we computed mean posttreatment differences. Effect sizes were computed from the Hamilton Depression Rating Scale or an alternative scale. RESULTS: In studies that compared active drugs with placebo, the heterocyclic drugs significantly reduced the posttreatment Hamilton Depression Rating Scale score (mean difference, -5.78; 95% confidence interval, -8.31 to -3.25); other drugs had smaller effects. In studies that compared active drugs, there were no significant differences overall between different classes of drugs; selective serotonin reuptake inhibitors appeared to be as effective as heterocyclic drugs. Rational psychological treatments performed significantly better than no treatment (mean posttreatment Hamilton Depression Rating Scale difference, -7.25; 95% confidence interval, -10.10 to -4.40) but not significantly better than that for controls who received similar attention. Adjustment for the study quality score did not affect these results. CONCLUSIONS: Based on comparisons with untreated controls, heterocyclic antidepressants and rational psychological therapies appear to be the most effective treatments for older ambulatory patients with mild to moderate depression. Based on drug-drug comparisons, selective serotonin reuptake inhibitors appear to be as effective as heterocyclic drugs. However, overall, the magnitude of the treatment effects is modest. Limitations in the quantity and quality of appropriate studies suggest a sober approach to treatment in this population.

Acute Disease↗

PubMed1998

Detection and diagnosis of delirium in the elderly: psychiatrist diagnosis, confusion assessment method, or consensus diagnosis?

The clinical diagnosis of delirium has traditionally been based on an assessment by one or more physicians. Because of the transient, ubiquitous, and fluctuating nature of the symptoms of delirium, however, this approach may be flawed. Therefore, we decided to compare diagnosis based on one assessment by a psychiatrist, diagnosis by a nurse clinician (using the Confusion Assessment Method [CAM] and multiple observation points), and diagnosis by consensus. The study subjects were 87 patients aged 65 and over who were admitted consecutively from the emergency department to the medical wards, and who scored 3 or more on the Short Portable Mental Status Questionnaire. All subjects were assessed independently by one of three psychiatrists (a chart review and clinical examination) and a nurse clinician (using the CAM and multiple observation points). A consensus conference, attended by the three psychiatrists and the nurse clinician, used all available information to reach a consensus diagnosis. Compared to the consensus diagnosis, the clinical diagnosis by a psychiatrist had a sensitivity of .73 (95% confidence interval [CI]: .61-.85), a specificity of .93 (95% CI: .79-1.0), and an agreement kappa coefficient of .58 (95% CI: .41-.74). The nurse clinician diagnosis had a sensitivity of .89 (95% CI: .81-.97), a specificity of 1.00, and an agreement kappa coefficient of .86 (95% CI: .75-.97). These results suggest that one clinical assessment by a psychiatrist may not be the best method for detecting and diagnosing delirium in the elderly. A consensus diagnosis or diagnosis by a trained rater (using the CAM and multiple observation points) may be more sensitive approaches.

Aged↗

PubMed1998

Reliability and validity of a new measure of severity of delirium.

The objective of this study was to assess the psychometric properties of a new instrument, the Delirium Index (DI), to measure changes in the severity of the symptoms of delirium among patients previously diagnosed with delirium. Subjects were medical inpatients aged 65 and over diagnosed with delirium by the Confusion Assessment Method. Interrater reliability of the DI was .78 between research assistants (concordance coefficient) and was .88 between research assistants and geriatric psychiatrists. Criterion validity, assessed by the correlation between DI and Delirium Rating Scale scores (Spearman's correlation coefficient, r), was .84. Construct validity was assessed using correlations of the DI with two measures of current function for convergent validity (r = -.60, -.70) and two measures of function before admission for discriminant validity (r = .26,-.42). We conclude that the DI has acceptable levels of interrater reliability, criterion validity, and construct validity.

Aged↗

PubMed1998

Delirium risk factors in elderly hospitalized patients.

OBJECTIVE: Delirium is frequent in elderly hospitalized patients. Many studies have examined its risk factors, but results have been quite variable. Thus, the goal of this study is to identify through systematic literature review the risk factors associated with the development of delirium in hospitalized geriatric patients. MEASUREMENTS AND MAIN RESULTS: First, MEDLINE/CURRENT CONTENTS databases were screened for relevant articles published from 1966 to December 1995, and from bibliographies of identified articles additional reports were selected. Second, the reports were screened by two different investigators and retained only if meeting the five following criteria: (1) original research in French or English; (2) prospective study; (3) patients over age 50; (4) minimum of one risk factor examined; (5) acceptable definition of delirium. Third, the methodology of each study was graded according to specific criteria for risk factor studies. Fourth, risk factors were identified and tabulated, unadjusted odds ratios (ORs) were computed, and where appropriate a combined OR with the Mantel-Haenszel estimator was calculated. Twenty-seven articles were retained meeting all of the above criteria. Among these studies, 11 were done on medical patients, 9 on surgical patients, 2 on medical and surgical patients, and 5 on psychiatric patients. In total 1,365 subjects with delirium were studied. Sixty-one different risk factors were examined, the five most common being dementia, medication, medical illness, age, and male gender. Mantel-Haenszel estimator was calculated for 10 risk factors, the most strongly associated being dementia (OR 5.2; 95% confidence interval [CI] 4.2, 6.3), medical illness (OR 3.8; 95% CI 2.2, 6.4), alcohol abuse (OR 3.3; 95% CI 1.9, 5.5), and depression (OR 1.9; 95% CI 1.3, 2.6). Methodologic weaknesses were present in many studies. CONCLUSIONS: Despite methodologic limitations, certain risk factors for delirium seem to be consistent and could help identify high-risk patients. These risk factors include dementia, advanced age, and medical illness. Other risk factors appear to play a contributory role in the development of delirium in elderly hospitalized patients.

Age Factors↗

PubMed1998

Factors associated with symptoms of depression among informal caregivers of demented elders in the community.

This study assessed variables associated with increased severity of depressive symptoms among 321 informal caregivers of demented subjects living in the community identified by a Canadian national population-based survey. Measures included patient and caregiver demographic variables; patient behavioral disturbance, activities of daily living, and cognitive impairment; living arrangement, and duration of disease. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D). Multiple regression analyses indicated that a higher CES-D score was significantly associated with three caregiver characteristics (being a spouse or child of the patient, self-identified ethnicity other than English and French Canadian, and lower education), and two patient characteristics (greater behavioral disturbance and moderate to severe functional impairment).

Adult↗

PubMed1998

Screening for geriatric problems in the emergency department: reliability and validity. Identification of Seniors at Risk (ISAR) Steering Committee.

OBJECTIVE: To determine the test-retest reliability and concurrent criterion validity of a self-report ED screening questionnaire for adverse outcomes in elders. METHODS: A cohort of 1,885 patients aged > or = 65 years were recruited from the EDs of 4 Montreal hospitals. Patients were excluded if they could not be interviewed because of their clinical status or cognitive impairment and no informant was available. The screening questionnaire, administered in the ED, contained 27 items on social, physical, and mental risk factors, medical history, and use of hospital services, medications, and alcohol. A random sample of 404 patients were invited to participate in a clinical assessment 1-3 weeks after the ED visit, that included re-administration of the screening questionnaire, and standardized instruments to assess disability, social resources, depression, alcohol use and abuse, and current medications. RESULTS: Study data were collected from 221 patients (54.7%), of whom 193 were included in the test-retest reliability analyses and 213 in the analyses of concurrent validity. The concordance correlation coefficient for test-retest reliability of the risk factor score was 0.78 (95% confidence interval: 0.71, 0.83; n=193). Several screening questions showed moderately good agreement with the appropriate criterion standard, particularly those on visual and hearing impairment, depression, and use of medications. The best subset of 9 screening questions explained approximately half of the variance in the total disability score. CONCLUSIONS: The screening questionnaire score has good test-retest reliability, but individual screening questions have, at best, modest concurrent validity. The final set of screening questions should be selected based on their predictive validity.

Aged↗

PubMed1997

Depression in elderly medical inpatients: a meta-analysis of outcomes.

OBJECTIVE: To determine the prognosis of elderly medical inpatients with depression. DATA SOURCES: A MEDLINE search for relevant articles published from January 1980 to September 1996 and a search of the PSYCH INFO database for articles published from January 1984 to September 1996. The bibliographies of identified articles were searched for additional references. STUDY SELECTION: Eight reports (involving 265 patients with depression) met the following 5 inclusion criteria: original research, published in English or French, population of general medical inpatients, mean age of depressed patients 60 years and over, and affective state reported as an outcome. The validity of the studies was assessed according to the criteria for prognostic studies described by the Evidence-Based Medicine Working Group. DATA EXTRACTION: Information about the patient population, the proportion of cases detected and treated by attending physicians, the length of follow-up, the affective outcome and the prognostic factors was abstracted from each report. DATA SYNTHESIS: All of the studies had some methodologic limitations. A meta-analysis of outcomes at 3 months or less indicated that 18% of patients were well, 43% were depressed and 22% were dead. At 12 months or more, 19% were well, 29% were depressed and 53% were dead. Factors associated with worse outcomes included more severe depression, more serious physical illness and symptoms of depression before admission. CONCLUSIONS: Elderly medical inpatients who are depressed appear to have a very poor prognosis: the recovery rate among these patients is low and the mortality rate high.

Aged↗

PubMed1997

Predictors of repeat emergency department visits by elders.

OBJECTIVE: To determine which characteristics of older patients who use a hospital ED are associated with repeat visits during the 90 days following the index visit. METHODS: The study was conducted in the ED of a 400-bed university-affiliated acute care community hospital in Montreal. Patients aged > or = 75 years who visited the ED between 08:00 and and 16:00 on a convenience sample of days over an 8-week period (July and August 1994) were assessed using a questionnaire, physical and cognitive status instruments, and a functional problem checklist. The hospital's administrative database was used to identify repeat visits during the 90 days following the ED visit. The representativeness of the sample was assessed by analyses of ED visits made by 4,466 persons aged > or = 65 years during a 12-month period (September 1993 to August 1994) using the hospital's administrative database. RESULTS: 256 patients aged > or = 75 years visited the ED during the study period and 167 were assessed. Of these, 54 (32%) were admitted to the hospital. Among the 113 patients released from the ED, 27 (24%) made repeat visits during the next 90 days. In univariate analyses, repeat visits were significantly associated with the number of functional problems, cognitive impairment, and previous ED visits. In multiple logistic regression, male gender, living alone, and number of functional problems were independent predictors of repeat visits. In the administrative data analyses, nighttime arrival to the ED for the index visit was significantly associated with repeat visits. CONCLUSIONS: Self-reported risk factors can help to identify a group of elders likely to make repeated ED visits; the development of a screening instrument incorporating questions on these problems and implementation of appropriate interventions might improve these patients' quality of life and reduce the demand for further ED care in this age group.

Aged↗

PubMed1997

Use of health services for anxiety disorders: a multisite study in Quebec.

OBJECTIVE: We investigated patient characteristics and use of services for anxiety disorders among patients seeking care from participating clinicians at 7 anxiety clinics in Quebec: 3 general hospital clinics, 3 psychologist-run clinics, and one psychiatric hospital clinic. METHODS: Persons eligible for the study were those who were visiting the clinics for the first time, had a current diagnosis of an anxiety disorder, and could communicate in French or English. Subjects recruited through advertisements were excluded. Data, collected by a self-administered questionnaire, included demographics, treatment history, use of services for anxiety, and the Beck Anxiety Inventory (BAI). RESULTS: The sample comprised 235 subjects: 146 seen at 3 general hospital clinics, 54 at 3 psychologist-run clinics, and 35 at a psychiatric hospital clinic. There were statistically significant differences by clinic type in the prevalence of specific anxiety diagnoses, BAI score, referral source, antidepressant use, and use of services. High-intensity use (10 or more consultations during the previous year) was reported by 23.4% of the sample for medical services and 19.6% for mental health services. Multiple logistic regression identified variables associated with high-intensity use of medical services (higher BAI score, 1 to 4 years since first sought treatment, and less than 12 years of education) and high-intensity use of mental health services (clinic type, obsessive-compulsive disorder [OCD], and 5 or more years since first sought treatment). CONCLUSIONS: The patient populations seen at different types of anxiety clinics differ in several respects, including referral source, previous treatment, and severity of symptoms. Regardless of type of clinic, patients with a longer time since they first sought treatment use more services, particularly mental health services. Those with less education use more medical services than those with greater education.

Adult↗

PubMed1997

The prognosis of depression in old age.

The authors sought to determine the prognosis of depression in old age by reviewing original literature on this topic from three computer databases. All reports used at least 20 patients over age 60, followed up for at least 1 year, with affective status as outcome, and a quantitative meta-analysis was performed to combine results. Sixteen hospital-based and five community-based studies were selected, involving 1,487 and 249 depressed subjects, respectively. Most studies had serious methodological limitations. For combined results, 60% of patients in the hospital-based studies were well or had relapses-with-recovery, and 14%-22% were continuously ill; 19%-34% of community subjects were well; 27% were continuously ill, and most of the remainder had died. Physical illness, cognitive impairment, and severe depressive symptoms were frequently but inconsistently related to poor prognosis. Future studies must attend to composition of study populations and outcome assessment and control of extraneous prognostic factors.

Aged↗

PubMed1997

Ethical conflicts in home care. Patient autonomy and physician advocacy.

OBJECTIVE: To identify whether and how family physicians practising home care resolve ethical dilemmas in clinical management of homebound patients and to examine whether the self-reported, theoretical ethical positions of these physicians match their actual patient management. DESIGN: Cross-sectional survey. SETTING: Quebec community-based home care program. PARTICIPANTS: Quebec family physicians actively involved in community-based home care: 85 men and 65 women. MAIN OUTCOME MEASURES: Physician level of agreement with theoretical ethical statements about autonomy, caregiver needs, and resource allocation; management options chosen for a clinical case vignette; and mechanisms used for resolving conflicts. RESULTS: There were 209 respondents to the 279 questionnaires sent (75%). Of these, 59 who were not currently involved in home care were excluded, leaving 150 participants. Most (83.3%) physicians surveyed agreed with the ethical principle of patient autonomy; 88.7% agreed that the interests of family caregivers are important in decisions regarding patients, and 72.0% agreed that limiting home care services is reasonable in the context of limited resources. In managing a patient, 65.3% of physicians thought the patient should be placed in a nursing home against her wishes because of "danger to self," while 82.7% felt she should be placed if the caregiver is "exhausted." Three quarters of physicians did not limit or decrease home care services, despite noncompliance. CONCLUSIONS: Family physicians practising community-based home care in Quebec have practical views on various ethical principles guiding home care practice. Except in the area of limiting or discontinuing home care services, their ethical framework is reflected in a case vignette of patient management.

Adult↗

PubMed1996

Long-term stability of atrophic ridges reconstructed with hydroxylapatite: a prospective study.

PURPOSE: This article reports the results of an investigation of the long-term efficacy and stability of reconstructive surgery of atrophic ridges using dense hydroxylapatite (HA). PATIENTS AND METHODS: Subperiosteal HA was used as a first stage of reconstruction in 678 ridges, 645 mandibular and 35 maxillary, followed after 4 to 5 weeks by a total lowering of the floor of the mouth, vestibuloplasty, and skin graft in the mandible: a same-stage submucous vestibuloplasty was done in the maxilla. Patients were followed for an average of 5.3 +/- 2.7 years by the same surgical and prosthodontic team. The presence of severe or moderate radiographic change was analyzed in relation to gender, age, severity of atrophy, postoperative complications, clinical changes, patient satisfaction, and type of HA particles used alone or with a binder. RESULTS: Seventy-seven percent of cases had no observable radiographic changes, 13% had moderate changes, and 10% had severe changes, of which fewer than half also had severe clinical changes. Relationships were established between the presence of radiographic change and certain parameters, especially postoperative delay in healing, severe or moderate clinical changes, and type of HA particles used. CONCLUSION: Hydroxylapatite, when used alone or with binding agents, and in association with basic techniques of reconstructive surgery and soft tissue handling, is a predictable and stable biomaterial for ridge reconstruction.

Age Factors↗

PubMed1996

Tests for the analysis of variance of crossover designs with correlated errors.

The usual analysis of variance based on ordinary least squares (OLS) may be inappropriate to analyze the crossover designs because of correlations within subjects arising from the repeated measurements. The tests used with OLS are compared with three alternative tests that take into account the structure of the covariance matrix for testing the treatment and carryover effects under the assumption of multivariate normality. A modified F-test approximation and a test derived from a Pearson curve fit are shown to give adequate control over Type I error compared to the OLS tests and to tests following an empirical generalized least squares analysis.

Analysis of Variance↗

PubMed1996

Excimer laser photorefractive keratectomy: one year follow-up.

BACKGROUND AND OBJECTIVE: To confirm the effectiveness of the 193 nm excimer laser to correct low myopia (1.00 to 6.00 D), moderate myopia (6.00 to 10.00 D), and high myopia (10.00 D and above). PATIENTS AND METHODS: One hundred eighty-one eyes of 114 patients underwent excimer laser photorefractive keratectomy (PRK). The minimum follow-up was 12 months. RESULTS: After one year, 96% of the eyes in the low myopia group, 69% in the moderate myopia group and 29% in the high myopia group achieved uncorrected visual acuity of 20/40 or better with one treatment using a single application with a 5 mm optic zone. There were no significant major complications. CONCLUSION: PRK is a safe, effective and relatively accurate procedure to correct low to moderate myopia.

Adolescent↗

PubMed1992

Epidemiological evidence of an interaction between calcium and sodium intake impacting on blood pressure. A Montréal study.

Nutritional calcium and sodium are considered to be important regulators of blood pressure. This study was performed on 182 randomly selected Canadians from Montréal to test the relative contribution of these ions to systolic and diastolic blood pressure, as well as their interaction with other demographic indices. Multiple analysis of the total study population revealed that 28% (P less than .001) of systolic blood pressure was predicted by gender sodium, and calcium interaction (P = .003), weight, and the additive effect of age and weight. The same characteristics contributed to 37% (P less than .001) of diastolic blood pressure with an additional contribution of alcohol intake. Analysis by terciles of sodium and calcium intake indicated that the positive effect of sodium on blood pressure occurred only in subjects given a low calcium diet, whereas blood pressure was lowest in the tercile of both high calcium and sodium intake. The impact of the sodium and calcium interaction on blood pressure represented as much as a 10 mm Hg decrement of systolic blood pressure with 400 mg calcium/1000 kcal intake at the highest level of sodium consumption and a 6 mm Hg decrease for diastolic blood pressure. In subjects without a family history of hypertension, the same indices contributed up to 53% of systolic and 55% of diastolic blood pressure with a synergetic effect of sodium and calcium, indicating that blood pressure was lowest in subjects given a high calcium and sodium diet. For subjects with a family history of hypertension, there was no significant impact of sodium, whereas calcium intake contributed negatively to both systolic and diastolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗