Table 1

Univariable association of baseline risk factors with in-hospital COVID-19 in 2020, pneumonia occurring after 2016 and influenza occurring after 2016

In-hospital COVID-19Pneumonia (after 2016)Influenza (after 2016)
No n=235 531Yes n=397RR*P valueNo n=96 605Yes n=209RRP valueNo n=96 720Yes n=94RRP value
Age (years) †66.53 (8.09)67.55 (8.68)1.140.0166.52 (8.06)68.78 (7.60)1.34<0.000166.53 (8.06)66.20 (7.83)0.960.69
Age categories (years), n (%)
 <6058 683 (24.92)102 (25.69)1REF23 707 (24.54)31 (14.83)1REF23 717 (24.52)21 (22.34)1REF
 60–6437 589 (15.96)42 (10.58)0.640.0215 230 (15.77)24 (11.48)1.200.4915 233 (15.75)21 (22.34)1.560.15
 65–6942 812 (18.18)58 (14.61)0.780.1317 606 (18.22)45 (21.53)1.950.00417 632 (18.23)19 (20.21)1.220.54
 70–7455 726 (23.66)93 (23.43)0.960.7823 233 (24.05)63 (30.14)2.070.000923 278 (24.07)18 (19.15)0.870.67
 ≥7540 721 (17.29)102 (25.69)1.440.00916 829 (17.42)46 (22.01)2.090.00216 860 (17.43)15 (15.96)1.000.99
Male sex, n (%)111 095 (47.17)219 (55.16)1.380.00145 548 (47.15)72 (34.45)0.590.000345 573 (47.12)47 (50.00)1.120.58
Ethnicity (%)
 White224 215 (95.20)356 (89.67)1REF92 477 (95.73)201 (96.17)1REF92 588 (95.73)90 (95.74)1REF
 Black3057 (1.30)14 (3.53)2.880.0001908 (0.94)3 (1.44)1.520.47911 (0.94)0 (0.00)0.000.97
 South Asian3508 (1.49)12 (3.02)2.150.0091605 (1.66)3 (1.44)0.860.801607 (1.66)1 (1.06)0.640.66
 Others4751 (2.02)15 (3.78)1.990.0091615 (1.67)2 (0.96)0.570.431614 (1.67)3 (3.19)1.910.27
Deprivation index (score)−1.44 (2.98)−0.56 (3.37)1.30<0.0001−1.48 (2.90)−1.28 (3.07)1.070.31−1.48 (2.90)−0.92 (3.32)1.200.06
Current/former smoker, n (%)106 829 (45.36)224 (56.42)1.56<0.000143 843 (45.38)93 (44.50)0.960.8043 891 (45.38)45 (47.87)1.110.63
Alcohol drinking status, n (%)
 Never8894 (3.78)27 (6.80)1REF3714 (3.84)13 (6.22)1REF3723 (3.85)4 (4.26)1REF
 Former7469 (3.17)19 (4.79)0.840.563090 (3.20)13 (6.22)1.200.643099 (3.20)4 (4.26)1.200.80
 Current219 168 (93.05)351 (88.41)0.530.00189 801 (92.96)183 (87.56)0.580.0689 898 (92.95)86 (91.49)0.890.82
BMI (kg/m2)27.32 (4.56)29.12 (5.25)1.40<0.000127.41 (4.56)28.61 (5.58)1.260.000227.42 (4.57)27.53 (4.70)1.030.80
BMI categories, n (%)
 Underweight787 (0.33)1 (0.25)1.170.88305 (0.32)1 (0.48)1.650.62306 (0.32)0 (0.00)0.000.97
 Normal78 073 (33.15)85 (21.41)1REF31 182 (32.28)62 (29.67)1REF31 209 (32.27)35 (37.23)1REF
 Overweight101 751 (43.20)172 (43.32)1.550.000941 867 (43.34)80 (38.28)0.960.8141 917 (43.34)30 (31.91)0.640.07
 Obese54 920 (23.32)139 (35.01)2.32<0.000123 251 (24.07)66 (31.58)1.430.0423 288 (24.08)29 (30.85)1.110.68
Body fat-free mass (Kg)53.76 (11.47)56.18 (11.50)1.23<0.000153.75 (11.49)52.08 (12.04)0.860.0453.74 (11.49)54.61 (12.17)1.080.46
Body fat mass (Kg)24.49 (9.19)27.44 (10.35)1.32<0.000124.69 (9.21)27.90 (11.25)1.35<0.000124.70 (9.22)24.31 (9.37)0.960.68
Body fat proportion (per cent)31.01 (8.40)32.36 (8.47)1.170.00131.19 (8.41)34.29 (8.68)1.44<0.000131.19 (8.41)30.51 (8.46)0.920.43
Systolic blood pressure (mm Hg)137.24 (18.07)138.49 (18.76)1.070.17137.55 (18.10)137.55 (18.03)1.001.00137.55 (18.10)137.60 (17.40)1.000.98
Diastolic blood pressure (mm Hg)82.08 (9.90)82.99 (10.47)1.100.0782.19 (9.90)80.90 (9.63)0.880.0682.19 (9.90)82.79 (10.74)1.060.56
FEV1 (L)2.86 (0.77)2.73 (0.78)0.840.00092.86 (0.78)2.53 (0.81)0.63<0.00012.86 (0.78)2.84 (0.88)0.980.84
FVC (L)3.79 (0.98)3.68 (0.97)0.890.033.79 (0.99)3.40 (1.01)0.65<0.00013.79 (0.99)3.73 (1.04)0.950.60
FEV1/FVC0.76 (0.06)0.74 (0.08)0.850.00040.76 (0.06)0.74 (0.08)0.820.00070.76 (0.06)0.76 (0.06)1.040.72
Walking pace (%)
 Slow14 887 (6.32)59 (14.86)2.29<0.00016190 (6.41)29 (13.88)2.070.00056209 (6.42)10 (10.64)1.780.10
 Average123 588 (52.47)213 (53.65)1REF50 839 (52.63)115 (55.02)1REF50 908 (52.63)46 (48.94)1REF
 Brisk97 056 (41.21)125 (31.49)0.750.01039 576 (40.97)65 (31.10)0.730.0439 603 (40.95)38 (40.43)1.060.78
Grip strength (kg) †31.31 (10.93)31.36 (10.31)1.000.9331.21 (10.96)27.83 (10.83)0.72<0.000131.20 (10.96)31.94 (11.27)1.070.51
Prevalent disease at baseline (%)
 Longstanding illness, n (%)68 208 (28.96)156 (39.29)1.59<0.000128 899 (29.91)89 (42.58)1.74<0.000128 954 (29.94)34 (36.17)1.330.19
 Diabetes10 969 (4.66)38 (9.57)2.16<0.00014575 (4.74)20 (9.57)2.120.0014591 (4.75)4 (4.26)0.890.82
 CVD11 238 (4.77)35 (8.82)1.930.00024870 (5.04)18 (8.61)1.770.024884 (5.05)4 (4.26)0.840.73
 Cancer15 849 (6.75)32 (8.12)1.220.286557 (6.81)27 (12.92)2.030.00066573 (6.82)11 (11.70)1.810.06
 Depression45 781 (19.44)68 (17.13)0.860.2518 651 (19.31)34 (16.27)0.810.2718 667 (19.30)18 (19.15)0.990.97
 CKD stages 3–5293 (0.12)2 (0.50)4.040.049128 (0.13)0 (0.00)0.000.97128 (0.13)0 (0.00)0.000.98
 SLE274 (0.12)0 (0.00)0.000.96125 (0.13)0 (0.00)0.000.97125 (0.13)0 (0.00)0.000.98
 Asthma27 722 (11.77)54 (13.60)1.180.2611 433 (11.83)34 (16.27)1.450.04911 454 (11.84)13 (13.83)1.190.55
 Sleep apnoea718 (0.30)4 (1.01)3.320.02317 (0.33)0 (0.00)0.000.97317 (0.33)0 (0.00)0.000.97
 COPD536 (0.23)3 (0.76)3.330.04241 (0.25)0 (0.00)0.000.96240 (0.25)1 (1.06)4.310.15
 Bronchitis2515 (1.07)8 (2.02)1.900.071085 (1.12)6 (2.87)2.590.021087 (1.12)4 (4.26)3.900.008
 Pneumonia2938 (1.25)8 (2.02)1.630.171152 (1.19)4 (1.91)1.610.341155 (1.19)1 (1.06)0.890.91
 Other respiratory disease1243 (0.53)3 (0.76)1.430.53511 (0.53)1 (0.48)0.900.92512 (0.53)0 (0.00)0.000.98
Medication at baseline, n (%)
 Statin36 314 (15.42)98 (24.69)1.80<0.000115 358 (15.90)39 (18.66)1.210.2815 389 (15.91)8 (8.51)0.490.055
 BP medication37 590 (15.96)105 (26.45)1.89<0.000115 719 (16.27)34 (16.27)1.001.0015 741 (16.27)12 (12.77)0.750.36
 Steroid876 (0.37)1 (0.25)0.680.70354 (0.37)1 (0.48)1.310.79355 (0.37)0 (0.00)0.000.98
Biomarker at baseline
 Total cholesterol (mmol/L)†5.62 (4.92–6.34)5.48 (4.68–6.21)0.850.0015.62 (4.91–6.34)5.62 (4.84–6.30)0.990.945.62 (4.91–6.34)5.62 (5.04–6.37)1.070.49
 HDL cholesterol (mmol/L)1.40 (1.17–1.67)1.29 (1.09–1.54)0.71<0.00011.39 (1.17–1.67)1.41 (1.14–1.70)1.010.871.39 (1.17–1.67)1.36 (1.12–1.64)0.920.44
 Cystatin C (mg/L)0.88 (0.80–0.97)0.92 (0.83–1.02)1.34<0.00010.88 (0.80–0.97)0.89 (0.80–1.01)1.120.070.88 (0.80–0.97)0.91 (0.82–0.98)1.030.76
 HbA1c (mmol/mol) †35.10 (32.60–37.60)36.20 (33.60–39.60)1.30<0.000135.10 (32.60–37.60)36.00 (33.50–39.00)1.22<0.000135.10 (32.60–37.60)35.10 (32.32–38.30)1.080.39
 CRP (mg/L) †1.25 (0.63–2.56)1.58 (0.86–3.28)1.150.00011.27 (0.64–2.59)1.37 (0.84–3.27)1.140.011.27 (0.64–2.59)1.34 (0.70–2.93)1.070.47
 Rheumatoid factor (IU/ml)3.16 (3.16–3.16)3.16 (3.16–3.16)1.020.643.16 (3.16–3.16)3.16 (3.16–3.16)1.040.503.16 (3.16–3.16)3.16 (3.16–3.16)1.040.64
 Red cell distribution width (%)13.30 (12.90–13.80)13.32 (12.97–13.95)1.120.0113.30 (12.89–13.80)13.38 (12.97–14.02)1.150.0213.30 (12.89–13.80)13.27 (12.97–13.70)0.900.36
 White cell count (*109/L)6.60 (5.61–7.80)6.90 (5.84–8.26)1.170.0016.63 (5.64–7.80)6.90 (5.80–8.29)1.150.036.63 (5.64–7.80)6.60 (5.50–7.76)1.020.82
 Neutrophil count (*109/L)4.00 (3.25–4.90)4.12 (3.29–5.13)1.120.024.01 (3.26–4.92)4.11 (3.41–5.15)1.100.134.01 (3.26–4.92)4.02 (3.30–5.05)0.990.93
 Lymphocyte count (*109/L)1.88 (1.52–2.29)1.90 (1.55–2.40)1.130.0091.88 (1.52–2.30)1.92 (1.60–2.36)1.110.121.88 (1.52–2.29)1.85 (1.51–2.53)1.040.68
 Monocyte count (*109/L)0.45 (0.36–0.56)0.47 (0.39–0.59)1.130.010.45 (0.37–0.57)0.48 (0.37–0.59)1.070.310.45 (0.37–0.57)0.50 (0.40–0.57)1.140.17
  • Numbers represent number (%) for categorical variables, mean (SD) for Gaussian continuous variables, and median (25–75 percentiles) for skewed variables

  • *Univariable risk ratio per 1 SD for continuous variables and using comparator group for categorical variables.

  • †Evidence for non-linear association with COVID-19 (see online supplemental table 33)

  • BMI, body mass index; BP, blood pressure; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CRP, C reactive protein; CVD, cardiovascular disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; SLE, systemic lupus erythematosus.