Distribution of risk factors in died patients
Seven of the qualitative risk factors were analyzed for their distribution and concentration in dead patients (n=40). These were: older age, heart disorder, lungs disorder, diabetes, hypertension, kidney disorder and smoking. The last two, though have non-significant effect on risk of death in current study, might have some contribution to the death in combination with others. Among 40 died patients, 3 had combinations of 5 factors present at same time (7.5%), 4 patients had combinations of 4 risk factors (10%), 14 patients had 3 risk factors combined at same time (35%), 9 patients had 2 risk factors (22.5%), 9 had only one risk factor (22.5%), while 1 (2.5%) patients had no risk factor at all (Table 1). The most frequent risk factor was older age, which was present in 29 out of 40 died patients, followed by diabetes (17) and lungs disorders (17), then hypertension (15), heart disorder (12), smoking (6) and then kidney disorder which was present in only 4 of the died patients (Table 1; Table 2). In the current study, 97.5% of the patients who died of COVID_19, had one or more than one risk factors present along with corona virus infection. However, 1 patient (2.5%) had no other obvious risk factor accept corona virus infection as the patient was a non smoker, non diabetic female of 45 years with no hypertension, cardiac, lungs or kidney disorder.
Patients' factors and co-morbidities
A total of 10 health conditions reported as co-morbidity with reference to COVID-19 were documented as commonly occurring and hence were analyzed. These included diabetes, lungs disorder, renal impairment, cardiovascular diseases, tuberculosis, cancer, and hypertension. The data about gender, age, fever, body weight and smoking was also recorded.
Data showed that, co-morbidities such as diabetes, lungs disorder, cardiovascular diseases, and hypertension were statistically significant factors influencing risk of mortality. Among the factors with quantitative data, age and fever were significantly different between dead and recovered patients while body weight difference was statistically non-significant. Among qualitative factors, gender, smoking and kidney disorder were found as non-significant factors. Patients' area of residence, profession, tuberculosis, cancer, liver disorder, autoimmune disorders and any other illness were not included in the final analysis because of insufficient data for both.
Heart disorder: Heart disorders were found to be most significant risk factor of death for COVID-19 patients in the current study as the risk of death in patients with heart disorder was found to be 5.07 times higher as compared to those without any cardiovascular disease (OR: 5.07; 95% CI: 2.30-11.17). The rate of death in patients with heart disorder was 57.1% while the same for patients without heart disorder was 16.4%, significantly higher in patients with heart disorder (P=0.000). The heart disorder is a powerful predictor of death in COVID-19 patients (Table 2).
Lungs disorders: A total of 33 patients in the study had lungs disorders, out of which, 51.5% died. The risk of death was calculated to be 4 times higher for the COVID patients with lungs disorders (OR: 4.0; 95% CI: 2.24-7.26) as compared to those with healthy lungs. Out of the total 149 patients without any lungs disorder, 23 (14.5%) died and the rate of death was significantly lower as compared to those with any lungs disorder (P=0.000). So, the lungs disorder is a very significant risk factor of death in COVID-19 patients (Table 2).
Diabetes: Diabetes was appeared as a significant risk factor in the study. A total of 43 patients were reported to be diabetic out of them, 17 (39.5%) were died conversely, 23 out of 149 (15.4%) non-diabetic patients died. The percentage of death was significantly higher in diabetic patients as compared to non-diabetic patients (P=0.001). Odds ratio of death for diabetic patients was 2.49 (95% CI: 1.5-4.1) as compared to non-diabetic patients. So, the diabetic patients have about 2.5 times more risk of death if infected with COVID-19 as compared to non-diabetic ones (Table 2).
Hypertension: Hypertension was appeared to be another significant risk factor associated with death in COVID-19 patients (Table 2) as 32.6% of the hypertensive patients died in the study as compared to 17.1% of the non-hypertensive patients and the rate of death was significantly higher in hypertensive patients (P=0.024). The hypertensive patients had almost double the risk of death (OR: 1.84; 95% CI: 1.11-3.06) as compared to non-hypertensive patients (Table 2).
Kidney disorder: A total of 11 patients in the study had some kidney disease in the present study out of which, 4 (36.4%) died as compared to 36 out of 181 (21%) patients without kidney disorder and the difference of death rate was not significant statistically (P=0.191). The odds of a patient to die was 2.17 as compared to the patients without kidney disorder but it was not significant (95% CI: 0.67-7.05). So, the kidney disorder was not found as a significant risk factor of death in present study (Table 2).
Smoking: Only 18 of the patients were reported as smokers in the study and the difference in death rate of smokers and non-smokers was not significant (i.e. 33.3% in smokers as compared to 19.5% in non-smokers (P=0.170). The odds ratio for death in smokers was 1.9 as compared to death in non-smokers but it was non-significant with a 95% CI of 0.76 to 4.75 (Table 2).
Gender: A total of 120 patients were male and 72 were female. No difference in death rate of male and female was found in the study as the death percentage was 20.8% (P=1.00) for both genders with an odds ratio of 1.0 for both (Table 2).
Age : Age was found to be a significant different both in quantitative and qualitative analysis (Table 2; Table 3). In quantitative analysis, the age of died patients was found to be significantly higher (P=0.000) as compared to the age of recovered patients. The mean age of died patients was 66.28±15.07 year with median age of 67.5 years ranging from 30 to 95 years, while the mean age of recovered patients was calculated to be 43.07±16.65 years with median age of 40 years ranging from 8 to 90 years (Table 3; Figure 1).
To analyze qualitatively, the patients were divided in two groups’ wiz. I. <60 and II. ≥60. The percentage of mortality was significantly higher in group II (P=0.000) as 29 out of 61 (47.5%) in the died as compared to 11 out of 131 (8.4%) group I. Odds ratio of death for group II was calculated as 3.44 as compared to the group I with 95% confidence interval from 2.40 to 4.95. So, the COVID-19 patients with 60 years or above age have a 3.44 times more risk of death as compared to those with age below 60 years (Table 2).
Body temperature: All the patients included in the study were symptomatic with higher than normal body temperature. By temperature we mean the average body temperature of patients recorded during their stay at hospital. The body temperature was reported to be significantly higher in patients who couldn’t survive at the end as compared to recovered patients (P=0.000). The median body temperature of died patients was calculated to be 102 with mean of 101.9±1.03 ranging from 99 to 104 Fahrenheit whereas the median temperature was 101 for recovered patients with mean of 100.84±1.51, ranging from 98 to 104 Fahrenheit (Table 3; Figure 1).
Body weight: Mean body weight of the dead patients was slightly higher as compared to the mean body weight of recovered patients as it was 72.55±11.1 kg with median value of 74 and ranging from 52 to 99kg while the mean body weight of recovered patients was 68.7±13.22 kg ranging from 30 to 100 with median of 70kg (Table 3). The difference however, was non-significant statistically (P=0.092).