Here, we present a systematic and comprehensive overview of the literature until September 2023 addressing DPW in ED settings in the geriatric and non-geriatric population. We searched five databases and two reviewers screened abstracts and full-text manuscripts following predefined inclusion and exclusion criteria. A risk of bias assessment was performed for all included studies. A descriptive analysis of all studies was conducted.
In the general population of patients presenting to the ED, one in five to one in four patients reported having a DPW, but the actual availability in the ED was much lower by comparison with no more than 7%. In geriatric populations, both existence and availability rates were highly variable: Existence rates were as high as 70%, whereas availability rates were below 50% in all studies. In addition to already known predictors, such as age and health status, further variables influencing rates of DPW were identified, such as social structure, institutional factors in nursing homes, patient education in primary care and previous hospital admissions in the last 12 months including intensive care treatment.
Existence, availability and predictors
The first available data on DPW in the general ED population were published more than 25 years ago, with reported rates of 22–27% [
20,
21] Despite increased efforts for education in recent years [
32], more recent studies from 2012 to 2021 did not show a clear upward trend in rates of DPW existence, which ranged from 20 to 28% [
27,
28,
36]. A possible increasing effect of the COVID-19 pandemic was shown in other contexts [
40], however all studies included in this review only presented data from pre-pandemic times.
The high variability of existence and availability rates in the geriatric population could be explained by heterogeneity of in- and exclusion criteria in different studies (e.g., geriatric defined in several studies by age ≥ 60, ≥65, ≥ 70 or ≥ 75 years [
11,
20,
24,
26,
29,
31‐
33], in others by being NH residents [
4,
23,
25,
30,
34,
35,
39]) as well as institutional circumstances (e.g., in one Australian study the nursing home was particularly well integrated with the hospital [
35]). One study showed that this variance is not only inter-individual but also inter-institutional: availability rates were 0% in some nursing homes, 94% in others [
5].
Of note, availability rates of DPW in the emergency department were distinctly lower than possession rates in all respective studies; affecting both geriatric and comparatively younger populations alike. Some studies found no more than 5% of existing DPW were actually available on presentation to emergency clinicians [
26,
27,
31,
36].
Studies which reported comparably high existence and availability rate, originated mainly from the United States and Australia [
23,
32,
35,
39]. This may partly be attributed to several initiatives aimed at increasing the number of DPW in nursing homes in Australia since 2007 [
29] or such as the
Choosing Wisely campaign in the US [
15].
Among the predictors identified, some were related to socioeconomic factors, such as education. Similar findings have previously been reported regarding the general availability and completion of advance care directives in the community [
41]. It can be hypothesized that the socioeconomic background influences the likelihood of DPW existence, which might be due to an influence of levels of awareness of palliative care and advance directives by race, ethnicity and socioeconomic variables e.g. in different Californian populations [
42].
Remarkably, fewer studies than expected identified having a general practitioner (GP) as a positive predictor. One study even found it to be a negative predictor [
20]. Conversely, having a specialist physician was consistently found to be a positive predictor, which might be confounded by higher morbidity (already identified as a positive predictor) when being in the need of a specialist physician.
We hypothesize that the general possibility of documenting patient wishes and the available options to do so is not known well enough in both patients and medical staff. Moreover, especially younger and healthier people may be reluctant to address preemptive decisions concerning significant sickness or their own death. Furthermore, patients already possessing DPW often don’t bring them to the ED. This may be corroborated by Emergency Medical Services (EMS) not asking or checking for DPW very often before transporting patients to the ED, as indicated by Harrison and Vranas [
33,
37].
According to this data, evaluating goals of care through DPW currently is rarely feasible in an ED setting, although essential. In the ED, a potential approach to increase both availability and patients’ awareness of DPWs would be the implementation of mandatory inquiry and documentation as part of standard operating procedure. In an outpatient setting, increased numbers of qualified low-threshold ACP advice services might reduce barriers for patients willing to document their preferences. Moreover, a visit to the ED, treatment in hospital or ICU seems to increase the willingness and demand to document one’s wishes, additionally confirmed by the increase of DPW possession rate after a 60-day-period simply due to the contact with this topic shown in one study [
36], which offers a possibility to ED medical staff to at least give an impulse and start the conversation. Finally, more research also including qualitative studies is needed to establish further causes for patients choosing not to have a DPW.
Limitations
One limitation is the strong heterogeneity of the included studies regarding time period, country, sample size, population, documentation, endpoints and concepts of DPW, which limits comparability. This is further complicated by regional differences in the definition of DPW (e.g., one study classified AD separately from DNR [
5]), even though these were accounted for in this analysis.
The use of “general population” and “geriatric population” as categories is not entirely consistent between studies. Therefore, some overlap between the two groups is present.
We acknowledge that visual depiction of descriptive analysis to facilitate comparison between studies has limitations, however due to the heterogeneity of the studies, the data set was not amenable to meta-analysis or meta-regression.
To the best of our knowledge the only other systematic review on this topic [
43] analyzed six studies from the US [
4,
20‐
22,
27,
31], all of which were also included in our review. The authors describe comparable results of patient-reported AD possession rates for the general population ranging between 20% and 27%. However, the results of one study [
20] were likely misreported by this review as “53%” instead of “22% (n = 53)” in the original publication, probably due to an error in data entry. Results and conclusions for the older cohorts might be affected by this.