Biomedical subjects

M Diane Lougheed

Publications and source records attributed to M Diane Lougheed.

5 recordsLinked to original sources

PubMed2006

The Ontario Asthma Regional Variation Study: emergency department visit rates and the relation to hospitalization rates.

BACKGROUND: Hospitalization rates for asthma vary more than threefold across regions of Ontario. It is not known whether this variation is primarily due to regional differences in the rate of emergency department (ED) visits or hospital admissions. OBJECTIVE: To determine the variation in ED visit rates for asthma in Ontario, and the relation between ED visit rates and hospitalization rates. DESIGN, SETTING, AND PATIENTS: We studied patients with an ED disposition diagnosis of asthma in a stratified sample of 16 hospitals (pediatric facilities, 13; adult facilities, 14) over a 1-year period. Pediatric patients were defined as those patients who were </= 19 years of age. MEASUREMENTS: Direct age-standardized and sex-standardized ED visit and hospitalization rates, and the percentages of patients presenting to EDs and subsequently admitted to the hospital were calculated for each site. High/low ratios (ie, extremal quotients [EQ]), weighted coefficients of variation (CVs), and the systematic component of variation (SCV) were used to summarize the variation among hospitals. RESULTS: The total number of ED visits for asthma at participating sites was 12,518 (7,825 children and 4,693 adults). A total of 847 children (10.8%) and 322 adults (6.9%) were admitted to the hospital. Age-standardized and sex-standardized ED visit rates ranged from 8.7 to 25.2 per 1,000 population for children (EQ, 2.9; CV, 30.9%; SCV, 173; p < 0.001) and 1.7 to 10.1 per 1,000 population for adults (EQ, 5.9; CV, 52.9; SCV, 445; p < 0.001). The proportion of pediatric and adult ED visits resulting in admission to the hospital varied significantly by site (p < 0.001) and was inversely related to ED visit rates in children (p < 0.001) but not in adults. ED visit rates were related to hospitalization rates in children (p = 0.042) and adults (p < 0.0001), but only accounted for 4% and 27%, respectively, of the variation in hospitalization rates. CONCLUSION: Hospitalization rates for asthma in Ontario are primarily influenced by the variation in the percentage of ED visitors admitted to the hospital rather than the ED visit rate.

Adolescent↗

PubMed2006

Dynamic hyperinflation during bronchoconstriction in asthma: implications for symptom perception.

OBJECTIVE: The objective of this study was to examine the relationship between respiratory symptom intensity and quality and dynamic lung hyperinflation (DH) during induced bronchoconstriction in asthma. PATIENTS AND METHODS: Subjects with asthma (n = 116) underwent baseline spirometry and lung volume measurement followed by high-dose methacholine challenge testing (MCT) [maximum decrease in FEV(1) of 50% from baseline]. Dyspnea intensity (Borg scale) was measured after each dose of methacholine. Qualitative descriptors of breathlessness and functional residual capacity (FRC) were measured at the doses nearest to the provocative concentration of methacholine causing a 20% fall in FEV (PC(20)) and at the highest dose of methacholine (maximum response). RESULTS: FEV(1) decreased by 24.7 +/- 0.7% (mean +/- SEM) at the dose nearest to PC(20) and by 46.1 +/- 1.1% at maximum response. Inspiratory capacity decreased by 0.62 +/- 0.04 L at the dose nearest to PC(20) and 1.06 +/- 0.06 L at maximum response. The descriptor clusters "inspiratory difficulty," "chest tightness," "unsatisfied inspiration," and "work" were selected at the dose nearest to PC(20) but were more frequently selected at maximum response (p < 0.0001). Individuals who reported chest tightness at maximum response had greater airflow obstruction and higher FRC (percentage of predicted) than those who did not report chest tightness. CONCLUSIONS: Four dominant qualities of dyspnea in asthma (inspiratory difficulty, chest tightness, unsatisfied inspiration, and work) were reported early in the course of MCT and evolved in parallel, becoming more prevalent at maximum response. Significant DH accompanied even mild bronchoconstriction during MCT in asthma, making it difficult to separate mechanisms of chest tightness from other dominant respiratory sensations.

Adult↗

PubMed2005

Perceived control and quality of life in asthma: impact of asthma education.

The purpose of this study was to determine the relationship between patients' perception of asthma control and generic and asthma-specific quality of life (QOL) post-completion of a behavior modification-based adult asthma education program. A secondary objective was to examine associations between changes in perceived control of asthma and generic and asthma-specific QOL. Outcome measures were collected via an asthma management questionnaire (AMQ), generic (SF-36) and asthma-specific (AQLQ) QOL questionnaires, and a perceived control of asthma questionnaire (PCAQ). The cohort (n = 55) consisted of predominately female (75%), married (56%), middle income (46%) patients with severe asthma (65%) who had completed a university or college education (20%) and were working full-time (42%). The mean age was 45.2 (SD = 17.5) years. Perceived control of asthma and generic and asthma-specific quality of life significantly improved after completing the behavior modification-based adult asthma education program. Significant associations were found between perceived control of asthma (PCAQ) and both generic (SF-36) and asthma-specific QOL (AQLQ). Baseline PCAQ was related to all four domains and the total score of the AQLQ and 5 of the 8 domains of the SF-36. PCAQ was related to 3 of the 4 AQLQ domains at 3 months and total AQLQ score at both 1 and 3 months post-education. PCAQ was related to all 8 domains of the SF-36 at 1 month; and 4 of 8 domains at 3 months. Change in PCAQ (deltaPCAQ) was related to change in symptom score, emotional functioning, and total AQLQ score from baseline to 1 month and change in symptom score from baseline to 3 months. In conclusion, perceived control of asthma in patients participating in a behavior modification-based asthma education program was related to generic and disease-specific QOL. An improvement in PCAQ was associated with improved QOL following asthma education. Using the PCAQ as part of an asthma educational needs assessment may be a quick, simple way to identify and target education towards asthma patients with low perceived control.

Adult↗

PubMed2002

Respiratory sensation and ventilatory mechanics during induced bronchoconstriction in spontaneously breathing low cervical quadriplegia.

Intensity of dyspnea during induced bronchoconstriction in asthma is strongly related to the reduction in inspiratory capacity (IC) as a result of dynamic hyperinflation. To determine the role of rib cage and intercostal muscle afferents in symptom perception during bronchoconstriction, we measured the relationship between dyspnea intensity and IC during induced bronchoconstriction in six subjects with complete C4-C7 quadriplegia who did not require assisted ventilation. Spirometry, lung volumes, breathing pattern, esophageal pressure (Pes), and dyspnea intensity (Borg Scale) were measured during high-dose methacholine bronchoprovocation up to 256 mg/ml or a maximum change (Delta) in FEV(1) of 50%. Contemporaneous control data from subjects with asthma (n = 12) who had completed the same protocol were used for comparison. At maximum response in quadriplegia, FEV(1) decreased by 1.42 +/- 0.18 L (62 +/- 4%predicted) (mean +/- SEM), and IC decreased by 0.89 +/- 0.12 L (30 +/- 4%predicted). Dyspnea at maximum response was rated "moderate" to "severe": Borg 3.6 +/- 0.3. The predominant qualitative respiratory sensations were inspiratory difficulty and unsatisfied inspiration. The best correlate of dyspnea (Borg) was DeltaIC(%predicted) (p < 0.0005), whereas changes in FEV(1), Pes-derived measurements and breathing pattern did not contribute further to the strength of this relationship. Dyspnea intensity, quality, and changes in spirometry and lung volumes at maximum response were similar to those reported previously in asthma. The relationship between dyspnea intensity and DeltaIC(%predicted) was linear and consistent across groups. We conclude that the quality and intensity of dyspnea during methacholine-induced bronchoconstriction and dynamic hyperinflation was not altered by extensive chest wall deafferentation.

Adult↗

PubMedDate not supplied

Outcomes of asthma education: results of a multisite evaluation.

BACKGROUND: This observational study compared the effectiveness of a standardized adult asthma education program administered in a variety of sites and practice settings on health care utilization, absenteeism, amount of leisure time missed and quality of life (using the Medical Outcomes Study 36-Item Short Form 1.0 [SF-36]). METHODS: Seven asthma centres participated in an uncontrolled, multicentre, prospective, observational study using a pre-post design. Variables included hospital- and community-based centres, an academic hospital setting and the presence or absence of physician attendance. Trained asthma educators administered a guided self- management education program, and standardized questionnaires were used for patient assessment at baseline and six months after education. RESULTS: Of the 517 patients enrolled at baseline, 396 were eligible for the six-month follow-up. Follow-up data were available for 252 patients. SF-36 data were collected for 241 patients at six sites, with follow-up data available for 103 of 155 eligible patients. Asthma education was associated with substantial improvements in scheduled and unscheduled physician visits, unscheduled specialist visits, emergency department visits, hospital admissions, hospitalized days, missed work or school days and missed days of leisure time. There were also statistically significant improvements in all but one SF-36 domain. These improvements were comparable across all geographical sites and physical settings. CONCLUSIONS: Standardized asthma education appears to be effective when administered in a variety of practice settings, and may be associated with significant improvements in patient outcomes. The significant decline in health care utilization implies that substantial health care savings may occur as a result of the implementation of standardized asthma education programs.

Absenteeism↗