Impact of Undiagnosed Chronic Obstructive Pulmonary Disease and Asthma on Symptoms, Quality of Life, Healthcare Use, and Work Productivity

Rationale: A significant proportion of individuals with chronic obstructive pulmonary disease (COPD) and asthma remain undiagnosed. Objectives: The objective of this study was to evaluate symptoms, quality of life, healthcare use, and work productivity in subjects with undiagnosed COPD or asthma compared with those previously diagnosed, as well as healthy control subjects. Methods: This multicenter population-based case-finding study randomly recruited adults with respiratory symptoms who had no previous history of diagnosed lung disease from 17 Canadian centers using random digit dialing. Participants who exceeded symptom thresholds on the Asthma Screening Questionnaire or the COPD Diagnostic Questionnaire underwent pre- and post-bronchodilator spirometry to determine if they met diagnostic criteria for COPD or asthma. Two control groups, a healthy group without respiratory symptoms and a symptomatic group with previously diagnosed COPD or asthma, were similarly recruited. Measurements and Main Results: A total of 26,905 symptomatic individuals were interviewed, and 4,272 subjects were eligible. Of these, 2,857 completed pre- and post-bronchodilator spirometry, and 595 (21%) met diagnostic criteria for COPD or asthma. Individuals with undiagnosed COPD or asthma reported greater impact of symptoms on health status and daily activities, worse disease-specific and general quality of life, greater healthcare use, and poorer work productivity than healthy control subjects. Individuals with undiagnosed asthma had symptoms, quality of life, and healthcare use burden similar to those of individuals with previously diagnosed asthma, whereas subjects with undiagnosed COPD were less disabled than those with previously diagnosed COPD. Conclusions: Undiagnosed COPD or asthma imposes important, unmeasured burdens on the healthcare system and is associated with poor health status and negative effects on work productivity.

Anticipating undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry: a decision tool for bronchial challenge testing

BACKGROUND

Some patients with asthma demonstrate normal spirometry and remain undiagnosed without further testing.

OBJECTIVE

To determine clinical predictors of asthma in symptomatic adults with normal spirometry, and to generate a tool to help clinicians decide who should undergo bronchial challenge testing (BCT).

METHODS

Using random-digit dialling and population-based case-finding, we recruited adults from the community with respiratory symptoms and no previous history of diagnosed lung disease. Participants with normal pre- and post-bronchodilator spirometry subsequently underwent BCT. Asthma was diagnosed in those with symptoms and a methacholine provocative concentration (PC20) of < 8 mg/ml. Sputum and blood eosinophils, and exhaled nitric oxide were measured. Univariate analyses identified potentially predictive variables, which were then used to construct a multivariable logistic regression model to predict asthma. Model sensitivity, specificity, and area under the receiver operating curve (AUC) were calculated.

RESULTS

Of 132 symptomatic individuals with normal spirometry, 34 (26%) had asthma. Of those ultimately diagnosed with asthma, 33 (97%) answered 'yes' to a question asking whether they experienced cough, chest tightness or wheezing provoked by exercise or cold air. Other univariate predictors of asthma included female sex, pre-bronchodilator FEV1 percentage predicted, and percent positive change in FEV1 post bronchodilator. A multivariable model containing these predictive variables yielded an AUC of 0.82 (95% CI: 0.72-0.91), a sensitivity of 82%, and a specificity of 66%. The model was used to construct a nomogram to advise clinicians which patients should be prioritized for BCT.

CONCLUSIONS

Four readily available patient characteristics demonstrated a high sensitivity and AUC for predicting undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry. These characteristics can potentially help clinicians to decide which individuals with normal spirometry should be investigated with bronchial challenge testing. However, further prospective validation of our decision tool is required.

Airway inflammation and hyperresponsiveness in subjects with respiratory symptoms and normal spirometry

BACKGROUND

Subjects without a previous history of asthma, presenting with unexplained respiratory symptoms and normal spirometry, may exhibit airway hyperresponsiveness (AHR) in association with underlying eosinophilic (type 2 (T2)) inflammation, consistent with undiagnosed asthma. However, the prevalence of undiagnosed asthma in these subjects is unknown.

METHODS

In this observational study, inhaled corticosteroid-naïve adults without previously diagnosed lung disease reporting current respiratory symptoms and showing normal pre- and post-bronchodilator spirometry underwent fractional exhaled nitric oxide (F _ENO) measurement, methacholine challenge testing and induced sputum analysis. AHR was defined as a provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC₂₀) <16 mg·mL^-1 and T2 inflammation was defined as sputum eosinophils >2% and/or F _ENO >25 ppb.

RESULTS

Out of 132 subjects (mean±sd age 57.6±14.2 years, 52% female), 47 (36% (95% CI 28-44%)) showed AHR: 20/132 (15% (95% CI 9-21%)) with PC₂₀ <4 mg·mL^-1 and 27/132 (21% (95% CI 14-28%)) with PC₂₀ 4-15.9 mg·mL^-1. Of 130 participants for whom sputum eosinophils, F _ENO or both results were obtained, 45 (35% (95% CI 27-43%)) had T2 inflammation. 14 participants (11% (95% CI 6-16%)) had sputum eosinophils >2% and PC₂₀ ≥16 mg·mL^-1, suggesting eosinophilic bronchitis. The prevalence of T2 inflammation was significantly higher in subjects with PC₂₀ <4 mg·mL^-1 (12/20 (60%)) than in those with PC₂₀ 4-15.9 mg·mL^-1 (8/27 (30%)) or ≥16 mg·mL^-1 (25/85 (29%)) (p=0.01).

CONCLUSIONS

Asthma, underlying T2 airway inflammation and eosinophilic bronchitis may remain undiagnosed in a high proportion of symptomatic subjects in the community who have normal pre- and post-bronchodilator spirometry.

Patient and physician factors associated with symptomatic undiagnosed asthma or COPD

BACKGROUND

It remains unclear why some symptomatic individuals with asthma or COPD remain undiagnosed. Here, we compare patient and physician characteristics between symptomatic individuals with obstructive lung disease (OLD) who are undiagnosed and individuals with physician-diagnosed OLD.

METHODS

Using random-digit dialling and population-based case finding, we recruited 451 participants with symptomatic undiagnosed OLD and 205 symptomatic control participants with physician-diagnosed OLD. Data on symptoms, quality of life and healthcare utilisation were analysed. We surveyed family physicians of participants in both groups to elucidate differences in physician practices that could contribute to undiagnosed OLD.

RESULTS

Participants with undiagnosed OLD had lower mean pre-bronchodilator forced expiratory volume in 1 s percentage predicted compared with those who were diagnosed (75.2% versus 80.8%; OR 0.975, 95% CI 0.963-0.987). They reported greater psychosocial impacts due to symptoms and worse energy and fatigue than those with diagnosed OLD. Undiagnosed OLD was more common in participants whose family physicians were practising for >15 years and in those whose physicians reported that they were likely to prescribe respiratory medications without doing spirometry. Undiagnosed OLD was more common among participants who had never undergone spirometry (OR 10.83, 95% CI 6.18-18.98) or who were never referred to a specialist (OR 5.92, 95% CI 3.58-9.77). Undiagnosed OLD was less common among participants who had required emergency department care (OR 0.44, 95% CI 0.20-0.97).

CONCLUSIONS

Individuals with symptomatic undiagnosed OLD have worse pre-bronchodilator lung function and present with greater psychosocial impacts on quality of life compared with their diagnosed counterparts. They were less likely to have received appropriate investigations and specialist referral for their respiratory symptoms.

Derivation and Validation of the UCAP-Q Case-finding Questionnaire to Detect Undiagnosed Asthma and COPD

BACKGROUND

Many people with asthma and COPD remain undiagnosed. We developed and validated a new case-finding questionnaire to identify symptomatic adults with undiagnosed obstructive lung disease.

METHODS

Adults in the community with no prior history of physician-diagnosed lung disease who self-reported respiratory symptoms were contacted via random-digit dialing. Pre- and post-bronchodilator spirometry was used to confirm asthma or COPD. Predictive questions were selected using multinomial logistic regression with backward elimination. Questionnaire performance was assessed using sensitivity, predictive values, and area under the receiver operating curve (AUC). The questionnaire was assessed for test-retest reliability, acceptability, and readability. External validation was prospectively conducted in an independent sample and predictive performance re-evaluated.

RESULTS

A 13-item UCAP-Q case-finding questionnaire to predict undiagnosed asthma or COPD was developed. The most appropriate risk cut-off was determined to be 6% for either disease. Applied to the derivation sample (N=1615), the questionnaire yielded a sensitivity of 92% for asthma and 97% for COPD, specificity of 17%, with an AUC of 0.69 (95% CI: 0.64-0.74) for asthma and 0.82 (95% CI: 0.78-0.86) for COPD. Prospective validation using an independent sample (n=471) showed sensitivities of 93% and 92% for asthma and COPD, respectively, specificity of 19%, with AUC's of 0.70 (95% CI: 0.62-0.79) for asthma and 0.81 (95% CI: 0.74-0.87) for COPD. AUC's for UCAP-Q were higher compared to AUC's for currently recommended case-finding questionnaires for asthma or COPD.Conclusions:The UCAP-Q demonstrated high sensitivities and AUC's for identifying undiagnosed asthma or COPD. A web-based calculator allows for easy calculation of risk probabilities for each disease.

Population-based case-finding to identify subjects with undiagnosed asthma or COPD

BACKGROUND

∼5-10% of adults may have undiagnosed airflow obstruction. The objective of this study was to develop a population-based case-finding strategy to assess the prevalence of undiagnosed airflow obstruction (asthma or COPD) amongst adults with respiratory symptoms in Canada.

METHODS

Adults without a previous history of asthma, COPD or lung disease were recruited using random digit-dialling and asked if they had symptoms of dyspnoea, cough, sputum or wheeze within the past 6 months. Those who answered affirmatively completed the Asthma Screening Questionnaire (ASQ), COPD-Diagnostic Questionnaire (COPD-DQ) and COPD Assessment Test (CAT). Those with an ASQ score of ≥6 or a COPD-DQ score of ≥20 underwent pre- and post-bronchodilator spirometry to diagnose asthma or COPD.

RESULTS

12 117 individuals were contacted at home and assessed for study eligibility. Of the 1260 eligible individuals, 910 (72%) enrolled and underwent spirometry. Ultimately, 184 subjects (20% of those enrolled) had obstructive lung disease (73 asthma and 111 COPD). Individuals found to have undiagnosed asthma or COPD had more severe respiratory symptoms and impaired quality of life compared with those without airflow obstruction. The ASQ, COPD-DQ, and CAT had ROC areas for predicting undiagnosed asthma or COPD of 0.49, 0.64 and 0.56, respectively. Four descriptive variables (age, BMI, sex and pack-years smoked) produced better receiver operating characteristic (ROC) values than the questionnaires (ROC area=0.68).

CONCLUSION

20% of randomly selected individuals who report respiratory symptoms in Canada have undiagnosed airflow obstruction due to asthma or COPD. Questionnaires could exclude subjects at low risk but lack the ability to accurately find subjects with undiagnosed disease.

Performance Characteristics of Spirometry With Negative Bronchodilator Response and Methacholine Challenge Testing and Implications for Asthma Diagnosis

BACKGROUND

In patients with a history suggestive of asthma, diagnosis is usually confirmed by spirometry with bronchodilator response (BDR) or confirmatory methacholine challenge testing (MCT).

RESEARCH QUESTION

We examined the proportion of participants with negative BDR testing who had a positive MCT (and its predictors) result and characteristics of MCT, including effects of controller medication tapering and temporal variability (and predictors of MCT result change), and concordance between MCT and pulmonologist asthma diagnosis.

STUDY DESIGN AND METHODS

Adults with self-reported physician-diagnosed asthma were recruited by random-digit dialing across Canada. Subjects performed spirometry with BDR testing and returned for MCT if testing was nondiagnostic for asthma. Subjects on controllers underwent medication tapering with serial MCTs over 3 to 6 weeks. Subjects with a negative MCT (the provocative concentration of methacholine that results in a 20% drop in FEV₁ [PC₂₀] > 8 mg/mL) off medications were examined by a pulmonologist and had serial MCTs after 6 and 12 months.

RESULTS

Of 500 subjects (50.5 ± 16.6 years old, 68.0% female) with a negative BDR test for asthma, 215 (43.0%) had a positive MCT. Subjects with prebronchodilator airflow limitation were more likely to have a positive MCT (OR, 1.90; 95% CI, 1.17-3.04). MCT converted from negative to positive, with medication tapering in 18 of 94 (19.1%) participants, and spontaneously over time in 25 of 165 (15.2%) participants. Of 231 subjects with negative MCT, 28 (12.1%) subsequently received an asthma diagnosis from a pulmonologist.

INTERPRETATION

In subjects with a self-reported physician diagnosis of asthma, absence of bronchodilator reversibility had a negative predictive value of only 57% to exclude asthma. A finding of spirometric airflow limitation significantly increased chances of asthma. MCT results varied with medication taper and over time, and pulmonologists were sometimes prepared to give a clinical diagnosis of asthma despite negative MCT. Correspondingly, in patients for whom a high clinical suspicion of asthma exists, repeat testing appears to be warranted.

Reevaluation of Diagnosis in Adults With Physician-Diagnosed Asthma

IMPORTANCE

Although asthma is a chronic disease, the expected rate of spontaneous remissions of adult asthma and the stability of diagnosis are unknown.

OBJECTIVE

To determine whether a diagnosis of current asthma could be ruled out and asthma medications safely stopped in randomly selected adults with physician-diagnosed asthma.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, multicenter cohort study was conducted in 10 Canadian cities from January 2012 to February 2016. Random digit dialing was used to recruit adult participants who reported a history of physician-diagnosed asthma established within the past 5 years. Participants using long-term oral steroids and participants unable to be tested using spirometry were excluded. Information from the diagnosing physician was obtained to determine how the diagnosis of asthma was originally made in the community. Of 1026 potential participants who fulfilled eligibility criteria during telephone screening, 701 (68.3%) agreed to enter into the study. All participants were assessed with home peak flow and symptom monitoring, spirometry, and serial bronchial challenge tests, and those participants using daily asthma medications had their medications gradually tapered off over 4 study visits. Participants in whom a diagnosis of current asthma was ultimately ruled out were followed up clinically with repeated bronchial challenge tests over 1 year.

EXPOSURE

Physician-diagnosed asthma established within the past 5 years.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of participants in whom a diagnosis of current asthma was ruled out, defined as participants who exhibited no evidence of acute worsening of asthma symptoms, reversible airflow obstruction, or bronchial hyperresponsiveness after having all asthma medications tapered off and after a study pulmonologist established an alternative diagnosis. Secondary outcomes included the proportion with asthma ruled out after 12 months and the proportion who underwent an appropriate initial diagnostic workup for asthma in the community.

RESULTS

Of 701 participants (mean [SD] age, 51 [16] years; 467 women [67%]), 613 completed the study and could be conclusively evaluated for a diagnosis of current asthma. Current asthma was ruled out in 203 of 613 study participants (33.1%; 95% CI, 29.4%-36.8%). Twelve participants (2.0%) were found to have serious cardiorespiratory conditions that had been previously misdiagnosed as asthma in the community. After an additional 12 months of follow-up, 181 participants (29.5%; 95% CI, 25.9%-33.1%) continued to exhibit no clinical or laboratory evidence of asthma. Participants in whom current asthma was ruled out, compared with those in whom it was confirmed, were less likely to have undergone testing for airflow limitation in the community at the time of initial diagnosis (43.8% vs 55.6%, respectively; absolute difference, 11.8%; 95% CI, 2.1%-21.5%).

CONCLUSIONS AND RELEVANCE

Among adults with physician-diagnosed asthma, a current diagnosis of asthma could not be established in 33.1% who were not using daily asthma medications or had medications weaned. In patients such as these, reassessing the asthma diagnosis may be warranted.

Implementation of a cystic fibrosis lung transplant referral patient decision aid in routine clinical practice: an observational study

Background

The decision to have lung transplantation as treatment for end-stage lung disease from cystic fibrosis (CF) has benefits and serious risks. Although patient decision aids are effective interventions for helping patients reach a quality decision, little is known about implementing them in clinical practice. Our study evaluated a sustainable approach for implementing a patient decision aid for adults with CF considering referral for lung transplantation.

Methods

A prospective pragmatic observational study was guided by the Knowledge-to-Action Framework. Healthcare professionals in all 23 Canadian CF clinics were eligible. We surveyed participants regarding perceived barriers and facilitators to patient decision aid use. Interventions tailored to address modifiable identified barriers included training, access to decision aids, and conference calls. The primary outcome was >80% use of the decision aid in year 2.

Results

Of 23 adult CF clinics, 18 participated (78.2%) and 13 had healthcare professionals attend training. Baseline barriers were healthcare professionals’ inadequate knowledge for supporting patients making decisions (55%), clarifying patients’ values for outcomes of options (58%), and helping patients handle conflicting views of others (71%). Other barriers were lack of time (52%) and needing to change how transplantation is discussed (42%). Baseline facilitators were healthcare professionals feeling comfortable discussing bad transplantation outcomes (74%), agreeing the decision aid would be easy to experiment with (71%) and use in the CF clinic (87%), and agreeing that using the decision aid would not require reorganization of the CF clinic (90%). After implementing the decision aid with interventions tailored to the barriers, decision aid use increased from 29% at baseline to 85% during year 1 and 92% in year 2 (p < 0.001). Compared to baseline, more healthcare professionals at the end of the study were confident in supporting decision-making (p = 0.03) but continued to feel inadequate ability with supporting patients to handle conflicting views (p = 0.01).

Conclusion

Most Canadian CF clinics agreed to participate in the study. Interventions were used to target identified modifiable barriers to using the patient decision aid in routine CF clinical practice. CF clinics reported using it with almost all patients in the second year.

Treatment of Aspergillus fumigatus in patients with cystic fibrosis: a randomized, placebo-controlled pilot study

Background

Many patients with cystic fibrosis develop persistent airway infection/colonization with Aspergillus fumigatus, however the impact of A. fumigatus on clinical outcomes remains unclear. The objective of this study was to determine whether treatment directed against Aspergillus fumigatus improves pulmonary function and clinical outcomes in patients with cystic fibrosis (CF).

Methods

We performed a double-blind randomized placebo-controlled pilot clinical trial involving 35 patients with CF whose sputum cultures were chronically positive for A. fumigatus. Participants were centrally randomized to receive either oral itraconazole 5 mg/kg/d (N = 18) or placebo (N = 17) for 24 weeks. The primary outcome was the proportion of patients who experienced a respiratory exacerbation requiring intravenous antibiotics over the 24 week treatment period. Secondary outcomes included changes in FEV₁ and quality of life.

Results

Over the 24 week treatment period, 4 of 18 (22%) patients randomized to itraconazole experienced a respiratory exacerbation requiring intravenous antibiotics, compared to 5 of 16 (31%) placebo treated patients, P = 0.70. FEV₁ declined by 4.62% over 24 weeks in the patients randomized to itraconazole, compared to a 0.32% improvement in the placebo group (between group difference = −4.94%, 95% CI: −15.33 to 5.45, P = 0.34). Quality of life did not differ between the 2 treatment groups throughout the study. Therapeutic itraconazole blood levels were not achieved in 43% of patients randomized to itraconazole.

Conclusion

We did not identify clinical benefit from itraconazole treatment for CF patients whose sputum was chronically colonized with A. fumigatus. Limitations of this pilot study were its small sample size, and failure to achieve therapeutic levels of itraconazole in many patients.

Trial Registration

ClinicalTrials.govNCT00528190

Persistency of Pseudomonas aeruginosa in sputum cultures and clinical outcomes in adult patients with cystic fibrosis

Our objective was to describe the natural history of infection with transmissible and unique strains of P. aeruginosa (PA) in adult CF patients and to determine if clearance of PA from sputum was associated with an improvement in clinical status. This was a 3-year prospective cohort study of adult patients with CF. Sputum was collected at baseline and annually. Rate of decline of FEV1, BMI, exacerbation rate, and time to death or transplant were compared between patients who cleared PA versus those in whom PA was persistent. A total of 373 patients were included in the study, 75% were infected with PA at baseline; 24% were infected with transmissible strains and 51% with unique strains. Patients infected with unique strains were more likely to clear PA from their sputum over 3 years compared to those infected with transmissible strains (19% vs 10%, P=0.05). Declines in FEV1 and rates of pulmonary exacerbations, deaths, or lung transplants were not different between patients who cleared PA compared to those who remained persistently infected. No clinical benefit was identified in patients who cleared PA from sputum compared to those who remained persistently infected.

Infection with transmissible strains of Pseudomonas aeruginosa and clinical outcomes in adults with cystic fibrosis

CONTEXT

Studies from Australia and the United Kingdom have shown that some patients with cystic fibrosis are infected with common transmissible strains of Pseudomonas aeruginosa.

OBJECTIVES

To determine the prevalence and incidence of infection with transmissible strains of P. aeruginosa and whether presence of the organism was associated with adverse clinical outcomes in Canada.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational cohort study of adult patients cared for at cystic fibrosis clinics in Ontario, Canada, with enrollment from September 2005 to September 2008. Sputum was collected at baseline, 3 months, and yearly thereafter for 3 years; and retrieved P. aeruginosa isolates were genotyped. Vital status (death or lung transplant) was assessed for all enrolled patients until December 31, 2009.

MAIN OUTCOME MEASURES

Incidence and prevalence of P. aeruginosa isolation, rates of decline in lung function, and time to death or lung transplantation.

RESULTS

Of the 446 patients with cystic fibrosis studied, 102 were discovered to be infected with 1 of 2 common transmissible strains of P. aeruginosa at study entry. Sixty-seven patients were infected with strain A (15%), 32 were infected with strain B (7%), and 3 were simultaneously infected with both strains (0.6%). Strain A was found to be genetically identical to the Liverpool epidemic strain but strain B has not been previously described as an epidemic strain. The incidence rate of new infections with these 2 transmissible strains was relatively low (7.0 per 1000 person-years; 95% confidence interval [CI], 1.8-12.2 per 1000 person-years). Compared with patients infected with unique strains of P. aeruginosa, patients infected with the Liverpool epidemic strain (strain A) and strain B had similar declines in lung function (difference in decline in percent predicted forced expiratory volume in the first second of expiration of 0.64% per year [95% CI, -1.52% to 2.80% per year] and 1.66% per year [95% CI, -1.00% to 4.30%], respectively). However, the 3-year rate of death or lung transplantation was greater in those infected with the Liverpool epidemic strain (18.6%) compared with those infected with unique strains (8.7%) (adjusted hazard ratio, 3.26 [95% CI, 1.41 to 7.54]; P = .01).

CONCLUSIONS

A common strain of P. aeruginosa (Liverpool epidemic strain/strain A) infects patients with cystic fibrosis in Canada and the United Kingdom. Infection with this strain in adult Canadian patients with cystic fibrosis was associated with a greater risk of death or lung transplantation.

Development of a decision aid for adult cystic fibrosis patients considering referral for lung transplantation

CONTEXT

Most adults with cystic fibrosis are eventually required to make a decision about referral for lung transplantation.

OBJECTIVE

To identify the decisional needs of these patients and to develop a decision aid to address these needs.

METHODS

A comprehensive review of the literature, a review of Canadian transplant statistics from 2002 to 2006, and a self-assessment survey of patients who had already made a decision about referral were performed to identify the decisional needs of patients. A decision aid was then developed and evaluated by an expert panel of health care professionals and patients.

RESULTS

Transplant referral patterns vary widely among Canadian cystic fibrosis clinics. Canadian patients with cystic fibrosis who were not residing in transplant centers between 2002 and 2006 were significantly less likely to undergo lung transplants (P < .001). Decisional needs identified by patients included wanting more information on (1) relocation to the transplant center, (2) the benefits and risks of surgery, and (3) how to cope with anxiety and depression when making the decision. In response to these identified needs, a decision aid for lung transplantation was developed. A panel of health care professionals and patients reviewed the decision aid and agreed that the content was appropriate, easy to understand, and unbiased.

CONCLUSION

The decisional needs of patients with cystic fibrosis who are considering lung transplantation are not being addressed in Canadian cystic fibrosis clinics, especially in clinics outside of transplant centers. An evidence-based decision aid could serve as a useful tool to help address these needs.

Multi analyte profiling and variability of inflammatory markers in blood and induced sputum in patients with stable COPD

BACKGROUND

We analyzed serial concentrations of multiple inflammatory mediators from serum and induced sputum obtained from patients with stable COPD and controls. The objective was to determine which proteins could be used as reliable biomarkers to assess COPD disease state and severity.

METHODS

Forty-two subjects; 21 with stable COPD and 21 controls, were studied every 2 weeks over a 6-week period. Serum and induced sputum were obtained at each of 3 visits and concentrations of 19 serum and 22 sputum proteins were serially assessed using multiplex immunoassays. We used linear mixed effects models to test the distribution of proteins for an association with COPD and disease severity. Measures of within- and between-subject coefficients of variation were calculated for each of the proteins to assess reliability of measurement.

RESULTS

There was significant variability in concentrations of all inflammatory proteins over time, and variability was greater for sputum proteins (median intra-subject coefficient of variation 0.58) compared to proteins measured in serum (median intra-subject coefficient of variation 0.32, P = 0.03). Of 19 serum proteins and 22 sputum proteins tested, only serum CRP, myeloperoxidase and VEGF and sputum IL-6, IL-8, TIMP-1, and VEGF showed acceptable intra and inter-patient reliability and were significantly associated with COPD, the severity of lung function impairment, and dyspnea.

CONCLUSIONS

Levels of many serum and sputum biomarkers cannot be reliably ascertained based on single measurements. Multiple measurements over time can give a more reliable and precise estimate of the inflammatory burden in clinically stable COPD patients.

Development of a Decision Aid for Adult Cystic Fibrosis Patients considering Referral for Lung Transplantation

Context

Most adults with cystic fibrosis are eventually required to make a decision about referral for lung transplantation.

Objective

To identify the decisional needs of these patients and to develop a decision aid to address these needs.

Methods

A comprehensive review of the literature, a review of Canadian transplant statistics from 2002 to 2006, and a self-assessment survey of patients who had already made a decision about referral were performed to identify the decisional needs of patients. A decision aid was then developed and evaluated by an expert panel of health care professionals and patients.

Results

Transplant referral patterns vary widely among Canadian cystic fibrosis clinics. Canadian patients with cystic fibrosis who were not residing in transplant centers between 2002 and 2006 were significantly less likely to undergo lung transplants ( P < .001). Decisional needs identified by patients included wanting more information on (1) relocation to the transplant center, (2) the benefits and risks of surgery, and (3) how to cope with anxiety and depression when making the decision. In response to these identified needs, a decision aid for lung transplantation was developed. A panel of health care professionals and patients reviewed the decision aid and agreed that the content was appropriate, easy to understand, and unbiased.

Conclusion

The decisional needs of patients with cystic fibrosis who are considering lung transplantation are not being addressed in Canadian cystic fibrosis clinics, especially in clinics outside of transplant centers. An evidence-based decision aid could serve as a useful tool to help address these needs.

Confirmation of asthma in an era of overdiagnosis

It was recently shown that 30% of adults with a physician diagnosis of asthma did not have asthma when objectively assessed using a four-step algorithm involving serial spirometry, bronchial challenge testing and subsequent tapering of asthma medications. The objective of the present study was to determine how many steps in the algorithm were required in order to confirm asthma, and whether any patient-related variables were associated with earlier asthma confirmation. A total of 540 subjects with a previous physician diagnosis of asthma were randomly recruited from the community. The number of subjects confirmed with asthma at each study visit was calculated. Regression analysis was used to determine variables associated with earlier asthma confirmation. Of the 499 subjects who completed the diagnostic algorithm, 346 (69%) had asthma confirmed and 150 (30%) had asthma excluded. Of subjects in whom asthma was confirmed, including those using regular asthma controlling medications, >90% were confirmed with only one or two study visits, by either pre- and post-bronchodilator spirometry or a single bronchial challenge test. Only 46 (9%) out of 499 subjects required tapering of asthma medications and repeated bronchial challenge tests for exclusion or confirmation of asthma. Lower forced expiratory volume in 1 s and younger age were associated with earlier asthma confirmation. For the majority with a previous physician diagnosis of asthma, only pre- and post-bronchodilator spirometry and a single methacholine challenge test are required in order to confirm asthma.

Overdiagnosis of asthma in obese and nonobese adults

BACKGROUND

It is unclear whether asthma is overdiagnosed in developed countries, particularly among obese individuals, who may be more likely than nonobese people to experience dyspnea.

METHODS

We conducted a longitudinal study involving nonobese (body mass index 20-25) and obese (body mass index >/= 30) individuals with asthma that had been diagnosed by a physician. Participants were recruited from 8 Canadian cities by means of random-digit dialing. A diagnosis of current asthma was excluded in those who did not have evidence of acute worsening of asthma symptoms, reversible airflow obstruction or bronchial hyperresponsiveness, despite being weaned off asthma medications. We stopped asthma medications in those in whom a diagnosis of asthma was excluded and assessed their clinical outcomes over 6 months.

RESULTS

Of 540 individuals with physician-diagnosed asthma who participated in the study, 496 (242 obese and 254 nonobese) could be conclusively assessed for a diagnosis of asthma. Asthma was ultimately excluded in 31.8% (95% confidence interval [CI] 26.3%-37.9%) in the obese group and in 28.7% (95% CI 23.5%-34.6%) in the nonobese group. Overdiagnosis of asthma was no more likely to occur among obese individuals than among nonobese individuals (p = 0.46). Of those in whom asthma was excluded, 65.5% did not need to take asthma medication or seek health care services because of asthma symptoms during a 6-month follow-up period.

INTERPRETATION

About one-third of obese and nonobese individuals with physician-diagnosed asthma did not have asthma when objectively assessed. This finding suggests that, in developed countries such as Canada, asthma is overdiagnosed.

Counting, analysing and reporting exacerbations of COPD in randomised controlled trials

BACKGROUND

Clinical trials measure exacerbations of chronic obstructive pulmonary disease (COPD) inconsistently. A study was undertaken to determine if different methods for ascertaining and analysing COPD exacerbations lead to biased estimates of treatment effects.

METHODS

Information on the methods used to count, analyse and report COPD exacerbation rates was abstracted from clinical trials of long-acting bronchodilators or long-acting bronchodilator/inhaled steroid combination products published between 2000 and 2006. Data from the Canadian Optimal Therapy of COPD Trial was used to illustrate how different analytical approaches can affect the estimate of exacerbation rates and their confidence intervals.

RESULTS

22 trials (17,156 patients) met the inclusion criteria and were reviewed. None of the trials adjudicated exacerbations or determined independence of events. 14/22 studies (64%) introduced selection bias by not analysing outcome data for subjects who prematurely stopped study medications. Only 31% of trials used time-weighted analyses to calculate the mean number of exacerbations/patient-year and only 15% accounted for between-subject variation. In the Canadian Optimal Therapy of COPD Trial the rate ratio for exacerbations/patient-year was 0.85 when all data were included in a time-weighted analysis, but was overestimated as 0.79 when data for those who prematurely stopped study medications were excluded and was further overestimated as 0.46 when a time-weighted analysis was not conducted; p values ranged from 0.03 to 0.24 depending on how exacerbations were determined and analysed.

CONCLUSIONS

Clinical trials have used widely different methods to define and analyse COPD exacerbations and this can lead to biased estimates of treatment effects. Future trials should strive to include blinded adjudication and assessment of the independence of exacerbation events, and trials should report time-weighted intention-to-treat analyses with adjustments for between-subject variation in COPD exacerbations.

Tiotropium in combination with placebo, salmeterol, or fluticasone-salmeterol for treatment of chronic obstructive pulmonary disease: a randomized trial

BACKGROUND

Treatment of moderate or severe chronic obstructive pulmonary disease (COPD) with combinations of inhaled corticosteroids, long-acting beta-agonists, and long-acting anticholinergic bronchodilators is common but unstudied.

OBJECTIVE

To determine whether combining tiotropium with salmeterol or fluticasone-salmeterol improves clinical outcomes in adults with moderate to severe COPD compared with tiotropium alone.

DESIGN

Randomized, double-blind, placebo-controlled trial conducted from October 2003 to January 2006.

SETTING

27 academic and community medical centers in Canada.

PATIENTS

449 patients with moderate or severe COPD.

INTERVENTION

1 year of treatment with tiotropium plus placebo, tiotropium plus salmeterol, or tiotropium plus fluticasone-salmeterol.

MEASUREMENTS

The primary end point was the proportion of patients who experienced an exacerbation of COPD that required treatment with systemic steroids or antibiotics.

RESULTS

The proportion of patients in the tiotropium plus placebo group who experienced an exacerbation (62.8%) did not differ from that in the tiotropium plus salmeterol group (64.8%; difference, -2.0 percentage points [95% CI, -12.8 to 8.8 percentage points]) or in the tiotropium plus fluticasone-salmeterol group (60.0%; difference, 2.8 percentage points [CI, -8.2 to 13.8 percentage points]). In sensitivity analyses, the point estimates and 95% confidence bounds shifted in the direction favoring tiotropium plus salmeterol and tiotropium plus fluticasone-salmeterol. Tiotropium plus fluticasone-salmeterol improved lung function (P = 0.049) and disease-specific quality of life (P = 0.01) and reduced the number of hospitalizations for COPD exacerbation (incidence rate ratio, 0.53 [CI, 0.33 to 0.86]) and all-cause hospitalizations (incidence rate ratio, 0.67 [CI, 0.45 to 0.99]) compared with tiotropium plus placebo. In contrast, tiotropium plus salmeterol did not statistically improve lung function or hospitalization rates compared with tiotropium plus placebo.

LIMITATIONS

More than 40% of patients who received tiotropium plus placebo and tiotropium plus salmeterol discontinued therapy prematurely, and many crossed over to treatment with open-label inhaled steroids or long-acting beta-agonists.

CONCLUSIONS

Addition of fluticasone-salmeterol to tiotropium therapy did not statistically influence rates of COPD exacerbation but did improve lung function, quality of life, and hospitalization rates in patients with moderate to severe COPD. International Standard Randomised Controlled Trial registration number: ISRCTN29870041.

Sex differences in the clinical presentation and management of airflow obstruction

The aim of the present study was to explore differences in the clinical expression, clinical diagnoses and management of airway diseases in a primary-care setting. Patients aged >or=35 yrs who had ever smoked were enrolled when they presented for any reason to one of eight rural primary-care practices. Respiratory symptom questionnaires and spirometry were administered. In total, 1,034 patients had acceptable and reproducible spirometry, of whom 550 (53%) were males and 484 (47%) were females. Males smoked more than females (41.2 versus 29.2 pack-yrs) respectively, and were more likely to have a pre-bronchodilator forced expiratory volume in one second/forced vital capacity <0.70 at 22.4 versus 11.8%, respectively. However, more females than males reported breathlessness (51.0 versus 42.8%, respectively), a prior diagnosis compatible with airflow obstruction and taking respiratory medications (23.4 versus 14.9%, respectively). In conclusion, the current results suggest that females are more likely than males to report breathlessness and be prescribed respiratory medications independent of differences in the severity of airflow obstruction.

Predictors of pulmonary exacerbations in patients with cystic fibrosis infected with multi-resistant bacteria

BACKGROUND

This study examined characteristics of adult and adolescent patients with cystic fibrosis (CF) to determine factors associated with an increased risk of pulmonary exacerbations.

METHODS

249 patients with CF infected with multidrug resistant bacteria were recruited and prospectively followed for up to 4.5 years until they experienced a pulmonary exacerbation severe enough to require intravenous antibiotics. Multivariable regression analyses were used to compare the characteristics of patients who experienced an exacerbation with those who did not.

RESULTS

124 of the 249 patients (50%) developed a pulmonary exacerbation during the first year and 154 (62%) experienced an exacerbation during the 4.5 year study period. Factors predictive of exacerbations in a multivariable survival model were younger age (OR 0.98, 95% CI 0.96 to 0.99), female sex (OR 1.45, 95% CI 1.07 to 1.95), lower forced expiratory volume in 1 second (FEV(1)) (OR 0.98, 95% CI 0.97 to 0.99), and a previous history of multiple pulmonary exacerbations (OR 3.16, 95% CI 1.93 to 5.17). Chronic use of inhaled corticosteroids was associated with an increased risk of exacerbation (OR 1.92, 95% CI 1.00 to 3.71) during the first study year.

CONCLUSIONS

Patients who experience pulmonary exacerbations are more likely to be younger, female, using inhaled steroids, have a lower FEV(1), and a history of multiple previous exacerbations. It is hoped that knowledge of these risk factors will allow better identification and closer monitoring of patients who are at high risk of exacerbations.

Spirometry in the primary care setting: influence on clinical diagnosis and management of airflow obstruction

STUDY OBJECTIVE

To determine if screening spirometry in the primary care setting influences the physician's diagnosis and management of obstructive lung disease.

DESIGN

Diagnosis and management assessed before and after the intervention of screening spirometry.

PARTICIPANTS

A total of 1,034 patients who had ever smoked and were at least 35 years of age presenting to primary care practices for any reason.

SETTING

Rural primary care practices.

MEASUREMENTS AND RESULTS

Physicians were asked prior to and following presentation of spirometry test results if they thought airflow obstruction was present and if they planned to change management based on the results. A new diagnosis of unsuspected airflow obstruction was made by the physician in 93 patients (9%), and a prior diagnosis of airflow obstruction was removed after spirometry in 115 patients (11%). After viewing the spirometry results, physicians reported that they would change patient management in 154 patients (15%). Most planned management changes occurred when airflow obstruction was newly diagnosed (57 of 93 patients, 61%) and when the diagnosis of airflow obstruction remained unchanged (80 of 195 patients, 41%). A 6-month chart review documented the addition of respiratory medications in 8% of patients.

CONCLUSION

Screening spirometry influences physicians' diagnosis of airflow obstruction and management plans especially in patients with moderate-to-severe obstruction.

The prevalence of airflow obstruction in rural primary care

Spirometry has been reported to be under-utilized, and airflow obstruction may be under-diagnosed, in primary care practice.

STUDY OBJECTIVES

The objective of this study was to determine the prevalence and severity of airflow obstruction in rural primary care settings and the degree to which it can be predicted by clinical characteristics. Spirometry was performed in patients 35 years and older who had smoked, presenting for any reason to one of eight rural primary care practices. Obstruction was defined as an FEV(1)/FVC<0.70. A total of 1046 subjects were recruited of whom 1034 had acceptable and reproducible spirometry. Airflow obstruction was detected in 17.4% (180 patients). Of those with obstruction, 77.2% (se 3.1%) had at least one respiratory symptom versus 62.4% (se 1.6%) without obstruction (P=0.0002). Only 44.9% (se 3.7%) of those with airflow obstruction had been previously diagnosed with obstructive lung disease. Of those with an FEV(1)<50% of predicted, 85% (se 5.6%) were breathless on exertion; however, only 63% (se 7.6%) were being treated with respiratory medications. We conclude that airflow obstruction is common in rural primary care practice and cannot be accurately predicted by symptoms. It is undiagnosed half of the time, and often not treated even when symptomatic.

Combination antibiotic susceptibility testing to treat exacerbations of cystic fibrosis associated with multiresistant bacteria: a randomised, double-blind, controlled clinical trial

BACKGROUND

We did a randomised, double-blind, controlled clinical trial to prospectively assess whether use of combination antibiotic susceptibility testing improved clinical outcomes in patients with acute pulmonary exacerbations of cystic fibrosis who were infected with multiresistant bacteria.

METHODS

251 patients with cystic fibrosis who were chronically infected with multiresistant gram negative bacteria gave sputum at 3-month intervals for conventional culture and sensitivity tests and for combination antibiotic susceptibility tests using multiple combination bactericidal antibiotic testing (MCBT). Patients who developed an exacerbation of pulmonary disease were randomised to receive a 14-day course of any two blinded intravenous antibiotics chosen on the basis of either results from conventional sputum culture and sensitivity testing or the result of MCBT. The primary outcome was time from randomisation until the patient's next pulmonary exacerbation. Analysis was by intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN60187870.

FINDINGS

132 patients had a pulmonary exacerbation and were randomised during the 4.5-year study period. The time to next pulmonary exacerbation was not prolonged in the MCBT-treated group (hazard ratio 0.86 in favour of the conventionally-treated group, 95% CI 0.60-1.23, p=0.40). There was no difference between the groups in treatment failure rate. After 14 days of intravenous antibiotic therapy, changes in lung function, dyspnoea, and sputum bacterial density were similar in both groups.

INTERPRETATION

Antibiotic therapy directed by combination antibiotic susceptibility testing did not result in better clinical and bacteriological outcomes compared with therapy directed by standard culture and sensitivity techniques. The non-bactericidal effects of antibiotic therapy might play an important part in determining improvement in patients with cystic fibrosis pulmonary exacerbations.

Evaluation of a decision aid for making choices about intubation and mechanical ventilation in chronic obstructive pulmonary disease

To assist patients with chronic obstructive pulmonary disease (COPD) in advance planning for life-threatening exacerbations, we developed a structured decision aid that describes the process, risks, and outcomes of intubation and mechanical ventilation (MV). Thirty-three patients with severe COPD took part in a before-after evaluation study. At baseline, only two participants (6%) reported that they had already made an advance decision about MV. After reviewing the decision aid, 31 participants (94%) reported that they had made a choice, which in 23 cases (74% of those deciding) was to forego MV. These choices were associated with more accurate expectations of MV outcome, and reduced decisional conflict. Qualitatively, participants who would accept MV emphasized their wish to prolong life, whereas those who would forego MV were more influenced by the burdens of treatment and the perception of a poor long-term outcome. However, there was evidence that 24% of participants did not completely comprehend the decision aid and 27% found the experience to be stressful. These findings indicate that a decision aid for MV helps patients plan for life-threatening exacerbations, and may be a useful adjunct to counseling for some patients with severe COPD.

Sputum versus bronchoscopy for diagnosis of Pseudomonas aeruginosa biofilms in cystic fibrosis

The present authors hypothesised that bronchoscopy with protected specimen brush may sample biofilm-forming bacteria adherent to the airway wall, whereas traditional sputum collection may not. Pseudomonas aeruginosa obtained from sputum, bronchoalveolar lavage and protected brush, taken from the right upper lung bronchus of 12 adult patients with cystic fibrosis, were compared. Retrieved bacteria were genotyped, and grown in planktonic cultures and as biofilms, and susceptibilities to individual antibiotics and to antibiotic combinations were determined. Bacterial cultures obtained using bronchoscopy did not yield any new strains of bacteria that were not also found in sputum. A total of 10 patients (83%) had a single strain of P. aeruginosa found using sputum, bronchoalveolar lavage and protected brush techniques, and two patients (17%) had two strains recovered in sputum, but only one strain was recovered using bronchoscopic techniques. Susceptibility to single antibiotics and to antibiotic combinations were not different between planktonically or biofilm-grown bacteria derived from sputum, as compared to those obtained by bronchoalveolar lavage and protected brush. In conclusion, sputum collection provides as much information as bronchoscopy for characterising the genotype and antibiotic susceptibility of chronic Pseudomonas aeruginosa infection in patients with stable cystic fibrosis.

Effect of weight reduction on respiratory function and airway reactivity in obese women

BACKGROUND

Population-based studies have documented an association between obesity and an increased prevalence of asthma in women.

METHODS

We prospectively studied 58 obese women with a body mass index of > 30 kg/m(2), 24 of whom had asthma, who were enrolled in an intensive 6-month weight loss program to determine whether loss of body mass would be correlated with improvements in bronchial reactivity, lung function, and disease-specific health status.

RESULTS

Patients lost an average of 20 kg over the 6-month period. For every 10% relative loss of weight, the FVC improved by 92 mL (p = 0.05) and the FEV(1) improved by 73 mL (p = 0.04), however, bronchial reactivity did not significantly change with weight loss (p = 0.23). Patients who lost > 13% of their pretreatment weight experienced improvements in FEV(1) (p = 0.01), FVC (p = 0.02), and total lung capacity (p = 0.05) compared to patients in the lowest quartile who failed to lose significant amounts of weight. Neither group experienced any significant change in methacholine responsiveness (p = 0.57). Patients who completed the 6-month weight loss program experienced improvements in respiratory health status, irrespective of weight loss.

CONCLUSION

We concluded that weight loss can improve lung function in obese women, however, the improvements appear to be independent of changes in airway reactivity.

Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments

STUDY OBJECTIVE

We evaluate the accuracy, reliability, and potential impact of the National Emergency X-Radiography Utilization Study (NEXUS) low-risk criteria for cervical spine radiography, when applied in Canadian emergency departments (EDs).

METHODS

The Canadian C-Spine Rule derivation study was a prospective cohort study conducted in 10 Canadian EDs that recruited alert and stable adult trauma patients. Physicians completed a 20-item data form for each patient and performed interobserver assessments when feasible. The prospective assessments included the 5 individual NEXUS criteria but not an explicit interpretation of the overall need for radiography according to the criteria. Patients underwent plain radiography, flexion-extension views, and computed tomography at the discretion of the treating physician. Patients who did not have radiography were followed up with a structured outcome assessment by telephone to determine clinically important cervical spine injury, a previously validated outcome measurement. Analyses included sensitivity and specificity with 95% confidence interval (CI), kappa coefficient, and potential radiography rates.

RESULTS

Among 8,924 patients, 151 (1.7%) patients had an important cervical spine injury. The combined NEXUS criteria identified important cervical spine injury with a sensitivity of 92.7% (95% CI 87% to 96%) and a specificity of 37.8% (95% CI 37% to 39%). Application of the NEXUS criteria would have potentially reduced cervical spine radiography rates by 6.1% from the actual rate of 68.9% to 62.8%. Of 11 patients with important injuries not identified, 2 were treated with internal fixation and 3 with a halo.

CONCLUSION

This retrospective validation found the NEXUS low-risk criteria to be less sensitive than previously reported. The NEXUS low-risk criteria should be further explicitly and prospectively evaluated for accuracy and reliability before widespread clinical use outside of the United States.

Topical tetracaine prior to arterial puncture: a randomized, placebo-controlled clinical trial

The objective of this randomized, double-blind, placebo-controlled clinical trial was to determine whether a topical anesthetic agent (tetracaine) provides effective local analgesia prior to radial arterial puncture. Tetracaine or placebo gel was applied 45 min prior to arterial puncture to patients who were referred for elective arterial blood gas. The primary outcome was the patient's perception of pain associated with the procedure as measured by a visual analog scale. Fifty patients were randomized into the study, 24 received tetracaine and 26 placebo. Mean pain score on the visual analog scale was 26.2 +/- 32.6 for the tetracaine-treated patients and 23.8 +/- 27.4 for the placebo-treated patients (P = 0.78). Mean time from the first skin puncture to successful procurement of 1 ml of arterial blood was 70 +/- 103s in the tetracaine group and 49 +/- 48s in the placebo group (P = 0.40). Difficulty of arterial puncture as assessed by the respiratory therapist performing the test was identical for the two groups (P = 0.86). We conclude that tetracaine gel did not decrease patient's perception of pain associated with arterial puncture, nor did its use facilitate the ABG procedure.

The Canadian C-spine rule performs better than unstructured physician judgment

STUDY OBJECTIVES

We compare the predictive accuracy of emergency physicians' unstructured clinical judgment to the Canadian C-Spine rule.

METHODS

This prospective multicenter cohort study was conducted at 10 Canadian urban academic emergency departments. Included in the study were alert, stable, adult patients with a Glasgow Coma Scale score of 15 and trauma to the head or neck. This was a substudy of the Canadian C-Spine and CT Head Study. Eligible patients were prospectively evaluated before radiography. Physicians estimated the probability of unstable cervical spine injury from 0% to 100% according to clinical judgment alone and filled out a data form. Interobserver assessments were done when feasible. Patients underwent cervical spine radiography or follow-up to determine clinically important cervical spine injuries. Analyses included comparison of areas under the receiver operating characteristic (ROC) curve with 95% confidence intervals (CIs) and the kappa coefficient.

RESULTS

During 18 months, 6265 patients were enrolled. The mean age was 36.6 years (range 16 to 97 years), and 50.1% were men. Sixty-four (1%) patients had a clinically important injury. The physicians' kappa for a 0% predicted probability of injury was 0.46 (95% CI 0.28 to 0.65). The respective areas under the ROC curve for predicting cervical spine injury were 0.85 (95% CI 0.80 to 0.89) for physician judgment and 0.91 (95% CI 0.89 to 0.92) for the Canadian C-Spine rule (P <.05). With a threshold of 0% predicted probability of injury, the respective indices of accuracy for physicians and the Canadian C-Spine rule were sensitivity 92.2% versus 100% (P <.001) and specificity 53.9% versus 44.0% (P <.001).

CONCLUSION

Interobserver agreement of unstructured clinical judgment for predicting clinically important cervical spine injury is only fair, and the sensitivity is unacceptably low. The Canadian C-Spine rule was better at detecting clinically important injuries with a sensitivity of 100%. Prospective validation has recently been completed and should permit widespread use of the Canadian C-Spine rule.

Outpatient oral prednisone after emergency treatment of chronic obstructive pulmonary disease

BACKGROUND

In this randomized, double-blind, placebo-controlled trial, we studied the effectiveness of prednisone in reducing the risk of relapse after outpatient exacerbations of chronic obstructive pulmonary disease (COPD).

METHODS

We enrolled 147 patients who were being discharged from the emergency department after an exacerbation of COPD and randomly assigned them to 10 days of treatment with 40 mg of oral prednisone once daily or identical-appearing placebo. All patients received oral antibiotics for 10 days, plus inhaled bronchodilators. The primary end point was relapse, defined as an unscheduled visit to a physician's office or a return to the emergency department because of worsening dyspnea, within 30 days after randomization.

RESULTS

The overall rate of relapse at 30 days was lower in the prednisone group than in the placebo group (27 percent vs. 43 percent, P=0.05), and the time to relapse was prolonged in those taking prednisone (P=0.04). After 10 days of therapy, patients in the prednisone group had greater improvements in forced expiratory volume in one second than did patients in the placebo group (mean [+/-SD] increase from base line, 34+/-42 percent vs. 15+/-31 percent; P=0.007). Patients in the prednisone group also had significant improvements in dyspnea, as measured by the transitional dyspnea index (P=0.04) and by the dyspnea domain of the Chronic Respiratory Disease Index Questionnaire (P=0.02), but not in health-related quality of life (P=0.14).

CONCLUSIONS

Outpatient treatment with oral prednisone offers a small advantage over placebo in treating patients who are discharged from the emergency department with an exacerbation of COPD.

Measurement of short-term changes in dyspnea and disease-specific quality of life following an acute COPD exacerbation

STUDY OBJECTIVE

To determine whether currently available measurement tools can be used to obtain valid measurements of short-term changes in dyspnea and disease-specific quality of life (QOL) in outpatients with an acute COPD exacerbation.

DESIGN

Prospective cohort study.

METHODS

Sixty-six patients with an acute COPD exacerbation who presented to the emergency department completed the chronic respiratory disease index questionnaire (CRQ) and the baseline dyspnea index (BDI) and were discharged home receiving 10 days of medical therapy. Reassessment with the CRQ and the transitional dyspnea index (TDI) occurred within 48 h of relapse (defined as an urgent hospital revisit within 10 days because of worsening respiratory symptoms), or 10 days later if relapse did not occur.

RESULTS

Patients who did not relapse (n = 49) showed moderate-to-large improvements in disease-specific QOL across all four CRQ domains (improvements in each domain of 1.4 to 1.9 U; p < 0.001 for all domains) and large positive changes in the TDI (total TDI score, + 5.02 plus minus 0.55 U; p = 0.0001). In contrast, patients who had a relapse (n = 17) did not have improved CRQ or TDI scores (mean negative change in three of four CRQ domains, total TDI score - 3.06 plus minus 1.14 U; p = 0.02). Changes in the CRQ dyspnea score and TDI correlated with each other (r = 0.78; p = 0.0001) and with changes in FEV(1) (CRQ, r = 0.48 and p = 0.0001; TDI, r = 0.46 and p = 0.0002). Ten control patients with stable COPD showed no changes in the CRQ or TDI over 10 days.

CONCLUSION

The CRQ and BDI/TDI can be used to obtain valid, responsive measures of acute changes in QOL and dyspnea associated with a COPD exacerbation. The direction and magnitude of change in these scores was highly correlated with clinical outcome and with other health measures. Most outpatients treated for a COPD exacerbation experience significant short-term improvements in QOL and dyspnea, with the exception of patients who have a clinical relapse of symptoms.

The Canadian C-spine rule for radiography in alert and stable trauma patients

CONTEXT

High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients.

OBJECTIVE

To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients.

DESIGN

Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments.

SETTING

Ten EDs in large Canadian community and university hospitals.

PATIENTS

Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15.

MAIN OUTCOME MEASURE

Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the kappa coefficient, logistic regression analysis, and chi(2) recursive partitioning techniques.

RESULTS

Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45 degrees to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%.

CONCLUSION

We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.

Vasopressin versus epinephrine for inhospital cardiac arrest: a randomised controlled trial

BACKGROUND

Survival rates for cardiac arrest patients, both in and out of hospital, are poor. Results of a previous study suggest better outcomes for patients treated with vasopressin than for those given epinephrine, in the out-of-hospital setting. Our aim was to compare the effectiveness and safety of these drugs for the treatment of in-patient cardiac arrest.

METHODS

We did a triple-blind randomised trial in the emergency departments, critical care units, and wards of three Canadian teaching hospitals. We assigned adults who had cardiac arrest and required drug therapy to receive one dose of vasopressin 40 U or epinephrine 1 mg intravenously, as the initial vasopressor. Patients who failed to respond to the study intervention were given epinephrine as a rescue medication. The primary outcomes were survival to hospital discharge, survival to 1 h, and neurological function. Preplanned subgroup assessments included patients with myocardial ischaemia or infarction, initial cardiac rhythm, and age.

FINDINGS

We assigned 104 patients to vasopressin and 96 to epinephrine. For patients receiving vasopressin or epinephrine survival did not differ for hospital discharge (12 [12%] vs 13 [14%], respectively; p50.67; 95% CI for absolute increase in survival 211.8% to 7.8%) or for 1 h survival (40 [39%] vs 34 [35%]; p50.66; 210.9% to 17.0%); survivors had closely similar median mini-mental state examination scores (36 [range 19-38] vs 35 [20-40]; p50.75) and median cerebral performance category scores (1 vs 1).

INTERPRETATION

We failed to detect any survival advantage for vasopressin over epinephrine. We cannot recommend the routine use of vasopressin for inhospital cardiac arrest patients, and disagree with American Heart Association guidelines, which recommend vasopressin as alternative therapy for cardiac arrest.