To our knowledge, the present study is the first to compare the prognostic value of both pneumonia and sepsis severity scores and scores evaluating comorbidities, malnutrition, cognitive status and functionality in predicting 1-year mortality in an elderly population hospitalized with a suspicion of pneumonia.
In our study, CURB-65 and SOFA were the only pneumonia and sepsis severity scores to prognosticate 1-year mortality. Among tools performed for the comprehensive geriatric assessment at patients’ admission, CIRS-G, MNA, and FIM evaluating comorbidity, malnutrition and functionality, were strong predictors of 1-year mortality.
Many studies reported a series of risk factors associated with long-term mortality in patients suffering from pneumonia7. Indeed, pulmonary infections may have significant impacts on various organ systems, such as respiratory, cardiovascular, and neurological ones, leading to the potential worsening of pre-existing comorbidities and subsequent higher fatality rates7. Therefore, a better understanding of long-term mortality prediction, measured at 30% in our study, seems urgent.
Amongst the risk factors commonly associated with poor long-term outcomes, we investigated the role of comorbidities, malnutrition, functionality and dementia. Concerning the latter, its contribution to elderly patients’ prognosis has been studied by Uranga et al. In their research, dementia was found to be the best predictor of one-year mortality in patients hospitalized with community-acquired pneumonia14. Similar results were found in a meta-analysis by Foley et al who showed that the odds of pneumonia-associated mortality increased more than 2-fold in patients with cognitive disorders15. We found that cognitive disorders were associated with poorer 1-year outcomes but only in univariate analysis.
Another aspect often playing a role in elderly patients’ mortality is malnutrition. The MNA was developed as a nutritional screening tool. Using this tool, we were able to identify a very strong correlation between malnutrition and poor outcomes at one year, indicating that assessment of the nutritional status at admission may help in reducing elderly patients’ mortality. Few other studies detected similar results. Yoon et al16, studying an elderly population with aspiration pneumonia, identified lower BMI and hypoalbuminemia as independent prognostic factors for 5-year mortality. Yeo et al17 recently highlighted that malnutrition was strongly linked with higher 2-year mortality in people suffering from pneumonia, particularly in the elderly, making essential a routine nutritional assessment at admission. Among elderly patients who have recovered from pneumonia, those who are malnourished have an increased risk of developing impaired muscle and respiratory function, which may lead to more severe long-term outcomes18.
Regarding comorbidities, we took into consideration the CCI and the CIRS-G. One of our main findings was a strong correlation between the CIRS-G and mortality at one year. Similar mortality results, although not focused on a specific disease, were found in the recent literature. A systematic review on the performance of different morbidity scores to predict mortality in inpatients hospitalized for any medical condition showed that CIRS-G, as per 1 point increase, was significantly associated with post-discharge mortality19. Zekry et al highlighted in patients hospitalized in an acute geriatric hospital that CIRS-G provided the most accurate risk prediction for 5-year mortality among six widely used multimorbidity scores20. Salvi et al confirmed the validity of the CIRS-G as an indicator of health status and demonstrated its ability to predict 18-month mortality and rehospitalisation amongst elderly inpatients21. In the same line, Ritt et al showed that CIRS-G proved accurate in forecasting 1-year mortality in elderly patients22. In alignment with the limitation of the Charlson Comorbidity Index, which is considered to be potentially misleading in rating elderly patients’ multimorbidity and not sufficiently able to predict long-term prognosis in geriatric populations19–20, we did not find any relevant correlation between this score and patients’ 1-year mortality.
Amongst several scales estimating patients’ dependence and functionality23–25, we decided to use the FIM, which in a recent study among critically ill elderly patients admitted to an intermediate care unit proved a correlation between low ratings on the scale and higher 1-year mortality rates26. Another research showed that frailty, defined as unintentional weight loss, self-reported exhaustion, weakness slow walking speed, and low physical activity, was strongly associated with the severity of pneumonia and a higher 1-year mortality in older patients, suggesting that frailty should be detected early to improve their management27. In our findings, lower FIM ratings were individually associated with a poorer long-term prognosis but failed in finding significant 1-year mortality correlations in multivariate models.
We investigated the ability of the two most widely used prognostic tools (CURB-65 and PSI), validated as 30-day pneumonia mortality predictors, to determine long-term prognosis amongst a population of elderly people. We did not find any association between the PSI and the prognosis of our patients. Interestingly, CURB-65 was an efficient long-term mortality predictor in our cohort. Similar results were found by Wesemann et al28 in a predominantly older population.
It has recently been shown that SOFA and qSOFA are useful scores for evaluating pneumonia mortality in geriatric populations29–31. In our study, we found a weak but significant correlation between SOFA scores at admission and 1-year mortality rates, probably due to a persistent impact of organ failure caused by pneumonia on frail people’s homeostasis. No significant association was found between the qSOFA and long-term prognosis.
The present study’s main strength was the consecutive inclusion of elderly patients hospitalized and treated for a suspicion of pneumonia. It has several limitations, however. As a single-centre study carried out with a relatively small number of patients, it should not be generalized to other hospitals. Since we focused our attention on elderly individuals with suspected pneumonia, our results should not be exported to other clinical contexts. Additionally, CIRS-G was retrieved retrospectively from medical records, exposing our analysis to potentials biases. Finally, we did not record the ‘Do not resuscitate’ orders in our cohort, which might affect patients’ outcomes and be a source of bias.