Table 1 Descriptive statistics (n = 1031) and bivariate analysis

 visit date

1028 (99.7%)

0.99 (0.99-0.99)

p < 0.001 **

 week day

1028 (99.7%)

range 0.64-1.28

p = 0.63

 time of day

1021 (99.0%)

0.99 (0.99-0.99)

p = 0.24

 gender

p = 0.03*

  female (reference group)

636 (61.7%)

-

  male

390 (37.8%)

1.34 (1.02-1.76)

  not recorded

5 (0.5%)

-

 race

p = 0.43

  white (reference group)

594 (57.6%)

-

  multiple

92 (8.9%)

0.90 (0.55-1.44)

  Asian

50 (4.8%)

0.97 (0.51-1.79)

  black

21 (2.0%)

1.04 (0.38-2.54)

  Hispanic

6 (0.6%)

-

  international

7 (0.7%)

-

  Pacific islander

1 (0.1%)

-

  not recorded

260 (25.2%)

-

 academic status

p = 0.27

  undergraduate student

932 (90.4%)

-

  graduate student

85 (8.2%)

0.86 (0.52-1.39)

  spouse/dependent

3 (0.3%)

-

  not recorded

11 (1.1%)

-

 height (inches)

1013 (98.2%)

1.04 (1.00-1.08)

p = 0.02*

 weight (pounds)

1016 (98.5%)

1.00 (0.99-1.01)

p = 0.09

 provider

see Fig 3

range 0.05–4.63

p < 0.001**

 days since onset (patient reported) ††

1016 (98.5%)

1.02 (1.01-1.03)

p < 0.001**

 severity (patient reported)

p = 0.009*

  mild (reference group)

61 (5.9%)

-

  moderate

342 (33.2%)

0.48 (0.27-0.86)

  severe

32 (3.1%)

1.13 (0.46-2.70)

  not recorded

596 (57.8%)

-

 progression (patient reported)

p < 0.001**

  stable/no change (reference group)

274 (26.6%)

-

  worsening

317 (30.7%)

2.27 (1.77-3.77)

  improving

108 (10.5%)

1.06 (0.60-1.84)

  not recorded

332 (32.2%)

-

 antibiotics in past month

40 (3.9%)

0.46 (0.19-1.00)

p = 0.07

 upper respiratory infection

197 (19.1%)

0.26 (0.16-0.39)

p < 0.001**

 suspicious cough

77 (7.5%)

1.02 (0.61-1.67)

p = 0.93

 allergic rhinitis

32 (3.1%)

0.51 (0.19-1.17)

p = 0.14

 fever

17 (1.6%)

2.58 (0.98-6.92)

p = 0.05

 viral syndrome

13 (1.3%)

-

-

 tonsillitis

6 (0.6%)

-

-

 influenza

4 (0.4%)

-

-

 mononucleosis

3 (0.3%)

-

-

  sore throat

402 (39.0%)

1.42 (1.08-1.85)

p = 0.01*

  painful swallowing

130 (12.6%)

0.58 (0.37-0.89)

p = 0.02*

  hoarseness

167 (16.2%)

0.80 (0.55-1.56)

p = 0.25

  swollen glands in neck

112 (10.9%)

1.08 (0.70-1.63)

p = 0.73

  headache

244 (23.7%)

0.79 (0.57-1.09)

p = 0.15

  documented fever

68 (6.6%)

0.70 (0.42-1.17)

p = 0.17

  fever symptoms (patient reported)

255 (24.7%)

0.94 (0.69-1.28)

p = 0.71

  chills

147 (14.2%)

0.94 (0.65-1.37)

p = 0.73

  sweats

159 (15.4%)

1.19 (0.82-1.75)

p = 0.36

  stuffy nose

665 (64.5%)

0.86 (0.66-1.14)

p = 0.29

  sinus congestion

344 (33.4%)

0.73 (0.55-0.98)

p = 0.03*

  clear nasal discharge

215 (20.9%)

0.71 (0.50-0.99)

p = 0.04*

  purulent nasal discharge

184 (17.8%)

0.83 (0.58-1.19)

p = 0.33

  post-nasal drip sensation

390 (37.8%)

0.93 (0.70-1.21)

p = 0.59

  sinus pain

79 (7.7%)

1.69 (1.05-2.69)

p = 0.03*

  sneezing

101 (9.8%)

0.39 (0.22-0.66)

p < 0.001**

  sleep disruption due to cough

610 (59.2%)

1.22 (0.93-1.59)

p = 0.15

  sputum production

638 (61.9%)

0.98 (0.75-1.29)

p = 0.91

  shortness of breath

348 (33.8%)

0.74 (0.56-0.97)

p = 0.03*

  chest tightness

277 (26.8%)

0.94 (0.69-1.26)

p = 0.67

  wheezing

275 (26.7%)

0.64 (0.48-0.86)

p = 0.003*

  chest pain

232 (22.5%)

0.82 (0.60-1.12)

p = 0.22

  paroxysms of cough

315 (30.6%)

0.98 (0.73-1.30)

p = 0.87

  ear pain

48 (4.7%)

1.02 (0.53-1.88)

p = 0.94

  ear pressure sensation

122 (11.8%)

0.89 (0.58-1.35)

p = 0.60

  decreased hearing

34 (3.3%)

0.81 (0.35-1.69)

p = 0.58

  loss of appetite

129 (12.5%)

0.82 (0.54-1.23)

p = 0.34

  abdominal pain

25 (2.4%)

0.30 (0.07-0.87)

p = 0.05

  post-tussive vomiting

74 (7.2%)

0.67 (0.41-1.09)

p = 0.10

  nausea

63 (6.1%)

0.46 (0.22-0.86)

p = 0.02*

  vomiting

48 (4.6%)

0.44 (0.19-0.89)

p = 0.03*

  diarrhea

34 (3.3%)

1.24 (0.59-2.49)

p = 0.56

  lightheadedness

47 (4.6%)

1.29 (0.69-2.35)

p = 0.41

 chest x-ray

177 (17.2%)

2.09 (1.50-2.90)

p < 0.001**

 rapid strep screen

31 (3.0%)

0.65 (0.26-1.45)

p = 0.32

 complete blood count

85 (8.2%)

1.40 (0.88-2.21)

p = 0.15

 Monospot

27 (2.6%)

1.83 (0.83-3.95)

p = 0.12

 influenza A + B

16 (1.6%)

0.32 (0.05-1.14)

p = 0.13

 ear exam

  tympanic membrane (TM)

27 (2.6%)

0.08 (0.004-0.40)

p = 0.01*

  TM retraction

42 (4.1%)

0.79 (0.38-1.55)

p = 0.51

  visible fluid behind TM

148 (14.3%)

0.17 (0.09-0.29)

p < 0.001**

  cerumen in canal

29 (2.8%)

0.46 (0.15-1.12)

p = 0.12

  mucosal edema

580 (56.2%)

0.83 (0.63-1.08)

p = 0.16

  mucosal erythema

510 (49.5%)

0.78 (0.59-1.01)

p = 0.06

  nasal discharge

324 (31.4%)

1.59 (1.20-2.09)

p = 0.001**

  maxillary sinus tenderness

30 (2.9%)

1.75 (0.83-3.64)

p = 0.13

  erythema

209 (20.3%)

0.79 (0.56-1.10)

p = 0.17

  lymphoid hyperplasia

104 (10.1%)

1.47 (0.96-2.22)

p = 0.07

  post-nasal drip

157 (15.2%)

1.44 (1.00-2.04)

p = 0.04*

  surgically absent

42 (4.1%)

1.13 (0.57-2.14)

p = 0.71

  erythema

84 (8.1%)

0.43 (0.23-0.74)

p = 0.004**

  enlarged

47 (4.5%)

1.17 (0.62-2.32)

p = 0.64

  anterior cervical lymphadenopathy, tender

53 (5.1%)

1.93 (1.10-3.38)

p = 0.02*

  anterior cervical lymphadenopathy, non-tender

87 (8.4%)

0.70 (0.41-1.14)

p = 0.16

  posterior cervical lymphadenopathy, non-tender

51 (4.9%)

0.60 (0.29-1.16)

p = 0.15

  anterior cervical lymphadenopathy

99 (9.6%)

3.05 (2.01-4.66)

p < 0.001**

  posterior cervical lymphadenopathy

26 (2.5%)

1.00 (0.41-2.25)

p = 0.10

  wheezing

215 (20.9%)

1.92 (1.40-2.61)

p < 0.001**

  rales

21 (2.0%)

10.05 (3.69-35.18)

p < 0.001**

  rhonchi

223 (21.6%)

2.33 (1.71-3.16)

p < 0.001**

  percussion abnormality

25 (2.4%)

9.55 (3.83-28.91)

p < 0.001**