Table 2.
Reasons for nonadherence to antipsychotic medication in patients with SMI: results of prospective studies
| References | Results |
|---|---|
| Novick et al19 | • Higher baseline insight and therapeutic alliance were associated with better adherence (each P<0.0001) |
| • After 1 year of follow-up, significant direct associations were found between an improvement in the patient’s insight or an improvement in the patient–physician relationship and improved medication adherence | |
| • Insight and therapeutic alliance co-vary during the course of the disorder and bidirectionally affect each other | |
| Brain et al20 | • Nonadherence rate was 27% (≤80% MEMS adherence) |
| • Negative drug attitude (OR =0.71, P<0.001) and worse psychosocial function (OR =0.94, P=0.007) were significant predictors of nonadherence in a multivariable model | |
| • Poor insight into illness was a significant predictor of nonadherence (OR =1.61, 95% CI: 1.08–2.42) in a univariable model but was not included in the best-fitting multivariable model | |
| Lam et al21 | • 33% of patients were nonadherent (<80% on composite score) |
| • At 3 months, nonadherent patients had significantly worse prospective memory, symptom severity, insight, and attitude toward medication | |
| • Poor insight (OR =1.26, P=0.03) and worse symptom severity (OR =1.94, P=0.03) were significant predictors of nonadherence at 3 months | |
| • Prospective memory moderated adherence-predictive effects of insight and psychopathology but was not an independent predictor in a regression model | |
| • Prospective memory accounted for only a small proportion of the variance of nonadherence; medication management ability was a better predictor of nonadherence than prospective memory | |
| Baloush-Kleinman et al22 | • Compared with non/partially adherent patients, adherent patients showed better attitude toward medication (P<0.0001), higher levels of insight into illness (P=0.009) and awareness of need for treatment (P=0.0003), better therapeutic alliance (P=0.012), greater family involvement in treatment (P=0.0001), more positive attitudes toward medication in family (P<0.0001), and greater severity of side effects (P=0.036) |
| • In a model predicting adherence at 6 months, attitudes toward medication mediated the effects of negative symptoms, awareness of the illness, and awareness of the need for medication adherence | |
| Novick et al12 | • 28.8% of patients were nonadherent (≤50% of doses taken) during the 3-year follow-up |
| • Prior adherence was the best predictor of adherence during follow-up (OR =4.01, P<0.001) | |
| • Baseline predictors of nonadherence (logistic regression): alcohol dependence (OR =0.63, P=0.013) and substance abuse (OR =0.67, P=0.043) in the previous month, independent housing (OR =0.8, P=0.001), presence of hostility (OR =0.85, P=0.02) | |
| • Good social functioning was a predictor of adherence (OR =1.26, P<0.001) | |
| Gonzalez-Pinto et al23 | • 23.4% of patients were nonadherent (answered “adherent about half of the time or almost never adherent” at ≥1 interview during maintenance phase) |
| • During maintenance, patients were more likely to be adherent if they had good insight (OR =1.98, 95% CI: 1.44–2.72; P<0.001) and less likely to be adherent if they used cannabis during the treatment (OR =0.31, 95% CI: 0.18–0.54; P<0.001) and had greater disease severity (OR =0.91, 95% CI: 0.84–0.99; P=0.028) | |
| Lepage et al24 | • 62%, 17%, and 21% of patients were fully (>75% of doses taken), partially (51%–75%), and poorly adherent (≤50%), respectively |
| • No significant associations were observed between global or domain-specific cognitive performance and adherence at 6 months | |
| Miller et al25 | • 18% of patients were nonadherent at the end of the study (<50% of the dose) |
| • 15%–20% of patients used cannabis | |
| • Patients who used cannabis were 2.4-fold (95% CI: 1.5–3.9) more likely to be nonadherent and 6.4-fold (95% CI: 1.2–35.6) more likely to drop out of the study | |
| Rabinovitch et al26 | • 45.1% of patients were nonadherent (≤75% of doses taken) over 6 months of treatment |
| • Low level of social support rated by case manager and poor early medication acceptance were significant predictors of nonadherence by logistic regression (OR =3.5, P=0.03 and OR =11.1, P<0.001), respectively | |
| • The level of social support based on patient ratings was not correlated with the case managers’ ratings and was not significantly associated with adherence | |
| • Insight into illness did not differ between adherent and nonadherent groups | |
| Mohamed et al27 | • Nonadherence percentage not reported |
| • ITAQ and DAI scores were significantly positively correlated (r=0.32, P<0.0001) | |
| • Attitude toward medication but not insight at baseline were significantly associated with medication adherence in prospective assessments (P<0.001 and P>0.05, respectively) | |
| • In a model not including attitude toward medication, insight was significantly associated with medication adherence | |
| Morken et al28 | • 44% of patients were nonadherent to oral antipsychotics over the study period (1 month or 4 separate week without medication) |
| • Patients with relatives showing low expressed emotion at baseline were significantly less adherent over the study period than those with relatives showing high expressed emotion (OR =6.0, 95% CI: 1.07–34.13, P=0.042) | |
| • Low expressed emotion is a marker of nonsupportive families | |
| Liu-Seifert et al29 | • A higher level of perceived beneficial effect of medication was the only factor associated with significantly reduced likelihood of early treatment discontinuation (HR =0.56, 95% CI: 0.40–0.79, P=0.001); ie, a higher level of perceived medication benefit by 1 point, such as strong vs mild or mild vs none, was associated with 44% less risk of discontinuation from the study during the following visit |
| de Haan et al30 | • The mean medication adherence score over 5 years was 2.6 (1%, <25%; 3%, >75%) |
| • 67.5% had score 2.5–3.0, indicating high adherence | |
| • Multivariable analysis: hostility and uncooperativeness (P=0.007), involuntary admission (P=0.02) but not cannabis use, SWN and ROMI total scores, and insight were associated with adherence during 5-year follow-up | |
| • Therapeutic alliance during acute admission appears to be critical for long-term adherence | |
| McEvoy et al31 | • Nonadherence defined as not taking any medication for >7 consecutive days (% not reported) |
| • Better insight treated as a time-dependent covariate was associated with longer time to nonadherence (P=0.0076) throughout the study | |
| • Baseline insight was not significantly related to the probability of early discontinuation | |
| Kamali et al32 | • 33% of patients were nonadherent (≤74% of doses taken) over the past 3 months of treatment |
| • Significant predictors of nonadherence at 6 months were positive symptoms (OR =8.56, P<0.01), alcohol misuse (OR =7.80, P=0.01), drug misuse (OR =4.38, P=0.04), lack of insight (OR =4.22, P=0.04) | |
| • Positive symptoms (OR =7.5, P=0.01) and lack of insight (OR =4.98, P=0.03) were the most significant predictors of nonadherence in patients without substance/alcohol abuse | |
| Yamada et al33 | • 16.7% of patients were nonadherent during the follow-up |
| • The score of “fulfillment of life goals” (good insight) was greater in the adherent compared with the nonadherent group (P=0.015) | |
| • The score of “no perceived daily benefit” (poor insight) was greater in the nonadherent compared with the adherent group (P=0.018) | |
| • No significant difference in patient characteristics or scores of BPRS, GAF, or other ROMI items | |
| Ascher-Svanum et al34 | • 18.8% of patients were nonadherent during the first year (MPR ≤80%) |
| • The best predictors of nonadherence were prior nonadherence (OR =4.1, P<0.001), illicit drug use (OR =1.8, P=0.025), alcohol use (OR =1.6, P=0.008), prior antidepressant use (OR =1.4, P=0.02), cognitive impairment (OR =1.3, P<0.001) |
Abbreviations: BPRS, Brief Psychiatric Rating Scale; CI, confidence interval; DAI, Drug Attitude Inventory; GAF, Global Assessment of Functioning; HR, hazard ratio; ITAQ, Insight and Treatment Attitudes Questionnaire; MEMS, Medication Event Monitoring System; MPR, Medication Possession Ratio; OR, odds ratio; ROMI, Rating of Medication Influences; SMI, serious mental illness; SWN, Subjective Well-Being Under Neuroleptics.