Among the 650 older adults who were recruited during the study period in selected hospitals, almost one fifth died within three months after their hospitalization. The majority of deaths recorded occurred during hospitalization and 16.2% of deceased older adults were malnourished. Overall survival rate was 82.8% after 90 days of follow-up. Factors associated with three-month mortality were the level of the hospital in the health pyramid, hospitalization service, length of stay, functional impairment, depression and malignant diseases.
Our study included both in-hospital and post-hospital mortality data. Deaths have been reported in almost one sixth of older adults, mostly during hospitalization. Similar findings have been reported in Africa. In a systematic review of the literature on hospital mortality among older adults in medical services in Africa which included five studies and 3,427 older adults from Nigeria, Senegal, Morocco and Kenya, 22.6% of deaths have been reported [26]. Also, in South Africa, out of 11,254 older adults admitted to medical services during a four-year period, 15.1% of deaths were reported [9]. Mortality among hospitalized older adults in Africa is higher than that reported in more developed countries, suggesting poor quality of health care for older adults. For example, mortality among hospitalized older adults was 11.1% in the US [27], 8.4% in Turkey [8], and 8.2% in Taiwan [28]. Several reasons may explain these differences such as a more performant technical platform and a higher number of geriatricians. Indeed, in Africa, in 2012, there was no geriatrician in 23 countries, and 12 countries had 1 to 4 geriatricians [29] while the national ratio in Canada was 5 certified specialists in geriatric for 100,000 persons aged 65 years and older [30]. However, it should be noted that hospital mortality could be biased in favor of health facilities that have short hospital stays policy. Other reasons that could explain the high hospital mortality in Africa could be linked to the three “Ds”: “Delay in healthcare seeking”; “Delay in diagnosis” and “Delay in treatment”. In general, in Africa, the population does not consult a health professional when first symptoms appear. In most cases, people use traditional medicine or self-medicate and only consult when the condition becomes life-threatening [31, 32]. Also, most older adults in Africa do not have health insurance and they have to make out-of-pocket payments for healthcare services [33, 34].
Three hospital-related factors were associated with mortality in this study: the level of the hospital in the health pyramid, the service of hospitalization, and the length of stay. Older adults who were hospitalized in secondary level hospitals had lower risk of death compared to those hospitalized in tertiary level facilities. In fact, all severe cases are referred for treatment to tertiary level hospital. However, there is no geriatric services in these tertiary level hospitals while it has been reported that co-management of older adults with geriatric specialists is associated with decreased mortality [35]. We did not find any data in the literature that included health structures from different levels of the health pyramid in Africa. These results should be confirmed by further studies. Being hospitalized in surgical services was associated with lower risk of death for older adults. Given the risk of complications which are frequent after traumatic episodes such as fractures or surgical procedures [36], older adults are taken care of as soon as possible in surgical services, leading to the lower mortality observed.
Geriatric syndromes such as frailty, delirium, falls, dementia, depression, functional impairment, or malnutrition, have been consistently reported as factors of increased risk of death in several studies [10–17]. In our study, older adults with functional impairment or depression were twice as likely as those without these geriatric syndromes to die within the 3 months after hospitalization. We found no significant association between malnutrition and mortality. In a cohort study in Brazilian patients aged 65 years and older, the risk of death at one year was 5 times higher in malnourished patients [17]. Similar results were reported in Spain [14]. Geriatric syndromes can be quickly detected using validated tools tailored for older adults [23–25, 37] and most of them can be prevented, treated or managed appropriately [38–40]. For example, studies have reported that early nutritional intervention could reduce morbidity and mortality in hospitalized patients [38]. Screening for geriatric syndromes in the management of older adults is essential in order to provide them with appropriate health care.
The almost significant low risk of death in older adults hospitalized for other cardiovascular diseases (excluding stroke) was an unexpected result since cardiovascular diseases constitute significant risk factor for mortality, especially in older populations [41]. However, some traditional risk factors known to have a poor prognosis may vary in older adults and may contrast with expected effects. For example, in older adults, low BMI, low diastolic blood pressure and low cholesterol (which indicate reverse metabolic syndrome) have been shown to be significant predictors of mortality [42]. Future studies, such as prospective cohorts among older adults, are needed to confirm this result. In Italy, Ponzetto et al., studied risk factors affecting mortality in 987 patients aged ≥70 years admitted to a geriatric ward and reported that cerebrovascular diseases and cancer were health conditions associated with a high risk of hospital mortality [10]. In our study, the risk of death was four times higher in older adults diagnosed with cancer. In fact, in Togo, there is no dedicated oncology or radiotherapy department for the management of cancer in hospitals. Cancers are managed in organ-specific departments. For example, breast and lung cancers are managed in the gynecology and pulmonology departments, respectively. Furthermore, access to anti-cancer drugs is limited and sometimes not available in Togo [43].
Old age has been found to be a risk factor for mortality in hospitalized older adults because the likelihood of having a chronic disease or geriatric syndrome increases with age. However, age was not associated with mortality in our study. This difference can be explained by the age threshold fixed to define older adults. We included in our study patients aged 50 years and older as recommended by the WHO [44]. The majority of studies on older adults have included subjects at an older age from 60 years [9], or even 65 years in some studies conducted in developed countries [8]. Older women had a higher risk of death compared to older men, but the difference was not statistically significant (HR = 1.11; p=0.579). These results contrast with that found in the literature where male sex was found to be associated with hospital mortality [10, 26, 45]. Reasons for gender-differences in mortality are that older women are more likely to seek healthcare and have healthier lifestyle [46]. Also, female hormones during fertile age may be protective for women with regards to cardiocirculatory events [46].
This study has some limitations. The main limitation is the non-documentation of causes of death due to the method of monitoring based on telephone contact. Abnormal laboratory tests results such as abnormal levels of hemoglobin, creatinine, urea, blood sugar have been found to be predictors of mortality in older adults [8, 26, 27]. For this study, we could not collect blood samples for laboratory testing due to the lack of financial means. Although deaths may be recorded in primary level structures, they were not selected for the study because these structures do not usually have hospitalization wards and are required to refer patients requiring hospitalization to tertiary and secondary level structures. Despite these limitations, to our knowledge, this study was the first to estimate mortality and to explore the associated risk factors in older adults after hospitalization in health facilities in Togo. The results of this study could help tailor strategies to the health needs of Togolese older adults.