Significance of comorbidities among COVID-19 patients as determinants of fatality in South Asia

Abstract

Several comorbidities have been reported to be associated with SARS-CoV-2 related severity and mortality. However, there has been considerable variation in the prevalence estimates of these underlying conditions and their effects on COVID-19 morbidity and mortality in prior studies. This thesis aimed to review all published literature to determine these differences in the prevalence of comorbidities in South Asia. A search was conducted using PubMed, Scopus and Google Scholar to include all COVID-19 studies published between January 1st, 2020 to December 21st, 2022 reporting comorbidities with severity and mortality in three South Asian countries- namely, Bangladesh, India and Pakistan. Of 91 studies with 48908 participants, the most prevalent comorbidity among the overall population was diabetes (30.83%), hypertension (30.38%), cardiovascular diseases (9.75%) and chronic kidney diseases (8.06%). The presence of these comorbidities resulted in more COVID-19 severity and mortality, while presence of multiple comorbidities aggravated the condition even further. In patients with pre-existing diabetes and hypertension, a patient’s condition deteriorated further when another comorbidity was present, mainly cardiovascular diseases and chronic kidney diseases. The study found that there were significant differences in the prevalence of comorbidities and the effect they had on disease severity and mortality across different geographical regions. In Bangladesh and India, the highest mortality was seen in diabetic patients infected with COVID-19 (61.23% and 49.25% respectively), whereas, in Pakistan, the highest mortality was seen in hypertensive patients infected with COVID-19 (63.69%). This study highlighted that the male gender, older age and comorbidities owned strong epidemiological evidence of associations with the severity and prognosis of COVID-19. Most frequent comorbidities reported in association with disease severity were diabetes, followed by hypertension and cardiovascular diseases. The data obtained from this study portrays the significant impact that the presence of pre-existing comorbidities had on the outcome of COVID-19 infection in Bangladesh, India and Pakistan. The study suggests that COVID-19 control strategies should be tailored according to comorbidities, age, and gender differences, and should take into account the specific geographical location to effectively stratify the risk and implement control measures. This study can also help to identify the gaps in the healthcare system and help to address the systemic issues that are leading to high mortality rates in these countries. From the public health perspective, this systematic review can help policymakers to better allocate resources and develop targeted interventions to improve the outcome of COVID-19 infection among these high-risk populations.