North India's largest study on hospitalised COVID-19 patients highlights increased mortality in 2nd wave

A study to investigate the differential characteristics of COVID-19 patients admitted to the hospital in the second wave, as opposed to the first wave, revealed a higher mortality rate. However, it is a pre-peer review study.

The study, according to Group Medical Director of Max Healthcare Dr Sandeep Budhiraja is north India's largest retrospective study of the Covid pandemic in India to investigate differential characteristics of COVID-19 patients admitted in the second wave, as opposed to the first wave.

"It is based on the records of a total of 14,398 cases admitted across 10 Max Hospitals in north India during the first wave last year and 5,454 cases admitted in the second wave," he said.

During the study, the team of the hospital chain compared characteristics including the severity of COVID-19 at admission, demographics (age and sex), co-morbidity, admission to ward/ICU, duration of hospitalization, oxygen and ventilator support, the drugs used for treatment, laboratory parameters, CT severity score, secondary infections, and mortality.

The age-sex distribution of the cases in the second wave was not much different from those admitted in the first wave, but the patients with co-morbidities and those with greater severity had a larger share.

"We found increased disease severity of patients admitted in wave-2 as compared to wave-1; 39.4 per cent vs 32.7 per cent; P<0.001). A higher number of patients with co-morbidities were admitted in the Wave-2, as compared to the Wave-1; 59.7 per cent V/s 54.8 per cent; P< 0.001," Dr Budhiraja said.

He further said, "More than 40 per cent of the admitted patients in both the waves had diabetes (DM) or hypertension (HTN) or both. Chronic kidney disease was reported in 13 per cent and 15 per cent of the patients respectively, while CAD was in 5 per cent and 6 per cent of the cases."

"Significantly more patients with DM (P=0.031), HTN (P=0.001) and CKD (P=0.004) were admitted during Wave-2." Dr Budhiraja added.

In higher severity cases, it was also noticed that during the time of second wave, a greater requirement for oxygen reported. "It was observed that there was higher severity of disease at the time of admission which necessitated a greater requirement for oxygen. More patients required oxygen support in Wave-2; 74.1 per cent V/s 63.4 per cent in Wave-1; P<0.001, and similarly a higher number required invasive ventilation 10.1 per cent V/s 8.7 per cent in Wave-1; P=0.002," says the statement from hospital on the basis of study.

The study also revealed that more patients during the second wave developed secondary bacterial and fungal infection. "We found that more patients developed secondary bacterial and fungal infections in Wave-2, 28 per cent V/s 11 per cent in Wave-1. So had the number of patients with Mucormycosis that were referred to our hospitals for treatment in Wave-2; 169 V/s 10."

Further, on the increased rate of mortality in Wave 2, Dr Budhiraja said: "The study revealed that mortality increased by almost 40 per cent in Wave-2, from 7.2 per cent in wave-1 to 10.5 per cent in wave-2. Patients less than 45 years recorded the sharpest increase in mortality during wave-2; 4.1 per cent V/s 1.3 per cent, with higher mortality in males. In this group, it was observed that the average duration of symptoms before admission was 7.3 days in wave-2 V/s 6.3 days in wave-1."

"In this age group, mortality increased in both males; 4.7 per cent in wave-2 V/s 1.4 per cent in wave-1, and females; 2.8 per cent V/s 1.0 per cent. In other age groups too, the mortality during wave-2 was significantly higher than in wave-1. The increasing trend in mortality was seen across all other age groups also: 45-59 years (5 per cent V/s 7.6 per cent), 60-74 years (12 per cent V/s 13.8 per cent), and in >= 75 years (18.9 per cent V/s 26.9 per cent)," he added.

According to the study mortality rate is higher in comparison to Wave -1, "Higher mortality rates during Wave-2 were seen across various treatment modalities, whether the patients were on a non-invasive ventilator (NIV) (40.8 per cent in wave-1 V/s 48.4 per cent in wave-2), on an invasive ventilator (62.5 per cent V/s 68.4 per cent) and even for those who were not on any ventilator support and those who received convalescent plasma (21.3 per cent V/s 27.6 per cent). Not only was the mortality higher in wave-2 for patients in ICU (19.8 per cent V/s 25.1 per cent) but steeply higher for those admitted in the wards (0.5 per cent V/s 3.0 per cent)," he said.

"The reasons for higher mortality could be later presentation to the hospital due to unavailability of hospital beds, higher secondary bacterial and fungal infections, and delta variant becoming the predominant strain during Wave-2. Also last year, in the early part of the pandemic in India, patients with mild disease also got admitted," the study stated.

( With inputs from ANI )