Clustering medication adherence behavior based on beliefs in medicines and illness perceptions in patients taking asthma maintenance medications

Objectives:

The prevalence of medication non-adherence is 50% in chronic disease conditions and varies from 30% to 70% in asthma maintenance medications. A major drawback in addressing medication non-adherence is the short time available for patient consultations, which limits the ability of the clinician in identifying the problem. Thus, this study explores how medication adherence behavior can be clustered and identifies the unique characteristics of each cluster so that clinicians can recognize the cluster characteristics in patients to provide targeted interventions. The study objectives were to: (1) cluster patients’ medication adherence behavior with asthma maintenance medications based on their beliefs in medicines and illness perceptions, and (2) describe the characteristics of the patients in each cluster based on psychosocial, clinical, and demographic characteristics.

Research design and methods:

A cross-sectional online survey design on a convenience sample of adult individuals who were taking asthma maintenance medications.

Main outcome measures:

Self-reported medication adherence using Morisky scale, beliefs in medicines using Beliefs in Medicines Questionnaire, and illness perceptions using the Brief Illness Perceptions Questionnaire.

Results:

The cluster analysis with 392 subjects resulted in five clusters based on patients’ beliefs in medicines and their illness perceptions. The clusters formed had distinct characteristics that lend themselves to monitoring or for which targeted interventions can be framed to improve medication adherence.

Limitations:

The study only examined asthma maintenance medications limiting the generalizability of the study. Also, all the data collected including medication adherence were self-reported data from an online panel. This can cause selection bias and lack of generalizability.

Conclusions:

The study demonstrated how the concept of ‘non-adherence’ is different for different patients and the need for tailored interventions for each type of non-adherence. With the limited consultation time available for clinicians to communicate with the patients, identifying the characteristics of patients in different clusters can assist clinicians in providing appropriate targeted interventions.     

Importance of balancing follow-up time and impact of oral-anticoagulant users’ selection when evaluating medication adherence in atrial fibrillation patients treated with rivaroxaban and apixaban

Objective: Studies comparing medications adherence have become common yet they often do not account for differences in relative follow-up. Patient selection criteria may impact validity and comparability of these studies as well.

Methods: Adults with non-valvular atrial fibrillation, ≥1 rivaroxaban or apixaban dispensing (index date), and ≥1 year of pre-index eligibility were selected from IMS Health Real World Data Adjudicated Claims (IMS RWD Adjudicated Claims) and Truven Health MarketScan Research (Truven MarketScan) databases. Adherence was evaluated using proportion of days covered (PDC)?≥?0.8 for treatment cohorts: (1) unmatched, with different follow-up, (2) propensity-score matched with similar follow-up, (3) matched, with similar follow-up and ≥2 rivaroxaban or apixaban dispensings, and (4) matched, with similar follow-up and chronic medication users only. Robustness was verified with PDC ≥0.9.

Results: In the IMS RWD Adjudicated Claims database, rivaroxaban users had a longer mean follow-up than apixaban users (408 versus 254 days, respectively; p?p?p?p?>?.05), and reversed after (3) excluding non-chronic medication users (5.0 pp; p?Conclusion: Medication adherence comparisons need to account for differences in follow-up. Selection of chronic medication users may impact comparative adherence advantage between medications.     

Adherence to iron chelation therapy in patients who switched from deferasirox dispersible tablets to deferasirox film-coated tablets

Objective: To compare real-world adherence to and persistence with deferasirox film-coated tablets (DFX-FCT) and deferasirox dispersible tablets (DFX-DT) among patients who switched from DFX-DT to DFX-FCT, overall and by disease type (sickle cell disease [SCD], thalassemia, and myelodysplastic syndrome [MDS]).

Methods: Patients were ≥2 years old and had ≥2 DFX-FCT claims over the study period and ≥2 DFX-DT claims before the index date (first DFX-FCT claim). The DFX-DT period was defined from the first DFX-DT claim to the index date; the DFX-FCT period was defined from the index date to the end of the study period. Adherence was measured as medication possession ratio (MPR) and proportion of days covered (PDC). Persistence was defined as continuous medication use without a gap ≥30 or 60 days between refills. Comparisons were conducted using paired-sample Wilcoxon sign-rank and McNemar’s tests.

Results: In total, 606 patients were selected (SCD: 348; thalassemia: 107; MDS: 106; other: 45). Adherence and persistence in the DFX-FCT vs DFX-DT period was significantly higher across all measures: mean MPR was 0.80 vs 0.76 (p?<?.001); 60.9% vs 54.3% of patients had MPR?≥?0.8 (p?=?.009); mean 3-month PDC was 0.83 vs 0.71 (p?<?.001); 64.2% vs 45.4% of patients had 3-month PDC?≥?0.8 (p?<?.001); 87.2% vs 63.4% of patients had 3-month persistence with no gap ≥30 days and 96.1% vs 79.9% with no gap ≥60 days (p?<?.001). Adherence and persistence improved after switching across all diseases, particularly MDS.

Conclusions: Adherence and persistence improved significantly after switching from DFX-DT to DFX-FCT for all diseases, but especially MDS.