Table 2 Main effect estimates of prognostic factors for cure, based on the random intercept model as derived from IPD of ten trials. Coefficients (log(OR)), standard errors, odds ratios (OR), and 95% confidence intervals (CI) were pooled across imputations. The mean standard deviation of the random intercepts was 0.33

Intercept

0.83

0.88

(−0.89, 2.56)

2.30 (0.41, 12.98)

Antibiotics (yes)

0.29

0.09

(0.12, 0.46)

1.34 (1.13, 1.59)

Sex, female

−0.09

0.09

(−0.27, 0.09)

0.92 (0.76, 1.10)

Age, per 10 years

−0.10

0.03

(−0.16, −0.03)

0.91 (0.85, 0.97)

Preceding URTI

0.23

0.19

(−0.15, 0.61)

1.26 (0.86, 1.84)

Symptom duration in log(days)

−0.27

0.08

(−0.42, −0.12)

0.76 (0.65, 0.89)

Pain on bending

0.12

0.18

(−0.23, 0.47)

1.13(0.80, 1.60)

Pain in teeth

−0.12

0.15

(−0.42, 0.18)

0.89 (0.66, 1.20)

Unilateral facial pain

0.14

0.13

(−0.11, 0.40)

1.15 (0.89, 1.49)

PNDsr

0.17

0.11

(−0.05, 0.39)

1.19 (0.95, 1.48)

Symptom severity^a

−0.14

0.03

(−0.20, −0.09)

0.87 (0.82, 0.91)

Fever

−0.25

0.19

(−0.63, 0.13)

0.78 (0.53, 1.14)

PNDex

0.07

0.10

(−0.12, 0.26)

1.07 (0.89, 1.29)

PPDex

−0.19

0.15

(−0.48, 0.10)

0.82 (0.62, 1.10)

Time to outcome measurement (days)

0.03

0.08

(−0.12, 0.18)

1.03 (0.89, 1.20)

Outcome type: other, (ref. diary)

−0.92

0.38

(−1.66, −0.18)

0.40 (0.19, 0.84)

Outcome type: telephone, (ref. diary)

−0.13

0.37

(−0.85, 0.59)

0.88 (0.43, 1.81)