Table 2

Detailed study outcomes

Primary outcomes
P1)Whether the CHICO intervention decrease the number of dispensed prescriptions for oral amoxicillin and macrolide antibiotics* (efficacy comparison).
P2)Whether the CHICO intervention result in no increase in hospital admissions† for children with a hospital diagnosis of RTI (non-inferiority comparison).
Secondary Outcomes
S1)Whether the CHICO intervention results in no change in the emergency department attendance rates‡ of children with a diagnosis of RTI.
S2)The costs to the NHS of using the CHICO intervention (health economic outcome).
S3)Whether there is any intervention effect modified by the no of locums used in the practice (treatment interaction).
S4)Whether there is any intervention effect modified by the practices’ prior antibiotic prescribing rate (treatment interaction).
S5)Whether the effects of the CHICO intervention differ between practices with or without nurse prescribers (treatment interaction).§
S6)¶Whether the effects of the CHICO intervention differ between practices with one site vs multiple sites (branches) at each practice (treatment interaction).
S7)¶Whether the effects of the CHICO intervention differ between practices with follow-up prior to COVID-19 pandemic and during the COVID-19 pandemic (treatment interaction).
S8)¶Whether the effects of the CHICO intervention differ in areas of high/low deprivation.
S9)Whether the effects of the CHICO intervention differ within child age groups.
S10)Whether the use of the CHICO intervention varies between practices (adherence) and over time (seasonal differences) and the influence this has on the dispensing rates.
S11)Whether the embedded CHICO intervention is acceptable to, and used by, primary care clinicians (GPs and practice nurses).
  • *The dispensing rate, calculated by adding the number of amoxicillin and macrolide antibiotics dispensed over the follow-up year divided by the number of children aged 0–9 years (median monthly list size) at each practice over the 12-month follow-up period.

  • †The rate of hospital admission for RTI among children aged 0–9 years using the same denominator as above.

  • ‡This is a secondary outcome already collected from practices by CCGs.

  • §If a large majority of practices have nurse prescribers then we may look at this as a continuous percentage of nurse prescribers, out of all GP and nurse prescribers.

  • ¶Added after the trial began, due to unforeseen circumstances including more variability in practices than we first anticipated. Therefore, these do not match those listed in the trial registration.

  • CCGs, Clinical Commissioning Groups; CHICO, CHICO; GP, general practitioner; NHS, National Health Service; RTI, respiratory tract infection.