Non-adherence to treatment regimes in difficult asthma

The accompanying picture of a Seretide ™ combined corticosteroid/ long- acting beta-agonist inhaler device hopefully evens the score a little in the war of the combination puffers on this blog (see comment on the post about use of eformoterol/budesonide in COPD) Each of Seretide ™ and Symbicort™ are excellent medications in airways disease (can I say it often enough?)– particularly asthma…… if our patients take them!

Which brings me to the topic of this post: non-adherence with prescribed medications in difficult asthma. A recent study from Northern Ireland, published in the American Journal of Respiratory and Critical Care Medicine (The Blue Journal) at the start of November, looked at this issue in a population of asthmatics referred to a tertiary – hospital ‘difficult asthma’ program. These were patients with persistent asthma symptoms in spite of regular combination inhaler use (one of the two above), with some on maintenance oral prednisolone. Around forty percent were referrals from other respiratory specialists to the hospital program.

I see many patients with ‘difficult asthma’, although they make up only about 5% of the adult asthmatic population. In general the first question I ask myself is always ‘does this person really have asthma?’ Frequently they do not, and the failure of asthma therapy reflects an initial misdiagnosis. The second question is ‘Is this person really using their medications?’ This recent study is the first that looks rigorously at adherence to prescribed medications amongst adults with ‘difficult asthma’.

The findings were startling. Although everyone claimed to use all of their medication as prescribed when asked at the commencement of the study, of 182 consecutive patients seen in the service 78% used less than their prescribed amount of combination inhaler medication, with at least 35% using less than half of what they were prescribed. Twenty-one percent used more of their combination inhaler (preventer) than had been prescribed, leaving 1% of patients using medication as prescribed!

The study then looked further at patients prescribed maintenance oral prednisolone, and found that 45% were non-adherent with that medication.

There were three variables that were associated with poor adherence to treatment. These were female gender (nearly 2/3 of the group on the whole was female. 42% of them were in the least-adherent group, where only 23% of the men were); low quality of life; and frequent hospitalizations in the previous year.

How was data collected? In Northern Ireland all medications that a patient is taking are prescribed by one GP only. Review of the number of prescriptions issued by that GP, compared against the dose of medication which the person is supposed to be using, allowed a reasonable measure of compliance to be obtained in this study. In the case of oral prednisolone dosing, regular use of prednisolone should lead to suppression of adrenal cortisol secretion. Blood test measures of prednisolone and cortisol levels were used in that patient group to evaluate compliance.

The findings of this study require reflection. Doctors of patients with ‘difficult asthma’ will be considering a range of alternative treatment approaches, including use of maintenance prednisolone orally, use of theophylline or montelukast (Singulair ™) or else a more expensive biological therapy (for example, Xolair™(omalizumab), with others on the horizon). It’s important that we don’t proceed to the more complicated, dangerous or expensive medications without clarifying whether the standard medications are, in fact, being used.

The authors of this study state that they believe ‘the key message off this study – that non-adherence is a significant issue in an unselected population with difficult-to-control asthma and significant asthma-related morbidity….is valid and needs to be proactively identified and addressed’. I agree. I suspect, however, that a systemic change in the way we distribute medication and monitor compliance may be required to effectively achieve this.

Andrew