NON-ADHERENCE IN CHRONIC MYELOID LEUKEMIA: RESULTS OF A GLOBAL SURVEY OF 2546 CML PATIENTS IN 79 COUNTRIES

Background:

Optimal adherence to oral chronic myeloid leukemia (CML) therapy is of key importance to maximise treatment effectiveness. Non-adherence as well as its biological effect on CML has been observed in clinical research, but data on potential driving factors of non-adherence are lacking in the scientific literature.

Aims:

The aim of this study is to investigate motivations and behavioural patterns of adherence in CML and subsequently support hematologists and patients to improve adherence and develop suitable adherence tools.

Methods:

A European workgroup of the CML Advocates Network, a network of leukemia patient groups in 55 countries, has conducted a large international study enrolling patients from 09/2012 to 01/2013 in 12 languages. The study was also supported by CML investigator groups in Germany, Italy and France. An ad hoc questionnaire was developed for the purpose of this study and this included questions on potential factors associated with non-adherence and other aspects related to patients’ perception of disease and treatment burden. Also, medication taking behavior was assessed with the 8-item Morisky Medication Adherence scale (MMAS-8). This scale allows classification of patients into their level of adherence to treatment (i.e. low, medium and high adherence). Patients completed this questionnaire online. An additional sample of patients were given this questionnaire, along with a pre-stamped envelope, by their own treating physicians in hospital with the request to completing it at home. These questionnaire were then returned to an independent Data Center for analyses. Differences in adherence groups were determined by χ² tests, differences of mean adherence were determined with Mann Whitney U tests and Kruskal Wallis tests.

Results:

Overall 2546 questionnaires filled in by CML patients from 79 countries were analyzed. 2151 were completed online, 395 were returned by patients invited to participate in hospital, all others (N=2151) were filled in online. 52.4% of participants were male. Mean age of participants was 50.4 years (range 18-96) and 52.4% of these were male.

According to the MMAS-8, 33% of participants could be classified as highly adherent, while 47% and 21% were respectively in the medium and low adherence group. Several factors influenced adherence: Men were more often highly adherent than women (57.3% vs. 42.7%, p<0.001). Mean age was higher in the more adherent groups (low 44.8 years, medium 50.6, high 58.8; p<0.001). Patients who live with a partner or family member (85.7%, p=0.006) are more adherent, suggesting that adherence tools should support not only patients but also their relatives.

27.1% of patients on Nilotinib treatment categorized into the low adherence group, compared to only 18.8% of patients on other CML therapies (p<0.001). This might also be due to the fact that most patients (91.2%) have to take Nilotinib twice a day while Imatinib and Dasatinib are mostly administered only once per day (86.8% and 92.5% respectively). Frequency of medication is a major factor of influence on adherence (p<0.001).

51.6% of participants accidentally missed at least one dose of medication within the last year. Main reasons were forgetting (41%) and interruption in the daily routine (27%). As reminder tools, 43% are reminded by family members, 40% use pill dispensers and 24% use cellphones.

The majority of patients (85.7%) are aware of the importance of CML therapy to their health. However 19.5% of patients consciously decided to miss a dose during the last year. Main reasons were not feeling well (35%) and the wish to reduce side effects (26%), of which 79% state gastrointestinal events as the reason. Patients state that CML medication impacts their work life (26%) and their social life (23.5%), which both influence adherence to treatment schedules (p<0.001).

Patients managed by an approachable doctor providing sufficient information on disease and medication were more adherent than patients with lower satisfaction with their doctor (p<0.001). Doctor’s support in managing side effects was also driving adherence (p<0.001).

Summary / Conclusion:

This is the most comprehensive study conducted to date to gain knowledge about motivations behind non-adherence in CML. Better information on disease, medication and management of side effects, supported by hematologists, is key to improve adherence.

Email address: info@cmladvocates.net

Keywords: Chronic myeloid leukemia, Regimen, Tyrosine kinase inhibitor

Abstrakta v časopise Haematologica 2013, Suppl1

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