Demographics, comorbidities and outcomes
Crude and adjusted values of mean and median age were lower in all COVID-19 case series compared with SPP (Table). The proportion of females differed between the case series, ranging from 32% in Wuhan to 59% in Zhejiang. The adjusted SPP showed a range from 39% to 42% in the proportions of females throughout the 5 years under consideration. The overall proportion of comorbidities was much smaller in the COVID-19 case series (range: 20–51%) than in German patients, where the proportion ranged from 70% to 77%, depending on the year. Hypertension and diabetes were the most important chronic comorbidities both among COVID-19 patients and among SPP. However, there were fewer patients with chronic obstructive pulmonary disease (COPD) or renal disease among COVID-19 patients than among SPP.
Table  Epidemiological and clinical characteristics of sentinel pneumonia patients, crude and adjusted for age and sex, and COVID-19 case series
Characteristics  SPP, crude  SPP, adjusted  COVID-19
Weeks 3–5, 2015–19  Weeks 3–5, 2015–19  20 days  28 days  31 days  26 days  22 days  30 days  17 days  23 days
Wuhan [5]  Wuhan [6]  Wuhan [7]  Hubei [10]  Beijing [8]  Shenzhen [9]  Zhejiang [11]  Zhejiang [12]
Number  5,829  NA  99  138  82  137  262  298  62  91
Mean age in years (range)  73 (71–75)  63 (61–66)  55.5  NA  NA  55  NA   NA   NA   NA
Median age in years (range)  77 (76–78)  67 (65–69)   NA  56   NA  57  47.5  47  41  50
Female, % (range)  45 (44–45)  41 (39–42)  32  46   NA  56  52  50  44  59
Any chronic disease, % (range)  82 (80–85)  74 (70–77)  51  46   NA  20   NA  32  32   NA
Hypertension, % (range)  58 (56–62)  49 (46–53)   NA  31   NA  10   NA  13  8  16
Endocrine condition/diabetes, % (range)  28 (26–30)  24 (22–26)  13  14   NA  10   NA  6  2  9
COPD, % (range)  20 (19–22)  20 (18–22)   NA  3   NA  2   NA   NA  2   NA
Cancer, % (range)  7 (6–8)  8 (7–9)  1  7   NA  2   NA  1   NA   NA
Renal disease, % (range)  37 (34–40)  27 (24–29)   NA  3   NA   NA   NA   NA  2   NA
Liver disease, % (range)  4 (3–4)  5 (3–6)   NA  3   NA   NA   NA  3  11   NA
Of total: ARDS, % (range)  1 (0–1)  1 (0–1)  17  20   NA   NA   NA  4  2   NA
Of total: ventilated, % (range)  8 (7–10)  9 (8–11)  20  23   NA  25   NA  11  2   NA
Of total: ICU, % (range)  19 (18–21)  20 (18–22)  23  26   NA   NA   NA  11  2  10
Of ICU: male, % (range)  58 (55–60)  61 (56–66)   NA  61   NA   NA   NA   NA   NA   NA
Of ICU: median age in years (range)  76 (74–78)  67 (64–68)   NA  66   NA   NA   NA   NA   NA   NA
Of ICU: without chronic, % (range)  10 (7–12)  16 (10–19)   NA  28   NA   NA   NA   NA   NA   NA
Of total: deceased, % (range)  9 (8–9)  6 (5–6)  11  4  6  12  1  0  0  0
Of deceased: median age, in years (range)  83 (82–84)  78 (76–79)   NA  NA  72.5   NA   NA   NA   NA   NA
Of deceased: < 60 years, % (range)  5 (2–9)  13 (7–22)  36   NA  20   NA  30   NA   NA   NA
Of deceased: without chronic disease, % (range)  13 (13–15)  13 (12–14)  18   NA  23   NA  30   NA   NA   NA
Still hospitalised, %  58  62  NA  56  82  77  98  66
ARDS: acute respiratory distress syndrome; COPD: chronic obstructive pulmonary disease; COVID-19: coronavirus disease; ICU: intensive care unit; NA: not available; SPP: sentinel pneumonia patients.