We showed that patients with nonmalignant pulmonary disease had longer survival in the palliative care phase than patients with lung cancer, and their specialist palliative care consultations occurred mostly during acute hospitalization. Patients with lung cancer visited the palliative care outpatient clinic more often, and the palliative care pathway had more effect on the use of acute hospital resources compared to patients with nonmalignant pulmonary disease.

The longer survival in the palliative care phase in patients with nonmalignant pulmonary disease compared to those with cancer challenges the planning for EOL care. In patients with nonmalignant pulmonary disease, the disease trajectories vary and are difficult to predict, and advanced disease is usually characterized by several acute exacerbations before final EOL care is needed [8, 15]. This may be a barrier for both patients and physicians in engaging in advance care planning and palliative care [16,17,18,19,20]. Furthermore, there is a risk that patients repeatedly contact acute care services instead of palliative care providers during the long palliative care phase if palliative care follow-up visits are not organized regularly.

In this study, contact with specialist palliative care in patients with nonmalignant pulmonary disease occurred mostly through consultations during acute exacerbation when it can be challenging to assess the patient’s prognosis and future palliative care needs. Wysham et al. also reported that patients with nonmalignant disease were more likely than cancer patients to have their initial palliative consultation at the intensive care unit and less likely as an outpatient [3]. Specialist consultation during an exacerbation may concentrate mostly on symptom relief, and after surviving an exacerbation, the actual referral to palliative care services may be missed. Previous studies suggest that the reasons for the lack of referral to palliative care services include uncertainty about the prognosis, fear of taking away the patient´s hope, lack of knowledge about palliative care, and that palliative care is falsely understood as a synonym for EOL care [16,17,18, 21,22,23]. Thus, more referrals and routine follow-up visits, phone calls, or video visits to palliative care units should be promoted for patients with nonmalignant pulmonary disease in the future to ensure the continuation of palliative care also after surviving an exacerbation. This continuation of care would also ensure that approaching EOL is recognized, and patients can be referred to EOL services well in advance.

The prognosis of patients with advanced lung cancer has changed due to the new landscape of cancer therapeutics, and cancer patients are now coping with greater uncertainty regarding their disease trajectory [6]. However, patients with advanced disease still seem to have poor survival if the disease leads to hospitalization shortly after diagnosis or if the disease progresses despite oncologic therapies leading to the palliative care phase [24]. In this study, the median survival of the lung cancer patients after the palliative care decision was only 52 days. Our results highlight the need for rapid access to palliative care services, including EOL care arrangements, for patients with lung cancer after changing the goal of care into palliative intent. In addition, patients with lung cancer probably benefit from early integration of palliative care and advance care planning visits to palliative outpatient clinics, where the focus can be addressed to symptom control and psychological support early enough [24,25,26].

Intake in a palliative care pathway was associated with a significant reduction in the number of ER visits and hospitalization days during the last month of life among patients with lung cancer, but this was not found among patients with nonmalignant pulmonary disease. Our results are in line with the recent study of McIagan et al., where palliative care did not reduce the use of hospital resources among COPD patients [27]. In our population of patients living in rural areas, palliative care pathways often rely on EOL care organized in primary palliative care, such as community hospital wards. Healthcare professionals working in primary palliative care may be more familiar with the symptoms and disease trajectory of cancer patients than patients with nonmalignant pulmonary disease. We hypothesize that the competency of primary palliative care may be insufficient for some patients with advanced nonmalignant pulmonary disease to take care of difficult symptoms, such as dyspnea. Dyspnea is known to be a common trigger for ER visits and hospitalization among palliative patients with nonmalignant pulmonary disease [28, 29]. Therefore, in the future, we should be more prepared to increase the intensity of palliative care for patients with nonmalignant pulmonary disease if necessary. This could include e.g. the use of high-flow nasal therapy or noninvasive mechanical ventilation (in order to relieve symptoms), which are not usually available at primary care hospitals or home care [30, 31]. Also, palliative sedation may be needed in some patients with nonmalignant pulmonary disease at EOL especially due to refractory dyspnea [32]. The ability for this around the clock may be only accomplished at specialist palliative care. In conclusion, in addition to primary palliative care, we need more specialist palliative care wards and home care teams to take care of the most challenging situations to avoid burdensome ER visits and admissions to acute hospitals for patients with nonmalignant pulmonary diseases.

Interestingly, patients with nonmalignant disease did not die in a secondary hospital despite the use of acute hospital services during the last month of life. Apparently, patients were taken care of at primary palliative care after ER visits or acute hospitalization, but as discussed above, avoiding this use of burdensome acute care in the first place should be prevented more effectively in the future.

Most of the patients with nonmalignant pulmonary disease needed help with ADLs, and they spent more time in the hospital during the last year of life compared to cancer patients. Considering the long palliative care phase of these patients, the need for help can last for several years. Supporting patients’ formal and informal caregivers and offering skillful home care as a part of palliative care is of utmost importance and has also recently recommended [5, 17, 33]. The fragility of patients with nonmalignant pulmonary disease may also be one of the reasons behind the low number of outpatient visits since they might be too burdensome in the palliative phase of the illness. This highlights the importance of the availability of home-delivered palliative care. The higher CCI score of the lung cancer patients than of the patients with nonmalignant pulmonary disease despite their lower need for ADLs is explained by the high points given by metastatic tumors in the CCI.

In this study, all patients with nonmalignant pulmonary disease had a DNAR order recorded, and most of them had a decision to withhold intensive care. These rates were higher than in patients with lung cancer and higher than in a study conducted by Raskin et al., in which 61% of patients with COPD had a DNAR order recorded before death [34]. In Finland, discussions about limits of care are seen as important, and it is known that in Northern Europe, DNAR and do-not-intubate orders are more frequently recorded during hospitalization than in Southern Europe [35].

Additionally, in patients with nonmalignant pulmonary disease, discussions about withholding resuscitation and intensive care might be seen as more important since the possibility of intubation and invasive mechanical ventilation in acute exacerbations are also present in the early palliative care phase, and the poor prognosis of these intensive treatments in patients with advanced disease are seen beforehand [36]. In contrast, in patients with lung cancer, respiratory insufficiency usually develops just before death during the EOL, when life-sustaining treatments are no longer an option. According to previous studies, the likelihood of invasive or noninvasive ventilation and cardiopulmonary resuscitation is greater in patients with nonmalignant pulmonary disease than in patients with lung cancer [15, 37]. Furthermore, the older age of patients with nonmalignant pulmonary disease likely increases the number of decisions to limit care [34]. It is also known that palliative care contact increases the number of these decisions [38]. Beyond DNAR and a decision to withhold admission to intensive care units, there are other limitations to care, such as avoiding hospitalizations or antibiotics, that can be addressed in the patient records. However, in this data, the numbers of these markings were so few and rather unclearly expressed that we did not include them in the analyses.

These were real-life data, and information relevant to this study was possible to retrieve retrospectively. A small sample size limits the statistical power, which may not have been sufficient to detect weaker associations in statistical analyses. This must be taken into account especially when interpreting our results on the relatively small number of patients with nonmalignant pulmonary disease. Since this was a single-center study from Finland, the generalizability of the results to other nations must be done with caution.

We collected data only from the patient records of Tampere University Hospital; thus, we lacked information on the use of other healthcare resources and places of death. On the other hand, we aimed to examine the role of specialist palliative care, and the information necessary for our results could be gathered at the university hospital level.

Although national recommendations instruct physicians to recognize patients in a palliative care phase by recording diagnosis code Z51.5 in patient records, we assume that particularly patients with nonmalignant pulmonary disease remained underrepresented in this study because of the lack of this diagnosis code. Thus, we are not able to describe the care of the patients with possible unrecognized need for palliative care during the last year of life in our hospital. Nevertheless, the use of this diagnosis code as a search criterion gives us a unique opportunity to specifically examine patients with advanced disease and a recognized palliative phase of the illness, where suitable palliative care arrangements should be equally available for all patients.