Biomedical subjects

Kim L Lavoie

Publications and source records attributed to Kim L Lavoie.

9 recordsLinked to original sources

PubMed2006

Asthma self-efficacy, high frequency heart rate variability, and airflow obstruction during negative affect in daily life.

BACKGROUND: Emotional stress has been considered an important asthma trigger for years, though the mechanisms by which stress may exacerbate asthma remain poorly understood. The stress-asthma morbidity association could occur through cognitive-behavioral pathways, such as decreased asthma self-efficacy and disorganized self-care, or through the more direct physiological effects of stress on autonomic (parasympathetic) nervous system activity. No study has examined how these two mechanisms may interact to contribute to greater airflow obstruction during emotional stress in daily life. This study investigated associations between peak expiratory flow rate (PEFR) and high frequency heart rate variability (HFHRV) during periods of negative affect and physical activity in daily life in patients with higher versus lower asthma self-efficacy scores. METHODS: Fifty-three patients with mild to moderate asthma completed the Asthma Self-Efficacy Scale (ASES) and underwent a 15 h ambulatory assessment of daytime HFHRV and PEFR, while completing self-report diaries of their physical activities and affect. RESULTS: In patients with lower asthma self-efficacy scores, increased levels of negative affect during daily life were associated with higher levels of HFHRV and decreased PEFR relative to patients with higher asthma self-efficacy scores. Increased levels of physical activity were associated with decreased levels of HFHRV irrespective of asthma self-efficacy scores. CONCLUSIONS: Findings suggest that lower asthma self-efficacy may be associated with increased parasympathetic activity and airflow obstruction during periods of negative affect during daily life.

Activities of Daily Living↗

PubMed2006

What is worse for asthma control and quality of life: depressive disorders, anxiety disorders, or both?

BACKGROUND: The high burden of asthma appears to be related to poor asthma control. Although previous studies have reported associations between depressive disorders (DDs) and anxiety disorders (ADs) and worse asthma control and quality of life, the relative impact of these disorders on asthma control and quality of life has not been explored. This study evaluated the relative impact of having a DD and/or AD on asthma control and quality of life. METHOD: Five hundred four consecutive adults with confirmed, physician-diagnosed asthma underwent a brief, structured psychiatric interview using the Primary Care Evaluation of Mental Disorders. Asthma control and asthma-related quality of life were assessed using the Asthma Control Questionnaire (ACQ) and the Asthma Quality of Life Questionnaire (AQLQ). All patients underwent standard spirometry. RESULTS: Thirty-one percent of patients (n = 157) met the diagnostic criteria for one or more psychiatric disorders (8% had DD only, 12% had AD only, and 11% had both). Analyses revealed independent effects for DDs on total ACQ scores (p < 0.01), and for DDs and ADs on total AQLQ scores and all four AQLQ subscales (p < 0.05). There were no interaction effects. CONCLUSIONS: Results suggest that DDs and ADs are associated with worse asthma-related quality of life, but only DDs are associated with worse asthma control. Interestingly, having both a DD and an AD did not confer additional risk for worse asthma control or quality of life. Physicians may want to consider the differential impact of negative mood states when assessing levels of asthma control and quality of life.

Adult↗

PubMed2006

Prescription privileges for psychologists: a comprehensive review and critical analysis of current issues and controversies.

The debate over whether clinical psychologists should be granted the right to prescribe psychoactive medications has received considerable attention over the past 2 decades in North America and, more recently, in the UK. Proponents of granting prescription privileges to clinical psychologists argue that mental healthcare services are in crisis and that the mental health needs of society are not being met. They attribute this crisis primarily to the inappropriate prescribing practices of general practitioners and a persistent shortage of psychiatrists. It is believed that, as they would increase the scope of the practice of psychology, prescription privileges for psychologists would enhance mental health services by increasing public access to qualified professionals who are able to prescribe. The profession of psychology remains divided on the issue, and opponents have been equally outspoken in their arguments. The purpose of the present article is to place the pursuit of prescription privileges for psychologists in context by discussing the historical antecedents and major forces driving the debate. The major arguments put forth for and against prescription privileges for psychologists are presented, followed by a critical analysis of the validity and coherence of those arguments. Through this analysis, the following question is addressed. Is there currently sufficient empirical support for the desirability, feasibility, safety and cost effectiveness of granting prescription privileges to psychologists? Although proponents of granting prescription privileges to psychologists present several compelling arguments in favour of this practice, there remains a consistent lack of empirical evidence for the desirability, feasibility, safety and cost effectiveness of this proposal. More research is needed before we can conclude that prescription privileges for psychologists are a safe and logical solution to the problems facing the mental healthcare system.

Drug Prescriptions↗

PubMed2005

Higher BMI is associated with worse asthma control and quality of life but not asthma severity.

Asthma and obesity tend to co-occur, but relatively few studies have linked obesity, measured using body mass index (BMI), to clinically relevant measures of asthma morbidity. This study assessed BMI in a Canadian sample of asthma outpatients, and evaluated associations between BMI and levels of asthma severity, asthma control, and asthma-related quality of life. A total of 382 adult asthma patients underwent demographic and medical history interviews on the day of their clinic visit. Patients' self-reported height and weight were used to calculate BMI (kg/m(2)). Asthma severity was classified according the GINA (2002) guidelines. Patients completed the Asthma Control (ACQ) and Asthma Quality of Life (AQLQ) Questionnaires and underwent standard pulmonary testing (spirometry). A total of 139 (36%) patients had a normal BMI; 149 (39%) patients were overweight; and 94 (25%) patients were obese. There was no relationship between BMI and asthma severity when controlling for age and sex. Patients with higher BMI scores had higher ACQ and lower AQLQ scores, independent of age, sex and asthma severity. Results identify higher BMI and obesity as potential behavioral factors related to worse asthma control and quality of life, but not asthma severity, and suggest important avenues for asthma management and control initiatives.

Adult↗

PubMed2005

Hemodynamic, hemostatic, and endothelial reactions to psychological and physical stress in coronary artery disease patients.

Episodes of psychological and physical stress may elicit thrombotic cardiac events, such as myocardial infarction. These events are triggered when there are concurrent hemodynamic, hemostatic, and endothelial abnormalities. Hemodynamic, hemostatic, and endothelial reactions of 72 (15 women, 57 men) coronary artery disease patients to psychological and physical stress were examined. Blood pressure, electrocardiography, and impedance cardiography were recorded during rest, mental arithmetic, and exercise. Blood was collected, via catheter, at rest and after each task. Mental arithmetic elicited increases in blood pressure, heart rate, cardiac output, and cardiac contractility, but no consistent changes in hemostatic and endothelial markers. In contrast, exercise, in addition to increasing blood pressure, heart rate, cardiac output, cardiac contractility, and lowering peripheral resistance, elicited increases in plasma viscosity, hematocrit, platelets, and tissue plasminogen activator together with a decrease in plasminogen activator inhibitor. This pattern of hemodynamic, hemostatic, and endothelial reactions suggests that acute psychological and physical stress influence the thrombotic system differently in these high risk patients. Future research is needed to investigate how these stress responses are prospectively related to acute cardiac events.

Acute Disease↗

PubMed2005

Are psychiatric disorders associated with worse asthma control and quality of life in asthma patients?

BACKGROUND: Achieving good asthma control has become the major goal of asthma treatment. Studies have reported a high rate of psychiatric disorders among asthma patients, though the impact of these disorders on asthma control and quality of life remains unexplored. This study evaluated the prevalence of psychiatric disorders in 406 adult asthma patients, and associations between psychiatric status, levels of asthma control, and asthma-related quality of life. METHODS: Consecutive asthma patients presenting to the asthma clinic underwent a brief, structured psychiatric interview, completed the Asthma Control Questionnaire (ACQ) and Asthma Quality of Life Questionnaire (AQLQ), and reported the frequency of bronchodilator use in the past week. All patients underwent standard pulmonary function testing. RESULTS: A total of 34% (n=136) of patients had one or more psychiatric diagnosis, including major depression (15%), minor depression (5%), dysthymia (4%), panic disorder (12%), generalized anxiety disorder (5%), and social phobia (4%). Though there were no differences in pulmonary function, patients with versus without psychiatric disorders had worse ACQ and AQLQ scores and reported greater bronchodilator use, independent age, sex and asthma severity. CONCLUSIONS: Results suggest that psychiatric disorders are prevalent among asthmatics and are associated with worse asthma control and quality of life. Physicians should be aware of the potential risk of poorer asthma control and functional impairment in this population.

Adult↗

PubMed2004

Heart rate variability in coronary artery disease patients with and without panic disorder.

Panic disorder (PD) and coronary artery disease (CAD) often co-occur, and CAD patients with comorbid PD suffer greater cardiovascular morbidity and mortality relative to CAD patients without PD. However, the mechanisms underlying these associations are still unknown. Reduced heart rate variability (HRV), a non-invasive measure of cardiac autonomic modulation, is an important predictor of adverse cardiac events. Interestingly, reduced HRV has been observed in patients with panic-like anxiety and PD, as well as in various CAD populations. However, the extent to which HRV is altered in patients with both PD and CAD is unknown. This study evaluated HRV in 42 CAD patients with (n=20) and without (n=22) PD. Patients underwent 48-h electrocardiographic monitoring. Power spectral analysis of HRV indicated that CAD patients with PD exhibited significantly lower LF/HF ratios, which may reflect lower sympathetic modulation, compared with non-PD patients. Additionally, total power in PD patients was made up of a significantly higher proportion of HF power and a significantly lower proportion of VLF power than in non-PD patients. No other significant differences in HRV indices were observed. Results suggest that contrary to what has been observed in the majority of PD-only and CAD-only populations; patients with both PD and CAD appear to exhibit lower sympathetic modulation during ordinary daily life conditions. Though preliminary, these findings suggest that changes in HRV may not be the mechanism underlying greater cardiovascular morbidity and mortality among CAD patients with PD.

Activities of Daily Living↗

PubMed2004

Are exercise stress tests appropriate for assessing myocardial ischemia in patients with major depressive disorder?

BACKGROUND: Major depressive disorder (MDD) disproportionately affects patients with coronary artery disease (CAD). Evidence of myocardial ischemia with electrocardiography (ECG) or single-photon-emission-computed-tomography (SPECT) assessments during exercise testing is an important determinant of CAD prognosis. However, many key symptoms of MDD, such as reduced interest in daily activities, lack of energy, and fatigue, may affect exercise performance and the detection of ischemia in patients with MDD. This study evaluated the extent to which MDD and depressive symptomatology moderate exercise test performance and compared the ability of ECG versus SPECT for detecting ischemia in 1367 consecutive patients who underwent exercise testing. METHODS: All patients underwent a brief, structured psychiatric interview (PRIME-MD) and completed the Beck Depression Inventory (BDI) on the day of their exercise (treadmill) test. RESULTS: A total of 183 patients (13%) met diagnostic criteria for MDD. Patients with MDD achieved a significantly lower percent of maximal predicted heart rate (%MPHR), exhibited lower peak exercise mets, and spent less time exercising compared with patients without MDD (all P values <.05). BDI scores were also negatively correlated with all 3 indices of exercise performance (all P values <.01). There were no differences in rates of SPECT ischemia in patients with MDD (40%) versus patients without MDD (45%; P =.23); however, rates of ECG ischemia were significantly lower (30%) in patients with MDD than in patients without MDD (48%; P <.0001). CONCLUSIONS: Results suggest that patients with CAD who have MDD, depressive symptomatology, or both exhibit poor exercise tolerance and performance and that ECG, as compared with SPECT, may not be as reliable in detecting ischemia in patients who are depressed.

Analysis of Variance↗

PubMed2002

Should psychologists be granted prescription privileges? A review of the prescription privilege debate for psychiatrists.

BACKGROUND: The debate over whether clinical psychologists should be granted the right to prescribe psychoactive medication has received considerable attention over the last 2 decades in the US, but there has been relatively little discussion of this controversial topic among Canadian mental health professionals, namely psychologists and psychiatrists. Proponents of prescription privileges (PPs), including the American Psychological Association (APA), argue that psychologists do not and cannot function as independent professionals because the medical profession places many restrictions on their practice. It is believed that PPs would help circumvent professional psychology's impending marginalization by increasing psychology's scope of practice. Proponents also argue that PPs would enhance mental health services by increasing public access to professionals who can prescribe. OBJECTIVE: The purpose of this article is to inform psychiatrists about the major arguments presented for and against PPs for psychologists and to discuss the major implications of PPs for both professional psychology and psychiatry. METHODS: We conducted a literature search of relevant articles published from 1980 to the present appearing on Psychlit and Medline databases, using "prescription privileges" and "psychologists" as search titles. CONCLUSION: Although proponents present several compelling arguments in favour of PPs for psychologists, pilot projects relating to feasibility and efficacy are either sparse or incomplete. Thus, it is too soon to tell whether PPs could or should be pursued. Clearly, more research is needed before we conclude that PPs for psychologists are a safe and necessary solution to psychology's alleged impending marginalization.

Canada↗