Table 1.

Sample size calculation.

Incidence of change in surgical conduct							Precision
20%	19%	18%	17%	16%	15%	14%
6,145	5,911	5,668	5,419	5,163	4,896	4,624	1%
2,731	2,627	2,518	2,408	2,294	2,176	2,057	1.50%
1,535	1,476	1,417	1,354	1,289	1,223	1,157	2%
981	944	906	866	826	782	739	2.50%
681	655	629	601	574	543	515	3%
501	481	462	442	420	400	379	3.50%
382	369	352	337	321	307	288	4%
302	291	279	266	253	241	229	4.50%
245	234	227	217	207	195	186	5%

The scenarios are obtained to get an estimated precision (bold values) of a certain level (rows) with a confidence level of 1 – alpha = 95%.