Determinants of patient satisfaction in clozapine users: results from the Clozapine International Consortium (CLOZIN)

Marte van der Horst, Nini de Boer, CLOZIN collaborators, Ahmet Müderrisoğlu, Alba Toll, Alde Bouhuis, Alkomiet Hasan, Amy Jongkind, Ana González‐Pinto, Anna Mané, Armando D’Agostino, Aygün Ertuğrul, A. Elif Anıl Yağcıoğlu, Benedicto Crespo‐Facorro, Bernhard T. Baune, Bianca Sánchez-Barbero, Carlos Spuch, Carla Lou Morgenroth, Carmen Fernandez de Pinedo, Cecilia Casetta, Chad Bousman, Christa Hohoff, Christos Pantelis, Claudia Ovejas-Catalán, Clemente García‐Rizo, Dan Cohen, Dragana Ignjatović Ristić, Edwin Beld, Eila Repo‐Tiihonen, Elias Wagner, Ellen Jeger-Land, Elisabet Vilella, Emilio Fernández-Egea, Erwin Bekema, Esteban Sepúlveda, Federico Wiedenmann, Francesca Martini, Francesca Serio, Francesca Vairano, Giacomo Mercuriali, Giovanni Boido, Gökhan Yoca, Hanneke van Beek, Harm J. Gijsman, Heli Tuppurainen, Ian Everall, Ivona Novakovic, Eric P. Zorrilla, İbrahim Mert Erdoğan, Jacopo Sapienza, Jan Bogers, Jari Tiihonen, Javier Vázquez-Bourgón, Jim van Os, Johannes Schneider‐Thoma, Jurjen J. Luykx, Koen P. Grootens, Lorea Mar‐Barrutia, Lourdes Martorell, Maarten Bak, Marco Spangaro, Marco Zierhut, Marije de Vos, Mariken de Koning, Marina Garriga, Markku Lähteenvuo, Marta Bosia, Marte van der Horst, Melih O. Babaoğlu, Mike Veereschild, Mirko Manchia, Mishal Qubad, Monika Edlinger, Paloma Fuentes-Pérez, Pasquale Paribello, Purificación López-Peña, René S. Kahn, Robert A. Bittner, Roberto Cavallaro, Selene Veerman, Stefan Gutwinski, Stefanie Schreiter, Stephan Ripke, Tania Rivera Baltanás, Tatiana Oviedo-Salcedo, Tero Hallikainen, Thomas Görlitz, Wouter Alink, Yavuz Ayhan, Cynthia Okhuijsen‐Pfeifer, Jurjen J. Luykx

Clozapine is highly effective for treatment-resistant schizophrenia but is underutilized due to patient and clinician-related concerns. Little is known about the general level of patient satisfaction with clozapine and determinants thereof. We therefore explored determinants of patient satisfaction with clozapine in individuals diagnosed with schizophrenia spectrum disorders (SSDs). Cross-sectional data from 480 clozapine users were used to examine demographic and clinical factors, including symptom severity, treatment response, and adverse drug reactions (ADRs). Patient satisfaction was self-rated on a scale of 1 to 10. Results showed a mean satisfaction score of 7.4 (SD = 1.9), with significant associations between satisfaction and treatment response (B = 0.42, R² = 0.19, p = 3.9 × 10⁻¹⁸), symptom severity (B = 0.10, R² = 0.05, p = 2.06 × 10^-9), occurrence of ADRs (B = -0.16, R² = 0.06, p = 3.2 × 10^-5), and recreational drug use (B = -1.32, R² = 0.05, p = 2.09 × 10^-4). Hypersalivation and prolonged sleep duration were the only ADRs linked to lower satisfaction (B = -0.72, R² = 0.06, p = 3.5 × 10^-5 and B = -0.57, R² = 0.04, p = 1.4 × 10^-3, respectively). Despite concerns about ADRs, treatment effectiveness showed a stronger association with patient satisfaction among clozapine users than the occurrence of ADRs. In conclusion, our findings suggest that strategies aimed at bolstering clozapine's effectiveness may help counter worldwide underprescription rates of clozapine in patients with SSDs.