Preplanned Studies: Prevalence and Associated Factors of Suicidal Behaviors Among Community-Dwelling Individuals with Serious Mental Disorders — Shandong Province, China, 2022

Suicide constitutes a significant global public health issue, as it accounts for one out of every hundred deaths (1). Although the suicide rate has experienced a decline in China, this decrease has gradually slowed, with certain sub-populations even witnessing a reverse trend and an increase in rates (2). Consequently, suicide remains an area of public health concern. Gaining a comprehensive understanding of the factors correlating with suicidal behaviors among high-risk populations is essential for addressing this issue effectively.

Serious mental disorders (SMD) represent significant public health concerns globally. Official reports indicate that approximately 4.7% of individuals in China experience SMD (3). Individuals with mental disorders exhibit a higher risk for suicidal behaviors compared to the general population. A meta-analysis revealed that the pooled suicide rate among SMD patients was 312.8 per 100,000 (4).

An increasing number of studies have examined the primary causes of suicidal behaviors among psychiatric inpatients; however, limited information is available regarding the prevalence and associated factors of suicidal behaviors among community SMD patients. These community patients are often more exposed to negative reactions and perceptions from their external environment (5). Consequently, there may be a disparity in suicidal behaviors between community patients and inpatients. To effectively prevent suicidal behaviors among community SMD patients in China, public health policymakers need to consider both prevalence and associated factors.

The cross-sectional study was conducted from August 2022 to September 2022 in Shandong Province, China. A randomized multistage stratified cluster sampling technique was employed for the study. Initially, the gross domestic product (GDP) of 16 administrative districts in Shandong Province was utilized to classify high and low economic zones within the province, resulting in the random selection of one city from each category (Jinan and Zaozhuang). Subsequently, one county from each city (Zhangqiu and Taierzhuang) was randomly selected. Following this step, six towns and streets were chosen at random from each county. Registered community SMD patients in the 12 towns and streets were then considered for the study. Ultimately, a total of 486 registered community SMD patients participated in the study.

All interviewers underwent training in communication techniques and received detailed information on the research and questionnaire materials prior to the study. Participants voluntarily provided written, fully informed consent. Patients capable of communicating were interviewed individually (n=37), while those unable to communicate were interviewed through their primary caregivers (n=449) using a proxy-informant-based approach. The differences in patients' characteristics answered between patients themselves and caregivers are shown in the Supplementary Table S1. Legal guardians were asked to provide informed consent on behalf of patients who were illiterate, below 18 years of age, or unable to communicate. Questionnaires were administered via face-to-face interviews between the interviewers and respondents, with interviewers completing the questionnaires based on the information received from the interviewees. Following the study, at least two trained postgraduate students checked the content and quality of the questionnaires; those with missing or unclear information were revisited and updated accordingly.

Suicidal ideation, suicide plans, and suicide attempts were assessed using three questions “During your lifetime, have you seriously considered committing suicide or taking your own life?”, “During your lifetime, have you ever made a plan to commit suicide or take your own life” and “During your lifetime, have you ever attempted to commit suicide or tried taking your own life?”. Response options included “no” and “yes”. Participants who responded “yes” to the first question were subsequently asked the latter two questions, whereas those who responded “no” were not asked further.

Religious beliefs in the study comprised none, Buddhism, Christianity, Catholicism, and others, with “none” coded as 0 and all other responses coded as 1. The Brief Psychiatric Rating Scale (BPRS), which assesses the severity of psychiatric symptoms, was administered by locally trained psychiatric professionals.

Statistical analyses were conducted using IBM SPSS Statistics (web version 24.0; New York, USA). Descriptive statistics were employed to examine means and standard deviations for continuous variables with normal distributions, as well as numbers and percentages for categorical variables. Additionally, the frequency and percentages of suicidal behaviors were described based on gender and age group. Analysis of variance (ANOVA) and chi-square tests were utilized to compare suicidal behaviors concerning socio-demographic variables, illness information, and unhealthy behaviors. Multivariable logistic regressions were applied to examine variables related to suicidal ideation, suicide plans, and suicide attempts. All tests were two-sided, with P<0.05 indicating statistical significance.

In the study, 210 (43.2%) male and 276 (56.8%) female participants were included, with 25.9% of patients being older than 65 years. The majority of patients were of Han ethnicity, married, had no religious affiliation, resided in rural areas, had children, and were not only child. A small percentage of patients engaged in alcohol use (8.4%) and cigarette smoking (14.2%). Furthermore, 37.0% of patients lived in impoverished families, and 27.8% were in debt. In total, 44.7% of the patients with SMD had other chronic diseases. Each patient lived with an average of 2.84 individuals, including themselves, and the mean BPRS score was 55.47 [standard deviation (SD)=21.19]. The majority of patients were diagnosed with schizophrenia (63.6%), followed by epileptic mental disorder (14.2%) and bipolar disorder (12.1%). Descriptive and single analyses of suicidal behaviors are presented in Table 1.

Furthermore, 63.2% of patients exhibited no suicidal behavior. There were significant differences in the prevalence of any suicidal behavior between males and females (χ²=4.639, P<0.05). Among the ideators, 18.1% had a plan, while 3.7% did not have a plan. In the case of attempters, 0.8% had a plan and 14.2% did not have a plan.

Figure 1 illustrates the percentages of suicidal behaviors across various age groups. Among these groups, patients aged 65–69 exhibited the highest percentage of suicidal ideation (47.3%), while those aged 55–59 demonstrated the highest percentages of both suicide planning and suicide attempts (31.0% and 29.3%, respectively). The percentages of suicidal ideation in younger patients showed a significant increase (P<0.01), whereas the percentages of suicide planning and attempts in the 55–59 age group significantly increased (P<0.05) and those in the 60–64 age group significantly declined (P<0.05).

Figure 1. 

Percentages of suicidal ideation, suicide plan, and suicide attempts across various age groups.

The logistic regression results for suicidal behaviors are presented in Table 2. Depressive symptoms were found to be significantly associated with suicidal behaviors [odds ratio (OR)=1.13, 95% confidence interval (CI): 1.09–1.18; OR=1.10, 95% CI: 1.05–1.15; OR=1.10, 95% CI: 1.05–1.15]. After adjusting for depressive symptoms, both religious belief and the number of persons living together including patients (NPLT) emerged as significant factors associated with suicidal ideation. Patients without a religious belief (OR=0.46, 95% CI: 0.26–0.81) and more NPLT (OR=0.80, 95% CI: 0.66–0.98) demonstrated a lower likelihood of experiencing suicidal ideation. Additionally, NPLT was significantly linked to suicide plans, with patients living with more individuals being less likely to consider such plans (OR=0.77, 95% CI: 0.60–0.98).

Higher BPRS scores were associated with an increased likelihood of suicidal behaviors (OR=1.02, 95% CI: 1.01–1.03; OR=1.03, 95% CI: 1.01–1.04; OR=1.03, 95% CI: 1.01–1.04). Compared to patients with other SMD, those diagnosed with schizophrenia (OR=3.33, 95% CI: 1.19–9.31) and bipolar disorder (OR=6.83, 95% CI: 2.08–22.44) exhibited a higher propensity for suicidal ideation. Furthermore, bipolar disorder patients were more likely to have a suicide plan (OR=7.70, 95% CI: 1.80–32.91).