2. Summary of clinical outcomes: delayed versus immediate antibiotics.
| Study | Outcome | Delay | Immediate | Favours | Result (95% CI) |
| Sore throat (pharyngitis) | |||||
| Pichichero 1987 | Fever severity on Day 3 | 37.2 °C (SD 1.2, n = 55) | 36.8 °C (SD 0.6, n = 59) | Immediate antibiotics | MD 0.40 (95% CI 0.05 to 0.75) |
| Malaise severity on Day 3 | 1.3 (SD 1.0, n = 55) | 1.1 (SD 0.7, n = 59) | No difference | MD 0.20 (95% CI ‐0.11 to 0.51) | |
| Pain severity on Day 3 | 1.6 (SD 1.4, n = 55) | 1.3 (SD 1.3, n = 59) | No difference | MD 0.30 (95% CI ‐0.15 to 0.75) | |
| Compliance | 55/55 | 59/59 | No difference | 100% in both groups | |
| Gerber 1990 | Recurrence rate | — | — | No difference | Data not available |
| Compliance | 44/50 | 59/63 | Delayed antibiotics | 88% in immediate group and 93% in delayed group | |
| El‐Daher 1991 | Vomiting | 57/118 | 4/111 | Immediate antibiotics | OR 25.00 (95% CI 8.65 to 72.25) |
| Pain on Day 3 | 106/118 | 42/111 | Immediate antibiotics | OR 14.51 (95% CI 7.14 to 29.50) | |
| Malaise on Day 3 | 45/118 | 4/111 | Immediate antibiotics | OR 16.49 (95% CI 5.68 to 47.83) | |
| Fever severity on Day 3 | 38.0 °C (SD 2.0, n = 118) | 37.1 °C (SD 1.0, n = 111) | Immediate antibiotics | SMD 0.58 (95% CI 0.31 to 0.84) | |
| Little 1997 | Vomiting | 15/179 | 18/215 | No difference | OR 1.00 (95% CI 0.49 to 2.05) |
| Diarrhoea | 23/179 | 23/215 | No difference | OR 1.23 (95% CI 0.67 to 2.28) | |
| Rash | 11/180 | 14/215 | No difference | OR 0.93 (95% CI 0.41 to 2.11) | |
| Stomach ache | 48/180 | 66/215 | No difference | OR 0.82 (95% CI 0.53 to 1.27) | |
| Fever (> 37.0 °C) | Unavailable | Unavailable | Immediate antibiotics | Data not available | |
| Pain | Unavailable | Unavailable | No difference | Data not available | |
| Cough | Unavailable | Unavailable | No difference | Data not available | |
| Malaise | Unavailable | Unavailable | No difference | Data not available | |
| Analgesic use | Unavailable | Unavailable | No difference | Data not available | |
| Time off work | Unavailable | Unavailable | No difference | Data not available | |
| De la Poza Abad 2016 | Pain duration (delayed prescription at time of visit) | 5.7 days (SD 5.1, n = 45) | 4.4 days (SD 2.4, n = 47) | No difference | MD 1.30 (95% CI ‐0.34 to 2.94) |
| Pain duration (delayed prescription requiring collection) | 7.4 days (SD 6.3, n = 46) | 4.4 days (SD 2.4, n = 47) | No difference | MD 3.00 (95% CI ‐1.03 to 4.95) | |
| Fever duration (delayed prescription at time of visit) | 3.1 days (SD 1.8, n = 45) | 2.9 days (SD 1.7, n = 47) | No difference | MD ‐0.20 (95% CI ‐0.52 to 0.92) | |
| Fever duration (delayed prescription requiring collection) | 3.4 days (SD 2.4, n = 46) | 2.9 days (SD 1.7, n = 47) | No difference | MD 0.50 (95% CI ‐0.35 to 1.35) | |
| Cough duration (delayed prescription at time of visit) | 8.1 days (SD 5.9, n = 45) | 8.1 days (SD 5.7, n = 47) | No difference | MD ‐2.50 (95% CI ‐5.52 to 0.52) | |
| Cough duration (delayed prescription requiring collection) | 8.2 days (SD 6.9, n = 46) | 8.1 days (SD 5.7, n = 47) | No difference | MD ‐2.40 (95% CI ‐5.59 to 0.79) | |
| Nasal mucosity duration (delayed prescription at time of visit) | 7.2 days (SD 4.3, n = 45) | 5.4 days (SD 3.9, n = 47) | Immediate antibiotics | MD ‐1.80 (95% CI 0.12 to 3.48) | |
| Nasal mucosity duration (delayed prescription requiring collection) | 9.7 days (SD 8.3, n = 46) | 8.9 days (SD 6.5, n = 46) | Immediate antibiotics | MD 4.30 (95% CI 1.65 to 6.95) | |
| Mas‐Dalmau 2021 | Headache duration | 5.5 days (SD 7.0, n = 146) | 5.8 days (SD 8.7, n = 148) | No difference | P = 0.867 |
| Headache severitya | 3 (IQR 2 to 3) | 2 (IQR 1 to 4) | Unavailable | Unavailable | |
| Sore throat duration | 5.0 days (SD 4.1, n = 146) | 5.2 days (SD 4.7, n = 148) | No difference | P = 0.824 | |
| Sore throat severitya | 3 (IQR 2 to 5) | 3 (IQR 2 to 3) | Unavailable | Unavailable | |
| Difficulty swallowing duration | 4.7 days (SD 3.8, n = 146) | 4.9 days (SD 4.8, n = 148) | No difference | P = 0.812 | |
| Difficulty swallowing severitya | 3 (IQR 2 to 4) | 2 (IQR 2 to 3) | No difference | Unavailable | |
| Acute otitis media | |||||
| Little 2001 | Diarrhoea | 14/150 | 25/135 | Delayed antibiotics | OR 0.45 (95% CI 0.22 to 0.91) |
| Rash | 8/150 | 6/135 | No difference | OR 1.21 (95% CI 0.41 to 2.58) | |
| Participants with pain on Day 3 | 28/111 | 15/101 | No difference | OR 1.93 (95% CI 0.96 to 3.88) | |
| Participants with pain on Day 7 | 3/111 | 0/101 | No difference | OR 6.55 (95% CI 0.33 to 128.35) | |
| Participants with malaise on Day 3 | 45/150 | 19/135 | Immediate antibiotics | OR 2.62 (95% CI 1.44 to 4.76) | |
| Malaise severity Day 3 | 0.8 (SD 1.7, n = 150) | 0.4 (SD 1.0, n = 134) | Immediate antibiotics | MD 0.43 (95% CI 0.11 to 0.75) | |
| Malaise severity on Day 7 | 2.2 (SD 2.0, n = 150) | 1.5 (SD 1.2, n = 135) | No difference | MD 0.01 (95% CI ‐0.11 to 0.13) | |
| Pain severity on Day 3 | 2.6 (SD 2.1, n = 111) | 1.8 (SD 1.4, n = 102) | Immediate antibiotics | MD 0.75 (95% CI 0.26 to 1.24) | |
| Pain severity on Day 7 | 1.17 (SD 0.75, n = 111) | 1.05 (SD 0.38, n = 101) | No difference | MD 0.12 (95% CI ‐0.04 to 0.28) | |
| Paracetamol consumption | 2.3 spoons | 1.7 spoons | Immediate antibiotics | MD 0.59 (95% CI 0.25 to 0.93) | |
| Last day of crying | 2.2 days | 1.5 days | Immediate antibiotics | MD 0.69 (95% CI 0.31 to 1.07) | |
| Little 2006 | Episodes of earache in the 3 months since randomisation | Unavailable | Unavailable | No difference | OR 0.89 (95% CI 0.48 to 1.65) |
| Episodes of earache over 1 year | Unavailable | Unavailable | No difference | OR 1.03 (95% CI 0.60 to 1.78) | |
| Spiro 2006 | Pain day 4 to 6 | 85/132 | 89/133 | No difference | OR 0.89 (95% CI 0.54 to 1.48) |
| Fever day 4 to 6 | 42/132 | 46/133 | No difference | OR 0.88 (95% CI 0.53 to 1.47) | |
| Vomiting | 15/132 | 15/133 | No difference | OR 1.01 (95% CI 0.47 to 2.16) | |
| Diarrhoea | 10/132 | 31/133 | Delayed antibiotics | OR 0.27 (95% CI 0.13 to 0.58) | |
| Mas‐Dalmau 2021 | Earache duration | 4.4 days (SD 3.9, n = 146) | 5.1 days (SD 5.3, n = 148) | No difference | P = 0.239 |
| Earache severitya | 2 (IQR 1 to 3) | 2 (IQR 1 to 3) | Unavailable | Unavailable | |
| Cough (bronchitis) | |||||
| Dowell 2001 | Clinical outcomes | Unavailable | Unavailable | No difference | Data not available |
| Little 2005a | Clinical outcomes | Unavailable | Unavailable | No difference | Data not available |
| De la Poza Abad 2016 | Pain duration (delayed prescription at time of visit) | 11.0 days (SD 8.0, n = 32) | 10.5 days (SD 8.0, n = 32) | No difference | MD 0.50 (95% CI ‐0.34 to 4.42) |
| Pain duration (delayed prescription requiring collection) | 8.9 days (SD 6.9, n = 32) | 10.5 days (SD 8.0, n = 32) | No difference | MD ‐1.60 (95% CI ‐5.26 to 2.06) | |
| Fever duration (delayed prescription at time of visit) | 5.6 days (SD 5.9, n = 32) | 4.1 days (SD 5.7, n = 32) | No difference | MD 1.50 (95% CI ‐1.34 to 4.34) | |
| Fever duration (delayed prescription requiring collection) | 4.7 days (SD 4.6, n = 32) | 4.1 days (SD 5.7, n = 32) | No difference | MD 0.60 (95% CI ‐1.94 to 3.14) | |
| Cough duration (delayed prescription at time of visit) | 15.6 days (SD 8.8, n = 32) | 13.0 days (SD 7.0, n = 32) | No difference | MD 2.60 (95% CI ‐1.30 to 6.50) | |
| Cough duration (delayed prescription requiring collection) | 12 days (SD 5.6, n = 32) | 13.0 days (SD 7.0, n = 32) | No difference | MD ‐1.00 (95% CI ‐4.11 to 2.11) | |
| Mas‐Dalmau 2021 | Cough duration | 9.5 days (SD 7.1, n = 146) | 7.9 days (SD 4.4, n = 148) | No difference | P = 0.295 |
| Cough severitya | 3 (IQR 2 to 3) | 2 (IQR 2 to 3) | Unavailable | Unavailable | |
| Common cold | |||||
| Arroll 2002a | Participants with fever on Day 3 | 5/67 | 6/62 | No difference | OR 0.75 (95% CI 0.22 to 2.6) |
| Participants with fever on Day 7 | 3/67 | 4/62 | No difference | OR 0.68 (95% CI 0.15 to 3.17) | |
| Participants with diarrhoea | 11/67 | 12/62 | No difference | OR 0.79 (95% CI 0.53 to 1.19) | |
| Participants with pain on Day 3 | 13/61 | 9/58 | No difference | OR 1.47 (95% CI 0.58 to 3.77) | |
| Participants with pain on Day 7 | 1/61 | 3/58 | No difference | OR 0.31 (95% CI 0.03 to 3.03) | |
| Participants with cough on Day 3 | 54/67 | 51/62 | No difference | OR 0.90 (95% CI 0.37 to 2.18) | |
| Participants with cough on Day 7 | 41/61 | 43/58 | No difference | OR 0.72 (95% CI 0.32 to 1.58) | |
| Fever severity on Day 3 | 36.2 °C (SD 0.7, n = 61) | 36.4 °C (SD 0.6, n = 58) | No difference | MD ‐0.24 (95% CI ‐0.48 to 0.00) | |
| Fever severity on Day 7 | 36.0 °C (SD 0.8, n = 59) | 36.3 °C (SD 0.6, n = 60) | Delayed antibiotics | MD ‐0.32 (95% CI ‐0.57 to ‐0.07) | |
| De la Poza Abad 2016 | Pain duration (delayed prescription at time of visit) | 8.4 days (SD 8.2, n = 29) | 6.7 days (SD 4.5, n = 20) | No difference | MD 1.70 (95% CI ‐1.88 to 5.28) |
| Pain duration (delayed prescription requiring collection) | 10.1 days (SD 7.5, n = 20) | 6.7 days (SD 4.5, n = 20) | No difference | MD 3.40 (95% CI ‐0.43 to 7.23) | |
| Fever duration (delayed prescription at time of visit) | 3.0 days (SD 1.2, n = 29) | 5.3 days (SD 6.2, n = 20) | No difference | MD ‐2.30 (95% CI ‐5.05 to 0.45) | |
| Fever duration (delayed prescription requiring collection) | 4.2 days (SD 3.0, n = 20) | 5.3 days (SD 6.2, n = 20) | No difference | MD ‐1.10 (95% CI ‐4.12 to 1.92) | |
| Cough duration (delayed prescription at time of visit) | 8.3 days (SD 5.2, n = 29) | 7.6 days (SD 5.6, n = 20) | No difference | MD ‐0.70 (95% CI ‐2.40 to 3.80) | |
| Cough duration (delayed prescription requiring collection) | 6.4 days (SD 4.6, n = 20) | 7.6 days (SD 5.6, n = 20) | No difference | MD ‐1.20 (95% CI ‐4.38 to 1.98) | |
| Nasal mucosity duration (delayed prescription at time of visit) | 15.2 days (SD 9.7, n = 29) | 13.0 days (SD 8.8, n = 20) | No difference | MD 2.20 (95% CI ‐3.03 to 7.43) | |
| Nasal mucosity duration (delayed prescription requiring collection) | 10.7 days (SD 7.2, n = 20) | 13.0 days (SD 8.8, n = 20) | No difference | MD ‐2.30 (95% CI ‐7.28 to 2.68) | |
CI: confidence interval IQR: interquartile range MD: mean difference OR: odds ratio SD: standard deviation SMD: standardised mean difference
aMas‐Dalmau 2021 symptom severity scored on Likert scale from 0 (no problem) to 6 (as bad as it could be) and reported as median (interquartile range (IQR)).