 These results contradict previous studies on the German case. 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 .
<coherence>  These results contradict previous studies on the German case. 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 .
 Thus, the effectiveness of most German interventions remains questionable. Moreover, assessing of interventions : a) the estimation of true infection dates , b) the usage of several indicators and c) the influence of test volume .