ASTHMA PHENOTYPE ALGORITHM
Background:
Asthma is chronic inflammatory disease of the airways characterized by airway inflammation, reversible
airflow obstruction and bronchial hyperresponsiveness. It is a complex disease caused by environmental and
genetic factors. An estimated 25.9 million people in the United States have asthma, including approximately 7
million children.
Cases:
Cases are defined by 1) a diagnostic history of one or more relevant asthma medication and 2) a history of asthma
as determined by ICD9 codes or chart review. For criteria 2, the individual should have either two or more
affirmative asthma ICD9 codes (493.x) or three or more confirmed medical encounters where “wheezing” or
“asthma” is confirmed in one 12-month period.
Case inclusion criteria:
1) One or more prescriptions of asthma related medications (see Table 1)
plus
2) Individuals 4 years of age or older with either two or more relevant ICD9 codes in
two or more in-person visits, on separate calendar days.
or
2) Three or more in person visits in any 12month period, on separate calendar days,
with affirmative mentions of “wheezing” or “asthma” (unqualified by negation) in
EMR notes.
Case exclusion criteria:
- Individuals with a history of smoking equal or more than 10pack years (packs/day x years use)
- Individuals with any of the ICD 9 codes shown in table 2
Stratification of cases:
*Stratified by presence or absence of allergies:
-Atopic: Individuals with ICD9 code 493.0 or two or more ICD9 codes in table 3 on separate
calendar days
*Stratified into mild moderate and severe:
-Severe:
=>3 prescriptions of oral steroids/ anti IgE medication in one 12-month period, and/or
=>3 relevant visits to the ER in one 12-month period, and/or
=>3 mentions of “severe exacerbation” in relation to asthma in one 12-month period, and/or
=> 1 relevant overnight stay specifically related to an asthma episode
-Moderate, excludes patients stratified as “severe”, meeting one of the following criteria:
1-2 prescriptions of oral steroids/ anti IgE medication in one 12-month period, and/or
1-2 mentions of “severe” exacerbation” in relation to asthma in one 12-month period, and/or
1-2 relevant visits to the ER in one 12-month period, and/or
=>1 prescription of inhaled steroids for daily use
-Mild, excludes patients stratified as “severe” or “moderate”, plus meeting one of the
following criteria:
1-2 prescriptions of inhaled steroids in one 12-month period, and/or
=>1 prescription of beta-agonist
-Unclassified, excludes patients stratified as “severe”, “moderate”, or “mild”.
Controls:
- No diagnosis codes for asthma (493.xx)
- No history of relevant medications (see Table 1)
- No positive confirmation of “wheezing” or “asthma” in patient chart (NLP)
- No exclusionary ICD 9 codes (see Table 4)
Covariates:
Age
Gender
Ethnicity
BMI
Pets
Smoking
IgE test
Positive RAST test
Positive rhinoconjuctivitis
History of Asthma medications
History of Asthma diagnosis
Table 1:
Asthma medication by sub-type.
Oral Steroids, anti-IgE
Inhaled Steroids
(-> severe)
(-> moderate)
Dexamethasone
Beclomethasone (QVAR)
(Decadron, Deltasone)
Methylprednisolone
Budesonide (Pulmicort
(Medrol, Medrol Dosepak) Turbuhaler, Pulmicort
Respules)
Prednisone (Orasone)
Prednisolone (Orapred,
Pediapred, Prelone)
Triamcinolone (Aristocort)
Anti IgE:
Omalizumab (Xolair)
Flunisolide (Aerobid,
Pulmicort Respules)
Fluticasone (Flovent),
Fluticasone propionate
HFA, Fluticasone
Propionate inhaled
Momethasone (Asmanex
Twisthaler)
Triamcinolone(Azmacort)
Triamcinolone Acetonide
Ciclesonide
Beta-Agonists
(-> mild)
β1 agonists
Other
(-> mild)
Mast cell stabilizers
Dobutamine
Cromolyn (Cromoglicic
acid, cromoglycate,
cromoglicate, Intal)
Cromolyn Sodium
Nedocromil (Alocril,
Rapitil, Tilade)
LeukotrieneAntagonists
Epinephrine
Racepinephrine
Isoproterenol (β1 and β2)
Methylxanthine
Montelukast
Theophylline (aminophylline,
Dimethylxanthine, Slo-Bid,
Theo, Theodur, Theolair,
Uniphyl)
Xamoterol
Zafirlukast
Zileuton
β2 agonists
Arformoterol (Brovana,
Sunovion, )
Albuterol, Albuterol Sulfate
(Salbutamol, Ventolin,
Proventil, ProAir, Accuneb)
Clenbuterol
Epinephrine
Fenoterol
Formoterol (Foradil)
Isoetarine
Isoproterenol (β1 and β2)
Levalbuterol, Levalbuterol
HCL, Levalbuterol Tartrate
(Levosalbutamol, Xopenex)
Metaproterenol
Pirbuterol (Maxair)
Procaterol
Ritodrine
Salmeterol (Serevent)
Terbutaline (Brethine)
Table 2:
Asthma Exclusionary ICD9 Codes.
ICD-9 Codes
277.xx
478.3xx
490.xx – 492.xx
494.xx
495.2
496.xx
769.xx
V81.3
ICD-9 Codes
238.77
996.8
E878.0
V42
V49.83
V58.44
Diagnosis
General
Cystic Fibrosis
Vocal Cord Dysfunction
Bronchitis, Emphysema
Bronchiectasis, Allergic Alveolitis
Bird-fanciers' lung
COPD
Respiratory Distress Syndrome
Chronic bronchitis and emphysema
Transplant
Diagnosis
Post-transplant lymphoproliferative disorder (PTLD)
Complications of transplanted organ
Surgical operation with transplant of whole organ
Organ or tissue replaced by transplant
Awaiting organ transplant status
Aftercare following organ transplant
Table 3:
ICD9 Codes Related to Allergies.
ICD-9 Codes
287.0
372.14
477
Diagnosis
Allergic purpura
Other chronic allergic conjunctivitis
Allergic rhinitis
Ipratropium Bromide
Aerovent
Apovent
Atrovent
Ipraxa
Phosphodiesterase
Inhibitors
Ibudilast
495
691.*
708.0
995.3
V14
V15.0
V15.01
V15.03
V15.09
V19.6
Extrinsic allergic alveolitis
Atopic dermatitis and related conditions
Allergic urticaria
Allergy, unspecified
Personal history of allergy to medicinal agents
Allergy, other than to medicinal agents
Allergy to peanuts
Allergy to eggs
Other allergy, other than to medicinal agents
Allergic disorders
Table 4
Control Exclusionary ICD9 Codes.
ICD-9 Codes
212.3
238.77
277.xx
279.4
283.0
283.1xx
287.0
372.14
416.xx
460 – 466.xx
470 – 478.xx
480 – 488.xx
490 – 492.xx
494 – 496.xx
500.xx-508.xx
510 – 519.xx
525.66
555
556
571.42
708.0
748.4
748.5
751.61
769.xx
995.3
996.8
E878.0
V14
V15.0
V15.01
V15.03
V15.09
V19.6
V42
Diagnosis
Bronchus and lung
238.77 Post-transplant lymphoproliferative disorder (PTLD)
Cystic Fibrosis
Autoimmune disease, not elsewhere classified
Autoimmune hemolytic anemias
Non-autoimmune hemolytic anemias
Allergic purpura
Other chronic allergic conjunctivitis
Chronic Pulmonary Heart Disease
Acute respiratory infections
Other diseases of the upper respiratory tract
Pneumonia and influenza
Diseases of the respiratory system
Diseases of the respiratory system
Pneumoconiosis
Other diseases of the respiratory system
Allergy to existing dental restorative material
Regional enteritis (Incl. Crohn's disease and Granulomatous enteritis)
Ulcerative colitis
Autoimmune hepatitis
Allergic urticaria
Congenital cystic lung
Agenesis, hypoplasia, and dysplasia of lung
Biliary atresia
Respiratory Distress Syndrome
Allergy, unspecified
Complications of transplanted organ
Surgical operation with transplant of whole organ
Personal history of allergy to medicinal agents
Allergy, other than to medicinal agents
Allergy to peanuts
Allergy to eggs
Other allergy, other than to medicinal agents
Allergic disorders
Organ or tissue replaced by transplant
V49.83
V58.44
Awaiting organ transplant status
Aftercare following organ transplant