The Prevalence of Depression Among Nurses in Iran : A Systematic Review and Meta-Analysis

Mental disorders are a primary cause of the total burden of disability and morbidity worldwide. One common mental disorder is depression, which is estimated to affect 15% of adults.1 According to the World Health Organization (WHO), depression will become the first cause of disability-adjusted life years by 2030.2 It is also expected that more than 350 million people will suffer from depression.2 The Center for Disease Control and Prevention (CDC) reported that for the period 2009-2012, 7.6% of Americans aged 12 and over had depression.3 Depression is defined as a disorder affecting the whole body and afflicting the person with mental, physical, social, and spiritual problems.4 Depression symptoms include low mood, feelings of worthlessness, suicidal thoughts and actions, and changes in the body’s natural patterns (e.g., insomnia and malnutrition).5 Depression also negatively affects interpersonal relationships, the ability to make decisions and judge correctly, and the quality of life.6,7 Nurses, as key members of the treatment team, experience a high level of stress daily due to the nature of their profession.8,9 Studies have shown a significant relationship between stress and depression symptoms in nurses. Nursing is a stressful profession that can cause depression.2 Nurses are twice as likely to suffer from depression for their professional life.2 Some major factors which cause depression in nurses are long work shifts, fatigue, and great stress.10 Studies have also indicated that depression makes nurses vulnerable in relationships and causes job dissatisfaction, job burnout, and early retirement.11,12 A nurse’s mental health is a crucial factor to consider in human resources retention programs. Nurses are the largest group of employees in a healthcare system, and they are exposed to a considerable level of occupational stress.10 The Prevalence of Depression Among Nurses in Iran: A Systematic Review and Meta-Analysis


Introduction
Mental disorders are a primary cause of the total burden of disability and morbidity worldwide.One common mental disorder is depression, which is estimated to affect 15% of adults. 1 According to the World Health Organization (WHO), depression will become the first cause of disability-adjusted life years by 2030. 2 It is also expected that more than 350 million people will suffer from depression. 2 The Center for Disease Control and Prevention (CDC) reported that for the period 2009-2012, 7.6% of Americans aged 12 and over had depression. 3epression is defined as a disorder affecting the whole body and afflicting the person with mental, physical, social, and spiritual problems. 4Depression symptoms include low mood, feelings of worthlessness, suicidal thoughts and actions, and changes in the body's natural patterns (e.g., insomnia and malnutrition). 5Depression also negatively affects interpersonal relationships, the ability to make decisions and judge correctly, and the quality of life. 6,7urses, as key members of the treatment team, experience a high level of stress daily due to the nature of their profession. 8,9tudies have shown a significant relationship between stress and depression symptoms in nurses.Nursing is a stressful profession that can cause depression. 2 Nurses are twice as likely to suffer from depression for their professional life. 2 Some major factors which cause depression in nurses are long work shifts, fatigue, and great stress. 10Studies have also indicated that depression makes nurses vulnerable in relationships and causes job dissatisfaction, job burnout, and early retirement. 11,12A nurse's mental health is a crucial factor to consider in human resources retention programs.Nurses are the largest group of employees in a healthcare system, and they are exposed to a considerable level of occupational stress. 10orkplace conditions, type of relationships, and organizational culture affect the mental health of all personnel. 13Nurses experience not only occupational stress, but also increasing pressure due to the necessity of providing care services in critical situations.They are thus prone to both stress and depression in their highly stressful workplaces. 14,15he fact that nurses are regarded as a crucial factor in systems of healthcare and health promotion requires the development of programs to improve their mental health based on the reported statistical data on the prevalence of depression among nurses.Due to the importance of the nurses' mental health and its impact on the quality of care services, the present study aimed to evaluate the prevalence of depression among Iranian nurses through a systematic review and meta-analysis.

Methods
This systematic review and meta-analysis analyzed all the related Persian and English articles published by both foreign and domestic journals during 1997-2017, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Figure 1) in order to evaluate the prevalence of depression among Iranian nurses.

Search Strategy and Eligibility Criteria
The main question of the researcher in this systematic review and meta-analysis was, "What is the prevalence of depression among Iranian nurses?"To answer this question, all related published articles on depression among Iranian nurses were searched using the keywords "Depression", "Nurses", and "Iran" both separately and in combination in local (SID, IranMedex, and MagIran) and international databases (Google Scholar, CINAHL, PubMed, and Science Direct).
The study's inclusion criteria for articles were access to the article's full text, Persian or English language articles, and articles reporting on the prevalence of depression among nurses.Accordingly, those articles lacking the full text or reporting merely on depression mean scores were excluded.

Data Collection and Extraction
After data collection and summarization were completed, the recorded data included year of publication, location, sampling method, depression measurement tool, sample size, and prevalence of depression.In the first step, a total of 643 articles were collected by searching the mentioned local and international databases.In the next step, the number of articles fell to 127 after duplicate and overlapping articles were excluded according to their title and abstract.Then, 113 articles were also excluded according to the criteria and the complete review.Finally, 14 articles (12 Persian and 2 English) were included in the final analysis (Table 1).

Data Analysis
The statistical software STATA version 11 was employed for analyzing the extracted data.The I²-heterogeneity test and the Random Effect Model were also used to measure the heterogeneity of the data.

Ethical Considerations
This study was approved by the Ethics Committee of Fasa University of Medical Sciences (IR.FUMS.REC.1397.137).It should also be noted all related ethical aspects, including intellectual property rights and accurate referencing, were considered in this study in accordance with the criteria of the Ethics Committee.

Results
The present study analyzed 14 articles published by Persian and English language journals and covered a total of 4062 nurses working in public, private, and military hospitals.In   Khalilzadeh et al 15 reported a 35% prevalence among nurses in Urmia using BDI.The highest prevalence rate of depression (62.5%) was reported by Yasemi et al 16 in their study which covered 60 nurses in Ilam based on BDI.Khamseh et al 8 reported a 25.8% prevalence among 413 nurses in Tehran using DASS-21.Khani et al 17 also reported a 26% prevalence among 196 nurses in Neyshabur using BDI.A prevalence of depression of 32% was reported among 142 nurses in Fasa using DASS-21. 18A study on 191 nurses in Ilam using BDI showed a 34% prevalence of depression. 7Khajeh Nasiri found a 26.9% prevalence in 130 nurses in Tehran using BDI. 19ahmoudi et al 20 concluded that 21.5% of nurses in Sanandaj were depressed through a survey of 314 nurses using BDI.Dehghani et al 21 indicated a 16.4% prevalence of depression among 311 nurses using the Zung Self-Rating Depression Scale (SDS).Ardekani et al 22 reported the lowest prevalence of depression (11.2%) in nurses in Shiraz through a survey of 1,195 nurses using DASS-21, while Kavari had previously reported a 26.9% prevalence among 130 nurses in Shiraz. 23he prevalence of depression among Iranian nurses with a sample size of 4062 was estimated to be at 26.68% (95% CI: 21.45-31.91)using the random effect model (Figure 2).To use this model, the main assumption was that the existing differences in the findings of different studies can be attributed to different sample sizes and prevalence rates.Heterogeneity was calculated to be 93.7%.Further analysis was carried out based on type of hospitals that were the workplaces of nurses.Subgroup analysis showed that the estimated prevalence rates of depression among military nurses and pubic nurses were 22.38% (95% CI: 19.45%, 25.30%) (Figure 3) and 28.12% (95% CI: 21.46%, 34.78%) (Figure 4), respectively.

Discussion
][7] The general prevalence of depression among Iranian nurses was estimated to be 26.68%(CI: 21.45-31.91).The present systematic review and meta-analysis discovered a relatively high prevalence of depression among Iranian nurses, which had been previously reported to range 11.2%-62.5%.This finding is fairly consistent with the prevalence of depression among the general population in Iran.Montazeri et al 24 concluded that the prevalence of depression varies from 5.69% to 73% in Iran, depending on the study population.According to the WHO, the global prevalence of depression in nurses is estimated to range 15%-30%. 14The findings regarding the prevalence of depression among military nurses is consistent with the WHO's estimate, whereas the reported rate was above 30% among public nurses. 7,13,16,18The difference may be attributed to several factors such as personality traits and workplace conditions in addition to social factors.
The remarkable finding in this analysis is the lower estimated prevalence of depression among military nurses as compared with public nurses.This difference may possibly be attributed to the choice of sampling method.With the highest reported rate, Yasemi et al 16 considered a sample size of 60 and  employed the non-random sampling method.Their reported prevalence is somewhat closer to the average rates in those studies using the random sampling method with a larger sample size.Nonetheless, this difference requires further research and additional comparative studies on both military and public nurses.
According to the reviewed studies, females accounted for more than 50% of the studies' populations. 11,12,14,18The literature expectedly represented a higher prevalence of depression among females, since nurses are mostly female.Accordingly, female nurses are twice as likely to suffer from depression in the United States. 2 The growing prevalence of depression in nurses, especially female ones, is attributed to factors like considerable workplace and home stressors for females. 25The researchers highlighted the role of other factors in the incidence of depression among nurses and argued that those who enjoy stronger social and familial support when facing problems and challenges are less likely to experience depression. 2 Education was also reported as a major contributory factor to depression.Asadzandi et al 14 demonstrated a relationship between education level and depression.
7][28] The focus on organizational factors in the incidence and improvement of depression among nurses plays a key role in reducing the prevalence of depression. 29Those nurses who do not feel they are effective in their workplace and those whose work requires no diversity or creativity are more prone to depression. 28Letvak et al 28 showed that workplace is a strong predictor of the incidence of depression in nurses and also suggested that improved working conditions could promote mental health and reduce depression.
Given the relatively high prevalence of depression among nurses and the importance of their mental health, it is necessary to identify those nurses prone to depression and thus minimize the prevalence of this disorder through the development of special programs and effectively protective interventions with the ultimate aim of improving the quality of care services delivered to patients.Depression screening for nurses should start from studying in nursing, so that susceptible individuals can be identified and the progress of the disease can be prevented. 30Furthermore, the presence of mental health counselors in the nursing workplace plays a vital role in the prevention of depression. 28he study results recommend adopting a combined approach that includes both clinical tests and depression measurement tools in future research.In addition, it is imperative for health policy-makers to devise and adopt those strategies required for early diagnosis, treatment, and followup of depression among nurses.

Conclusions
According to the present systematic review and metaanalysis, the prevalence of depression among Iranian nurses is estimated to be 26.68%.This considerable rate requires conducting supportive interventions for the prevention and early diagnosis of depression.It also necessitates providing a healthy and hygienic workplace for nurses where they feel safe and comfortable in order to improve the quality of care services.

Figure 1 .
Figure 1.Diagram of the Study Protocol.
terms of geographical distribution, most of the studies (n = 5) had focused on nurses in Tehran (

Figure 2 .
Figure 2. Prevalence of Depression Among Iranian Nurses Based on the Reviewed Studies.Horizontal lines around the main mean show a confidence interval of 95% for each study.The dotted line in the middle indicates the estimated total prevalence, and the lozenge shows the confidence interval of the total prevalence of depression.

Figure 3 .
Figure 3. Prevalence of Depression Among Military Nurses Based on the Reviewed Studies.Horizontal lines around the main mean show a confidence interval of 95% for each study.The dotted line in the middle indicates the estimated total prevalence, and the lozenge shows the confidence interval of the total prevalence of depression.

Figure 4 .
Figure 4. Prevalence of Depression Among Public Nurses Based on the Reviewed Studies.Horizontal lines around the main mean show a confidence interval of 95% for each study.The dotted line in the middle indicates the estimated total prevalence, and the lozenge shows the confidence interval of the total prevalence of depression.

Table 1 )
with the age range of 30-40 years.Prevalence rates of 11.2-62.5% for depression among Iranian nurses were reported in 14 articles.Taghva et al 12 included the participation of 173 military nurses in a survey based on the Beck Depression Inventory (BDI) in Tehran and reported a 20.2% prevalence of depression.Kazemi et al 13 reported a 21.7% prevalence of depression among 335 military nurses in Tehran using BDI.Asad-zandi et al 14 also reported a 24.9% prevalence among 272 military nurses in Tehran based on the Depression, Anxiety and Stress Scale (DASS-21).

Table 1 .
Summarized Findings of Studies Included in the Final Analysis