Observational Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Psychiatr. Nov 19, 2020; 10(11): 260-271
Published online Nov 19, 2020. doi: 10.5498/wjp.v10.i11.260
Testing the hypothesis of subtypes of nonadherence in schizophrenia and schizoaffective disorder: A prospective study
Dulcinea Vega, Francisco J Acosta, Pedro Saavedra
Dulcinea Vega, Department of Psychiatry, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria 35016, Las Palmas, The Canary Islands, Spain
Dulcinea Vega, Francisco J Acosta, Department of Psychiatry, Insular University Hospital of Gran Canaria, Las Palmas de Gran Canaria 35016, Las Palmas, The Canary Islands, Spain
Francisco J Acosta, Department of Mental Health General Management of Healthcare Programs, Canary Islands Health Service, Las Palmas de Gran Canaria 35004, Las Palmas, The Canary Islands, Spain
Francisco J Acosta, Research Network on Health Services for Chronic Conditions (REDISSEC), Carlos III Health Institute, Madrid 28029, Spain
Pedro Saavedra, Department of Mathematics, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria 35016, Las Palmas, The Canary Islands, Spain
Author contributions: Acosta FJ designed the study and wrote the protocol, wrote the first draft of the manuscript, and coordinated the project; Vega D managed the literature searches and was in charge of the recruitment and assessments of all patients; Saavedra P was in charge of data management and undertook the statistical analysis; and all authors contributed to and have approved the final manuscript.
Supported by College of Physicians of Las Palmas, No. I03/19.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of Insular University Hospital of Gran Canaria, Approval No. CEIm-CHUIMI-2016/893.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Francisco J Acosta, MD, PhD, Doctor, Department of Mental Health General Management of Healthcare Programs, Canary Islands Health Service, Las Palmas de Gran Canaria 35004, Las Palmas, The Canary Islands, Spain. fjacostaartiles@hotmail.com
Received: August 4, 2020
Peer-review started: August 4, 2020
First decision: September 21, 2020
Revised: October 2, 2020
Accepted: October 20, 2020
Article in press: October 20, 2020
Published online: November 19, 2020
ARTICLE HIGHLIGHTS
Research background

Despite important advances in the management of schizophrenia in recent decades, nonadherence remains a common phenomenon, with prevalence rates of approximately 40%-50%. The heterogeneity of findings regarding several risk factors for nonadherence could also be due to real heterogeneity among nonadherent patients.

Research motivation

The existence of two main subtypes according to intentionality has been hypothesized: Intentional and unintentional. Identification of subtypes as well as specific reasons for nonadherence would provide guidance in terms of different types of interventions.

Research objectives

To evaluate possible subtypes of nonadherence according to intentionality and to determine whether identified subtypes show a differential profile.

Research methods

This naturalistic, observational, and 6-mo follow-up prospective study included 110 admitted patients diagnosed with schizophrenia or schizoaffective disorder. Baseline evaluation included sociodemographic, clinical, psychopathologic and treatment-related variables. Adherence was defined as the concurrence of adherence to antipsychotic treatment and outpatient follow-up during the six-month period. Adherence to antipsychotic treatment was defined as the concurrence of objective and subjective adherence. Subtypes were assigned at 6 mo follow-up based on a set of reasons for nonadherence.

Research results

Sixty-four patients (58%; n = 64) fulfilled nonadherence criteria at the end of the follow-up period and were categorized according to subtype of nonadherence: 32 (50%) fulfilled criteria of intentional nonadherence, and 32 (50%) unintentional nonadherence (UNA). Several variables were independently associated with UNA: Low educational level (OR = 26.1; 95%CI: 2.819-241), worse treatment knowledge at six months (OR per unit = 0.904; 95%CI: 0.853-0.957) and nonpsychiatric treatment at six months (OR = 15.8; 95%CI: 1.790-139).

Research conclusions

This study specifically tests the subtypes hypothesis in psychotic disorders. We found two subtypes of nonadherence according to intentionality, as well as differentiated profiles. Our results support the nonadherence subtypes hypothesis in psychotic disorders.

Research perspectives

We propose some directions for future research: (1) Replication studies to confirm the existence of differentiated subtypes of nonadherence in psychotic disorders; and (2) If confirmed, adoption of a differentiated approach, both in future research and clinical practice.