Table 1 Structured statement of estimands
Total effect | Overall effect | |
|---|---|---|
Description | Effect of offering vaccination to clusters in 1–30-year-olds who would take it | Effect of offering vaccination to clusters in 1–30-year-olds |
Target population (to whom the treatment effect applies) | Residents of Vellore aged 1–30 years who would take their assigned treatment | Residents of Vellore aged 1–30 years |
Treatment condition (including the population exposed to an offer) | TyphiBEV® vaccination of those aged 1–30 years, including catch-up for late recruits (but not for participants who move from a control to a vaccination cluster) | Offer of TyphiBEV® vaccination to those aged 1–30 years, including catch-up for late recruits (but not for participants who move from a control to a vaccination cluster) |
Endpoint | Blood culture-confirmed typhoid fever within 2 years | Blood culture-confirmed typhoid fever within 2 years |
Summary measure/s | Marginal individual average incidence rate ratio | Marginal individual average incidence rate ratio |
Intercurrent event handling | Refusal of vaccine offer by participants in vaccine clusters will be handled using a principal stratum strategy (which is our interpretation of the total effect), as will taking of vaccine by participants in non-vaccine clusters | Refusal of vaccine will be handled using a treatment policy strategy (which corresponds to the overall effect) |
Migration | Migration | |
Out of the study area will be handled by censoring the participant at the point they leave | Out of the study area will be handled by censoring the participant at the point they leave | |
Into study area will be treated as late recruitment | Into study area will be treated as late recruitment | |
From control cluster to control cluster does not affect the estimand | From control cluster to control cluster does not affect the estimand | |
From vaccine cluster to vaccine cluster does not affect the estimand | From vaccine cluster to vaccine cluster does not affect the estimand | |
From vaccine cluster to control cluster will be censored | From vaccine cluster to control cluster will be censored | |
From control cluster to vaccine cluster will be censored | From control cluster to vaccine cluster will be censored |