Breathing for two: now we can all breathe a little easier.
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Administration, Inhalation↗
Biomedical subjects
Michael Schatz
Publications and source records attributed to Michael Schatz.
Relationship of validated psychometric tools to subsequent medical utilization for asthma.
BACKGROUND: Risk stratification is used to identify patients with asthma at increased risk of experiencing morbidity and resource utilization. Validated psychometric tools are infrequently studied sources of data for this purpose. PURPOSE: To evaluate 4 types of validated psychometric tools as predictors for subsequent asthma utilization and determine their clinical usefulness. METHODS: Eleven hundred patients with active asthma from a Health Maintenance Organization completed surveys that included demographic information and validated psychometric tools measuring generic quality of life (physical and mental components), asthma-specific quality of life, asthma control, and asthma symptom severity. Survey records were linked to administrative data that captured emergency department and hospital care, short-acting beta-agonist, and oral corticosteroid utilization for the year of and the year following the survey. Relationships of survey variables with subsequent utilization were assessed, adjusting for both baseline demographic and asthma utilization factors. RESULTS: Scores of each psychometric tool were significantly related to subsequent utilization in univariate analyses and after adjusting for baseline utilization and demographic risk factors. Patients with higher scale-defined morbidity were as much as 4 times more likely to have subsequent utilization (sensitivity as high as 58%; specificity as high as 78%). Addition of an asthma-specific tool to either demographic or utilization prediction models added sensitivity (as much as 15%) but did not substantially improve the prediction properties of models containing both demographic and utilization predictors. CONCLUSION: Validated psychometric tools appear useful for asthma risk stratification in individuals and in populations in which both utilization and demographic predictors are not available.
Adolescent↗
Relationships among quality of life, severity, and control measures in asthma: an evaluation using factor analysis.
BACKGROUND: Validated psychometric tools measuring quality of life, asthma control, and asthma severity have been developed, but their relationships with each other and with other important patient-centered outcomes have not been rigorously assessed. OBJECTIVE: To use factor analysis to evaluate the relationships of these validated tools with each other and with other patient-centered outcomes. METHODS: Surveys were completed by a random sample of 2854 Health Maintenance Organization members age 18 to 56 years with persistent asthma. Surveys included demographic information; validated tools measuring generic (Short Form-12; SF-12) and asthma-specific (Juniper Mini Asthma Quality of Life Questionnaire; AQLQ) quality of life, asthma control (Asthma Therapy Assessment Questionnaire), and asthma symptom severity (Asthma Outcomes Monitoring System); self-described severity, control, and course over time; and history of acute exacerbations. RESULTS: Principal component analysis suggested a 5-factor model that accounted for approximately 59% of the variability. The most prominent rotated factor reflected asthma symptom frequency (19.4% of variability), was measured by the symptom subscale of the AQLQ, and was the only factor significantly related to the Asthma Therapy Assessment Questionnaire, Asthma Outcomes Monitoring System, or the self-reported assessments of severity, control, or course. Other factors included symptom bother (12.1% of variability), reflected by the environment and emotion AQLQ subscales; activity limitation (13.9% of variability), reflected by the activity AQLQ subscale and the SF-12 physical component scale; mental health (8.3% of variability), reflected by the SF-12 mental component scale; and acute exacerbations (5.0% of variability), not measured by any of the validated scales. CONCLUSION: Distinct components of patient-reported asthma health status can be identified by factor analysis. Distinct constructs of severity versus control cannot be identified by the use of these tools alone.
Adolescent↗
Asthma medication use in pregnancy and fetal growth.
BACKGROUND: Given the high prevalence of asthma in pregnancy, it is important to understand the relationship between asthma medications and fetal growth in the context of appropriate treatment. OBJECTIVE: This study examines the effect of inhaled corticosteroids, systemic corticosteroids, and beta(2)-agonists on fetal growth in 654 infants born to women with asthma compared with 303 infants born to controls without asthma. METHODS: Subjects for this prospective study were enrolled throughout North America between 1998 and 2003 and followed up by the Organization of Teratology Information Services. Incidence of small for gestational age (SGA) infants and mean birth size measures were compared among groups. RESULTS: Mean birth weight of full-term infants born to mothers who used systemic corticosteroids (3373 g) was lower than in the beta(2)-agonist group (3552 g) and controls without asthma (3540 g; P < .05) after adjustment for other risk factors. However, no differences in the incidence of SGA for weight were observed among groups. Adjusted mean birth length was slightly shorter in the systemic steroid group compared with controls (P=.02). Incidence of SGA for length and head circumference and mean head circumference did not vary among groups (P>.05). CONCLUSION: The treatment of asthma with systemic corticosteroids resulted in a deficit of about 200 g in birth weight compared with controls and exclusive beta(2)-agonist users and no increased incidence of SGA. These results suggest that asthma management with beta(2)-agonists and/or inhaled corticosteroids during pregnancy does not impair fetal growth, whereas systemic corticosteroids have a minimal effect which should be weighed against the necessity to control severe asthma.
Administration, Inhalation↗
Fourier shell correlation threshold criteria.
The resolution value claimed for an electron microscopical three-dimensional reconstruction indicates the overall quality of the experiment. The Fourier shell correlation (FSC) criterion has now become the standard quality measure. However, what has continued to be controversial is the issue of the FSC threshold level at which one defines the reproducible resolution. Here, we discuss the theoretical behaviour of the FSC in conjunction with the various factors which influence it: the number of "voxels" in a given Fourier shell, the symmetry of the structure, and the size of the structure within the reconstruction volume. Both the theoretical considerations and our model experiments show that fixed-valued FSC threshold (like "0.5") may never be used in a reproducible criterion. Fixed threshold values are-as we show here-simply the result of incorrect assumptions in the basic statistics. Two families of FSC threshold curves are discussed: the sigma-factor curves and the new family of bit-based information threshold curves. Whereas sigma-factor curves indicate the resolution level at which one has collected information significantly above the noise level, the information curves indicate the resolution level at which enough information has been collected for interpretation.
Computer Simulation↗
Inhaled corticosteroid use and outcomes in pregnancy.
BACKGROUND: Current asthma management guidelines recommend aggressive asthma treatment for women who are pregnant. OBJECTIVE: To examine asthma medication use and asthma-related health care use before and during pregnancy. METHODS: Women aged 15 to 45 years with a pregnancy claim (index event) and an asthma claim (diagnosis or asthma medication prescription) were identified from a database of US managed care organizations (PharMetrics Patient-Centric Database). Medical claims 6 months before and after the index event were studied to determine the impact of pregnancy on asthma medication use (ie, prescription claims) and asthma-related physician visits, emergency department (ED) visits, and hospitalizations. RESULTS: Of 7,235 women with a pregnancy claim and 6 months of preindex and postindex data, 633 had an asthma claim (334 had an asthma-related medication claim and 299 had no asthma-related medication claim before the index event). During the preindex period, 142 patients were using asthma controller medications, with inhaled corticosteroids (ICSs) the most commonly used controller (n = 101); 283 were using short-acting beta2-adrenergic agonists (SABAs) with or without controllers. Among the 334 patients using asthma medication before pregnancy, the number using any controller decreased from 142 to 94 (-34%), those using ICSs decreased from 101 to 65 (-36%), and those using SABAs decreased from 283 to 137 (-52%) after the pregnancy claim. For these 334 patients, the number with an asthma-related ED visit increased from 14 to 17 (21%) after the pregnancy claim. Among those without a pharmacy record of medication use before pregnancy (n = 299), the number with an asthma-related ED visit increased from 4 to 7 (75%) after the pregnancy claim. For the 101 patients using ICSs before pregnancy, the number with an asthma-related physician visit decreased from 39 to 25 (-36%) and the number with an ED visit was unchanged. For the 532 patients not using an ICS before pregnancy, the number with an asthma-related physician visit increased from 84 to 107 (27%) and the number with an ED visit increased from 12 to 18 (50%). CONCLUSION: For patients using an ICS before pregnancy, the rate of asthma-related physician visits decreased and the number of ED visits was unchanged after pregnancy, whereas physician and ED visits increased after pregnancy for patients not using an ICS before pregnancy. Overall, the data suggest that asthma is undertreated in women contemplating pregnancy and in those who are pregnant.
Administration, Inhalation↗
Treatment of asthma during pregnancy and perinatal outcomes.
PURPOSE OF REVIEW: Asthma is the most common, potentially serious medical problem to complicate pregnancy. Women with asthma have been shown to be at increased risk of complications during pregnancy. Managing asthma during pregnancy is unique because the effect of both the illness and the treatment on the developing fetus as well as the patient must be considered. This review summarizes the recent studies addressing the effects of asthma or asthma medications on perinatal outcomes, including the 2004 Asthma and Pregnancy Working Group of the National Asthma Education and Prevention Program. RECENT FINDINGS: This review summarizes the recent studies addressing the effect of asthma or asthma medications on perinatal outcomes. SUMMARY: The prevalence of asthma in pregnant women appears to be increasing. Recent evidence supports that pregnant women with moderate to severe asthma may have an increased risk of adverse perinatal outcomes. The goal of asthma management during pregnancy is to optimize maternal and fetal health.
Administration, Inhalation↗
Pregnancy and asthma: recent developments.
PURPOSE OF REVIEW: Asthma is the most common potentially serious medical problem to complicate pregnancy. Asthmatic women have been shown to be at an increased risk of complications during pregnancy. Managing asthma during pregnancy is unique because the effects of both the illness and the treatment on the developing fetus and the patient must be considered. RECENT FINDINGS: This review summarizes the recent studies addressing the interrelationships between asthma and pregnancy and general aspects of pharmacologic therapy of gestational asthma. SUMMARY: The prevalence of asthma in pregnant women appears to be increasing. Recent evidence supports that pregnant asthmatic women with moderate to severe asthma may have an increased risk of adverse perinatal outcomes. The goal of asthma management during pregnancy is to optimize maternal and fetal health.
Administration, Inhalation↗
Soluble transferrin receptor and zinc protoporphyrin--competitors or efficient partners?
OBJECTIVES: Soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZPP) are both parameters of iron deficient erythropoiesis (IDE), the sTfR measurement is commonly regarded to be the more sensitive test. sTfR also reflects erythropoietic activity, it is increased in enhanced erythropoiesis. METHODS: We investigated the diagnostic accuracy of sTfR in assessment of iron deficiency (ID) and compared it with ZPP. The study was performed on 174 subjects, in which ID has been precisely staged. RESULTS: Individuals without ID and patients with storage iron depletion only, had normal sTfR values. Patients classified as IDE and patients with iron deficiency anemia had significantly increased sTfR. There was a good correlation between sTfR and hemoglobin (r = -0.86; P < 0.0001) and between sTfR and ZPP (r = 0.86; P < 0.0001). When diagnosing ID, ZPP was the more sensitive test. In mildly developed IDE associated with ZPP-ratios between 40 and 70 micromol/mol heme, the sTfR concentration was elevated in only 25% of the cases. Reliably elevated sTfR values were observed only in more advanced IDE, associated with ZPP > 70 mumol/mol heme. CONCLUSIONS: ZPP is not inferior to sTfR when diagnosing IDE. Given the good correlation between sTfR and ZPP and because ZPP is uninfluenced by the erythropoietic activity, sTfR and ZPP are not competitors, rather efficient partners in diagnosing anemias. By measuring ZPP and sTfR simultaneously, the diagnostic uncertainty inherent in each of them individually can be eliminated. In particular, the simultaneous determination of ZPP and sTfR enhances the diagnostic power of sTfR in assessment of the erythropoietic activity.
Adolescent↗
Asthma quality-of-care markers using administrative data.
STUDY OBJECTIVE: To evaluate the relationship of potential asthma quality-of-care markers to subsequent emergency hospital care. DESIGN: Retrospective administrative database analysis. SETTING: Managed care organization. PATIENTS: Asthmatic patients aged 5 to 56 years of age. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Candidate quality measures included one or more or four or more controller medication canisters, a controller/total asthma medication ratio of > or = 0.3 or > or = 0.5, and the dispensing of fewer than six beta-agonist canisters in 2002. Outcome was a 2003 asthma emergency department visit or hospitalization. Multivariable analyses adjusted for age, sex, and year 2002 severity (based on utilization). In the total sample (n = 109,774), one or more controllers (odds ratio, 1.35) and four or more controllers (odds ratio, 1.98) were associated with an increased risk of emergency hospital care, whereas a controller/total asthma medication ratio of > or = 0.5 (odds ratio, 0.73) and the dispensing of fewer than six beta-agonist canisters (odds ratio 0.30) were associated with a decreased risk. After adjustment for baseline severity in the total asthma sample, the controller/total asthma medication ratio (odds ratio, 0.62 to 0.78) and beta-agonist measure (odds ratio, 0.42) were associated with decreased risk, whereas the dispensing of four or more canisters of controller medication was associated with increased risk (odds ratio, 1.33). After stratification by year 2002 beta-agonist use, all of the measures were associated with decreased risk in those who received fewer than six beta-agonist canisters, whereas all of the measures except the medication ratio of > or = 0.5 were associated with increased risk in the cohort who received six or more beta-agonist canisters. CONCLUSION: Controller use and beta-agonist use may function as severity indicators in large populations rather than as asthma quality-of-care markers. A medication ratio of > or = 0.5 appeared to function as the best quality-of-care marker in this study.
Adolescent↗
The prevalence of reversible airflow obstruction and/or methacholine hyperreactivity in random adult asthma patients identified by administrative data.
BACKGROUND: Asthma is a chronic inflammatory lung disease. It is commonly diagnosed and treated on the basis of clinical impression, although national guidelines recommend documenting reversible airflow obstruction. OBJECTIVES: Determine the frequency of reversible airflow obstruction, and/or methacholine hyperreactivity during 2003 in a well-characterized population with a low-risk asthma diagnosis during 2001. METHODS: Of a total population of 7460 low-risk adult (18-64 years) asthma patients (no hospitalizations or emergency department visits; < 3 oral steroid courses; < 12 beta-agonist canisters; and < 3 prescibers, all in prior 12 months) cared for by a large health care program, a random sample of 400 was recruited to undergo a diagnostic asthma evaluation. The evaluation included a physical examination, medical record review, questionnaires, allergy testing, spirometry for airflow obstruction and reversibility, and/or methacholine hyperreactivity. RESULTS: Of the 400 randomly selected patients, 106 (26.5%) started and 82 (77.3%) completed the asthma evaluation. Evaluated subjects were predominately female (71%), middle-aged (mean 51.0 +/- 11.0 years), diagnosed asthmatics for long duration (mean 22.1 +/- 17.5 years), and nonsmokers (88.7%). Asthma was confirmed in 62.1% (51 of 82) based on a deltaFEV1 12% or greater after albuterol (n = 38), deltaFEV1 15% or greater after Advair (n = 6), or a positive methacholine challenge (n = 7). Only 35 of 400 patients (8.7%) ever had reversibility measured in their medical record. Of these, only 12 (34.3%) had a deltaFEV1 12% or greater after albuterol. Reversibility was confirmed in all six who had asthma evaluations. CONCLUSIONS: More than one third of low-risk adult asthmatics cannot be confirmed to have asthma 2 years later. Spirometry that documented reversibility in the medical record accurately predicted asthma confirmation. Physicians should more widely perform spirometry with reversibility to establish the diagnosis of asthma as recommended by national asthma guidelines.
Adult↗
How well do the HEDIS asthma inclusion criteria identify persistent asthma?
OBJECTIVES: (1) To determine if the Health Plan Employer Data and Information Set (HEDIS) asthma inclusion criteria consistently identify persistent asthma on a year-to-year basis and (2) to explore whether variation in the number of years of qualification is associated with medication and resource utilization outcomes. STUDY DESIGN: Retrospective observational study. METHODS: We identified 132 414 patients in a large healthcare program who were included in 1 or more HEDIS persistent asthma cohorts between 1999 and 2002 and who had continuous insurance and pharmacy benefit coverage for the entire 4-year observation period. Medication, emergency department, and hospital use in 2002 was identified using electronic claims and pharmacy information. RESULTS: Overall, 47.9% of the patients were identified as having persistent asthma in only 1 of 4 years, 40.8% had at least 2 consecutive years, and 28.2% had at least 3 consecutive years. In bivariate and multivariate analyses, more consecutive years of HEDIS persistent asthma qualification significantly increased the likelihood of frequent short-acting b-agonist use, inhaled antiinflammatory corticosteroid use, at least 1 emergency department visit, and at least 1 hospitalization. The strongest relationship was for 3 or more consecutive years of HEDIS qualification. CONCLUSIONS: A significant portion of the HEDIS persistent asthma cohort does not qualify on a year-to-year basis, suggesting that the current 1-year qualification period or the underlying administrative case definition for persistent asthma may be suboptimal. Further clinical validation studies are needed to determine the optimal criteria for a more useful HEDIS persistent asthma case definition.
Adolescent↗
Automated correction of genome sequence errors.
By using information from an assembly of a genome, a new program called AutoEditor significantly improves base calling accuracy over that achieved by previous algorithms. This in turn improves the overall accuracy of genome sequences and facilitates the use of these sequences for polymorphism discovery. We describe the algorithm and its application in a large set of recent genome sequencing projects. The number of erroneous base calls in these projects was reduced by 80%. In an analysis of over one million corrections, we found that AutoEditor made just one error per 8828 corrections. By substantially increasing the accuracy of base calling, AutoEditor can dramatically accelerate the process of finishing genomes, which involves closing all gaps and ensuring minimum quality standards for the final sequence. It also greatly improves our ability to discover single nucleotide polymorphisms (SNPs) between closely related strains and isolates of the same species.
Algorithms↗
Sex differences among children 2-13 years of age presenting at the emergency department with acute asthma.
Hospitalization rates for asthma have been reported to be higher in males than females in children under age 15, but it is not clear whether this disparity reflects gender differences in prevalence, severity, or treatment. We performed a prospective cohort study as part of the Emergency Medicine Network. Patients aged 2-13 years who presented to the emergency department (ED) with acute asthma underwent a structured interview in the ED and another by telephone 2 weeks later. Of 1,602 patients, 61% (95% CI, 59-64%) were boys. Girls were slightly older than boys, although no material differences existed in acute presentation, chronic asthma characteristics, ED treatment, or ED course. There was no difference in admission rates for boys or girls (20% vs. 22%; P = 0.48). This finding persisted when adjusting for other factors in a multivariate logistic regression model. No sex differences were observed for relapse or ongoing exacerbation on univariate or multivariate analysis. These data suggest that asthma is not inherently more severe in boys with asthma compared to girls, and that the increased rate of hospitalizations in boys under age 13 is due to differences in prevalence, not severity.
Acute Disease↗
Randomized trial of inhaled beclomethasone dipropionate versus theophylline for moderate asthma during pregnancy.
OBJECTIVE: This study was undertaken to compare the efficacy of inhaled beclomethasone dipropionate to oral theophylline for the prevention of asthma exacerbation(s) requiring medical intervention. STUDY DESIGN: A prospective, double-blind, double placebo-controlled randomized clinical trial of pregnant women with moderate asthma was performed. RESULTS: There was no significant difference (P=.554) in the proportion of asthma exacerbations among the 194 women in the beclomethasone cohort (18.0%) versus the 191 in the theophylline cohort (20.4%; risk ratio [RR]=0.9, 95% CI=0.6-1.3). The beclomethasone cohort had significantly lower incidences of discontinuing study medications caused by side effects (RR=0.3, 95% CI=0.1-0.9; P=.016), and proportion of study visits with forced expiratory volume expired in 1 second (FEV1) less than 80% predicted (0.284+/-0.331 vs 0.284+/-0.221, P=.039). There were no significant differences in treatment failure, compliance, or proportion of peak expiratory flow rate less than 80% predicted. There were no significant differences in maternal or perinatal outcomes. CONCLUSION: The treatment of moderate asthma with inhaled beclomethasone versus oral theophylline resulted in similar rates of asthma exacerbations and similar obstetric and perinatal outcomes. These results favor the use of inhaled corticosteroids for moderate asthma during pregnancy because of the improved FEV1 and because theophylline had more side effects and requires serum monitoring.
Administration, Inhalation↗
Development of the asthma control test: a survey for assessing asthma control.
BACKGROUND: Asthma guidelines indicate that the goal of treatment should be optimum asthma control. In a busy clinic practice with limited time and resources, there is need for a simple method for assessing asthma control with or without lung function testing. OBJECTIVES: The objective of this article was to describe the development of the Asthma Control Test (ACT), a patient-based tool for identifying patients with poorly controlled asthma. METHODS: A 22-item survey was administered to 471 patients with asthma in the offices of asthma specialists. The specialist's rating of asthma control after spirometry was also collected. Stepwise regression methods were used to select a subset of items that showed the greatest discriminant validity in relation to the specialist's rating of asthma control. Internal consistency reliability was computed, and discriminant validity tests were conducted for ACT scale scores. The performance of ACT was investigated by using logistic regression methods and receiver operating characteristic analyses. RESULTS: Five items were selected from regression analyses. The internal consistency reliability of the 5-item ACT scale was 0.84. ACT scale scores discriminated between groups of patients differing in the specialist's rating of asthma control (F = 34.5, P <.00001), the need for change in patient's therapy (F = 40.3, P <.00001), and percent predicted FEV(1) (F = 4.3, P =.0052). As a screening tool, the overall agreement between ACT and the specialist's rating ranged from 71% to 78% depending on the cut points used, and the area under the receiver operating characteristic curve was 0.77. CONCLUSION: Results reinforce the usefulness of a brief, easy to administer, patient-based index of asthma control.
Adolescent↗
Use of inhaled steroids by pregnant asthmatic women does not reduce intrauterine growth.
BACKGROUND: Inhaled steroids are recommended for the treatment of persistent asthma during pregnancy, but their potential effects on intrauterine growth have been inadequately evaluated. OBJECTIVE: The purpose of this study was to evaluate the association between maternal use of specific inhaled steroids and inhaled steroid dose during pregnancy and the incidence of infants who are small for gestational age (SGA) and mean birth weight. METHODS: Pregnant asthmatic women being treated with inhaled steroids were enrolled in the study before delivery by their managing allergists. Information regarding the specific inhaled steroid and daily dose used, requirement for oral steroids, occurrence of acute asthmatic episodes, maternal race, birth weight, gestational age, and congenital malformations was obtained for each patient. SGA was defined through use of a published normative sample of American births. RESULTS: A total of 474 women were enrolled in the study; of the 451 enrolled participants whose pregnancy ended in a singleton live birth, 396 (88%) completed the study. The incidence of infants with low birth weight, preterm births, and congenital malformations in this cohort was not greater than expected in the general population. The incidence of SGA was 7.1% (95% CI, 5.0% to 10.1%). No significant relationships between specific inhaled steroid or dose of inhaled steroid used and either SGA or mean birth weight were observed. CONCLUSION: These data suggest that the use of inhaled steroids by pregnant asthmatic women does not reduce intrauterine growth and supports the recommendation that inhaled steroids should be used in the management of persistent asthma during pregnancy.
Administration, Inhalation↗
The relationship of asthma medication use to perinatal outcomes.
BACKGROUND: Maternal asthma has been reported to increase the risk of preeclampsia, preterm deliveries, and lower-birth-weight infants, but the mechanisms of this effect are not defined. OBJECTIVE: We sought to evaluate the relationship between the use of contemporary asthma medications and adverse perinatal outcomes. METHODS: Asthmatic patients were recruited from the 16 centers of the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network from December 1994 through February 2000. Gestational medication use was determined on the basis of patient history at enrollment and at monthly visits during pregnancy. Perinatal data were obtained at postpartum chart reviews. Perinatal outcome variables included gestational hypertension, preterm births, low-birth-weight infants, small-for-gestational-age infants, and major malformations. RESULTS: The final cohort included 2123 asthmatic participants. No significant relationships were found between the use of inhaled beta-agonists (n=1828), inhaled corticosteroids (n=722), or theophylline (n=273) and adverse perinatal outcomes. After adjusting for demographic and asthma severity covariates, oral corticosteroid use was significantly associated with both preterm birth at less than 37 weeks' gestation (odds ratio, 1.54; 95% CI, 1.02-2.33) and low birth weight of less than 2500 g (odds ratio, 1.80; 95% CI, 1.13-2.88). CONCLUSIONS: Use of inhaled beta-agonists, inhaled steroids, and theophylline do not appear to increase perinatal risks in pregnant asthmatic women. The mechanism of the association between maternal oral corticosteroid use and prematurity remains to be determined.
Adolescent↗