This systematic review will be conducted in accordance with the Cochrane Handbook for Systematic Reviews of Intervention, 2nd edition . As recommended by the handbook, we derived the review question through consultation with stakeholders, consisting of a community mental health center practitioner, a psychiatric nurse, and mental health policy experts. Finally, the search strategy was reviewed by search experts (medical librarians).
2.1. Review Inclusion Criteria
This review will include all patients with schizophrenia spectrum disorders who received/were subject to a community-based intervention program. The patients considered in our study are diagnosed as having schizophrenia spectrum disorders as defined by the Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5) . Schizophrenia spectrum disorders include schizophrenia, schizoaffective disorder, schizophreniform disorder, brief psychotic disorder, delusional disorder, and psychotic disorder not otherwise specified. Because psychotic symptoms are common characteristics, all diagnoses are included in the review literature, but the results are presented separately according to the individual diagnosis.
In addition to the differences inherent to their diagnosis, patients with these diagnoses may experience differences in treatment effects over the duration of the disease, so the results will be presented separately, based on the duration of the patients’ illness (divided into the first episode or chronic status).
This review will consider studies that evaluate any type of intervention programs that originated from the community-based intervention program for patients with schizophrenia. Those interventions may include but are not limited to, case management, cognitive behavioral therapy, occupational rehabilitation, and physical intervention programs.
The comparison groups will include one group of patients with schizophrenia spectrum disorders who are receiving the usual care (outpatient treatment that includes only medication) and a group who also receive community-based interventions in addition to the usual care.
Exploratory analysis will be conducted to identify the relapse, recovery, and/or remission rates of psychotic symptoms. In addition, the review will include the patients’ symptomatic severity and quality of life as outcomes of the community-based intervention. The patients’ conditions will be verified by the number and duration of hospitalizations after the community-based intervention, by their scores on the Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), and Global Assessment of Functioning (GAF). Quality of life will be defined by the patients’ and their respective caregivers’ Quality of Life Scale scores. Thus, any studies that report any of the above outcomes will be included.
2.3. Study Design
This review will only consider randomized controlled trials (RCT). Non-randomized controlled trials (non-RCT), cohort studies, case studies, and review articles will be excluded. It will report the specific characteristics of all included studies, using the inclusion criteria that the studies must be written in either English or Korean. We will not include data in the study results because it is difficult to extract data accurately for non-English or non-Korean written papers, but we will inform readers of ‘Studies Awaiting Classification’ through the PRISMA flowchart so that they can be used in other possibly-relevant reports. As community-based mental health services would have been implemented at various times in different countries, we will place no restrictions on the date of publication, and will consider any papers published until January 2021. We will include not only peer reviewed papers but also gray literature (e.g., conference papers, reports, theses/dissertations, protocols) to reduce the bias in our research findings. Therefore, in cases of conference proceedings or protocols without data, we will hand-search for full-text or contact the author to request unpublished data for systematic review.
2.4. Electronic Bibliographic Databases
Electronic searches will be conducted on the following databases: MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, EMBASE and the Cumulative Index to Nursing and Allied Health Literature, Research Information Sharing Service (Korean database). To supplement these searches and to reduce the publication bias, we will expand to search for gray literature using System for Information on Grey Literature in Europe (SIGLE) and GreySource. We will search dissertations and theses by using Open Access Theses and Dissertations (OATD) and ProQuest Dissertations and Theses Global (PQDT). We will manually-search the ClinicalTrials.gov website and International Clinical Trials Registry Platform search portal to identify relevant studies. Other avenues for identifying studies will be to use advanced search on Google Scholar, Scopus, and Web of Science. If only conference proceedings or trial protocols are in the search document, we will email the author to request the unreleased data.
2.5. Search Strategy
The search strategy aims to find published or unpublished that are in accordance with the Population Intervention Comparison and Outcome Process. An initial search of PubMed will utilize text words related to the systematic review research question: “schizophrenia” and “community based” or “community mental health services.” Then, we will identify relevant keywords by an analysis of the text words contained in the title and abstract, and of the index terms used to describe the relevant articles to refine our search. Specific search strategies are provided as attachments.
2.6. Study Screening and Selection
Search results will be downloaded using Endnote software, X9 version, and duplicate studies will be eliminated. In the first review, we will review the title and abstract of the selected studies to identify populations, intervention and outcome variables, and study designs to eliminate non-relevant literature; in the second review, a full-text review will identify the final literature of the selected studies. Each selected study will be independently reviewed by two researchers and will be cross-reviewed by both researchers. During the process, if opinions do not agree among researchers, the text will be reviewed together until the researchers reach an agreement.
2.7. Data Extraction
Data extraction will include specificities about populations, types of interventions, study designs, and outcome variables. Researchers will select five articles to create a pilot-format data extraction tool, and this tool will use the EPPI reviewer version 18.104.22.168 (http://eppi.ioe.ac.uk/).
In addition to the outcome data, descriptive details such as study designs (e.g., multicenter or cluster), participants' characteristics (e.g., age, gender, diagnosis, disease status), methods used in the analysis, and methods of intervention (handling) will also be recorded and reviewed. The amount, duration, frequency, and intensity of each reported intervention will also be included in the record. The demographic characteristics and types of interventions will also be specified to enhance the study analysis and synthesis.
If there are any missing or unclear data, we will contact the author of the original research to clarify.
2.8. Assessing Risk of Bias
For RCT studies, we will use the Cochrane RoB 2.0 tool . RoB is a tool that combines both the checklist method and area evaluation method, and it is an important tool because its area evaluation randomizes sequence generation, which blinds parts of the study and study personnel, blinds the outcome assessments, and does not include incomplete outcome data, which helps us avoid selective reporting and other possible types of biased selection. To avoid the risk of biases in each question, they will be judged as “high,” “low,” and “uncertified” bias, in accordance with the specific presented guidelines. And any disagreement will be resolved by discussion.