Variables Impacting the Quality of Care Provided by Professional Caregivers for People with Mental Illness: A Systematic Review

People with mental illness may need the support of caregivers in certain areas of their lives, and there is an increasing need for quality care for people with mental health problems by qualified health professionals. Often, these professionals may develop so-called burnout syndrome, although some authors point out that positive emotions may also arise. In addition, several variables can act as both protectors and stressors. Therefore, the main aim of the current study is to identify variables related to the professional care of people with mental illness (i.e., protective or stressor variables) through a systematic review. The review was conducted according to the PRISMA guidelines with a final selection of 20 articles found in the Web of Science, PubMed, ScienceDirect and Dialnet databases between the months of October and November 2019, and updated in June 2022. The results show that job satisfaction is a strong predictor of the quality of care, and that congruence between personal and organizational values is a very important factor. Meanwhile, working in the same job for successive years, working in community mental health teams and experiencing burnout act as stressors and reduce the quality of care provided.


Introduction
With the arrival of the 21st century and changes to family structures, there is a growing need to invest resources to meet the demands of people in situations of dependency. According to the International Classification of Functioning, Disability and Health (ICF), dependency is defined as the result of a deficit in bodily function (i.e., physiological functions of the body systems, including psychological functions), bringing with it a limitation in activity. When environmental adaptation is unable to compensate for this limitation, there is a restriction in participation that causes the individual to depend on the help of others to carry out the activities of daily life [1]. There are several causes that can be the origin of a person's dependence, the most common being aging, accidents or chronic illnesses, and they can give rise to different types of dependence, such as physical, mental or psychic, sensory or mixed dependence. fore considered a process that includes the relationships between the individual and his or her environment, in which the perception of threat and/or damage causes physical and psychological reactions.
With regard to emotional intelligence, Mayer and Salovey [16] defined this concept as the ability of human beings to sense and identify emotions, understand and modify mental states. Emotional intelligence includes the mechanisms that allow the individual to manage the emotional adaptation necessary to face stressful situations. Thus, a positive attitude toward helping third parties can determine positive emotional functioning among caregivers and, in this way, help to offset the negative consequences that may arise from care [17].
Despite the recognized value of mental health and the need for care and support of people with mental illness, our understanding of the aspects that affect the quality of care to these patients is lacking. It is vitally important to study and analyze the impact that negative variables, such as burnout or perceived stress, can have on professional caregivers, and to focus on the abilities and strengths that act as protective factors to achieve improvement in the quality of life of both professionals and the patients in their charge.
Therefore, the main aim of the current study is to identify variables related to the professional care of people with mental illness (i.e., protective or stressor variables) through a systematic review.
The secondary objective is to identify the main interventions that are currently being implemented in relation to these variables for professional caregivers of people with mental illness.

Materials and Methods
This study is a systematic review of the published scientific literature regarding variables impacting the professional care of people with mental illness. The guidelines for carrying out systematic reviews proposed in the PRISMA statement were followed [18] (Appendix A). In addition, the SPIDER tool for qualitative and mixed studies was used to establish the research questions and search strategies [19]. Regarding the ethical standards, no ethical approval or participant consent is required for this type of research (i.e., systematic review).

Information Sources
The systematic search was performed between October and November 2019, and updated in June 2022, in the Web of Science (WoS), PubMed, ScienceDirect and Dialnet databases, including all articles published from 1900 to 2021 (inclusive). A total of 2429 articles were recovered: 135 articles from PubMed, 221 from WoS, 1637 from ScienceDirect and 436 from Dialnet.

Eligibility Criteria
A protocol was registered in PROSPERO and the search was conducted according to the following criteria. The identification code is CRD42022340313.

Inclusion Criteria
The inclusion criteria were as follows: (a) articles that reported empirical research or interventions; (b) articles that referred to variables related to the professional practice of professional caregivers in the field of mental health; (c) articles in any language (to collect as many articles as possible, as well as to reduce the "Tower of Babel" effect; i.e., the prevalence of studies in a certain language over others written in lesser-represented languages [20]), and (d) articles to which full-text access was possible.

Exclusion Criteria
The exclusion criteria were as follows: (a) articles that did not include narrative articles; (b) articles that included non-professional caregivers as participants; (c) articles that included professional caregivers who work in a field other than mental illness; (d) articles that include systematic reviews or metanalysis, and (e) articles that did not include variables related to the professional practice of care.

Search Strategy
The bibliographic search was carried out in three phases: an initial search to obtain an overview of the current situation, the application of inclusion and exclusion criteria, and a manual search to evaluate the results obtained. The combinations of terms used were as follows.
In PubMed, the following terms were used: "professional caregiver" AND "mental health"; "professional caregiver" AND "mental illness"; "professional care' AND "mental health"; "professional care" AND "mental illness" in the title and abstract fields. In WoS: "professional caregiver" AND "mental health"; "professional caregiver" AND "mental illness"; "professional care" AND "mental health"; "professional care" AND "mental illness" in the topic field. In ScienceDirect: "professional caregiver" AND "mental health"; "professional caregiver" AND "mental illness"; "professional care" AND "mental health" NOT "family" NOT "relative"; "professional care" AND "mental illness", narrowing the search to research articles and in title, abstract and keywords fields. In Dialnet: "professional caregiver" AND "mental health"; "professional caregiver" AND "mental illness"; "professional care" AND "mental health"; "professional care" AND "mental illness".
This process was carried out by one of the authors and corroborated by another through the Covidence tool [21].

Data Collection
The data to be extracted from each of the instruments were also defined in advance to ensure that the information was extracted in a uniform manner. The selected documents were then recorded in a Microsoft Excel spreadsheet and in Covidence software.
Thus, the recorded information included (1) the name of the authors and the year of publication, (2) the aims, (3) the methodology used and the presence of a control group, (4) the number of participants in the sample, (5) the variables or themes included and the results obtained in each study, and (6) the limitations of each article.

Selection Process
The summaries of all the articles were read, and only 67 articles were considered adequate after passing an initial screening process (after eliminating 635 duplicate articles in different combinations of the various databases). After screening, an analysis of the full text of these 67 articles was carried out. As a result, 47 articles were eliminated because they included narrative articles (n = 5), they did not include professional caregivers in the mental health field (n = 13), they did not include variables related to the professional practice of care (n = 22), they include systematic reviews (n = 2) or the full text was not accessible (n = 5). The remaining 20 articles that met all the inclusion criteria were selected for inclusion in the systematic review. The various phases of execution of the procedure are detailed in Figure 1.

Results
The synthesis of the results of the selected studies is shown chronologically and alphabetically in Table 1. The order of analysis of the articles presented below differs from that shown in the table to facilitate the understanding of the results.
Professional caregivers whose personal values are consistent with the commonly shared values of a caring profession experience less exhaustion and greater personal wellbeing [33]. In addition, this well-being is also implicitly and explicitly linked to personal experiences and professional practices [33], and relates to factors such as honesty, clearly defined work, competence and fulfillment of obligations [39]. In addition, the feeling of calm and a healthy perception of oneself are critical components of effective professional practice [41]. On the other hand, caregivers with psychological distress report higher burnout and compassion fatigue scores, and lower levels of compassion satisfaction [35]. Furthermore, it has been seen that with each additional year that is spent in the caregiver position, emotional tension, burnout and mental health problems increase significantly [35]. Inability to obtain access to a hospital and lack of cooperation from certain staff members when participating in in-depth interviews. Mindfulness, compassion, stress and burnout; significant improvement in four of the five mindfulness facets and in compassion levels, and a significant reduction in stress following intervention, but no change was observed for burnout.
Small sample size; participants from the same institution; lack of control group; experimental and social desirability bias (the researcher was the instructor for the program); study not generalizable to other health professionals.
Yang et al., (2017) [29] Provide an interdisciplinary community mental health training program and assess the effect of training on staff knowledge of mental health and confidence in their roles Group design with preand post-testing Quantitative (scales and questionnaires) No control group 48 mental health professionals, China Community mental health knowledge and confidence in managing people with mental health issues; the score on every item, except the item on empathy and the total/average score, was significantly increased.
Non-objective measure of knowledge improvement; transfer of learning to the workplace was not measured.
Frajo-Apor et al., (2015) [30] Investigate emotional intelligence and resilience in mental health professionals compared to a control group who did not work in healthcare Cross-sectional design Quantitative (test and scales) With control group 61 mental health professionals and 61 participants working in unrelated areas, Austria Emotional intelligence and resilience; the two groups did not differ significantly from each other, neither in terms of emotional intelligence nor resilience; positive correlation between emotional intelligence and resilience; mental health professionals were not more resilient than the general population. Understanding psychosis, building relationships, using own reactions, multidisciplinary collaboration, teamwork and collaboration and supporting relatives; significant increase in participants' experienced competence in all variables, especially for the understanding of psychosis and relationship building; no significant variance at the program level.
The study focused solely on the changes in competence experienced by the participants, and not on whether patients experienced an improvement in services; data used was collected between 1999 and 2005.  Burnout; about one fourth of the respondents in both groups showed a high degree of burnout, but no significant differences were found in the three dimensions of burnout (emotional exhaustion, depersonalization, and personal accomplishment) for the two groups of caregivers.
Low response rate; only partners of people with schizophrenia and depression were interviewed; the results might not be generalizable beyond Germany. Rose and Glass (2006) [39] Examine the degree of emotional well-being in community mental health nurses and identify factors that impact their professional practice Descriptive, inductive design Qualitative (interviews) No control group 5 nurses in community mental health centers, Australia Three themes: (1) being able to speak out (or not); (2) being autonomous (or not); (3) being satisfied (or not).
None described Knowledge in the field of caring for chronic mental disorders; mental health professionals were moderately knowledgeable on this topic (mean score 66%); errors made were more commonly in the direction of overenthusiastic support for the community approach; there were no differences in knowledge scores by a demographic or professional status variables included in this study.

None described
When comparing various dimensions of burnout (emotional exhaustion, depersonalization and personal fulfillment) between dyads of people with schizophrenia and depression and nurses who work as caregivers in psychiatric hospitals, there are no significant differences, and approximately a quarter of both have a high degree of exhaustion [38]. For other positive variables, such as emotional intelligence and resilience, it has been seen that both workers in this sector and subjects not working in this sector have an average level of both, so mental health professionals are no more "protected" from stressors than the rest of the population [30].
Other variables that may affect adequate care dispensing include recovery-oriented care, which is related to other variables, such as team support and interdependence, knowledge sharing, confidence, and belief in multidisciplinary collaboration, and which could be enhanced through the promotion of appropriate resources, training on best recovery practices and standardized assessment tools [25]. Job satisfaction is also an important variable in the provision of adequate care. Significant correlates of the reduction in job satisfaction include higher levels of education, increased work experience, a large number of cases, low income and few opportunities for professional development [40]. On the other hand, it has been seen that intrinsic motivational factors, such as satisfaction with the amount of responsibility, with the recognition of work, with the amount of variety in work and with the freedom of working method, lead to an increase in overall satisfaction [27]. In addition, social support plays a fundamental role in mental healthrelated jobs [40].
It has also been found that caregivers have a system of clearly articulated values, and twenty-one qualities can be identified that are classified into values about humans, values about disease/disability and values about the work of care, which are of critical importance for job effectiveness and satisfaction [37]. Another factor that may affect the provision of adequate care may be job satisfaction. It has been seen that it is essential that all caregivers work with a common goal, so a leader who manages the group and increases the individual skill of each worker has been proposed as a necessary figure [26]. Another aspect that plays a key role in this regard is the proximity provided by home care. This type of care is seen by professional caregivers as an opportunity to get to know the person beyond their role as a patient, which increased their involvement in the job and provided greater satisfaction than conventional care in hospitals or centers [22].
On the other hand, to reduce the negative effects that can arise as a result of the role of a professional caregiver in this area, a number of interventions have been developed in recent years. Mindfulness is used to teach participants to develop the capacity for observation, acceptance and compassion towards the emotions and thoughts that occur in the workplace. Mindfulness has been found to be useful for significant improvement in various facets of mindfulness (i.e., observational, descriptive, non-judgmental and nonreactive skills). There is also a significant increase in levels of compassion and a significant reduction in stress. Moreover, these changes have been maintained for up to 3 months after the training [28]. Another type of intervention is the Schwartz Rounds, a type of meeting in which staff discuss the emotional impact of their professional performance. In the study by Allen et al. [23], this intervention was rated as useful and beneficial by 10 professionals who perceived the rounds as an opportunity to express their feelings. This resulted in increased acceptance of their decisions, adaptive coping strategies and empathy towards and from their co-workers. They also expressed that it could help their relationship with patients. Six years later, rounds are still perceived as positive and as an opportunity to make the profession more humane.
On the other hand, the study of Barnes and Toews [41] showed that, years ago, mental health professionals had only a moderate knowledge of the principles of care, which has been seen to have important implications on the quality of care provided to patients. Another more current study yielded similar results [29]. It reported that community mental health workers caring for people with such diseases lack experience and training in this area, as only 8.7% of the participants had received community mental health training, although the post-training assessment they employed led to improvements in knowledge, especially related to home visits, case management and follow-up. According to a current study, a fundamental variable in caring for the group of people with mental illness would be continuous education and training, in addition to other aspects such as mentorship and the frequency of care [24].
In addition, individuals with certain mental illnesses, such as borderline personality disorder, often engage in countertransference toward their caregivers, who often react with avoidance and experience considerable stress [32]; as a result, many training programs are employed. Most of the work analyzed in this regard have generated benefits for participants in the form of significant increases in the competence for understanding of psychosis and relationship building [31], in the knowledge and attitudes of mental health professionals toward the recovery of people with serious mental illnesses [36], and in attitudes, self-efficacy and behavioral intent [34].

Discussion
The aim of the study is to carry out a qualitative analysis of a set of studies with different methodologies that include empirical research or interventions to identify variables affecting the professional care exercise of people with mental illness (i.e., protective or stressor variables). The secondary objective is to identify the main interventions that are currently being implemented in relation to these variables for professional caregivers of people with mental illness.
Regarding the main objective, the results of this study show that an important protective variable against caregiver burnout is the existence of coherence between the caregivers' personal values and those values required by the profession. In this way, the actions and behaviors carried out in the workplace become meaningful for the person. There are several recent studies that confirm that congruence between the individual values of the person, and those defended by an organization are related to less emotional exhaustion and greater work commitment [42], as well as greater emotional well-being [43].
In addition, as Rose and Glass [39] state in their work, this emotional well-being would have a bilateral character since, at the same time, it is implicitly and explicitly related to personal events, as well as professional ones. This generalized interconnection was found again in a later study by the same authors in a sample of palliative care nurses [44]. Later studies, such as that of Boamah et al. [45], conducted with a sample of 3743 nurses, confirmed the importance of the relationship between these values and, in addition, it also highlighted the special relevance of the figure of a leader who unifies the group, establishes tasks with a common goal for the whole team and ensures an empowering work environment. This can help to reduce burnout, increase employee job satisfaction and improve the quality of patient care [45].
Job satisfaction also has a significant influence on the care provided to the patient, as it has been shown to have a moderating effect on the effort and eagerness dispensed. Related to this, it has also been shown that caregivers with higher satisfaction in their work environment are more likely to engage in a greater number of caregiving behaviors [46]. Other factors related to this occupational well-being are, positively, resilience developed by caregivers [47], and patients' perception of the quality of care provided by their caregiver [48]; negatively, related factors include patients' relapses [49]. In addition, being able to establish a closer relationship with the patient results in an increase in this job satisfaction, and at the same times prevents burnout and reduces stress. This closeness between patient and caregiver is fundamental in the patient's recovery, as it results in more personalized care, a factor also related to the satisfaction of caregivers of people with mental illness [50,51]. Closely related to this is the concept of recovery-centered care, which, likewise, provides a more personalized and closer treatment, and would provide the same benefits for the caregiver. This term refers to a process that supports the patient's long-term recovery efforts and that includes processes of fostering relationships, conveying hope, focusing on strengths (rather than deficits), supporting the person in engaging in purposeful activities, and educating and empowering people for self-care [52].
However, the findings of Acker's study [40] are striking. The author states that aspects such as higher educational level and more work experience have a negative relationship with job satisfaction. A recent meta-analysis of more than 70 studies revealed that this association is established because people with a higher educational level, although they tend to benefit from aspects such as higher income, autonomy and role variety, also tend to suffer greater demands on their job in terms of working hours, task pressure, work intensity and time urgency [53]. These negative aspects would unbalance the benefits derived, a priori, from a higher educational level, and lead to higher job stress and lower job satisfaction. As for experience, it may be negatively correlated with job satisfaction due to the self-development of professionals related to caring fields, such as nursing [54]. Those who are new to their careers often experience this step as an opportunity for growth and development, something that would continue until six years of experience. After this point, professionals may begin to experience a sense of stagnation, leading to a period of disenchantment and reduced job satisfaction [54]. However, the opposite effect may occur, since job satisfaction may start to increase after 15 years of experience due to a reconciliation between the personal and professional development of professionals, and because those who continue to maintain a lower level of satisfaction tend to change careers [54].
Regarding the training of professionals about mental illness, comparing studies such as the Barnes and Toews study from almost 20 years ago [41], it can be seen that the picture is still similar. Several articles reveal a lack of knowledge and experience in this regard [29,55,56]. Apparently, this lack of staff training would be perceived as a key challenge in providing good quality care to patients with mental illness [55]. There are several elements that would play a key role in providing higher quality care to people with mental illness by professional caregivers [55]: increased knowledge about symptoms and diagnoses, increased communication and interactions with the patient, and a reduction in the stigma of mental illness.
Another aspect related to the main objective is the identification of the variables that act as stressors in the professional care practice of people with mental illness. Results show that with each additional year spent as a professional caregiver, emotional stress, burnout and mental health problems increase significantly. A systematic review by the team of O'Connor et al. [57] shows that mental health professionals have high levels of emotional exhaustion and moderate depersonalization. In addition, staff working in community mental health teams may be more vulnerable to burnout than those working in specialized teams [57]. On the other hand, a study conducted with a sample of 420 healthcare professionals analyzed the different dimensions of burnout in different time periods [58]. The results show a significant increase in emotional exhaustion and depersonalization over time. This shows that the demands and conditions of work environments can become stressors that can also increase the emotional exhaustion of workers chronically if they persist over time.
In addition, this emotional exhaustion can have a negative impact on patient care, as it has been shown to affect performance. In recent years, numerous mindfulness programs have been developed to alleviate this exhaustion in workers; however, the results do not show a high level of effectiveness. A systematic review [59] of thirty-four studies using this type of program also showed a low level of evidence. Only four of the interventions showed a significant improvement in burnout; however, this may be due to the fact that most of the studies had numerous methodological limitations. Other types of interventions that have been found to improve the quality of life of workers in this type of environment are those that promote open discussion, as they allow for the provision of mutual support among peers and result in decreased feelings of isolation and greater comfort in sharing social and emotional experiences [60]. These results are consistent with those found in a systematic review conducted in 2019 [61], which reveals that the most commonly used interventions in these types of professions that tend to have a positive effect on reducing burnout are those that promote communication skills, teamwork, and participatory programs. This work has some limitations. These include a possible publication bias (i.e., the tendency to publish research with significant results and not those without significant differences), which is characteristic of review-type studies. This, added to the fact that the review was performed only on peer-reviewed publications, may have contributed to a possible loss of information or another line of argument. On the other hand, there is a high degree of methodological heterogeneity among the articles included in terms of the characteristics of the study.
On the other hand, the article has several strengths. First, four different databases have been used, which has allowed greater coverage of the results. In addition, one of them is WoS, the oldest, most widely used and authoritative database of research publications and citations in the world [62], which allows greater efficiency in obtaining greater coverage of articles [63], and which has a human team that avoids total automation of the process [64]. In addition, the study tried to minimize linguistic bias or the "Tower of Babel" effect [20], by searching for articles presented in any language, to avoid including only those studies published in English. In the future, this article could be enriched by a manual search for additional articles, for example, in the references of other articles or in the gray literature. Moreover, both the search process and the data extraction process should be performed and corroborated by more than one researcher. It is also necessary to develop a protocol for recording inclusion and exclusion criteria for primary studies.

Conclusions
After integrating and analyzing the results, it can be concluded that there are multiple factors of various kinds that can influence the quality of care provided by professional caregivers to persons with mental illness. Predictors of the quality of care provided include job satisfaction, congruence between personal values and those advocated by the organization where they work, and working with a common goal in an environment that facilitates employee empowerment.
On the other hand, it has also been seen that professional caregivers face several stressors in their work environment: working in the same job for consecutive years, working in community mental health teams and burnout. These stressors are related to increased emotional stress, mental health problems, greater vulnerability to burnout and poorer performance and quality of care.
Likewise, several studies report that there is a clear lack of training and experience on the part of caregivers about mental illness and how to provide adequate care. In this regard, promoting knowledge of the symptoms and the disease, facilitating communication and interactions with the patient and reducing the stigma of mental illness among workers can play a key role.
This study identifies different variables related to professional care for people with mental illness. However, it is not focused exclusively on those centered on a pathologizing view of caregiving, but also on variables that promote the well-being of the caregiver and, as a consequence, of the person being cared for, and that can act as protective factors. In this way, the aim is to raise awareness among researchers of the importance of changing the point of view and the focus of research towards a more positive and strengths-based approach of the caregiving profession. On a practical level, it is worth stressing the importance of carrying out training programs and specific training of caregivers towards mental illness, since several studies have highlighted the lack of knowledge and stigma that still prevails among these professionals towards this condition.
Research and clinical practices related to caregivers, both formal and informal, are of vital importance in all societies today, since it is predicted that mental illness may become the leading cause of disability worldwide by 2030 [4]. However, they are also necessary because of the rise of other factors such as the aging of the population, which is expected to double in the next 30 years to 1.5 billion people by 2050 [65]. It is therefore vitally important to care for those who care, because only in this way will it be possible to provide quality care for each and every person who requires it.

Data Availability Statement:
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation. Specify the methods used to decide whether a study met the inclusion criteria of the review, including how many reviewers screened each record and each report retrieved, whether they worked independently, and if applicable, details of automation tools used in the process.

4
Data collection process 9 Specify the methods used to collect data from reports, including how many reviewers collected data from each report, whether they worked independently, any processes for obtaining or confirming data from study investigators, and if applicable, details of automation tools used in the process. List and define all outcomes for which data were sought. Specify whether all results that were compatible with each outcome domain in each study were sought (e.g., for all measures, time points, analyses), and if not, the methods used to decide which results to collect.

10b
List and define all other variables for which data were sought (e.g., participant and intervention characteristics, funding sources). Describe any assumptions made about any missing or unclear information.

4
Study risk of bias assessment 11 Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and if applicable, details of automation tools used in the process.

3-4
Effect measures 12 Specify for each outcome the effect measure(s) (e.g., risk ratio, mean difference) used in the synthesis or presentation of results. NA

Synthesis methods 13a
Describe the processes used to decide which studies were eligible for each synthesis (e.g., tabulating the study intervention characteristics and comparing against the planned groups for each synthesis (item #5)).

13b
Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics, or data conversions. 4 13c Describe any methods used to tabulate or visually display results of individual studies and syntheses. 4 13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If meta-analysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used.

NA 13e
Describe any methods used to explore possible causes of heterogeneity among study results (e.g., subgroup analysis, meta-regression). NA 13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results. NA

Reporting bias assessment 14
Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases). -

Certainty assessment 15
Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome. -

Study selection 16a
Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram.

16b
Cite studies that might appear to meet the inclusion criteria, but which were excluded, and explain why they were excluded. 5 Study characteristics 17 Cite each included study and present its characteristics. 6-14 Risk of bias in studies 18 Present assessments of risk of bias for each included study. -

Results of individual studies 19
For all outcomes, present, for each study: (a) summary statistics for each group (where appropriate), and (b) an effect estimate and its precision (e.g., confidence/credible interval), ideally using structured tables or plots.

Results of syntheses 20a
For each synthesis, briefly summarize the characteristics and risk of bias among contributing studies. 6-13 20b Present results of all statistical syntheses conducted. If meta-analysis was done, present for each the summary estimate and its precision (e.g., confidence/credible interval) and measures of statistical heterogeneity. If comparing groups, describe the direction of the effect.

Discussion 23a
Provide a general interpretation of the results in the context of other evidence. 15-17 23b Discuss any limitations of the evidence included in the review. 16 23c Discuss any limitations of the review processes used. 17 23d Discuss implications of the results for practice, policy, and future research. 17

Other Information
Registration and protocol 24a Provide registration information for the review, including register name and registration number, or state that the review was not registered. 3 24b Indicate where the review protocol can be accessed, or state that a protocol was not prepared. Report which of the following are publicly available and where they can be found: template data collection forms; data extracted from included studies; data used for all analyses; analytic code; any other materials used in the review.