Although stroke patients with suicidal ideation do not all eventually commit suicide, it is understandable that the continued suicidal idea can increase the risk of commit suicide in patients suffered from the sequelae of stroke. Consistent with previous studies, our meta-analysis demonstrated a high rate of suicidal ideation, accounting for approximately 12% subjects with stroke worldwide. Similar to previous studies, our results demonstrated the occurrence and development of PSS were influenced by multiple risk factors, including men, smoking, depression, sleep disorders, previous stroke and low household income. Although previous studies have suggested that female gender can confer increased risk for commit suicide, this study revealed that male stroke survivors were more likely to commit suicide. This may be related to a variety of factors such as the age structure of a population and the different study regions, and to a certain extent, we remain skeptical about the role of gender in PSS. Indeed, this trend was consistent with the published studies showing that the incidence rates of suicide were higher in men than in women, regardless of stroke status.25
Smoking, alcohol consumption, low family income, depression, heart disease and sleep disorders were the important risk factors for the pathogenesis of suicide after stroke. According to the results of our meta-analysis, stroke-related clinical factors, such as male, smoking, depression, sleep disturbance, recurrent stroke, appear to play a critical role in the increased rates of PSS. Recurrent stroke, depression and sleep disturbance raised the PSS rates approximately twice, while older age, men, smoking and depression were closely related to PSS for more than 1 year. The main risk factors for PSS were previous stroke and depression26, but only the predictive value of depression was confirmed.12 Depression after stroke, together with suicidal ideation, could worsen stroke outcomes and life expectancy, by affecting treatment adherence.27–28The results of this meta-analysis showed that depression was significantly associated with suicidal ideation, regardless of stroke duration. Therefore, prevention and early intervention of depression after stroke should be an essential part of stroke rehabilitation, in order to reduce the risk of PSS-related behaviors, even though the biological mechanisms underlying PSS remain largely unclarified.19,29
Contradictory results have been reported on the location and laterality of PSS30–31, but we did not observe a clear trend on this point as well. Both socioeconomic and clinical factors have been shown to increase the risk for suicide.8,32From the clinical points of view, it can be speculated that Asian populations are more embarrassed towards stroke disability and patients who receive less support from their families tend to be more skeptical of continuing to live. Epidemiological evidence has indicated that the incidence of PSS is higher in Asian populations, accounting for approximately 15%. In this study, we sought to explore the difference in risk factors between PSS in Asia and other regions. Regardless of the whole study populations or Asian subgroup, our findings showed that low household income nearly doubled the incidence of PSS. This suggests that stroke survivors with low socioeconomic status may be more susceptible to commit suicide.33Considering that delayed suicidal plans were associated with poor social support12, the improvement of medical care and insurance investment for low-income groups can potentially help to prevent suicidal ideation, especially in Asian populations.
A considerable proportion of stroke survivors attempted to commit suicide within one year34–35, and the risk decreased sharply after 5 years.7 Other studies also found that the risk of suicide was particularly high in Europe within the first two years after stroke20,36.Similar results were revealed in the present study. In fact, compared to PSS more than one year, the incidence of suicide within one year after stroke was more likely to be statistically significant. Thus, more efforts should be focused on this point, which can effectively help to prevent PSS.
In addition, among the tested sociodemographic characteristics, being employed was identified as a protective factor for PSS, which corresponded to our findings that low household income is a risk factor for PSS. Our findings revealed that 4 out of every 1,000 stroke survivors committed suicide, which was the most innovative aspect of this study. Given that a previous suicide attempt is a strong predictor for future suicide attempt37, targeted treatment with the above-mentioned risk factors can help to improve the overall prognosis of stroke. For instance, stroke survivors who smoke and jobless as well as those with low household income, depression, sleep disorders and recurrent stroke, should be specifically targeted for suicide prevention.
Nevertheless, this meta-analysis has some limitations, thus, the results should be interpreted with caution. Firstly, we found moderate to high heterogeneity across some studies for assessing the rate and risk factors of PSS. Consistent with other studies, such phenomenon might be attributed to some methodological differences with regard to inclusion criteria, stroke severity, assessment time points, study regions and screening measures for suicidal ideation.
Secondly, data on the assessment of suicidal ideation were overlapped, leading to a high study heterogeneity. In particular, only few studies have examined PSS with the purposively developed measure, such as the Beck Scale for Suicidal Ideation (BSI). The majority of studies acquired the information of suicidal ideation from the scales for exploring depression. Moreover, only a limited number of included studies reported on the detailed data of risk factors, such as alcohol consumption, smoking, diabetes severity, hypertension grades and heart disease types, which in turn limits the actual confidence of estimates for some variables.
Thirdly, numerous studies excluded stroke patients with communication or cognitive impairment, and no conclusion can be drawn from these studies. Although the limitation regarding cognition or communication impairment is common in many studies, it is necessary to pay some attention on patients with less-severe illness in the study populations.
Finally, although comprehensive literature search and contacting corresponding authors for additional data could help us to minimize the possibility of bias, as consistent with other studies, it is impossible to fully exclude the potential bias. Besides, we are focusing on Asian patients who committed suicide after stroke. Therefore, it is essential to retrieve Chinese academic articles; but unfortunately, there is a lack of articles written in Chinese about the risk factors of PSS. We also hope to encourage Chinese doctors to explore this aspect through our meta-analysis.