This study is the first focusing primarily on PES presentations BIBP during the COVID-19 pandemic. The current study is also the first showing an absolute increase in PES presentations BIBP during the second wave compared to a control period one year earlier. We have shown the same for the first wave (based on a part of the current study’s sample (9)). However, in the current study, the COVID-19-period itself was not a predictor for PES presentations BIBP, neither during the first, nor during the second wave compared to their control periods (Table 3). Hence, the absolute increases in presentations BIBP that were measured during the first and second wave in comparison to their control periods (Tables 1 and 2) cannot directly be attributed to the COVID-19 pandemic but are likely due to coincidental differences in sociodemographic and clinical characteristics.
One study from Taiwan on PES presentations during the COVID-19 pandemic did show an increase in police/emergency medical service presentations in 2021 but not in 2020, compared to pre-pandemic times (21). Unfortunately, police and emergency medical service referrals were not reported separately. Studies from Switzerland, Turkey and Australia cover only the first wave of the COVID-19 pandemic and report, in comparison to the current study, considerably lower rates of presentations BIBP and only minor changes to pre-pandemic times (22, 23, 27). The current study’s rates are more in line with pre-pandemic studies (3–7). One may assume that rates of presentations BIBP may differ between PES in more urban areas and those in more rural areas (although there is no scientific evidence for this assumption). When comparing the mentioned and the current study, however, all studies concern metropolitan areas. In summary, the differences in rates of presentations BIBP in PES in between different sites and countries are rather important. These differences may be due to country-bound differences such as different mental health care policies and police responsibilities on the one hand (8) and due to local-bound differences such as sociodemographic differences and differences in clinical characteristics on the other hand (5, 9). More research is necessary to better understand the factors of influence of presentations BIBP to PES.
In the logistic regression analysis, the only COVID-19-associated effects were seen during the first wave. No COVID-19-associated effects were seen during the second wave. A reason for this might be that outpatient facilities were less available, especially in the beginning of the pandemic (28–32). During the first wave, COVID-19-period showed a negative interaction effect on inpatient admission of patients BIBP, meaning that patients BIBP were less often admitted to the hospital during the COVID-19-period and more often during the control period. At the same time, inpatient admission was a time-independent predictor for presentations BIBP, emphasizing the need for inpatient care of this group of patients. In a prior publication on a part of this dataset it could be shown that the admission capacity in our district hospital was significantly reduced during the first wave due to the implementation of infection-limiting measures (9). As there was an absolute increase in presentations BIBP during the first wave and coincidentally less beds for admission were available, one can imagine that the threshold to admit patients BIBP consequently increased. Involuntary admissions were not affected, which is in line with Feeney et al. who found in pre-pandemic times that the bed capacity was a predictor for involuntary referrals: in Dublin areas where reduced inpatient treatment options were available, individuals BIBP were prioritized (33).
Our data does not comprise a standardized marker of disease severity. However, indirect markers such as aggression, suicidality and diagnostic groups did not differ between the COVID-19-periods and the control periods. The only exception was the group of schizophrenia and psychotic disorders, where we saw a positive interaction effect during the first wave, meaning that patients BIBP were more likely diagnosed with schizophrenia and psychotic disorders during the first wave than during its control period. Patients with chronic psychotic disorders and high need of psychosocial facilities might have suffered particularly from the limited accessibility of many psychosocial (28) and psychotherapeutic (34) facilities, especially during the first wave. What is more, people with a diagnosis of schizophrenia and psychotic disorders may had trouble to adjust to social distancing measures and may have suffered more than others under these measures. This view is supported by the fact that many studies show an increase in PES presentations of patients with psychotic disorders during the pandemic (16, 35–39).
Independently of COVID-19, the following factors predicted presentations BIBP: male gender, lower age, involuntary admission (inpatient treatment), aggressive behavior towards others, suicide attempts prior to the presentation and substance use disorders. Patients with depressive disorders were less likely to be BIBP to the PES. Male gender as predictor for presentations BIBP is a common finding in the literature (3–7). In the rather underpowered American studies (ca. 100 patients BIBP per study), age was not shown to be a predictor of presentations BIBP (3, 4, 6). In more large-scale studies, such as Wang et al. from Taiwan (> 3000 patients BIBP), however, the group of patients between 30 and 39 years old were the most at risk of being BIBP (5). This is in line with our findings. Involuntary admissions and aggressive behavior towards others have also been shown several times to be associated with presentations BIBP (3–6). The higher risk of being BIBP to PES in patients with substance use disorder and the positive association of patients BIBP to a PES with suicide attempts prior to the presentation, are findings that were earlier reported in Taiwan but not yet in Western countries (5). As depressive patients do rather often present with suicidal thoughts and after suicide attempts, the coincidental negative association with depressive disorders in patients BIBP might seem in the first place contradictory. However, these findings are in line with results of a meta-analysis conducted by Walker et al. in 2021, in which they found that young patients with a primary diagnosis of affective disorders were significantly less at risk of involuntary admission when compared to patients perceived to be at risk of self-harm (including suicidal ideation or suicide attempts) (OR 2.05, p = .015) (40). The same meta-analysis shows that young patients with substance use disorder were more likely to be hospitalized involuntarily (OR 1.87, p = .032) as well as patients who showed behavior of harm to others (e.g. aggression, violent acts) (OR 2.37, p = .002), which is also in line with the current study’s findings.
Strengths and Limitations
This study is the first focusing primarily on PES presentations BIBP during the COVID-19 pandemic. The current study covers a relatively long observation period with a comparably large number of assessed PES presentations. Indicators of mental health were based on clinical diagnoses rather than self-reports. In addition, we performed a detailed clinician-led review of each case, based on thorough clinical documentation.
The following limitations need to be considered: the control data is limited to the previous year only. The study is based on clinical routine data which can differ in quality and extent which may introduce bias. We cannot completely rule out the possibility of an interrater bias. However, to limit this bias we implemented the following measures: consulting all available data and scheduling regular meetings to discuss pressing questions, resolving them in consensus.
A further limitation is that we only gathered information about patients BIBP in a single-center psychiatric emergency department. Extrapolation of results should therefore be done with caution.