Variable | Adjusted odds ratio (95% CI) | P-value |
---|---|---|
Number of RTI antibiotic courses in previous year | ||
None, n= 1050 | 1 (reference) | |
1 antibiotic, n= 230 | 1.03 (0.88 to1.21) | 0.67 |
≥2 antibiotics, n= 97 | 1.32 (1.04 to 1.66) | 0.02 |
Age at index prescription (T0) (years) | 0.95 (0.90 to 0.99) | 0.018 |
Sex | ||
Male | 1 (reference) | |
Female | 0.85 (0.76 to 0.95) | 0.003 |
Seasona | ||
Winter | 1 (reference) | |
Spring | 1.09 (0.96 to 1.26) | 0.18 |
Summer | 1.22 (1.03 to 1.43) | 0.02 |
Autumn | 1.00 (0.87 to 1.16) | 0.99 |
RTI typeb | ||
URTI | 1 (reference) | |
LRTI | 0.88 (0.75 to 1.04) | 0.13 |
AOM | 1.05 (0.88 to 1.25) | 0.60 |
URTI and LRTI | 2.37 (1.48 to 3.79) | <0.001 |
Other mix | 0.84 (0.31 to 2.27) | 0.73 |
Comorbidity | ||
None | 1 (reference) | |
Present | 1.20 (0.98 to 1.48) | 0.08 |
Antibiotic drug class | ||
Cephalosporin | 1 (reference) | |
Macrolides | 0.77 (0.50 to 1.19) | 0.25 |
Broad-spectrum penicillin (amoxicillin, co-amoxiclav) | 0.47 (0.30 to 0.71) | 0.001 |
Penicillinase-resistant (flucloxacillin) | 0.46 (0.14 to 1.54) | 0.21 |
Penicillin V (phenoxymethylpenicillin) | 0.60 (0.39 to 0.94) | 0.03 |
Quinolones | 0 (empty) | |
Trimethoprim-cotrimoxazole | 1.01 (0.41 to 2.53) | 0.98 |
Number of response failures in previous year | ||
None | 1 (reference) | |
1 | 2.08 (1.67 to 2.58) | <0.001 |
2 | 3.93 (1.18 to 13.12) | 0.03 |
Number of acute RTI consultations in previous year | 1.03 (1.02 to 1.05) | <0.001 |
Social deprivation | ||
1 (least deprived) | 1 (reference) | |
2 | 0.96 (0.81 to 1.13) | 0.61 |
3 | 1.08 (0.92 to 1.28) | 0.34 |
4 | 1.12 (0.95 to 1.32) | 0.17 |
5 (most deprived) | 0.99 (0.84 to 1.18) | 0.96 |
Vaccination status at index prescription (T0) | ||
Incomplete or none | 1 (reference) | |
Complete | 1.41 (1.26 to 1.59) | <0.001 |
↵a Seasons: winter (December to February); spring (March to May); summer (June to August); autumn (September to November).
↵b URTI: acute sinusitis, sore throat, laryngitis, coughs, for example, LRTI: pneumonia, bronchitis, for example. URTI and LRTI: two separate RTI Read codes for antibiotic prescribing event on same day. AOM = acute otitis media. IQR = interquartile range. LRTI = lower respiratory tract infection. RTI = respiratory tract infection. URTI = upper respiratory tract infection.