1. Introduction

On December 31, 2019, the discovery of a novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19) in Wuhan, China, was reported to the World Health Organization (WHO). On January 30, 2020, the WHO declared COVID-19 as a public health emergency of global concern, and Africa was the last continent to confirm the virus. The continent confirmed its first case in Egypt on February 14, 2020, and from sub-Saharan Africa (SSA), the first case was reported in Nigeria on February 27 [1, 2]. The first case of COVID-19 was diagnosed in The Gambia on March 17, 2020, and as of March 13, 2023, 12,631 confirmed COVID-19 cases with 372 deaths were recorded.

The clinical presentation of COVID-19 ranges from mild infection to severe disease to fatal illness [3]. The most commonly reported symptoms were cough, fever, and dyspnea [3–6]. Critically ill patients were older, more likely to be male, and have underlying comorbidities. The mortality rate ranges from 8.7% to 21% among those patients admitted with pneumonia [3–6]. In a larger report, 49% of all 2087 critically ill patients with COVID-19 in China died [7].

In Western countries, the response to the COVID-19 pandemic has been to increase hospital capacity and to provide more intensive care units (ICUs) and more ventilators [3–6]. There had been little discussion of the provision of oxygen as this is a standard clinical tool widely available in hospitals [3]. However, in SSA, there is a shortage of oxygen in health facilities, and thus, two things should be at the top of the list before ICUs and ventilators [3]. These are personal protective equipment (PPE) for frontline health workers and oxygen for the patients [8]. In The Gambia, there is only one hospital that has a dedicated ICU with eight ICU beds, making an estimated 0.4 ICU beds/100,000 population in the country. This very low ICU bed capacity and lack of human resources and equipment necessary to diagnose and treat the large number of critically ill patients admitted to public hospitals in the country [9, 10] may hinder the countries response to COVID-19.

In The Gambia, Abatan et al. [11] examined transmission rates among 1366 employees of the Medical Research Council in The Gambia (MRCG), where systematic surveillance of symptomatic cases and contact tracing were implemented. Additionally, Lowe et al. [12] conducted a brief evaluation of the measures and challenges facing The Gambia’s COVID-19 response, offering policy and practical recommendations for policymakers and implementers. A qualitative study [13] was also carried out to assess the acceptability of a clinical trial for COVID-19 prevention and treatment in The Gambia, aiming to identify strategies to enhance community engagement in such trials. Various studies [6, 14–16] have described the clinical and epidemiological characteristics, risk factors, case management, and outcomes of COVID-19 in patient cohorts globally. Other research [17, 18] has reviewed the clinical features, diagnosis, and treatment of COVID-19 in different regions. However, limited information is available regarding the clinical characteristics of COVID-19 patients in Africa [19]. In this study, we assessed the clinical features, comorbidities, and prognosis of COVID-19 patients admitted at the national treatment center in The Gambia. The morbidity and mortality data from this study will be of considerable value for the identification of individuals who are at risk of becoming critically ill or dying and who are most likely to benefit from early screening and possible treatment. The overall goal of this study is to identify prognostic factors for poor outcome among COVID-19 patients admitted into the national treatment center in The Gambia.

2. Methods

3. Results

4. Discussion

The study underscores the vital role of SPO₂ levels in predicting mortality risk in COVID-19 patients. This study revealed that patients with SPO₂ levels below 90% faced a fivefold higher risk of death, which is consistent with previous research showing the significant prognostic value of SPO₂ in assessing the severity and potential mortality of COVID-19 [27]. For instance, Fernando Mejía and colleagues [28], in their study of hospitalized adult COVID-19 patients at a public hospital in Lima, Peru, discovered that oxygen saturation levels below 90% at the time of admission were linked to a higher risk of mortality. Similarly, an investigation by Junior Carbajal et al. [29] into the risk factors for in-hospital mortality among patients with COVID-19 and type 2 diabetes mellitus (T2DM) identified that a partial pressure of oxygen below 60 mmHg was an independent risk factor for in-hospital mortality. Furthermore, researchers [30] developed an early predictive model using baseline clinical factors and found that a SPO₂ below 94% was an independent predictor of mortality in COVID-19 patients. Jiang Xie et al. [31] research on in-hospital mortality also reported that higher SPO₂ levels following oxygen supplementation were associated with a reduced risk of death, independent of age and sex. Additional studies by Takahisa Mikami et al. [32] in New York City, Peter M. Mphekgwana et al. [33] in South Africa, and a global systematic review and meta-analysis of 76 studies by Adam Booth et al. [34] further confirmed that SPO₂ levels below 94% are associated with an increased mortality risk. These collective findings emphasize the crucial role of SPO₂ as an early indicator for identifying patients at high risk of death from COVID-19, highlighting the importance of timely medical intervention to improve patient outcomes. Maintaining adequate oxygen saturation (95%–100%) [35–37] is essential not only for improving survival chances but also for informing clinical decisions and prioritizing care for the most vulnerable patients.

We found that age was a significant risk factor for COVID-19 severity (SPO₂ < 90). Specifically, COVID-19 patients aged 60 and above were associated with an approximately threefold increased risk of severe outcomes. This aligns with numerous studies that have linked older age to a heightened risk of severe COVID-19. For instance, a retrospective study by Sevda et al. [38], using data from 6906 hospitalized adults across a community health system in five states in the western United States, highlighted variations in the significance and predictive value of risk factors between older and younger patients. Additionally, a rapid review, meta-analysis, and meta-regression of 12 studies by Karla et al. [39] showed that the unadjusted impact of age indicated a 5.2% and 13.4% higher risk of disease severity and death per additional year, respectively. However, after adjusting for major age-related risk factors such as diabetes, hypertension, cardiovascular/CSD, compromised immunity, previous respiratory conditions, and renal disease, the risk increase for severity was reduced to 2.7% (in two studies), and there was no additional risk of death per year (in five studies). The authors emphasized that the modest impact of age on COVID-19 severity, once key comorbidities were considered, should inform age-targeted preventive strategies, including age-related work policies.

A study by Liu et al. [40] involving 4806 COVID-19 patients without chronic comorbidities identified that age ≥47 was linked to the progression from nonsevere to severe illness using LASSO and stepwise logistic regression models. Wolff et al. [40], in their systematic review of 28 studies, also reported that age was a primary risk factor for severe and fatal COVID-19 cases. Furthermore, according to Diendéré et al. [41], hospital-based cross-sectional study in Burkina Faso showed that patients over 65 years had an approximately eightfold increased risk of severe hypoxemia.

Other researchers, including Terada and colleagues in Japan [42], Davarpanah and colleagues in Iran [43], Sohrabi and colleagues in Tehran [44], and Booth [34] and colleagues [34] global review of 76 studies, have consistently identified age as a significant risk factor for severe COVID-19 at admission, with age over 75 associated with an approximately threefold increased risk of severe outcomes. Conversely, a systematic review, meta-analysis, and meta-regression [45] on COVID-19 risk factors in China found that age did not significantly impact disease severity.

The findings underscore that while age is a strong independent risk factor, the overall impact can be influenced by underlying conditions. Preventive and clinical measures should therefore prioritize older adults and incorporate strategies that consider age alongside comorbidities. Conversely, findings like those from Zhang et al. [45], which showed no significant age impact after statistical adjustments, highlight that the implications of age might vary by population and methodology. Overall, these insights are critical for shaping targeted health policies, age-specific interventions, and resource allocation during pandemics.

The findings also indicated that COVID-19 patients with pre-existing comorbidities were approximately twice as likely to experience severe COVID-19. Multiple studies [46] have confirmed the high prevalence of comorbidities among those with severe COVID-19, with common conditions including cardiovascular disease [47, 48], hypertension [49, 50], diabetes [30, 47, 49], chronic obstructive pulmonary disease (COPD) [47, 49, 50], malignancy [47], CSD [49], and chronic kidney disease [50]. A meta-analysis [51] highlighted that hypertension, diabetes, and cardiovascular disease significantly raise the risk of severe COVID-19, ICU admission, and mortality across all age groups. Additionally, obesity (BMI ≥ 30) has been associated with worse outcomes [52], driven by immune system dysregulation, chronic inflammation, and high ACE2 expression in adipose tissue [53]. Reduced immune function in patients with diabetes and hypertension weakens their resistance to infections, while chronic conditions can impair vascular and cardiac function, increasing the risk of severe COVID-19 [54].The virus’s potential to damage organs, including the liver, kidneys, and heart, further elevates the risk of severe and fatal outcomes for individuals with existing organ-related comorbidities [55]. A study [56] in Bangladesh examining comorbidities and COVID-19 severity among recovered patients found that comorbidities were linked to greater severity, with diabetes and cardiovascular disease notably increasing the likelihood of severe illness. Similarly, research [57] on the impact of comorbidities across ethnic groups demonstrated an elevated risk of severe COVID-19 in both South Asian and White participants, with a relatively higher risk observed in South Asian individuals.

These findings underscore the importance of targeted prevention and management strategies for individuals with underlying health conditions. Prioritizing the monitoring and protection of these high-risk groups is crucial for reducing severe health outcomes. The results advocate for comprehensive health strategies that emphasize early identification and targeted interventions for those with pre-existing conditions while addressing disparities across demographic groups.

Our findings align with studies from other low- and middle-income countries (LMICs). For example, research conducted in LMICs such as Peru [28], China [31], and South Africa [33] also found that an SPO₂ level below 94% is linked to an increased risk of mortality. Regarding age as a risk factor for COVID-19 severity, studies from countries like Burkina Faso [41], Iran [43], and Tehran [44] have reported that older COVID-19 patients are more likely to experience severe hypoxemia. Additionally, findings from other LMICs, including China [49, 50] and Bangladesh [56], support our results, indicating that COVID-19 patients with pre-existing comorbidities are at a higher risk of developing severe disease. Research on COVID-19 patients in Africa [58] revealed that older age was associated with increased risk of mortality.

The centralized healthcare approach employed in The Gambia, where all COVID-19 patients were admitted to a single treatment center, offers distinct advantages for managing the pandemic. This setup likely facilitated consistent protocols for diagnosis, treatment, and data collection, contributing to the reliability of findings and the ability to generalize outcomes for the Gambian population. It also enabled efficient resource allocation, centralized monitoring, and the ability to rapidly implement changes to clinical protocols based on emerging evidence. In contrast, findings from decentralized or fragmented healthcare systems may vary significantly due to challenges such as inconsistent care standards, variable resource availability, and diverse patient management strategies. For instance, in decentralized systems, discrepancies in record-keeping can compromise the accuracy of findings and hinder comparisons. Decentralized systems may struggle with equitable distribution of such resources, particularly in regions with significant urban–rural disparities and variations in healthcare quality and access across regions could lead to disparities in COVID-19 outcomes. For example, rural facilities might lack the advanced equipment and trained personnel found in urban centers, potentially resulting in higher mortality rates. Also, decentralized systems may face delays in disseminating and implementing new protocols across multiple facilities, and findings from decentralized systems may reflect the heterogeneity of healthcare delivery, making it difficult to disentangle the effects of patient characteristics from healthcare system variables. For regions with fragmented healthcare systems, efforts should focus on enhancing coordination and standardization across facilities to mitigate disparities.

5. Conclusions

The findings from the study strongly highlight the critical role of oxygen saturation (SPO₂) levels, age, and pre-existing comorbidities in predicting the severity and mortality risk in COVID-19 patients. These findings advocate for targeted preventive measures, including early identification and continuous monitoring of high-risk patients. Clinical guidelines should emphasize maintaining adequate SPO₂ levels and prioritizing resources for older adults and individuals with pre-existing health conditions. Moreover, age-specific and comorbidity-focused interventions can enhance patient outcomes and inform policies that better allocate healthcare resources during pandemics. Addressing health disparities and ensuring equitable care for vulnerable populations is paramount in reducing severe health outcomes and mortality.

Ethics Statement

Ethics approval for this study was granted by the Institutional Review Board of Edward Francis Small Teaching Hospital (EFSTH).

Disclosure

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Author Contributions

S.O.B. was involved in all stages of the study. A.J., R.N., L.E.S.J., O.N., Y.F.B.M.J., S.J., S.J., M.D., E.B., C.R., and M.B., M.C. participated in the design of the study and data collection. A.K.I. performed the data analysis and interpretation and writing of the manuscript. All authors contributed to the writing of the manuscript. All authors read and approved the final manuscript.

Funding

No funding was received for this research.