Medication ‘compliance’ in asthma

In the current issue of the Canadian Respiratory Journal, Jobin et al (1) (pages 97–104) assess the use of asthma therapy in relatively unselected patients. Briefly, they recruited patients 12 to 45 years of age through pharmacies that dispensed the drugs, obtaining consent to an interview and delivering a detailed questionnaire. Self-reported drug use was recorded, as were a host of potential factors believed to be related to compliance. These included socioeconomic status, perceptions of general health and asthma severity, perceived risk of asthma, knowledge of drugs and disease, side effects of drugs, and care processes such as the caregiver and relationships to the patient, lung function tests, the presence of an action plan and a previous educational program. This was an ambitious undertaking involving multiple individuals from differing disciplines.

Nick R Anthonisen

Of 349 patients interviewed, only 43 (12%) used their asthma drugs in compliance – characterized by Jobin et al as ‘appropriate’ – with Canadian guidelines (2). These included the daily use of a controller medication, sparing use of short-acting bronchodilators and reasonable use of add-on medications. There were three main causes of noncompliance: use of only one drug, underuse of controller medication and overuse of short-acting bronchodilators. This, as the authors note, is a list familiar to students of the real world of asthma therapy. Making the criteria less stringent, chiefly by relaxing the intensity of controller use, increased the ‘appropriate’ figure only to 16%. Several discouraging items were revealed, such as only 52 patients possessed an action plan, and only 45 had been in an asthma education program.

Of the potential determinants of appropriate drug use, only a few appeared to be significantly related to the outcome. These were knowledge of the nature of asthma drugs, good perceived general health, a history of specialist care and previous difficulty with paying for drugs. To some extent these are rational. We all know that specialists are wonder workers, and that good knowledge of asthma drugs is beneficial, and can imagine that people who are confident about their health will do relatively well. The fact that people who had trouble paying for their drugs used them better than others is counterintuitive, and Jobin et al (1) hypothesized that the reason for the payment problem may have been the devoted use of expensive controllers, which may or may not be true.

Of perhaps greater interest are the characteristics that did not relate to appropriateness of drug use. These included perceived asthma severity, knowledge of asthma per se, perception of the value of therapy, side effects, age and socioeconomic status and care processes, including action plans and educational programs. Some of the solutions we propose for compliance problems appeared not to matter.

The design of the study by Jobin et al (1) is unlikely to account for the disappointing results. Self-report by volunteers should bias results in favour of appropriate therapy, not against it. We must, therefore, accept the outcome as something approximating the truth. It is tempting, but unacceptable, to blame the patients – they are what they are, and it is the job of the health care worker to induce desirable behaviour on their part. The fact is, we have seen the problem and, as Pogo said, “it is us”. I can think of only two prescriptions: more time spent per individual patient with asthma, and better knowledge of the guidelines, which sounds a lot like motherhood.