TY - JOUR
T1 - The predictive validity of subjective adherence measures in patients with schizophrenia
AU - Robson, Deborah Jean
AU - Burti, Lorenzo
AU - Decker, JJM
AU - Koeter, Maarten
AU - Kikkert, Martijn
PY - 2011/5/9
Y1 - 2011/5/9
N2 - Despite frequent use of subjective adherence measures in patients with schizophrenia as well as other chronic conditions, there are several reports that question the validity of these instruments. Three well known, representative subjective measures are the Medication Adherence Questionnaire (MAQ), the Drug Attitude Inventory (DAI), and the Compliance Rating Scale (CRS). In this study we explored the predictive validity of these instruments in a European sample of 119 stabilized outpatients with schizophrenia. Clinical outcome variables were relapse and admission to a psychiatric hospital during a follow-up period of 12 months. Results indicate that the predictive validity of all three measures was poor. The MAQ was the least problematic predictor for relapse (Nagelkerke R2 = 0.09), and time to relapse (R2 = 0.07) and had the best sensitivity for relapse (63.6%) as well as admission (87.5%). The MAQ and CRS were both moderate predictive for admission (Nagelkerke R2 = 0.21, and R2 = 0.29). We conclude that the validity of the instruments studied here is questionable and have limited clinical relevance. Given the feasibility and ease of most subjective instruments, researchers may be tempted to use them but should be aware of the serious drawbacks of these instruments. Copyright © 2011 John Wiley & Sons, Ltd.
AB - Despite frequent use of subjective adherence measures in patients with schizophrenia as well as other chronic conditions, there are several reports that question the validity of these instruments. Three well known, representative subjective measures are the Medication Adherence Questionnaire (MAQ), the Drug Attitude Inventory (DAI), and the Compliance Rating Scale (CRS). In this study we explored the predictive validity of these instruments in a European sample of 119 stabilized outpatients with schizophrenia. Clinical outcome variables were relapse and admission to a psychiatric hospital during a follow-up period of 12 months. Results indicate that the predictive validity of all three measures was poor. The MAQ was the least problematic predictor for relapse (Nagelkerke R2 = 0.09), and time to relapse (R2 = 0.07) and had the best sensitivity for relapse (63.6%) as well as admission (87.5%). The MAQ and CRS were both moderate predictive for admission (Nagelkerke R2 = 0.21, and R2 = 0.29). We conclude that the validity of the instruments studied here is questionable and have limited clinical relevance. Given the feasibility and ease of most subjective instruments, researchers may be tempted to use them but should be aware of the serious drawbacks of these instruments. Copyright © 2011 John Wiley & Sons, Ltd.
U2 - 10.1002/mpr.335
DO - 10.1002/mpr.335
M3 - Article
SN - 1049-8931
VL - 20
SP - 73
EP - 81
JO - International Journal of Methods in Psychiatric Research
JF - International Journal of Methods in Psychiatric Research
IS - 2
ER -