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Outcomes of Asthma. A. Sonia Buist M.D. Oregon Health & Science University, Portland, Oregon. OUTCOMES. Markers of success or failure in managing a disease, focused on the important characteristics that influence the course and consequences of that disease for patients and society
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Outcomes of Asthma A. Sonia Buist M.D. Oregon Health & Science University, Portland, Oregon
OUTCOMES • Markers of success or failure in managing a disease, focused on the important characteristics that influence the course and consequences of that disease for patients and society • Meaningful correlation with benefit • Outcome must be measurable • Outcome must be amenable/sensitive to change • Valid reflections of the process of care
Asthma outcomes • Mortality • Prevalence • Hospital admissions & re-admissions • Heath resource utilisation & costs • Severity - Control • Morbidity • Time lost from school, work • Treatment impact • Doctor visits • QOL • Exacerbations
Asthma Control as New Outcome for Asthma • FEV1 infrequently measured and doesn’t correlate well with health status • Adherence to peak flow monitoring poor • Need for a simple, inexpensive instrument that can be used in clinical practice and clinical research
Goals of Asthma Management • Maintain “near normal” pulmonary function • Prevent chronic and troubling symptoms • Maintain normal activity levels • Prevent recurrent exacerbations • Minimal or no adverse effects of treatment National Asthma Education and Prevention Program Expert Panel (NAEPP) Report 2: Guidelines for the Diagnosis and Management of Asthma. Update on selected topics. Allergy Clin Immunol 2002;110(5 pt 2):S141-219.
Stepwise Approach to Asthma Therapy - Adults Outcome: BestPossible Results Outcome: Asthma Control • Controller: • Daily inhaled corticosteroid • Daily long –acting inhaled β2-agonist • plus (if needed) • When asthma is controlled, reduce therapy • Monitor • Controller: • Daily inhaled corticosteroid • Daily long-acting inhaled β2-agonist • Controller: • Daily inhaled • corticosteroid Controller: None -Theophylline-SR -Leukotriene modifier -Oral corticosteroid Reliever: Rapid-acting inhaled β2-agonist prn STEP 1: Intermittent STEP 2:Mild Persistent STEP 3: Moderate Persistent STEP 4: Severe Persistent STEP Down Alternative controller and reliever medications may be considered
Problems with Using Guideline-Defined Severity • Spirometry often not done • Patients are already on asthma meds (guidelines say “pre-drug”) • ICS affect lung function so hard to assess severity accurately • Lung function is measured at one point in time (not a composite measurement) • Severity is often underestimated
What is Severity? Depends on your perspective
What is Severity? To a Clinician: a patient who needs: • several different kinds of asthma medications • who goes to the ED frequently • who has low lung function that doesn’t reverse completely with short-acting bronchodilators
What is Severity? To a Patient: asthma that seriously interferes with their life: • wakes them at night • needs several medications • involves a complicated management regimen • interferes with school/work • prevents them from doing what they would like to do
What is Severity? To a Healthcare Manager: a patient who uses healthcare that is costly: • frequent ED visits/hospitalizations • needs a specialist • needs costly medications
What is Severity? To a pathologist: very severe chronic inflammatory changes in the airways, probably with remodeling. To a physiologist: a patient with severe airflow limitation that is largely (but not necessarily entirely) reversible.
Why is Severity Important? • Closely linked to cost-of-care • Enables targeted interventions • clinical trials • guidelines implementation
Global severity Level of control Medical management Health outcomes • HCU • QOL • Factual • status Self- management Other personal factors Environmental exposures
Alternative to Management Algorithm • Use asthma control as a guide rather than asthma severity SeverityControl
Interplay of Asthma Severity, Management and Control Asthma management Good Poor Severe good control Severity poor control Mild Severe
Red Flags That Asthma Is Not Well Controlled • Frequent use of short-acting beta-agonists • Use of >1 canister of SABA/month or >8 puffs/day • Need for unscheduled care (ED or hospitalization) • Missed school or work
What Is Good Control? • Virtually no use of short-acting -agonist (<2x/week) • Isn’t woken at night by asthma • No unscheduled health care utilization (ED visits/hospitalization) • No lost work or school • No exacerbations
Why is Level of Control Important? • Reflects patients current health status • Reflects outcome of care • Typically a very patient-oriented measure
Which is More Important: Severity or Level of Control? • Depends on your perspective • Individual clinician: level of control is key • FDA/pharmaceutical industry • Health plan manager • Epidemiologist/ • outcomes researcher Level of control is outcome, severity is a confounder
Control Instruments Available • ATAQ (Asthma Therapy Assessment Questionnaire). Cross-sectional & prospective validation 4 dimensions • ACQ (Asthma Control Questionnaire). Juniper 7 questions • ACT (Asthma Control Test—QualityMetric Inc) 5 dimensions
Development & Validation of Asthma Therapy Assessment Questionnaire • We developed a simple 4-question instrument to assess asthma control • Scored as 0-4 (control problems) • Validated the instrument in a large health management organization (cross-sectional validation) • Prospectively validated the instrument over 12 months Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-1652
Asthma Therapy Control Questionnaire (ATAQ) • In the past 4 weeks, did you feel that your asthma was well controlled? • In the past 4 weeks, did you miss any work, school or normal activity because of your asthma? • In the past 4 weeks, did your asthma wake you up at night? • In the past 4 weeks, what was the highest # of puffs a day you took of your quick relief inhaler? Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-1652 Score is 0-4
ATAQ Asthma Control Index In the past four weeks (12 months): Has your asthma been well-controlled? Score 1 point if “no” or “unsure”
ATAQ Asthma Control Index In the past four weeks (12 months): Has your asthma been waking you up at night? Score 1 point if “yes” or “unsure”
ATAQ Asthma Control Index In the past four weeks (12 months): Has your asthma been interfering with your usual activities? Score 1 point if “yes” or “unsure”
ATAQ Asthma Control Index In the past four weeks (12 months): What is the highest number of puffs of your reliever medication on any single day? Score 1 point if more than 12
Cross-sectional validation of ATAQ • ATAQ mailed to 5,181 adult members of large health maintenance organization (HMO) in Pacific Northwest of U.S.(K.P.) • Quality of life instruments (generic [SF-36] and asthma-specific [Juniper]) also sent to one-quarter. Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-1652
Distribution of ATAQ Control Index Ref: Vollmer et al., AJRCCM 1999
ATAQ Validation Within last Within last4 weeksyearSelf-perception of asthma control 30% - -Missed activities 27% 47%Nocturnal awakening 40% 66%Overuse of rescue meds 8% 15%At least one problem 52% - - Vollmer WM, et al. Am J Respir Crit Care Med. 1999;160:1647-1652.
0 80 1 70 2 60 3 50 4 40 30 20 10 0 Retrospective Validation of ATAQ Relation Between Control of Problems During Previous 4 Weeks & Health Care Utilization During Previous Year # of Problems with Asthma Control Patients (%) ≥2 Visits worsening ≥1 Urgent visit ≥1 Hospitalization asthma Within each control group, p<0.001 Vollmer et al. Am J Respir Crit Care Med. 1999;160:1647-1652.
Mean Quality of Life Scores by Number of Control Problems Number of Control Problems in Past 4 Weeks Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-52
Association of Asthma Control with Health Care Utilization: A Prospective Evaluation • Prospectively validated control instrument (ATAQ) • Studied HCU over subsequent 12 months Vollmer et al, AJRCCM 2002; 165: 195-99
1600 200 1400 175 1200 150 1000 125 100 800 600 75 400 50 200 25 0 0 Prospective Validation of ATAQ 4795 Subjects with Asthma Who Completed ATAQ Followed Prospectively for 1 Year # of Problems with Asthma Control 0 1 2 Rate per 1000 Patient Years 3 or 4 Routine Visits Acute Visits ED Visits Hospitalizations Vollmer et al. Am J Respir Crit Care Med. 2002;165:195-199.
Conclusions from ATAQ Validation • The majority of asthma patients are probably not in optimal control • Asthma control as assessed by the ATAQ can predict past & future health care utilization • ATAQ is simple to use & can be self-administered
Assessing Outcomes of Care • Level of control can be viewed as a legitimate outcome in its own right • Can also be used to predict more traditional outcomes of care, such as health care utilization and quality of life
Asthma Control : a worthy outcome? Ideal asthma control • Absent or minimal symptoms • Absent or minimal rescue medication • No nocturnal or early am symptoms • Absent morbidity • Lung function normal or best Professor Ann Woolcock
Time course of asthma control No night symptoms am PEF 100 No SABA use FEV1 AHR % improvement 0 Days Weeks Months Years Woolcock AJ Clin Exp Allergy Rev, 2001. 1(2): p. 62-4.
Gaining Optimal Asthma Control (GOAL) Study Background: “to date no studies have assessed the benefits of aiming for complete, comprehensive, and sustained clinical control in a controlled study that allows for dose escalation, as necessary, to achieve this”
Gaining Optimal Asthma Control (GOAL) Study • 1-yr RCT with 3,421 pts aged 12-80 yrs from 44 countries with uncontrolled asthma • 2 arms: fluticasone + salmeterol and fluticasone alone • Treatment was stepped up until total control was reached (or 500µg CS bid) • Control assessed over 8wks before visits at 12,24,36 52 months Bateman et al AJRCCM 2004; 170: 836-44
Gaining Optimal Asthma Control (GOAL) Study • 2 control definitions used: “totally controlled” and “well controlled”. If neither, “uncontrolled” • Control definitions were composite measures that included: PEF, rescue med use, symptoms, night-time wakenings, exacerbations, ED visits, adverse events Bateman et al AJRCCM 2004; 170: 836-44
Outcomes of GOAL Study • Proportion of pts who achieved well-controlled asthma with the combo compared to fluticasone alone in phase 1 • Many secondary outcomes Bateman et al AJRCCM 2004; 170: 836-44
Gaining Optimal Asthma Control (GOAL) Study Phase 1: Dose escalation. Regimen stepped up every 12 weeks until total control achieved or max dose Phase 2: Maintenance control dose or max dose for 1 year (double blind) Bateman et al AJRCCM 2004; 170: 836-44