Skip to main content

Table 1 Clinical characteristics of patients diagnosed with influenza

From: Factors associated with hospitalization for seasonal influenza in a Japanese nonelderly cohort

  Total 2013/2014 season 2014/2015 season
Parameters Non-hospitalized patient Hospitalized patient P Non-hospitalized patient Hospitalized patient P Non-hospitalized patient Hospitalized patient P
  No. (%) No. (%)   No. (%) No. (%)   No. (%) No. (%)  
Number of patients 87,778   276    74,101   239    13,677   37   
 Female, n (%) 39,122 (44.57) 141 (51.09) 0.034 32,896 (44.39) 122 (51.05) 0.045 6226 (45.52) 19 (51.35) 0.585
 Age, (years)      <0.001   0.00    <0.001      
  <2 2916 (3.32) 58 (21.01)   2553 (3.45) 56 (23.43)   363 (2.65) 2 (5.41)  
  2–4 7932 (9.04) 58 (21.01)   6934 (9.36) 48 (20.08)   998 (7.30) 10 (27.03)  
  5–17 35,066 (39.95) 75 (27.17)   29,397 (39.67) 62 (25.94)   5669 (41.45) 13 (35.14)  
  18–64 41,864 (47.69) 85 (30.80)   35,217 (47.53) 73 (30.54)   6647 (48.60) 12 (32.43)  
Virus type      <0.001   0.00    <0.001      0.769
 A 54,643 (62.25) 188 (68.12)   41,160 (55.55) 152 (63.60)   13,483 (98.58) 36 (97.30)  
 B 32,048 (36.51) 78 (28.26)   31,863 (43.00) 77 (32.22)   185 (1.35) 1 (2.70)  
 Both A and B 1030 (1.17) 10 (3.62)   1021 (1.38) 10 (4.18)   9 (0.07) 0 (0.00)  
 Unknown 57 (0.06) 0 (0.00)   57 (0.08) 0 (0.00)   0 (0.00) 0 (0.00)  
Comorbidity
 Asthma 20,631 (23.50) 109 (39.49) <0.001 17,536 (23.66) 99 (41.42) <0.001 3095 (22.63) 10 (27.03) 0.659
 COPD 444 (0.51) 8 (2.90) <0.001 382 (0.52) 7 (2.93) <0.001 62 (0.45) 1 (2.70) 0.422
 Cardiovascular disease 811 (0.92) 5 (1.81) 0.222 705 (0.95) 5 (2.09) 0.14 106 (0.78) 0 0.00 1.000
 Cerebrovascular disease 357 (0.41) 4 (1.45) 0.025 304 (0.41) 3 (1.26) 0.126 53 (0.39) 1 (2.70) 0.352
 Diabetes mellitus 811 (0.92) 6 (2.17) 0.065 711 (0.96) 4 (1.67) 0.425 100 (0.73) 2 (5.41) 0.019
 Mental disorder 4294 (4.89) 25 (9.06) 0.002 3618 (4.88) 22 (9.21) 0.003 676 (4.94) 3 (8.11) 0.612
 Neurologic disease 4425 (5.04) 33 (11.96) <0.001 3708 (5.00) 26 (10.88) <0.001 717 (5.24) 7 (18.92) 0.001
 Anemia 1749 (1.99) 15 (5.43) <0.001 1458 (1.97) 12 (5.02) 0.002 291 (2.13) 3 (8.11) 0.052
 Immunodeficiency 113 (0.13) 1 (0.36) 0.811 97 (0.13) 1 (0.42) 0.741 16 (0.12) 0 0.00 1.000
 Liver disease 1768 (2.01) 11 (3.99) 0.035 1494 (2.02) 6 (2.51) 0.755 274 (2.00) 5 (13.51) <0.001
 Dialysis 19 (0.02) 1 (0.36) 0.08 14 (0.02) 1 (0.42) 0.039 5 (0.04) 0 0.00 1.000
 Malignancy 547 (0.62) 6 (2.17) 0.004 464 (0.63) 4 (1.67) 0.102 83 (0.61) 2 (5.41) 0.008
 Regular steroid use 796 (0.91) 8 (2.90) 0.002 665 (0.90) 7 (2.93) 0.003 131 (0.96) 1 (2.70) 0.808
Complication
 Respiratory co-infection 59,597 (67.90) 201 (72.83) 0.092 50,589 (68.27) 177 (74.06) 0.064 9008 (65.86) 24 (64.86) 1.000
 Encephalitis 0 (0.00) 6 (2.17) <0.001 0 (0.00) 6 (2.51) <0.001 0 (0.00) 0 (0.00)
 Pneumonia 0 (0.00) 6 (2.17) <0.001 0 (0.00) 4 (1.67) <0.001 0 (0.00) 2 (5.41) <0.001
 Death 0 (0.00) 1 (0.36) <0.001 0 (0.00) 1 (0.42) <0.001 0 (0.00) 0 (0.00)
  1. COPD chronic obstructive pulmonary disease