Before revision:  The study also exhibits three methodological challenges with respect to assessing of interventions : a) the estimation of true infection dates , b) the usage of several indicators and c) the influence of test volume . In conclusion, the effectiveness of most German interventions remains questionable .
After revision:  The study also exhibits three methodological challenges with respect to assessing of interventions : a) the estimation of true infection dates , b) the usage of several indicators and c) the influence of test volume .