The prevalence of nonadherence in difficult asthma.
BACKGROUND
With the advent of new and expensive therapies for severe refractory asthma, targeting the appropriate patients is important. An important issue is identifying nonadherence with current therapies. The extent of nonadherence in a population with difficult asthma has not been previously reported.


OBJECTIVE
To examine the prevalence of nonadherence to corticosteroid medication in a population with difficult asthma referred to a Specialist Clinic and to examine the relationship of poor adherence to asthma outcome.


METHODS
General practitioner prescription refill records for the previous 6 months for inhaled combination therapy and short-acting beta-agonists were compared with initial prescriptions and expressed as a percentage. Blood plasma prednisolone and cortisol assay levels were used to examine the utility of these measures in assessing adherence to oral prednisolone. Patient demographics, hospital admissions, lung function, oral prednisolone courses, and quality of life data were analyzed to indentify the variables associated with reduced medication adherence.


RESULTS
A total of 182 patients were assessed. Sixty-three patients (35%) filled 50% or fewer inhaled medication prescriptions; 88% admitted poor adherence with inhaled therapy after initial denial. Twenty-one percent of patients filled more than 100% of presciptions, and 45% of subjects filled between 51 and 100% of prescriptions. Twenty-three of 51 patients (45%) prescribed oral steroids were found to be nonadherent.


CONCLUSIONS
A significant proportion of patients with difficult-to-control asthma remained nonadherent to corticosteroid therapy. Objective surrogate and direct measures of adherence should be performed as part of a difficult asthma assessment and are important before prescibing expensive novel biological therapies.
Gamble
Jacqueline
J
Centre for Infection and Immunity, Queen's University of Belfast, Northern Ireland, UK.
Stevenson
Michael
M
McClean
Elizabeth
E
Heaney
Liam G
LG
D000280:Administration, Inhalation; D000284:Administration, Oral; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000097:blood / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000150:complications; D001249:Asthma / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000150:complications; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D011239:Prednisolone / Q000097:blood / Q000627:therapeutic use*; D015995:Prevalence; D011788:Quality of Life; D012189:Retrospective Studies; D016896:Treatment Outcome; D016903:Drug Monitoring
D000893:Anti-Inflammatory Agents; D011239:Prednisolone; D006854:Hydrocortisone