outcomes of asthma
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Outcomes of Asthma
A. Sonia Buist M.D.A. Sonia Buist M.D.
Oregon Health & Oregon Health & Science University, Science University, Portland, OregonPortland, 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.
NAEPP Severity Symptoms Nighttime Sx Lung Function
Severe Persistent
Continual symptoms Limited phys activity Freq exacerbations
Frequent FEV1<60% pred PEF var >30%
Moderate Persistent
Daily symptoms Daily BA use Exac > 2/week
> once/week FEV1 60-80% pred PEF var > 30%
Mild Persistent
Sx > 2-6 days/week Exac may affect activity
> twice/month FEV1 >80% pred PEF var 20-30%
Mild intermittent
Sx < 2 days/week Asympt between exac Exac are brief
< 2 times/month FEV1 > 80% pred PEF var < 20%
NAEPP Severity Symptoms Nighttime Sx Lung Function
Severe Persistent
Continual symptoms Limited phys activity Freq exacerbations
Frequent FEV1<60% pred PEF var >30%
Moderate Persistent
Daily symptoms Daily BA use Exac > 2/week
> once/week FEV1 60-80% pred PEF var > 30%
Mild Persistent
Sx > 2-6 days/week Exac may affect activity
> twice/month FEV1 >80% pred PEF var 20-30%
Mild intermittent
Sx < 2 days/week Asympt between exac Exac are brief
< 2 times/month FEV1 > 80% pred PEF var < 20%
Stepwise Approach to Asthma Therapy - Adults
Reliever: Rapid-acting inhaled β2-agonist prn
Controller: Daily inhaled corticosteroid
Controller: Daily inhaled
corticosteroid Daily long-
acting inhaled β2-agonist
Controller: Daily inhaled
corticosteroid Daily long –
acting inhaled β2-agonist
plus (if needed)
When asthma is controlled, reduce therapy
Monitor
STEP 1:Intermittent
STEP 1:Intermittent
STEP 2:Mild Persistent
STEP 3:STEP 3: Moderate Moderate PersistentPersistent
STEP 4:STEP 4:Severe Severe
PersistentPersistent
STEP DownSTEP DownSTEP DownSTEP Down
Outcome: Asthma Control Outcome: Best Possible Results
Alternative controller and reliever medications may be considered
Controller:None
-Theophylline-SR -Leukotriene modifier -Oral corticosteroid
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
To a ClinicianTo 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: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: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:To a pathologist: very severe chronic inflammatory changes in the airways, probably with remodeling.
To a physiologistTo a physiologist: a patient with severe airflow limitation that is largely (but not necessarily entirely) reversible.
What is Severity?
Why is Severity Important?
Closely linked to cost-of-care
Enables targeted interventions
clinical trials guidelines implementation
Environmentalexposures
Self-management
Globalseverity
Medicalmanagement
Other personal
factors
Level ofcontrol
• HCU• QOL• Factual
status
Health outcomes
Alternative to Management Algorithm Use asthma control as a guide
rather than asthma severity
Severity
Control
Interplay of Asthma Severity, Management and Control
Asthma managementAsthma managementGood Poor
good control
poor control
Sev
erit
yS
ever
ity
Mild
SevereSevere
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
Depends on your perspectiveDepends on your perspective
Individual clinician: level of control is key
FDA/pharmaceutical industry
Health plan manager
Epidemiologist/ outcomes researcher
Which is More Important: Severity or Level of Control?
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 AAsthma TTherapy AAssessment 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?
Score is 0-4Score is 0-4Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-1652
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
0%10%20%30%40%50%60%70%80%90%
100%
None One Two Three Four
Ref: Vollmer et al., AJRCCM 1999
ATAQ Validation
Within last Within last 4 weeks year
Self-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.
Retrospective Validation of ATAQ
Vollmer et al. Am J Respir Crit Care Med. 1999;160:1647-1652.
Relation Between Control of Problems During Previous4 Weeks & Health Care Utilization During Previous Year
asthma
01234
Within each control group, p<0.001
# of Problems with Asthma
Control
0
10
20
30
40
50
60
70
80
≥2 Visits worsening ≥1 Urgent visit ≥1 Hospitalization
Pat
ien
ts (
%)
None One Two Three Four P-value
SF-36 Scales Physical Mental
66 71
58 65
50 59
36 47
35 45
<.001 <.001
Asthma QOL Overall
St. George’s Resp Quest
5.7
4.9
4.3
3.1
2.9
<.001
Overall 30 40 46 56 63 <.001
Number of Control Problems in Past 4 Weeks
Mean Quality of Life Scores by Number of Control Problems
Vollmer et al, Am J Resp Crit Care Med 1999;160:1647-52
Prospectively validated control instrument (ATAQ)
Studied HCU over subsequent 12 months
Association of Asthma Control with Health Care Utilization: A Prospective Evaluation
Vollmer et al, AJRCCM 2002; 165: 195-99
Prospective Validation of ATAQ
Vollmer et al. Am J Respir Crit Care Med. 2002;165:195-199.
4795 Subjects with Asthma Who Completed ATAQ Followed Prospectively for 1 Year
# of Problems with Asthma
Control
0123 or 4
0
200
400
600
800
1000
1200
1400
1600
Routine Visits Acute Visits ED Visits Hospitalizations
Rat
e p
er 1
000
Pa
tie
nt
Yea
rs
0
25
50
75
100
125
150
175
200
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 controlIdeal 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 No night symptomssymptoms
DaysDays
% i
mp
rove
men
t
100 am PEFam PEFFEV1
AHRAHR
YearsYearsMonthsMonthsWeeksWeeks
No SABA useNo SABA use
0
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
Bateman et al, Am J Resp Crit Care Med 2004;170:836-844.
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
Bateman et al, Am J Resp Crit Care Med 2004;170:836-844.
Proportion of patients achieving a well-controlled week
GOAL Study
Conclusions of GOAL Study The majority of patients with uncontrolled
asthma across a wide range of severities, comprehensive guideline-defined control can be achieved & maintained
The combo of ICS & LABA allows better control The combo of ICS & LABA allows better control than ICS alonethan ICS alone
Exacerbations were virtually eliminated if total Exacerbations were virtually eliminated if total control was achieved control was achieved
QOL was near normal in most with total controlQOL was near normal in most with total control
Bateman et al AJRCCM 2004; 170: 836-44
Questions that GOAL Raises When should stepping down occur? How far can we generalize the
findings? To kids <12 years? To clinical practice?
Is “total control” the right goal to shoot for?
Does aiming at total control over-treat?
Conclusions Asthma severity & control are different
although related metrics. Both are important
There are now several validated instruments for assessing asthma control
An algorithm for asthma management based on asthma control has the advantage of simplicity & is easy for patient & provider to understand & apply
Asthma control is a good outcome for RCTs
Rule of 2’s
Rescue inhaler not needed more than: 2 days / week 2 nights/month
Patients can understand this easily and apply it
Unanswered Questions Will an algorithm based on asthma
control lead to better adherence in asthma?
Will stressing asthma control lead to even fewer asthma patients receiving spirometry?
Study OutcomesPrimary
Adherence to asthma anti-inflammatory and other controller medications
Asthma-related quality of life
Acute asthma health care utilization
Secondary Asthma control Use of reliever medications Symptom-free days; lung
function Satisfaction with asthma care Preferences, values, &
attitudes towards adherence Asthma-related health care
costs Total asthma health care
utilization
Summary Asthma control is a feasible clinical
outcome
Future asthma guidelines will probably use control to guide therapy rather than severity