Poor Adherence to Antipsychotic Medication in People with Schizophrenia: Diffusion, Consequences and Contributing Factors

Measuring Adherence to Medication in Schizophrenia: The Relationship between Attitudes toward Drug Therapy and Plasma Levels of New-Generation Antipsychotics

“…Of note, no consistent correlation between patients’ attitude toward drug therapy and the ratio of observed vs expected plasma levels of medication was detected. This is in line with previous studies investigating the relationship between different measures of medication adherence ( Sacchetti and Vita, 2014 ).…”

“…Depending on the different assessment methods used, reported average adherence rates for schizophrenia patients vary widely, that is, between 10 and 90% ( Sacchetti and Vita, 2014 ). Subjective methods like self-reports and physician reports are most commonly used ( Velligan et al, 2009 ); however, they frequently underestimate the degree of nonadherence ( Sacchetti and Vita, 2014 ). Using objective methods like pill counting, electronic monitoring, or measuring plasma levels may enhance the chance of detecting adherence problems, but none of these methods can reflect the dosage actually ingested by the patient.…”

Measuring Medication Adherence in Patients With Schizophrenia: An Integrative Review

“…Another bias is by informants, such as family, who may rate patients adherent where clinicians may rate them as non-adherent. There have also been reports of physician frequently underestimating the degree of nonadherence of their patients (Sacchetti & Vita, 2014). Results analyzed indicate that neither physician report nor patient self-report accurately identified adherence when compared with data from electronic monitoring or pill counts (Velligan et al, 2007).…”

“…Additionally, patients knowing they are in a research study may take loading doses prior to laboratory blood sample draws and may wrongly be rated adherent. Similarly, misinterpretation in laboratory values, increases in dosage of medications, switching, and even the prescription of additional medications could affect these results (Sacchetti & Vita, 2014). These inter-individual pharmacokinetic differences can be attributed to age, concurrent diseases, concomitant medication, genetics, lifestyle activities (i.e.…”

“…Subjective measures are reported to underestimate nonadherence rates (Byerly et al, 2005), while results from objective measures are reported to have possibly been influenced by extraneous factors Hiemke et al, 2011;Sacchetti & Vita, 2014;Velligan et al, 2006Velligan et al, , 2007Velligan et al, , 2010Yalcin-Siedentopf et al, 2015). Additionally, irrespective of objective measures being the recommended method for measuring medication adherence in this population (Velligan et al, 2009), varying results have been noted in studies (Velligan, Lam, Ereshefsky, & Miller, 2003;Velligan et al, 2007;Yang et al, 2012).…”