This Article Full Text Full Text (PDF) All Versions of this Article: 200902-0166OCv1 180/9/817    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Gamble, J. Articles by Heaney, L. G. PubMed PubMed Citation Articles by Gamble, J. Articles by Heaney, L. G.

The Prevalence of Nonadherence in Difficult Asthma

¹ Centre for Infection and Immunity, Queen's University of Belfast; ² Regional Respiratory Centre, Belfast City Hospital; ³ Department of Epidemiology and Public Health, Queen's University of Belfast; and ⁴ Department of Clinical Chemistry, Belfast City Hospital, Belfast, Northern Ireland

Correspondence and requests for reprints should be addressed to Dr. Liam Heaney, M.D., Regional Respiratory Centre, Belfast City Hospital, Lisburn Road, Belfast, Northern Ireland, UK BT9 7AB. E-mail: l.heaney{at}qub.ac.uk

Rationale: 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.

Objectives: 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 β-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.

Measurements and Main 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.

Key Words: adherence • objective measures • medication

AT A GLANCE COMMENTARY Scientific Knowledge on the Subject Nonadherence with medication in subjects with different severities of asthma, including subjects with mild and moderate disease has been consistently demonstrated to be common with concomitant asthma morbidity. Data on the degree of nonadherence in a difficult asthma population (symptomatic despite treatment GINA step 4/5) assessed in a specialist service has not been previously presented. What This Study Adds to the Field A significant proportion of patients with difficult-to-control asthma are nonadherent to inhaled and oral corticosteroid therapy. This study supports the importance of using objective, surrogate, and direct measures of adherence. Identifying non-adherence in this population is crucially important, given currently available (and imminent) expensive biological therapies but is also central to research efforts to define mechanisms and phenotypes of refractory asthma.