Donna Rennie

Health care utilization of patients with chronic obstructive pulmonary disease and lung cancer in the last 12 months of life

BACKGROUND Previous studies have documented similar levels of end-of-life symptom burden for lung cancer and chronic obstructive pulmonary disease (COPD) patients, yet there has been little comparison of health care utilization during this period. This study contrasts health care utilization by people with COPD and those with lung cancer in the 12 months prior to death. METHODS We performed a retrospective cohort study of 1098 patients who died in 2004 with a cause of death recorded as COPD or lung cancer using administrative health data. Our outcomes of interest included acute, long-term and home care service utilization. RESULTS The study population was 42% female with a mean age of 77 years (S.D.=11). In the last 12 months of life, decedents with COPD were more likely to be institutionalized in a LTC setting (41% vs. 12.5%, p<0.05) and to receive long-term home care (26% vs. 9.7%, p<0.05), but were much less likely to receive palliative care in hospital (47.6% vs. 5.1%, p<0.001) or at home (37.4% vs. 2.8%, p<0.05) than people with lung cancer. In contrast, decedents with lung cancer made greater use of acute care services than those with COPD in that they were more likely to be hospitalized (94.2% vs. 80.4%, p<0.05) and had longer median LOS (7.0 vs. 5.7 days, p<0.05) than those with COPD. No differences in the number of out-patient physician visits were noted. CONCLUSIONS Patterns of end-of-life health care utilization differ significantly between people with lung cancer and those with COPD. Further research is needed to establish need and determine gaps in services to better address the needs of people dying with COPD.

Influence of environmental tobacco smoke on asthma in nonallergic and allergic children

The relation between past induced abortions and subsequent fetal loss is still unclear. We report a case-control study with 331 cases of first spontaneous abortion and 993 controls with no previous spontaneous abortion and a normal pregnancy at the same period of pregnancy. In comparison with primigravid women, the odds ratio for a fetal loss in the current one was 1.41 [95% confidence interval (CI) = 0.81-2.43] among women with one previous pregnancy ending in induced abortion, 4.43 (95% CI = 1.46-13.36) among those with two previous induced abortions out of two pregnancies, and 1.35 (95% CI = 0.64-2.82) among women with three or more previous pregnancies ending in one or more induced abortions.&NA; The relation between exposure to environmental tobacco smoke and childhood asthma is not clear. A 1993 study of 892 subjects age 6‐17 years (87.5% of 1,019 eligible subjects) living in Humboldt, Saskatchewan, showed that a lifetime history of asthma and asthma attack during the past 12 months were more common among allergic children than among nonallergic children. The number of household smokers and total daily cigarette consumption by household members were linearly related to both lifetime history of asthma and recent asthma in nonallergic children, but not in allergic children. Our study indicates that allergic status does alter the relation between exposure to environmental tobacco smoke and childhood asthma.

Assessment of endotoxin levels in the home and current asthma and wheeze in school-age children

UNLABELLED The relationship between household endotoxin and asthma in children is not clear. To further investigate the relationship between sources of endotoxin and childhood asthma, we conducted a case-control study of children with and without asthma and examined their more frequent household exposures in the home. Children ages 6-13 years with current asthma (n = 70) or wheeze only (n = 19) were sex and age matched (+/-1 year) to 107 controls. Play area and mattress dust were collected for endotoxin analysis. Atopic status was determined by skin prick testing for allergies. A family size of >4 per household was associated with higher endotoxin levels (EU/mg) in the bed dust (P < 0.05). Passive smoking (P < 0.05) and the presence of a cat were associated with higher levels of endotoxin in mattress dust. Endotoxin levels in either the play dust or the bed dust did not differ between cases and controls. Within atopic cases, those with higher endotoxin loads (EU/m2) in bed or play areas were more likely to miss school for chest illness (P < 0.05). In this study, household endotoxin is not a risk factor for current asthma overall but may be associated with increased severity in children with atopic asthma. PRACTICAL IMPLICATIONS This study did not find that household sources of endotoxin were associated with asthma. However, within atopic asthmatics, asthma severity (as measured by a history of being kept home from school because of a chest illness in the past year) was associated with higher levels of endotoxin in dust from the childs bed. There is a need to further investigate the nature of the relationship between household endotoxin and asthma severity in children which could lead to better management of childhood asthma.

Waist circumference associated with pulmonary function in children.

In adults abdominal obesity is related to lung dysfunction and waist circumference (WC) predicts pulmonary function. It is not known how WC affects pulmonary function in children. A cross‐sectional study of 718 children 6–17 years of age was conducted in a rural community to determine the predictability of WC for pulmonary function in children. Height, weight, WC, and pulmonary function were measured. Multivariate analysis was conducted. WC was positively associated with FVC and FEV1 and was more strongly associated with FVC than with FEV1. Increase in WC significantly predicted a reduction in FEV1/FVC. After adjustment for sex, age, and height, an increase of 1 cm for WC was associated with an increase of 7 ml of FVC and 4 ml of FEV1, and with an increase of 4 ml of FVC and 2 ml of FEV1 with an additional adjustment for weight. Height and weight were not significantly associated with FEV1/FVC. WC but not body mass index predicted a decline of FEV1/FVC. WC had a larger impact on FVC than FEV1. WC, but not BMI, was negatively associated with FEV1/FVC in children. Pediatr Pulmonol. 2009; 44:216–221.

Segregation analysis of two lung function indices in a random sample of young families: the Humboldt Family Study.

The Humboldt Family Study was conducted in the town of Humboldt, Saskatchewan, in 1993. Familial correlations and segregation analyses of lung function were carried out in 799 individuals in 214 nuclear families that included 214 fathers, 214 mothers, and 371 children. Forced expiratory volume in 1 second (FEV1) and maximal mid‐expiratory flow rate (MMFR) were first regressed on age, height, weight, and their quadratic and cubic terms as well as on smoking status in four groups separately (mothers, fathers, daughters, and sons), with terms significant at the 0.10 level being retained. Residual phenotypes were standardized within the four groups. Class D regressive models were used to perform familial correlations and segregation analyses. For both FEV1 and MMFR, father‐mother correlations were not significantly different from zero, and mother‐offspring, father‐offspring, and sibling‐sibling correlations showed no statistically significant difference from each other. Based on the “polygenic” models, the estimated intraclass correlation is 0.132 (±0.035) for FEV1 and 0.171 (±0.039) for MMFR, and the narrow‐sense heritability is 0.264 for FEV1 and 0.342 for MMFR.

Association of polymorphisms of toll-like receptor 4 with a reduced prevalence of hay fever and atopy

BACKGROUND The response to innate immune stimuli seems to be critical to conditioning adaptive immunity. Early exposure to endotoxin initiates immune responses that have been shown to alter the risk of asthma and allergic diseases. The toll-like receptor 4 (TLR4) gene encodes the principal innate immunity receptor in humans for bacterial endotoxin. Polymorphisms in the TLR4 gene may regulate the effects of endotoxin exposure and could play a role in the development of asthma and atopy-related phenotypes. OBJECTIVE To investigate the association between TLR4 polymorphisms and allergic phenotypes in nonsmokers. METHODS The data from 915 nonsmoking students were available for the study. The TLR4 299 and 399 polymorphisms were genotyped using mouthwash samples. The TLR4 299 and 399 polymorphisms were grouped together to define the TLR4 polymorphic group. Skin prick tests were conducted in a subgroup of healthy participants. A brief questionnaire was administered to determine demographic characteristics and chronic health conditions. RESULTS The prevalence of hay fever was 0% in the TLR4 polymorphic group and 7.5% in the wild-type group (P = .01). After controlling for age group and sex using logistic regression, the odds of having hay fever were reduced by 88% (P = .009) in the TLR4 polymorphic group compared with the wild-type group. In a subgroup analysis, the association between TLR4 polymorphisms and atopy was only observed among females. CONCLUSIONS To our knowledge, this study is the first to report an association between TLR4 polymorphisms and atopy-related phenotypes in a nonsmoking population. Further investigation of the role of TLR4 polymorphisms in asthma and atopy-related phenotypes is warranted.

Association between Obesity and Atopy in Adults

Background/Aim: Previous literature on the association between obesity and atopy has been inconsistent. The aim of the study was to determine the relationship between obesity and atopic sensitization in adults. Methods: The study included a total of 1,997 residents aged 18–79 years and was conducted in the town of Humboldt, Sask., Canada in 2003. Body mass index (BMI) and waist circumference (WC) were objectively measured. Allergy skin tests were conducted to determine atopic sensitization. Results: Overall, the prevalence of one or more positive skin tests for atopy was 33.3% among those with a BMI of at least 30.0, 28.2% among those with a BMI of 25.0–29.9 and 27.3% among those with a BMI of less than 25 (p = 0.003). The odds ratio for atopy among those with a BMI of at least 30.0 versus those with a BMI of less than 25.0 was 1.51 (95% confidence interval, CI: 1.17, 1.95) after adjustment for sex, age, and other covariates. Stratified by sex, the adjusted odds ratios for obesity versus normal weight were 1.27 (95% CI: 0.73, 1.93) for men and 1.63 (95% CI: 1.18, 2.26) for women. WC was also significantly associated with the prevalence of atopy in both sexes after controlling for covariates. Conclusion: The data demonstrated a significant association between obesity, defined either by BMI or by WC, and atopy.

Regular Use of Corticosteroids and Low Use of Short-Acting β2-Agonists Can Reduce Asthma Hospitalization

OBJECTIVES Inhaled corticosteroids (ICS) and inhaled short-acting beta(2)-agonists (ISABA) are the most commonly used medications for management of asthma. Increased asthma morbidity and mortality have been reported with excess use of ISABA in several studies. In these studies, authors have used different indicators to control for the potential confounding by asthma severity. The objective of this study was to determine the effect of ICS use on the association between use of ISABA and first hospitalization for asthma after controlling for several indicators of asthma severity. DESIGN An inceptional cohort study using Saskatchewan Health databases. SETTING The Province of Saskatchewan, Canada. PARTICIPANTS A total of 29,957 persons aged 5 to 54 years who had at least five asthma-related visits to physicians between 1991 and 2000. RESULTS Among the subjects with increased asthma severity, indicated by one or more average number of asthma-related physician visits per 3 months during the follow-up, high use of ISABA was a risk factor for hospitalization when no ICS were used (rate ratio [RR], 2.16; 95% confidence interval [CI], 1.51 to 2.95). There was a beneficial effect of ISABA when there was low use of ICS (RR, 0.65; 95% CI, 0.42 to 0.93) or high use of ICS (RR, 0.23; 95% CI, 0.12 to 0.41). Among the subjects with less severe asthma, indicated by less than one asthma-related physician visits per 3 months, on average, during the follow-up, the risk of hospitalization was even greater for high use of ISABA when no ICS were used (RR, 10.06; 95% CI, 6.99 to 14.47). This was reduced but not abolished when there was low use of ICS (RR, 3.24; 95% CI, 2.29 to 4.59) and negated altogether by high use of ICS (RR, 1.10; 95% CI, 0.39 to 3.12). CONCLUSION Among both severe and less severe asthma groups, high use of ISABA was associated with an increased risk of asthma hospitalization in the absence of any use of ICS, which was progressively reduced with low and high use of ICS. This finding was independent of asthma severity and could result from lack of control through over reliance on ISABA in asthma management.

Disparate geographic prevalences of asthma, allergic rhinoconjunctivitis and atopic eczema among adolescents in five Canadian cities.

Wang H‐Y, Pizzichini MMM, Becker AB, Duncan JM, Ferguson AC, Greene JM, Rennie DC, Senthilselvan A, Taylor BW, Sears MR. Disparate geographic prevalences of asthma, allergic rhinoconjunctivitis and atopic eczema among adolescents in five Canadian cities.
Pediatr Allergy Immunol 2010: 21: 867–877.
© 2010 John Wiley & Sons A/S

Fatigue in patients with COPD participating in a pulmonary rehabilitation program

Background Fatigue is a distressing, complex, multidimensional sensation common in individuals with chronic obstructive pulmonary disease (COPD). While fatigue negatively impacts functional performance and quality of life, there has been little study of the fatigue that affects participants in pulmonary rehabilitation programs. The purpose of this study was to examine the emotional, behavioral, cognitive, and physical dimensions of fatigue and their relationships to dyspnea, mental health, sleep, and physiologic factors. Patients and methods A convenience sample of 42 pulmonary rehabilitation participants with COPD completed self-report questionnaires which measured dimensions of fatigue using the Multidimensional Fatigue Inventory, anxiety and depression using the Hospital Anxiety and Depression Scale, and sleep quality using the Pittsburgh Sleep Quality Index. Data on other clinical variables were abstracted from pulmonary rehabilitation program health records. Results Almost all (95.3%) participants experienced high levels of physical fatigue. High levels of fatigue were also reported for the dimensions of reduced activity (88.1%), reduced motivation (83.3%), mental fatigue (69.9%), and general fatigue (54.5%). Close to half (42.9%) of participants reported symptoms of anxiety, while almost one quarter (21.4%) reported depressive symptoms. Age was related to the fatigue dimensions of reduced activity (ρ = 0.43, P < 0.01) and reduced motivation (ρ = 0.31, P < 0.05). Anxiety was related to reduced motivation (ρ = −0.47, P < 0.01). Fatigue was not associated with symptoms of depression, sleep quality, gender, supplemental oxygen use, smoking status, or Medical Research Council dyspnea scores. Conclusions Fatigue (particularly the physical and reduced motivation dimensions of fatigue) was experienced by almost all participants with COPD attending this pulmonary rehabilitation program. Fatigue affected greater proportions of participants than either anxiety or depression. The high prevalence of fatigue may impact on enrolment, participation, and attrition in pulmonary rehabilitation programs. Further investigation of the nature, correlates, and impact of fatigue in this population is required.