Table 3.

Characteristics of included studies.

Study	Methods	Participants	Intervention A	Intervention B	Measured outcomes, Instruments, assessment periods, Limitations of the studies
Van Hassel J.H., Bloom L.J., Gonzalez A.M. (1982) USA	RCT	39 individuals (37 male, 2 female) served as Ss (Study Subjects). All Ss carried schizophrenic diagnoses in their outpatient records, with 62% classified as chronic undifferentiated subtype, 28% as paranoid subtype, and 10% as other forms of schizophrenia. Ages ranged from 23 to 70, with a mean age of 47.5. Most Ss (72%) were receiving antipsychotic or tranquilizing medication during the period of the study. Setting: Denver Veterans Administrations Hospital	13 Ss in the Applied Relaxation (R) group Description: Initial training in deep muscle relaxation (Jacobson). Groups patients were required to practice relaxation exercises at home. The group continued to practice standard relaxation procedures throughout the 6-week period and engaged in discussions of how to apply the techniques to life stresses. No stressful imagery was used, nor were Ss encouraged to attend to anxiety cues. Emphasis was placed on using standard relaxation procedures in stressful situations encountered away from the hospital. Ss were seen in groups of 3–8, dependent upon scheduling constraints. Number of sessions: 6 total sessions Frequency: once per week Duration: 45 minutes	14 Ss in the Anxiety Management Training (AMT) group Description: The training was conducted in three stages. In the first stage, patients were taught standard deep muscle relaxation (Jacobson). Groups patients were required to practice relaxation exercises at home. In the second stage, patients were stressed via stressful imagery and encouraged to pay attention to exactly where and how the tension was registered. The third stage, patients were stressed and then taught to reduce tension via cue-controlled relaxation. Groups completed post-training assessment scales. Ss were seen in groups of 3–8, dependent upon scheduling constraints. Number of sessions: 6 total sessions Frequency: once per week Duration: 45 minutes Intervention C 12 Ss in the Wait List (WL) group Description: The group met once to complete pre-training assessment scales and to have the goals and procedures of the training explained to them. They were informed that their group would not begin meeting for approximately 6 weeks. After the 6-week waiting period, the WL group met again. At that time the WL, AMT,and R groups completed post-training assessment scales. Post-training therapist rating scales also were completed at this time. Once the scales were complete, the WL group began the AMT training program. After 6 weeks of AMT training, the remaining 8 WL group Ss once again completed post-training questionnaires.	The nature, purposes, and requirements of the study were explained fully to each S prior to inclusion in the program. Pretests were administered to the Ss (STAI) and their therapists (Therapist Rating Scale). Measured Outcomes: •Generalized anxiety. •Reported anxiety, observed anxiety, ability to work effectively in therapy, social ability, ability to manage anger, ability to manage emotions, ability to achieve personal goals, and psychiatric status. Instruments: The Spielberger Trait Anxiety Inventory (STAI) and the Therapist Rating Scale (scale consisted of eight questions) post-treatment anecdotal questionnaire (to allow the participants to voice their opinions of the program in their own words.) Assessment periods: Pretests were administered to the Ss (STAI) and their therapists (Therapist Rating Scale). Therapists were instructed to consider only the preceding 30 days when they were rating their patients; After 6 weeks of training WL, AMT, and R groups completed post-training assessment scales. Post-training therapist rating scales also were completed. Limitations of the studies: Because of constraints imposed by the hospital administration, it was not possible to alter the patient's regular therapy program or medication regime for purposes of this study.
Chen et al., 2009 Taiwan	RCT	Eighteen patients were block randomised and then assigned to an experimental or control group. Only 14 Patients with DSM-IV diagnosis of schizophrenia. (4 male and 10 female) completed the study. Setting: Acute psychiatric ward of a medical center in Taiwan.	Progressive muscle relaxation (n = 8; 1 male and 7 female) Progressive muscle relaxation training. One session of PMRT was applied to the experimental group per day at a set time each morning for 11 consecutive days, during 40 minutes each. Subjects were led into a sound-proof therapy room and asked to sit in a half recumbent position on a therapy chair with no distractions. Each person was covered with a comfortable sheet and the room lights were then dimmed. The air-conditioned temperature of the room was set at 23 °C. The volume of the instructions played to the experimental group was set between 40–50 decibels, which was an acceptable sound level. To ensure program standardization, the PMRT audiotape employing Jacobson's progressive muscle relaxation protocol included progressive relaxation of groups of muscles and deep breathing for 25 minutes. The PMRT tape contained instructions for systematic tensing and relaxation of specific muscle groups, starting with the groups of muscles in the upper body and progressing down to the lower part of the body. Number of sessions: 11 total sessions Frequency: once a day (11 consecutive days) Duration: 40 minutes	Control group (n = 6; 3 male and 3 female) Control group patients received a placebo intervention (they were quietly led to a therapy chair in the same therapy room, at the same set time each morning, with no other interventions given).	Measured outcomes: anxiety, positive symptoms, most frequently diagnosed psychiatric illness/disorder; patient's perceived overall disease status, finger temperature. Despite the positive findings, we must underline the potential biases related to the blindness, randomization methods, and therapist's factors. We must also underline the fact of this clinical evaluation was conducted from 11 consecutive sessions of during 40 minutes of progressive muscle relaxation intervention. Beck Anxiety Inventory (BAI). The BAI developed by Aaron Beck in 1988 includes 21 questions, each question having four possible scores between 0–3. When the scores are summed, 0–7 points are normal, 8–15 points indicate mild anxiety, 16–25 points indicate moderate anxiety and 26–63 points indicate severe anxiety (Julian, 2011). Scale for the assessment of positive symptoms (SAPS). The semi-structured questionnaire assesses characteristics of hallucinations, delusions, bizarre behaviours, aggressive and anxious behaviours and impaired active reasoning. Each question is evaluated at six levels, from ‘problem non-existent’ to ‘extremely severe’ (Chen et al. 2009). Mini-international neuropsychiatric interview is a structural interview scale that assesses for the most frequently diagnosed psychiatric illness/disorder. It is based upon the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM-IV) and the tenth edition of the International Classification of Diseases (ICD-10). Clinical global impression. Developed by Guy in 1976, this tool measures the patient's perceived overall disease status. Disease severity has seven levels, from ‘no disease’ to ‘extremely severe’. Changes in the progression of the disease are divided into seven levels, from ‘improved greatly’ to ‘very bad’. Treatment efficacy is divided into four levels, from ‘improved greatly’ to ‘no improvements’ (Chen et al. 2009). During the baseline procedure, finger temperature was continuously recorded for five minutes allowing the subjects to stabilize from previous activities and thus reducing arousal associated with the experimental setting. The first two minutes of baseline were discounted; the remaining three minutes were averaged and obtained as the baseline levels. Assessment periods: On the day prior to commencement of the intervention, the following instruments were administered the Mini-international neuropsychiatric interview (MINI); the scale for the assessment of positive symptoms (SAPS); clinical global impression (CGI) and the BAI. The BAI and the SAPS were again completed at the end of 11 days of PMRT or control intervention and one week after cessation of PMRT or control intervention. Finger temperature was measured prior to and three minutes after each PMRT session.
Vancampfort et al., 2011 Belgium	RCT	64 out of 88 eligible patients with schizophrenia met the inclusion criteria. Only 52 Patients (31 male and 21 female) completed the study. Setting: Acute inpatient care unit University Psychiatric Centre of the Catholic University of Leuven, Belgium.	Progressive muscle relaxation (n = 27; 18 male and 9 female) Progressive muscle relaxation was offered one time in a week and lasted approximately 25 minutes. Training consisted of successive tensing and relaxing at least five major muscle groups, beginning with the upper body and proceeding to the lower parts. Tensing for about 8 seconds and relaxing for about 30 seconds of each muscle group was practiced twice prior to proceeding to a subsequent muscle group. Number of sessions: 1 session Frequency: once a week Duration: 25 minutes	Resting control condition (n = 25; 13 male and 12 female) Resting control condition sat quietly in a room for 25 minutes and was told that they could read. Reading material was provided for participants who did not bring their own material. The same physiotherapist was also here present in the room and only left during completion of the questionnaires	Measured outcomes: State anxiety; Stress and subjective well-being; schizophrenia symptoms. Despite the positive findings, we must underline the potential biases related to the blindness, randomization methods, and therapist's factors. We highlight also that the Cutoff point for inclusion of the study's in the review were established by reviewers in five mandatory "yes" answers to questions in the standardized critical appraisal instrument from JBI-MAStARI. We must also underline the fact of this clinical evaluation was conducted from one only 25 minutes session of progressive muscle relaxation intervention. Progressive muscle relaxation is part of a larger clinical physiotherapy program consisting of aquatic sessions (once a week), walking (twice a week), yoga training (once a week), fitness training (twice a week), psycho-education about an active lifestyle (once every two weeks) and group-related movement sessions with psychosocial and cognitive objectives (twice a week). Progressive muscle relaxation was offered once a week and lasted approximately 25 minutes. Instruments: State Anxiety Inventory. State anxiety was assessed by the State Anxiety Inventory of Spielberger. The range of possible total scores is 20–80. Higher scores indicate higher levels of anxiety. Subjective Exercise Experiences Scale. Stress, subjective well-being and fatigue were measured using the Subjective Exercise Experiences Scale. Each subscale contains four items, which are scored on a scale from 0 (not at all) to 7 (entirely). Higher scores on a subscale indicate a higher perception for this factor. The psychosis evaluation tool for common use by caregivers. The psychosis evaluation tool for common use by caregivers was used by an independent and well-trained nurse to evaluate schizophrenia symptoms. It evaluates 20 symptom items on a 7-point scale, resulting in an overall score ranging from 20 to 140. Symptoms are grouped in five factors: positive (hallucinations, delusions, unusual thought content, grandiosity), negative (poor rapport, passive/apathetic withdrawal, blunted affect, motor retardation), depressive (anxiety, depression, feelings of guilt, somatic concerns), cognitive (poor attention, disorientation, difficulties with abstract thinking, conceptual disorganization) and excitatory (poor impulse control, lack of cooperation, hostility, excitement) symptoms. The scores for each factor range from 4 to 28. Assessment periods: Before and after the single interventions the State anxiety inventory and the subjective exercise experiences scale were completed. Effect sizes were calculated.
Georgiev et al., 2012 Bulgaria	RCT	Out of 78 patients with schizophrenia, 64 met the inclusion criteria. Only 59 Patients (28 male and 21 female) completed the study. Setting: Chronic department of the State Psychiatric Hospital in Tzerova Koria, Bulgaria.	Progressive muscle relaxation (n = 31; 15 male and 16 female) Progressive muscle relaxation was offered one time in a week and lasted approximately 25 minutes. Training consisted of successive tensing and relaxing at least five major muscle groups, beginning with the upper body and proceeding to the lower parts. Tensing for about 8 seconds and relaxing for about 30 seconds of each muscle group was practiced twice prior to proceeding to a subsequent muscle group. Number of sessions: 1 session Frequency: once a week Duration: 25 minutes	Resting control condition (n = 28; 13 male and 15 female) Resting control condition sat quietly in a room for 25 minutes and was told that they could read. Reading material was provided for participants who did not bring their own material.	Measured outcomes: State anxiety; Stress and subjective well-being Despite the positive findings, we must underline the potential biases related to the blindness, randomization methods, and therapist's factors. We must also underline the fact of this clinical evaluation was conducted from one only 25 minute of progressive muscle relaxation intervention. During two weeks participants undertook one weekly habituation session in order to get used to the environment and the protocol. The PMR is part of a larger clinical physiotherapy program consisting of aquatic sessions (once a week), walking (twice a week), yoga training (once a week), fitness training (twice a week), psychoeducation about an active lifestyle (once every two weeks) and group related movement sessions with psychosocial and cognitive objectives (twice a week). Scales: State anxiety was assessed by the State anxiety inventory (SAI) of Spielberger. The range of possible total scores is 20–80. Higher scores indicate higher levels of anxiety. Subjective Exercise Experiences Scale. Stress, subjective well-being and fatigue were measured using the Subjective Exercise Experiences Scale. Each subscale contains four items, which are scored on a scale from 0 (not at all) to 7 (entirely). Higher scores on a subscale indicate a higher perception for this factor. Assessment periods: During the week of the test condition also psychiatric symptoms were administered.
Wang et al., 2015 China	RCT	Sixty-four patients with acute schizophrenia were randomly assigned to four groups. Only 52 Patients (29 male and 23 female) completed the study. Setting: Acute psychiatric ward of Changsha Psychiatric Hospital, Changsha, China.	Progressive muscle relaxation (n = 12; 7 male and 5 female) Progressive muscle relaxation (PMR) group. This technique involved systematically relaxing major muscle groups of the body with the goal of physical and mental relaxation. The PMR group received ten 30-minute group PMR practice sessions, in two sessions per week, during 5 weeks of PMR training. Each session preceded by a 15-minute group discussion of PMR experiences. Self-practice of PMR at least once per day and recording of relaxation experiences on a specific form. Brochure describing the mechanisms and benefits of relaxation. Relaxation audio CD providing a guide for self-practice of PMR. Dedicated e-mail address where patients could communicate with the intervention staff about PMR experiences. Number of sessions: 10 total sessions Frequency: twice per week Duration: 30minutes + 15 minutes = 45 minutes Intervention C Education plus progressive muscle relaxation (n = 13; 7 male and 6 female) Combination of intervention activities and materials in education and PMR groups. Group PMR practice and group education provided on separate days each week. Group PMR practice Number of sessions: 5 total sessions Frequency: one per week Duration: 30minutes + 15 minutes = 45 minutes Group education Number of sessions: 5 total sessions Frequency: one per week Duration: 30minutes + 15 minutes = 45 minutes	Education (n = 14; 7 male and 7 female) Five 30-minute group education sessions respectively covering five topics: illness, treatment, well-being, support, and patients' rights; one session per week; each session followed by a 15-minute group discussion of the contents taught. Brochure summarizing topics in the group education sessions. Video CD containing a 30-minute video showing typical stories told by other patients with acute schizophrenia. Dedicated e-mail address where patients could send e-mails to the intervention staff for counseling. Number of sessions: 5 total sessions Frequency: one per week Duration: 30minutes + 15 minutes = 45 minutes Intervention D Control (n = 13; 8 male and 5 female) Patient education according to usual ward procedures Ten 30-minute group exercise sessions; two sessions per week; Each session preceded by 15-minute free group chat. Number of sessions: 10 total sessions Frequency: twice per week Duration: 30minutes + 15 minutes = 45 minutes	Measured outcomes: Quality of Life; Functional disability; Severity of positive schizophrenia symptoms Despite the positive findings, we must underline the potential biases related to the blindness, randomization methods, and therapist's factors. We must also underline the fact of this clinical evaluation was conducted from ten 30 minute sessions of progressive muscle relaxation. Quality of Life Enjoyment and Satisfaction Questionnaire Short Form (Q-LES-Q-SF), a self-report instrument developed to assess the degree of enjoyment and satisfaction experienced by respondents.13 The Q-LES-Q-SF, with 16 items, is identical to the General Activities subscale of the larger QLES- Q instrument. Each question is scored on a 5-point scale (1 = very poor degree of enjoyment or satisfaction, 5 = very good degree of enjoyment or satisfaction). The first 14 items are summed to produce a global QoL index with a maximum of 70 points. The last two questions concern medication and overall life satisfaction. Functional disability was assessed with the Sheehan Disability Scale (SDS), which was developed to measure impairment in functioning of psychiatric patients in treatment outcome studies. The SDS is a self-report instrument assessing patient functioning using three items (work/study, social life, family life/home responsibilities). Each item is rated on a 10- point visual analogue scale (0 = no disability, 1–3 = mild, 4–6 = moderate, 7–9 = marked, and 10 = extreme disability). SDS has been used previously in studies of patients with schizophrenia. Scale for the Assessment of Positive Symptoms (SAPS). This semi-structured questionnaire assesses characteristics of hallucinations, delusions, bizarre behaviors, aggressive and anxious behaviors, and impaired active reasoning. Each question is evaluated at six levels, from ‘‘problem nonexistent’’ to ‘‘extremely severe.’’ Assessment periods: All patients were evaluated at baseline (within 72 hours before the interventions) and at the end of weeks 5 (when the interventions ended) and week 15 (a 10-week follow-up after the interventions).