2. Pre‐/post‐test probabilities and likelihood ratios with 95% confidence intervals.
| Symptom/sign | Study | Pre‐test probability | Post‐test probability (symptom/sign positive) | Post‐test probability (symptom/sign negative) | Positive likelihood ratio | Negative likelihood ratio |
| Cough | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.10 (0.06 to 0.15) | 0.08 (0.02 to 0.22) | 1.03 (0.88 to 1.21) | 0.83 (0.28 to 2.50) |
| Kumar 2011 | 0.36 (0.29 to 0.43) | 0.35 (0.29 to 0.42) | 0.50 (0.01 to 0.99) | 0.99 (0.96 to 1.03) | 1.82 (0.12 to 28.6) | |
| Maheshwari 2011 | 0.31 (0.21 to 0.42) | 0.33 (0.22 to 0.46) | 0.18 (0.02 to 0.52) | 1.10 (0.93 to 1.32) | 0.50 (0.12 to 2.15) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.38 (0.32 to 0.45) | 0.33 (0.27 to 0.41) | 1.09 (0.92 to 1.31) | 0.89 (0.71 to 1.12) | |
| Somer 2006 | 0.27 (0.20 to 0.35) | 0.29 (0.20 to 0.38) | 0.22 (0.09 to 0.40) | 1.08 (0.90 to 1.30) | 0.75 (0.36 to 1.60) | |
| Wheeze | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.08 (0.04 to 0.15) | 0.11 (0.06 to 0.17) | 0.81 (0.45 to 1.46) | 1.13 (0.84 to 1.53) |
| Chan 2001 | 0.24 (0.17 to 0.31) | 0.17 (0.90 to 0.28) | 0.28 (0.16 to 0.55) | 0.66 (0.39 to 1.14) | 1.24 (0.98 to 1.58) | |
| Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.11 (0.04 to 0.22) | 0.16 (0.11 to 0.22) | 0.71 (0.33 to 1.54) | 1.09 (0.92 to 1.28) | |
| Maheshwari 2011 | 0.31 (0.21 to 0.42) | 0.33 (0.17 to 0.53) | 0.29 (0.16 to 0.44) | 1.13 (0.63 to 2.02) | 0.92 (0.61 to 1.40) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.30 (0.19 to 0.43) | 0.37 (0.32 to 0.42) | 0.77 (0.46 to 1.28) | 1.04 (0.97 to 1.13) | |
| Somer 2006 | 0.27 (0.20 to 0.35) | 0.21 (0.11 to 0.33) | 0.32 (0.22 to 0.43) | 0.70 (0.42 to 1.17) | 1.25 (0.94 to 1.65) | |
| Coryza | Kumar 2011 | 0.36 (0.29 to 0.43) | 0.36 (0.28 to 0.43) | 0.35 (0.19 to 0.55) | 1.00 (0.88 to 1.13) | 1.00 (0.51 to 1.97) |
| Maheshwari 2011 | 0.31 (0.21 to 0.42) | 0.31 (0.16 to 0.48) | 0.31 (0.17 to 0.48) | 0.99 (0.60 to 1.66) | 1.00 (0.51 to 1.97) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.32 (0.21 to 0.46) | 0.36 (0.32 to 0.42) | 0.85 (0.51 to 1.41) | 1.03 (0.95 to 1.11) | |
| Somer 2006 | 0.27 (0.20 to 0.35) | 0.30 (0.07 to 0.65) | 0.27 (0.20 to 0.35) | 1.15 (0.31 to 4.22) | 0.99 (0.89 to 1.10) | |
| Crepitations | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.08 (0.05 to 0.13) | 0.17 (0.07 to 0.31) | 0.84 (0.65 to 1.10) | 1.83 (0.91 to 3.65) |
| Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.15 (0.11 to 0.20) | 0.13 (0.03 to 0.32) | 1.02 (0.91 to 1.14) | 0.83 (0.26 to 2.64) | |
| Maheshwari 2011 | 0.31 (0.21 to 0.42) | 0.36 (0.24 to 0.50) | 0.15 (0.03 to 0.38) | 1.29 (1.01 to 1.65) | 0.40 (0.13 to 1.23) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.38 (0.32 to 0.43) | 0.28 (0.19 to 0.40) | 1.08 (0.99 to 1.19) | 0.71 (0.46 to 1.1) | |
| Somer 2006 | 0.27 (0.20 to 0.35) | 0.32 (0.22 to 0.42) | 0.19 (0.09 to 0.33) | 1.24 (0.98 to 1.56) | 0.62 (0.33 to 1.15) | |
| Fever | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.10 (0.06 to 0.15) | 0.10 (0.03 to 0.24) | 0.99 (0.82 to 1.20) | 1.04 (0.41 to 2.68) |
| Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.14 (0.10 to 0.19) | 0.33 (0.04 to 0.78) | 0.96 (0.89 to 1.05) | 2.90 (0.55 to 15.27) | |
| Kumar 2011 | 0.36 (0.29 to 0.43) | 0.35 (0.28 to 0.43) | 0.36 (0.21 to 0.53) | 1.00 (0.86 to 1.15) | 1.02 (0.57 to 1.83) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.37 (0.32 to 0.42) | 0.31 (0.21 to 0.44) | 1.04 (0.95 to 1.13) | 0.82 (0.51 to 1.31) | |
| Somer 2006 | 0.27 (0.20 to 0.35) | 0.26 (0.16 to 0.37) | 0.29 (0.18 to 0.42) | 0.93 (0.66 to 1.31) | 1.10 (0.73 to 1.64) | |
| Rhonchi | Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.11 (0.04 to 0.22) | 0.16 (0.11 to 0.22) | 0.71 (0.33 to 1.54) | 1.09 (0.92 to 1.28) |
| Kumar 2011 | 0.36 (0.29 to 0.43) | 0.38 (0.30 to 0.48) | 0.22 (0.13 to 0.33) | 1.32 (1.07 to 1.64) | 0.59 (0.37 to 0.94) | |
| Maheshwari 2011 | 0.31 (0.21 to 0.42) | 0.27 (0.15 to 0.42) | 0.37 (0.19 to 0.58) | 0.84 (0.56 to 1.26) | 1.33 (0.72 to 2.44) | |
| Principi 2001 | 0.36 (0.31 to 0.41) | 0.24 (0.15 to 0.36) | 0.38 (0.33 to 0.43) | 0.57 (0.34 to 0.97) | 1.10 (1.01 to 1.19) | |
| Shortness of breath | Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.13 (0.08 to 0.18) | 0.21 (0.11 to 0.34) | 0.85 (0.67 to 1.08) | 1.55 (0.91 to 2.63) |
| Headache | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.04 (0.00 to 0.21) | 0.01 (0.00 to 0.03) | 4.56 (0.43 to 48.48) | 0.97 (0.89 to 1.05) |
| Chest pain | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.22 (0.03 to 0.60) | 0.09 (0.06 to 0.14) | 2.61 (0.57 to 11.85) | 0.95 (0.84 to 1.07) |
| Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.33 (0.15 to 0.57) | 0.13 (0.09 to 0.18) | 2.90 (1.26 to 6.69) | 0.86 (0.73 to 1.02) | |
| Diarrhoea | Agarwal 2009 | 0.10 (0.06 to 0.14) | 0.10 (0.03 to 0.21) | 0.10 (0.06 to 0.15) | 0.97 (0.43 to 2.20) | 1.01 (0.81 to 1.25) |
| Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.14 (0.05 to 0.29) | 0.15 (0.10 to 0.20) | 0.94 (0.39 to 2.25) | 1.01 (0.88 to 1.17) | |
| Myalgia | Deerojanawong 2006 | 0.15 (0.11 to 0.20) | 0.16 (0.05 to 0.33) | 0.15 (0.10 to 0.20) | 1.08 (0.44 to 2.61) | 0.99 (0.86 to 1.14) |