Physical measures and biomarker collection in health surveys: Propensity to participate

Population-based surveys have long been a key tool for health researchers, policy makers and program managers. The addition of bio-measures, including physical measures and specimen collection, to self-reported health and health behaviors can increase the value of the research for health sciences. At the same time, these bio-measures are likely to increase the perceived burden and intrusiveness to the respondent. Relatively little research has been reported on respondent willingness to participate in surveys that involve physical measures and specimen collection and whether there is any associated non-response bias.This paper explores the willingness of respondents to participate in surveys that involve physical measures and biomarkers. A Census-balanced sample of nearly 2000 adults from a national mobile panel of persons residing in the U.S. were interviewed. Willingness to participate in six specific bio-measures was assessed. The survey finds a high correlation in the willingness of respondents to participate among these specific bio-measures. This suggests there is a general propensity towards (and against) bio-measures among potential respondents, despite some differences in willingness to participate in the more sensitive, intrusive or burdensome biomarkers. This study finds the general propensity to participate in bio-measures is correlated with a number of key measures of health and illness. This suggests that the inclusion of biomarkers in health surveys may introduce some bias in key measures that need to be balanced against the value of the additional information.     

The efficacy and safety of inhaled fluticasone propionate/salmeterol and ipratropium/albuterol for the treatment of chronic obstructive pulmonary disease: an eight-week, multicenter, randomized, double-blind, double-dummy, parallel-group study

BACKGROUND: The pathology of chronic obstructive pulmonary disease (COPD) includes both obstructive and inflammatory components. OBJECTIVE: The aim of this study was to confirm the findings of a previous study that compared the efficacy of a combination of 2 short-acting bronchodilators with the use of an inhaled corticosteroid and a long-acting beta-agonist in the treatment of COPD. METHODS: We conducted an 8-week, multicenter, randomized, double-blind, double-dummy, parallel-group study of subjects with moderate to severe COPD to compare fluticasone propionate/salmeterol 250/50 microg BID (FSC) with ipratropium/albuterol 36/206 microg QID (IB/ALB). The primary efficacy measure was morning preadministration forced expiratory volume in 1 second (FEV(1)). Secondary measures were morning peak expiratory flow (PEF), 6-hour FEV(1) AUC, percentage of symptom-free nights, Transition Dyspnea Index (TDI) score, and overall daytime symptom score. Additional measures included sleep symptoms, supplemental albuterol use, and nighttime awakenings due to respiratory symptoms. Safety evaluations were based on clinical adverse events and COPD exacerbations. RESULTS: Baseline characteristics were similar between the FSC (n = 180) and IB/ALB (n = 181) groups, including mean age (63.7 and 65.4 years, respectively), mean body weight (81 and 79 kg, respectively), screening pulmonary function (mean [SD], 43.7% [14.2%] and 41.6% [13.4%] of predicted FEV(1)), race (82% and 91% white), and sex (64% and 62% male). FSC resulted in greater improvements in morning preadministration FEV(1), morning PEF, and 6-hour FEV(1) AUC (all, P < 0.001), TDI score (P = 0.026), overall daytime symptom score (P = 0.024), percentage of symptom-free nights (P = 0.010), nighttime awakenings due to respiratory symptoms (P = 0.002), sleep symptom score (P = 0.003), and percentage of days and nights without rescue albuterol use compared with IB/ALB (P = 0.021 and P < 0.001, respectively). Compared with day 1, the FEV(1) AUC at week 8 increased by 0.38 L-h with FSC and decreased by 0.18 L-h with IB/ALB (P < 0.001 between groups). The type and incidence of adverse events were similar between the 2 groups. One or more adverse event was reported for 81 (45%) and 85 (47%) subjects in the FSC and IB/ALB groups, respectively. CONCLUSION: In this 8-week study, subjects with moderate to severe COPD experienced greater improvements in lung function and symptom measures with FSC than with IB/ALB.     

How are you doing? What are you doing? Differing perspectives in the assessment of individuals with COPD

COPD exacerbations often lead to a downward spiral of physical activity. To compensate for the discomfort brought on by exertional dyspnea and the accompanying fatigue, patients with COPD will settle into a sedentary lifestyle that deconditions their bodies, serves to further aggravate breathlessness, and results in a further downward adjustment of physical activity. Progression of COPD imposes profound limitation on activities of daily living and gives rise to anxiety and depression. The distressing symptoms of breathlessness and the perception of these abnormalities by the patient lead to a reduction in health-related quality of life. The clinician's therapeutic interventions have to address these symptom and activity limitations with the goal of improving the patient's quality of life.     

Pulmonary function studies in patients with prolapse of the mitral valve.

We studied the pulmonary function and chest x-ray films of 20 nonsmokers with idiopathic prolapse of the mitral valve. Forty-five percent of these patients complained of dyspnea. Of the 16 chest films reviewed, 44 percent had radiographic evidence of pectus excavatum and 25 percent thoracic scoliosis. The most common pulmonary function abnormalities were increased residual volume (63 percent) and a reduced steady state diffusing capacity (50 percent of patients). There was no relationship between the presence of dyspnea and either chest wall deformity of abnormality of pulmonary function. These pulmonary function abnormalities may reflect a pulmonary parenchymal disorder possibly secondary to a connective tissue abnormality in the lung.     

The roles of bronchodilators, supplemental oxygen, and ventilatory assistance in the pulmonary rehabilitation of patients with chronic obstructive pulmonary disease

In patients with chronic obstructive pulmonary disease, pulmonary rehabilitation significantly improves dyspnea, exercise capacity, quality of life, and health-resource utilization. These benefits result from a combination of education (especially in the promotion of collaborative self-management strategies and physical activity), exercise training, and psychosocial support. Exercise training increases exercise capacity and reduces dyspnea. Positive outcomes from exercise training may be enhanced by 3 interventions that permit the patient to exercise train at a higher intensity: bronchodilators, supplemental oxygen (even for the nonhypoxemic patient), and noninvasive ventilatory support.     

Mood states associated with transitory changes in asthma symptoms and peak expiratory flow

OBJECTIVE: This study examined the within-person relations between transitory changes in mood, asthma symptoms, and peak expiratory flow rate (PEFR). METHODS: Thrice-daily for 21 consecutive days, 48 adults with moderate to severe asthma entered information in palm-top computers about their mood and asthma symptoms. A multidimensional model of mood, ie, the mood circumplex, informed the assessment of mood arousal and mood pleasantness. At each observation, participants also recorded their PEFR with peak flow meters that stored blinded data. Albuterol doses were also monitored electronically. Before and after the 21-day study, spirometric measures of airways obstruction were taken under controlled conditions. RESULTS: Random effects regression models revealed a significant, but weak, within-person relation between symptoms and PEFR. Changes in mood vectors with an arousal component were significantly related to PEFR changes, whereas changes in mood vectors with a pleasantness component tracked changes in asthma symptom reports, even after adjustment for contemporaneous PEFR and after controlling for time of day and albuterol dosing. Comparison of spirometric assessments with unsupervised PEFR suggested that part of the relation between mood arousal and PEFR may be attributable to the "effort-dependence" of peak flow self-monitoring. CONCLUSIONS: Different dimensions of mood were associated with transitory changes in asthma symptoms and PEFR. This may be one reason why individuals with asthma misperceive the severity of their symptoms in relation to underlying airways obstruction.     

Use of a long-acting inhaled beta2-adrenergic agonist, salmeterol xinafoate, in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a condition in which continuous bronchodilation may have clinical advantages. This study evaluated salmeterol, a beta-agonist bronchodilator with a duration of action substantially longer than that of short-acting beta-agonists, compared with ipratropium, an anticholinergic bronchodilator, and placebo in patients with COPD. Four hundred and five patients with COPD received either salmeterol 42 microg twice daily, ipratropium bromide 36 microg four times daily, or placebo for 12 wk in this randomized, double-blind, parallel-group study. Patients were stratified on the basis of bronchodilator response to albuterol (> 12% and > 200-ml improvement) and were randomized within each stratum. Bronchodilator response was measured over 12 h four times during the treatment period. Salmeterol provided similar maximal bronchodilatation to ipratropium but had a longer duration of action and a more constant bronchodilatory effect with no evidence of bronchodilator tolerance. Both active treatments were well tolerated. Salmeterol was an effective bronchodilator with a consistent effect over this 12-wk study in patients with COPD, including those "unresponsive" to albuterol. The long duration of action of salmeterol offers the advantage of twice daily dosing compared with the required four times a day dosing with ipratropium.     

The impact of nutritional depletion in chronic obstructive pulmonary disease

Nutritional depletion is prevalent in patients with advanced chronic obstructive pulmonary disease (COPD). These nutritional abnormalities are pronounced in patients with the "emphysematous" form of COPD on chronic corticosteroid therapy. The pathophysiologic mechanisms for the involuntary weight loss appear to be multifactorial. Clinical research has revealed that nutritional depletion in advanced COPD is associated with an increased morbidity and mortality. This review will address the implications of nutritional depletion in addition to potential therapeutic options.