Table 4.
Reasons for nonadherence to antipsychotic medication in patients with SMI: results of cross-sectional observational studies
| References | Results |
|---|---|
| Eticha et al35 | • Nonadherence rate was 26.5% |
| • Better adherence was significantly associated with positive attitude toward medication (OR =1.40, 95% CI: 1.26–1.55); fewer medication side effects (OR =0.97, 95% CI: 0.94–0.99); less khat chewing (OR =0.24, 95% CI: 0.09–0.68); and 2 dimensions of insight: better ability to relabel symptoms (OR =1.57, 95% CI: 1.19–2.07) and better awareness of illness (OR =1.44, 95% CI: 1.12–1.85) | |
| Na et al36 | • Nonadherence rate was 15.4% |
| • Nonadherence was significantly associated with poor insight into need for treatment (P=0.0005), depression (P=0.03), and 1 of the cognitive measures: number of errors in word reading (P=0.0008) | |
| Jonsdottir et al37 | • Adherence in SZ: 33.8% partial adherence, 11% nonadherence |
| • Adherence in BPD: 26.2% partial adherence, 16.5% nonadherence | |
| • Patients with SZ from a full-adherence group showed a significantly higher mean level of insight compared with those from a nonadherent group | |
| • The difference was not significant for patients with BPD | |
| • The use of illicit substances and alcohol was greater in nonadherent and partially adherent groups in both SZ and BPD compared with that in the adherent groups | |
| Dibonaventura et al38 | • 57.5% of patients were nonadherent |
| • 71.7% of patients were taking atypical antipsychotics | |
| • ~80% of respondents reported ≥1 medication side effect | |
| • Agitation/EPS (OR =0.57, P=0.0007), sedation/cognition (OR =0.70, P=0.033), prolactin/endocrine effects (OR =0.69, P=0.034), metabolic effects, including weight gain (OR =0.64, P=0.008) were associated with nonadherence | |
| Alene et al39 | • 52.1% of patients were fully adherent (self-report) but only 19.6% based on refill data |
| • Forgetfulness was stated as the main reason for missing medication (36.2%) | |
| • Experiencing side effects, exposure to social drugs, and number of medications taken concurrently were associated with worse adherence | |
| Adelufosi et al40 | • 40.3% of patients were nonadherent |
| • Adherence was significantly better among respondents with good level of perceived social support from families and friends, respondents satisfied with their outpatient care, and among employed vs unemployed respondents (univariate analysis) | |
| • Poor outpatient clinic attendance (OR =4.97, P=0.001), moderate satisfaction with outpatient care (OR =2.78, P=0.002), and symptom severity (OR =1.08, P=0.001) were independent predictors of nonadherence (multivariable analysis) | |
| McCabe et al41 | • 24.3% of patients had average or poor adherence |
| • Patient and clinician ratings of therapeutic alliance weakly correlated (rs =0.13, P=0.004; ie, the perspectives differ) | |
| • For each unit increase in clinician-rated therapeutic alliance score, the OR of good adherence was increased by 65.9% (95% CI: 34.6%–104.5%) | |
| • For each unit increase in patient-rated therapeutic alliance score, the OR of good adherence was increased by 20.8% (95% CI: 4.4%–39.8%) | |
| Magura et al42 | • 71% of patients were at least partially nonadherent |
| • 3 factors were significantly associated with adherence: self-efficacy for drug avoidance, medication side effects, and recovery support (multivariable analysis) | |
| • The final model explained 21% of the variance in adherence, indicating that other factors were not accounted for | |
| • Intensity of substance use was not associated with adherence | |
| Sajatovic et al43 | • 41%–43% of patients were nonadherent |
| • Forgetting to take medication and side effects were the most common self-reported reasons for nonadherence (55% and 20%, respectively) | |
| • Difficulty with medication routine, denial of illness severity, and fear of medication side effects ranked highest among negative attitudes toward medication | |
| • 95% of participants reported good relationship with their HCP | |
| • The results may reflect adherence problems independent of therapeutic alliance | |
| Zeber et al44 | • 46% of patients had adherence problems |
| • Multivariable analysis: OR of reasons most influencing poor adherence (95% CI): attitude toward medication, 2.41 (1.17–3.91); binge drinking, 1.95 (1.04–2.93); limited access to mental health specialist, 1.73 (1.08–2.69) | |
| • Therapeutic alliance did not show statistical significance in the same model (OR =1.55, 95% CI: 0.94–2.13, P=0.09) | |
| Wong et al45 | • Multivariable analysis: perception of being overweight was associated with significantly worse adherence (P<0.01); better attitude toward medication (P<0.01) and insight into illness (P=0.006) were associated with significantly better adherence |
| • Attitude toward medication was the most influential factor | |
| • 72% of patients who believed that antipsychotics led to weight gain had reduced/omitted the drug dosages (P<0.001) | |
| • The concerns of weight gain occurred in those who perceived themselves as overweight and contributed significantly to poor adherence | |
| Beck et al46 | • Attitude toward antipsychotic medication impacts adherence over and above insight into illness; it differs from attitude toward medication in general in association with adherence |
| • Attitude toward antipsychotic medication has 2 dimensions interacting with each other: necessity and concerns | |
| • Awareness of illness influences adherence indirectly through perceived necessity of medication | |
| Dassa et al47 | • 30% of patients were nonadherent |
| • Multivariable analysis: nonadherence increased with increasing lack of insight into effect of medication (OR =3.23, 95% CI: 1.05–9.89), a lower level of therapeutic alliance (OR =0.45, 95% CI: 0.32–0.64), and duration of untreated psychosis (OR =1.12, 95% CI: 1.03–1.22) | |
| • Awareness of effect of medication was more important than awareness of illness for adherence | |
| Acosta et al48 | • 24.3% of patients were nonadherent (≤75% MEMS adherence) |
| • Subjective assessments of adherence were in agreement with the MEMS in 77%–78% of cases when rated by psychiatrists, patients, and relatives | |
| • Multivariable analysis: nonadherence was associated with poor insight (OR =1.22, P=0.04) and higher scores on the PANSS items indicating conceptual disorganization (OR =1.74, P=0.07) | |
| Baldessarini et al49 | • 33.8% of patients were nonadherent (≥1 missed dose in last 10 days, patient self-report) |
| • Multivariable analysis: factors significantly (P<0.05) and independently associated with nonadherence: alcohol dependence (OR =4.89) > cognitive side effects (OR =2.59) > affective comorbidity (OR =1.10) | |
| • Major adverse effects associated with nonadherence in patients with self-reported nonadherence: weight gain (58.5%), excessive sedation (54.2%), physical awkwardness or tremor (33.1%) | |
| McCann et al50 | • 19.7% of patients were nonadherent (≥1 missed dose over the past week) |
| • Multivariable analysis: independent predictors of nonadherence were self-rated poor access to psychiatrists (OR =25.0; 95% CI: 1.85–333) and side effects (OR =12.8, 95% CI: 1.35–120.9) | |
| • Stigma was not associated with nonadherence | |
| Rummel-Kluge et al51 | • 68%–69% of patients were considered partially nonadherent (for unintentional partial nonadherence: missing 1 dose in last month) |
| • The most common reasons for partial adherence were lack of insight into the need for prophylactic medication (68%), lack of insight/denial of illness (63%–66%), and stigma (embarrassment about taking daily medication, 62%) | |
| Pratt et al52 | • Mean nonadherence rate was ~40% based on pill count, but only 9%–17% based on self-report and MARS score |
| • Significantly better adherence, expressed as a composite score, was correlated with SZ-spectrum disorders relative to BPD or MDD, higher level of medication supervision, greater level of insight, more prescribed medications, fewer negative symptoms, and better community functioning | |
| Elbogen et al53 | • 22% of patients were nonadherent (doses taken never or sometimes during past 30 days) |
| • Multivariable analysis: 6 factors significantly associated with nonadherence: substance abuse (OR =1.72; P=0.0177), functional impairment (OR =1.94; P=0.0023), having moved in the past 30 days (OR =1.92; P=0.0028), feeling emotionally numb (OR =2.18; P=0.0006), loss of interest in daily activities (OR =1.81; P=0.0075), and reporting recent suicidal ideation (OR =1.98; P=0.0047) | |
| • Substance abuse, living instability, and depressive symptoms increased the probability of nonadherence from 0.14 to 0.66 | |
| • The relationship between substance abuse and adherence was not mediated by depression or living instability – the effect is independent for all 3 factors |
Abbreviations: BPD, bipolar disorder; CI, confidence interval; EPS, extrapyramidal symptoms; HCP, health care professional; MARS, Medication Adherence Rating Scale; MDD, major depressive disorder; MEMS, Medication Event Monitoring System; OR, odds ratio; PANSS, Positive and Negative Syndrome Scale; SZ, schizophrenia.