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editorial
. 2018 Sep 6;28(Suppl 2):381–388. doi: 10.18865/ed.28.S2.381

Table 3. Sample size required for detecting mortality (proportion), 20%-25% reduction, CEP vs TA/OR.

Mortality Proportion in TA/OR and under null With 25% change CEP vs RS With 20% change CEP vs RS
Proportion in treatment Total N required if ICC=0 Total N required if Cluster=200 ICC=.01 Proportion in treatment Total N required if ICC=0 Total N required if Cluster=200 ICC=.01
.025 .01875 17196 130050 .020 27618 NAa
.050 .03750 8404 14580 .040 13490 42240
.075 .05625 5474 7560 .060 8782 15760

a. 80% power cannot be reached due to large design effects of clustering. For example, the sample sizes of 200,000 in one arm can only achieve 66% power to detect a difference between the group proportions of .005.

CEP, community engagement and planning; RS, resources for services; ICC, intracluster correlation coefficient.