A Comparison Study of Multiple Measures of Adherence to Antipsychotic Medication in First-Episode Psychosis

Abstract

This study evaluates how much agreement there is between subjective reports of adherence to antipsychotic medication and objective or derived measures of adherence in first-episode psychosis (FEP) and asks if any adherence measure could approximate a gold standard based on correlation to symptom improvement in the early phase of treatment. Adherence was assessed in 81 FEP subjects on a monthly basis by reports from patients, clinicians, family, and pill counting. A consensus measure of adherence was derived from all available sources of adherence data. Symptoms were measured using the Positive and Negative Syndrome Scale at study entry and 3 months subsequently. Adherence as measured by patient report, pill count, and clinician report were in good agreement with each other (intraclass correlation coefficient = 0.84), and all of these measures were highly correlated to consensus adherence (r values between 0.86 and 0.98). Mean adherence was slightly higher as rated by patients (83% full doses taken per month) and family members (91%) than by clinicians (76%), pill counting (73%), or consensus value (74%). Early in treatment, each measure of adherence (except family report) was significantly associated with positive symptom reduction, although the order of magnitude of this correlation was greater for pill count and consensus adherence (P < 0.01) compared with patient- or clinician-reported adherence (P < 0.05). Patient or clinician reports provide a reasonable estimate of medication adherence in FEP, but introducing pill counting or a derived measure of adherence may allow more accurate measurement.

Les antipsychotiques injectables à action prolongée: Avis d'experts de l'Association des médecins psychiatres du Québec

“…Par ailleurs, la non-observance thérapeutique s'inscrit plutôt dans un continuum que dans une binarité de type tout ou rien. Il n'existe pas de méthode standard et fiable en pratique courante pour l'évaluation de l'observance thérapeutique et par conséquent, il est difficile d'obtenir une évaluation vraiment exacte de celle-ci [5][6][7][8] . Toutefois, un consensus d'experts conclut sur l'importance d'utiliser plusieurs méthodes d'évaluation à la fois pour mesurer l'observance 9 .…”

Case Manager- and Patient-Rated Alliance as a Predictor of Medication Adherence in First-Episode Psychosis

“…1Y3 Specifically in firstepisode psychosis (FEP), improved adherence to antipsychotic pharmacotherapy during the early course of treatment was shown to improve the short-term clinical outcome of patients with psychotic disorders. 4 In our previous study, 5 we reported that 20% to 56% nonadherence to medication in FEP and that nonadherence was highly correlated to a poorer clinical outcome. The link between poor adherence and poor outcome has been clearly established.…”

Modeling Determinants of Medication Attitudes and Poor Adherence in Early Nonaffective Psychosis: Implications for Intervention

“…84 and similar predictive validity. 11 Individuals' adherence fluctuates: one group 12 found 33%-44% were nonadherent sometime in any 6-month period and 53% sometime in the first 2 years, while another 13 found 63% nonadherent for at least a week over a year. Another study 14 estimated 45% took under 75% of antipsychotics in the first 6 months, while 42%-60% were rated as nonadherent at some point in first episode psychosis cohorts followed up for at least 1 year, 12,13,[15][16][17] particularly if the samples were juvenile or all had schizophrenia.…”