• Days with wheeze [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Days of slowed down or discontinued physical activities due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Nights awoken due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Days on which plans were changed due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Days missed school/work due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Unscheduled office/clinic visit due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Emergency room/urgent care center due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Hospitalization due to asthma [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
• Number of asthma exacerbations requiring prednisone or prednisone equivalent [ Time Frame: Throughout study ] [ Designated as safety issue: No ]

The purpose of this study is to determine whether an asthma treatment strategy that measures exhaled nitric oxide (eNO) to indicate disease progression is more effective in treating asthma symptoms when combined with existing asthma treatment guidelines than treatment using the guidelines alone.

Over the past two decades, the prevalence of asthma has dramatically increased in many parts of the world. The current National Asthma Education and Prevention Program (NAEPP) identifies inhaled corticosteroids (ICS) as the preferred long-term control therapy for all forms of persistent asthma. However, there is still a significant proportion of patients with persistent asthma who are not receiving ICS therapy or do not follow their treatment plan. Individualized asthma treatment plans are needed. The use of biomarkers, in addition to NAEPP guidelines, may help enhance the level of asthma assessment, guide medication regimens, and improve overall asthma control. This study will determine whether NAEPP-recommended treatment, combined with eNO measurement, is more effective in reducing asthma symptoms than NAEPP-recommended treatment alone.

This study will last 46 weeks and will comprise 8 study visits. At Visit 1, the Aerocrine® NIOX device will be used to perform eNO measurements on all participants. A physical exam will be performed and participants will be asked to complete asthma-related questionnaires. Participants will be assigned a 3-week individual asthma control regimen; the regimen will be determined by evaluations performed during screening. At the end of 3 weeks, participants will have a home visit; during this visit, participants' home environment will be observed, dust samples will be taken, and an adherence check will be performed.

At Visit 2, participants will be randomly assigned to either the reference strategy group or the biomarker strategy group for 46 weeks. Participants in the reference strategy group will undergo the eNO procedure but will follow NAEPP guidelines alone for asthma treatment without eNO measurements for the rest of the study. Participants in the biomarker strategy group will follow NAEPP treatment guidelines as well as eNO measurements to determine asthma treatment at each study visit.

At Visits 2 through 7, participants will receive an asthma medication regimen based on symptoms, albuterol use, forced expiratory volume in one second (FEV), their current level of therapy and, for participants in the biomarker strategy group, their current eNO level. The assigned regimens may be adjusted if visit assessments indicate significant changes in condition. At each study visit, rescue bronchodilator usage, medication adherence, asthma symptoms, and medication side effects will be assessed, and the volume of air that is exhaled by the lungs will be measured; blood collection will also occur. At Visit 2, a skin prick test will be performed to determine allergies; if necessary, this test will be performed at Visit 3 or 4. At Visit 8, a final treatment regimen will be prescribed for all participants, but no medication will be given at the visit.

• Drug: Inhaled corticosteroids
• Procedure: eNO measurement

• Active Comparator: Participants in the reference strategy group will undergo the eNO procedure but will follow NAEPP guidelines alone for asthma treatment without eNO measurements for the rest of the study.
• Experimental: Participants in the biomarker strategy group will follow NAEPP treatment guidelines, as well as eNO measurements, to determine asthma treatment at each study visit.

• Reid DW, Johns DP, Feltis B, Ward C, Walters EH. Exhaled nitric oxide continues to reflect airway hyperresponsiveness and disease activity in inhaled corticosteroid-treated adult asthmatic patients. Respirology. 2003 Dec;8(4):479-86.
• Strunk RC, Szefler SJ, Phillips BR, Zeiger RS, Chinchilli VM, Larsen G, Hodgdon K, Morgan W, Sorkness CA, Lemanske RF Jr; Childhood Asthma Research and Education Network of the National Heart, Lung, and Blood Institute. Relationship of exhaled nitric oxide to clinical and inflammatory markers of persistent asthma in children. J Allergy Clin Immunol. 2003 Nov;112(5):883-92.
• Langley SJ, Goldthorpe S, Custovic A, Woodcock A. Relationship among pulmonary function, bronchial reactivity, and exhaled nitric oxide in a large group of asthmatic patients. Ann Allergy Asthma Immunol. 2003 Oct;91(4):398-404.
• Jones SL, Herbison P, Cowan JO, Flannery EM, Hancox RJ, McLachlan CR, Taylor DR. Exhaled NO and assessment of anti-inflammatory effects of inhaled steroid: dose-response relationship. Eur Respir J. 2002 Sep;20(3):601-8.
• Szefler SJ, Mitchell H, Sorkness CA, Gergen PJ, O'Connor GT, Morgan WJ, Kattan M, Pongracic JA, Teach SJ, Bloomberg GR, Eggleston PA, Gruchalla RS, Kercsmar CM, Liu AH, Wildfire JJ, Curry MD, Busse WW. Management of asthma based on exhaled nitric oxide in addition to guideline-based treatment for inner-city adolescents and young adults: a randomised controlled trial. Lancet. 2008 Sep 20;372(9643):1065-72.

Inclusion Criteria:

• Clinical diagnosis of asthma made by a doctor over a year prior to study entry OR symptoms have been present more than a year if the diagnosis was made less than a year prior to study entry
• Have symptoms consistent with persistent asthma OR have evidence of uncontrolled disease. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Currently reside in a pre-selected area containing at least 20% of households below the U.S. government poverty level
• Do not smoke and have not used smokeless tobacco products in the year prior to study entry
• Able to perform eNO measurement procedures and spirometry at study screening
• Parent or guardian willing to provide informed consent, if applicable
• History of clinical varicella (chicken pox) or have received varicella vaccine
• Planning to stay in the area for the next 12 months
• Primary language is English. Spanish speakers may enroll at centers with Spanish-speaking staff.
• Parent or guardian primarily speaks English (or Spanish at centers with Spanish-speaking staff), for participants with parent or guardian providing informed consent
• Willing to allow the study physician to manage disease for the duration of the study
• Willing to change asthma medications in order to follow the protocol

Exclusion Criteria:

• Adherence to controller medication between Visits 1 and 2 is less than 25%. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Determined to have mild intermittent asthma at Visit 1
• Have had a life-threatening asthma exacerbation requiring intubation, mechanical ventilation, or resulting in a hypoxic seizure in the 5 years prior to study entry
• Have significant medical illnesses other than asthma. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Unable to use a metered-dose inhaler for administration of a beta-agonist rescue medication or a dry powder inhaler for the administration of asthma controller regimens
• Known hypersensitivity to any medications commonly used for the treatment of asthma
• Have not completed a home evaluation within 4 weeks of study screening
• Currently participating in another asthma-related drug or intervention study, or have participated in another asthma-related drug or intervention study in the month prior to study entry
• Does not sleep at least 4 nights per week in one home
• Lives with a foster parent (not applicable if patient is able to provide informed consent)
• Does not have access to a phone
• Requires certain medications. More information on this criterion can be found in the DAIT ICAC-01 protocol.
• Urine cotinine level above 100 ng/ml at study screening
• Pregnant or breastfeeding