Table 2 Analysis methods for vaccine effectiveness against persistent HPV infections
| Â | Conditional exact method for comparing two independent Poisson rates using a binomial distribution | Cox proportional hazard | GEE Poisson | Prentice Williams Peterson-Total time |
|---|---|---|---|---|
Outcome | Rate ratio | Hazard ratio | Rate ratio | Hazard ratio |
Assumption(s) | * Rate of events constant over time * Groups are considered to be equally exposed [52] | * Proportional hazard assumption (hazard ratio over time should be constant) * Independence assumption (estimate only for 1st event) [52] | * Rate of events constant over time [52] * Measurements are independent across subjects * Measurements may be correlated within subjects | * Event specific baseline hazard (baseline hazard for kth event allowed to be different) [51] |
Check assumptions in HAVANA | Assumption for constant rate over time violated among unvaccinated | Proportional hazard assumption not violated | Assumption for constant rate over time violated among unvaccinated | Assumption for event-specific hazard not violated |