A patient perspective of the impact of medication side effects on adherence: results of a cross-sectional nationwide survey of patients with schizophrenia

Abstract

BackgroundAntipsychotic medications often have a variety of side effects, however, it is not well understood how the presence of specific side effects correlate with adherence in a real-world setting. The aim of the current study was to examine the relationship between these variables among community-dwelling patients with schizophrenia.MethodsData were analyzed from a 2007-2008 nationwide survey of adults who self-reported a diagnosis of schizophrenia and were currently using an antipsychotic medication (N = 876). The presence of side effects was defined as those in which the patient reported they were at least "somewhat bothered". Adherence was defined as a score of zero on the Morisky Medication Adherence Scale. To assess the relationship between side effects and adherence, individual logistic regression models were fitted for each side effect controlling for patient characteristics. A single logistic regression model assessed the relationship between side effect clusters and adherence. The relationships between adherence and health resource use were also examined.ResultsA majority of patients reported experiencing at least one side effect due to their medication (86.19%). Only 42.5% reported complete adherence. Most side effects were associated with a significantly reduced likelihood of adherence. When grouped as side effect clusters in a single model, extra pyramidal symptoms (EPS)/agitation (odds ratio (OR) = 0.57, p = 0.0007), sedation/cognition (OR = 0.70, p = 0.033), prolactin/endocrine (OR = 0.69, p = 0.0342), and metabolic side effects (OR = 0.64, p = 0.0079) were all significantly related with lower rates of adherence. Those who reported complete adherence to their medication were significantly less likely to report a hospitalization for a mental health reason (OR = 0.51, p = 0.0006), a hospitalization for a non-mental health reason (OR = 0.43, p = 0.0002), and an emergency room (ER) visit for a mental health reason (OR = 0.60, p = 0.008).ConclusionsAmong patients with schizophrenia, medication side effects are highly prevalent and significantly associated with medication nonadherence. Nonadherence is significantly associated with increased healthcare resource use. Prevention, identification, and effective management of medication-induced side effects are important to maximize adherence and reduce health resource use in schizophrenia.

Improving medication adherence for severely mentally ill adults by decreasing coercion and increasing cooperation

“…Between 1992 and 2001, there were approximately 53 million emergency mental health contacts (Zeller, 2010). In 2002, public expenditures associated with the 1% of the U.S. population diagnosed with schizophrenia totaled 63 billion dollars (DiBonaventura, Gabriel, Dupclay, Gupta, & Kim, 2012). According to Winkler et al (2011), 10% of the total patient population is associated with 80% of the direct costs associated with severe psychiatric illnesses.…”

“…Haloperidol and chlorpromazine were the first medications to be widely used and were found to have positive effects on auditory hallucinations and agitated behavior that would otherwise result in involuntary hospitalizations (DiBonaventura et al, 2012 ;Morrison et al, 2000). However, patients taking older antipsychotics often reported akathisia and loss of willpower, coherent thinking, and spontaneity (Covell et al, 2007;Jarrett et al, 2008).…”

“…The severity of (antipsychotic) side effects has been found to be a strong predictor of lower medication adherence in multiple studies (Allison, 2012;Deegan, 2007;DiBonaventura et al, 2012;Faasse, 2012;Townsend, 2009). In studies by DiBonaventura et al (2012) and Covell et al (2007), it was noted that 80%-90% of patients reported experiencing at least one side effect that interfered significantly in their daily life.…”

“…In multiple studies, patients reported being most concerned about medications interfering with their sleep and causing restlessness, trouble concentrating, sedation, dry mouth, drooling, dizziness, and weight gain (Bentley, 2010;Covell et al, 2007;DiBonaventura et al, 2012;Meehan et al, 2011). Patients have also been found to be less adherent to medications that interfere with personal goals such as working, exercising, and keeping busy (Roe et al, 2009).…”

“…well as estimated annual costs of between $1.4 and $1.8 billion (DiBonaventura et al, 2012;Morrison, Meehan, Gaskill, Lunney, & Collings, 2000).…”