Related Links:
Phase II Studies Explained Page
Sample Size for Phase II Study (Gehan's Procedure) Program Page
Introduction
Sample Size Tables
R Code
Gehan's procedure, and its comparison against other procedures available for the Phase II trial, are discussed in
the Phase II Studies Explained Page
. This page provides support for the use of the program in the
Sample Size for Phase II Study (Gehan's Procedure) Program Page
and the tables in this page.
Gehan's is a preliminary study of a new treatment, to test whether the proportion of success from the treatment
satisfies the level required to warrant further detailed study in a Phase II trial.
- Stage 1 :
- Sample size for stage 1 (s1) is the number of cases to be used in stage 1. This depends on
- The proportion of success required (p) is defined, a value between 0 (0%) and 1 (100%)
- The power required, the ability to detect that proportion if it is there. Mathematically power = 1-β,
where β is the probability of error in rejecting the new treatment
- At the end of stage 1, after s1 cases are included, k = the number of successes found
- If k=0 or k< a critical value where reaching the required proportion of success is unlikely, the treatment
is rejected without proceeding to stage 2
- If k> a critical value where reaching the required proportion of success is likely, the treatment
is accepted without proceeding to stage 2
- Otherwise, stage 2 of the procedure is required for decision making.
- Stage 2 :
- The sample size in stage 2 is the number of additional cases to be used in stage 2 This depends on
- The number of cases alr3eady used in stage 1 (s1)
- The number of successes (k) found in stage 1
- The acceptable probability of error for a decision to acceot the treatment (ε)
- The total number of successes is the number of successes in stage 1 (k) + number of successes in stage 2 .
- The required total number of successes for a decision to accept the treatment is n = p(s1+s2)
- if the total number of successes reached n, then the trial can be terminated, with a decision to accept the treatment
- If at the end of stage 2, the total number of successes had not reached n, then a decision to reject the treatment is made.
The program in the Sample Size for Phase II Study (Gehan's Procedure) Program Page
produces the results of Gehan's 2 stage procedures.
- The entry data is a single column of 3 rows, where
- Row 1 = ε, Probability of error for accepting the treatment for further study
- Row 2 = Power(1-β), where β is the probability of error for rejecting the treatment for further study
- Row 3 = p, the probability or proportion of successes required for accepting the treatment for further study
- The result are :
- The sample size for stage 1
- A table where each row is the parameters related to each value of k
- k = the number of successes in stage 1
- s2 = the sample size for stage 2
- n = the number of successes required (combine stage 1 and 2) for the treatment to be accepted.
The tables on this page provides the results of calculations for Gehan's 2 stage prod=cdures
- Three levels of power (1-β) at 0.8, 0.9, and 0.95
- Two level of error (ε) at 0.05 and 0.1
- Required proportion of successes :
- From 0.03 (3%) to 0.2 (20%) at 0.01 (1%) intervals
- From 0.2 (20%) to 0.3 (30%) at 0.02 (2%) intervals
- From 0.3 (30%) to 0.5 (50%) at 0.05 (5%) intervals
- From 0.5 (50%) to 0.9 (90%) at 0.1 (10%) intervals
- The cells contains results
- Blanks for impossible situations, where k>s1
- R is the combination of s1 and k that allows the treatment to be rejected at the end of stage 1
- A is the combination of s1 and k that allows the treatment to be accepted at the end of stage 1
- Cells with numbers are combinations of s1 and k that From 0.3 (30%) to 0.5 (50%) at 0.05 (5%) intervals
- From 0.5 (50%) to 0.9 (90%) at 0.1 (10%) intervals
References
Gehan E A (1961) The determination of the number of patients required in a preliminary and a follow-up trial of a
new chemotherapeutic agent Journal of Chronic Diseases. 13:4, Pages 346-353
Machin D, Campbell M, Fayers, P, Pinol A (1997) Sample Size Tables for
Clinical Studies. Second Ed. Blackwell Science IBSN 0-86542-870-0 p. 255-256
Power=0.8
Power=0.9
Power=0.95
Power=0.8, π=proportion of success required, ε=Error of accepting treatment Stage 1 : s1=sample size for stage 1 r=numbers success in stage 1 Stagte 2 [cells] : sample size for stage 2 + (total number of successes required to accept treatment, inclusive of stage 1 and 2) R = Reject and A = Accept treatment for further studies at the end of stage 1
| | Error (ε) = 0.1 | Error (ε) = 0.05 |
π | s1 | r=1 | r=2 | r=3 | r=4 | r=5 | r=1 | r=2 | r=3 | r=4 | r=5 | r=6 | r=7 | r=8 | r=9 |
0.03 | 53 | R | A | A | A | A | R | A | A | A | A | A | A | A | A |
---|
0.04 | 40 | R | A | A | A | A | R | A | A | A | A | A | A | A | A |
---|
0.05 | 32 | R | A | A | A | A | R | 10(3) | A | A | A | A | A | A | A |
---|
0.06 | 27 | R | A | A | A | A | 8(3) | 22(3) | 33(4) | 43(5) | A | A | A | A | A |
---|
0.07 | 23 | R | A | A | A | A | 18(3) | 32(4) | 44(5) | 54(6) | 62(6) | 69(7) | A | A | A |
---|
0.08 | 20 | R | A | A | A | A | 25(4) | 41(5) | 54(6) | 64(7) | 71(8) | 76(8) | 80(8) | A | A |
---|
0.09 | 18 | R | A | A | A | A | 31(5) | 48(6) | 61(8) | 70(8) | 77(9) | 81(9) | 82(9) | 81(9) | A |
---|
0.10 | 16 | R | A | A | A | A | 38(6) | 55(8) | 68(9) | 77(10) | 82(10) | 84(10) | 83(10) | 79(10) | A |
---|
0.11 | 14 | 1(2) | 6(3) | A | A | A | 46(7) | 64(9) | 76(10) | 83(11) | 86(11) | 85(11) | 81(11) | 72(10) | A |
---|
0.12 | 13 | 3(2) | 8(3) | A | A | A | 50(8) | 68(10) | 80(12) | 86(12) | 87(12) | 84(12) | 77(11) | 66(10) | A |
---|
0.13 | 12 | 5(3) | 10(3) | 12(4) | A | A | 55(9) | 73(12) | 84(13) | 88(13) | 87(13) | 81(13) | 71(11) | 56(9) | A |
---|
0.14 | 11 | 7(3) | 11(4) | 14(4) | A | A | 60(10) | 77(13) | 87(14) | 89(14) | 86(14) | 76(13) | 62(11) | A | A |
---|
0.15 | 10 | 9(3) | 13(4) | 15(4) | A | A | 65(12) | 82(14) | 90(15) | 89(15) | 82(14) | 68(12) | 48(9) | A | A |
---|
0.16 | 10 | 9(4) | 13(4) | 15(4) | A | A | 65(12) | 82(15) | 90(16) | 89(16) | 82(15) | 68(13) | 48(10) | A | A |
---|
0.17 | 9 | 11(4) | 15(5) | 16(5) | 15(5) | A | 71(14) | 87(17) | 91(17) | 87(17) | 74(15) | 54(11) | A | A | A |
---|
0.18 | 9 | 11(4) | 15(5) | 16(5) | 15(5) | A | 71(15) | 87(18) | 91(19) | 87(18) | 74(15) | 54(12) | 30(8) | A | A |
---|
0.19 | 8 | 14(5) | 17(5) | 17(5) | 15(5) | A | 77(17) | 91(19) | 91(19) | 81(17) | 61(14) | 35(9) | A | A | |
---|
0.20 | 8 | 14(5) | 17(5) | 17(5) | 15(5) | A | 77(17) | 91(20) | 91(20) | 81(18) | 61(14) | 35(9) | A | A | |
---|
0.22 | 7 | 16(6) | 18(6) | 17(6) | 12(5) | A | 83(20) | 93(22) | 88(21) | 69(17) | 41(11) | A | A | | |
---|
0.24 | 6 | 18(6) | 19(6) | 15(6) | A | A | 90(24) | 93(24) | 78(21) | 49(14) | A | A | | | |
---|
0.26 | 6 | 18(7) | 19(7) | 15(6) | A | A | 90(25) | 93(26) | 78(22) | 49(15) | A | A | | | |
---|
0.28 | 5 | 20(8) | 19(7) | 11(5) | A | A | 95(29) | 88(27) | 58(18) | 17(7) | A | | | | |
---|
0.30 | 5 | 20(8) | 19(8) | 11(5) | A | A | 95(30) | 88(28) | 58(19) | 17(7) | A | | | | |
---|
0.35 | 4 | 21(9) | 15(7) | A | A | | 96(35) | 70(26) | 22(10) | A | | | | | |
---|
0.40 | 4 | 21(10) | 15(8) | A | A | | 96(40) | 70(30) | 22(11) | A | | | | | |
---|
0.45 | 3 | 19(10) | 6(5) | A | | | 85(40) | 31(16) | A | | | | | | |
---|
0.50 | 3 | 19(11) | 6(5) | A | | | 85(44) | 31(17) | A | | | | | | |
---|
0.50 | 3 | 19(11) | 6(5) | A | | | 85(44) | 31(17) | A | | | | | | |
---|
0.60 | 2 | 10(8) | A | | | | 45(29) | A | | | | | | | |
---|
0.70 | 2 | 10(9) | A | | | | 45(33) | A | | | | | | | |
---|
0.80 | 2 | 10(10) | A | | | | 45(38) | A | | | | | | | |
---|
0.90 | 1 | A | | | | | A | | | | | | | | |
---|
Power=0.9, π=proportion of success required, ε=Error of accepting treatment Stage 1 : s1=sample size for stage 1 r=numbers success in stage 1 Stagte 2 [cells] : sample size for stage 2 + (total number of successes required to accept treatment, inclusive of stage 1 and 2) R = Reject and A = Accept treatment for further studies at the end of stage 1
| | Error (ε) = 0.1 | Error (ε) = 0.05 |
π | s1 | r=1 | r=2 | r=3 | r=4 | r=5 | r=6 | r=1 | r=2 | r=3 | r=4 | r=5 | r=6 | r=7 | r=8 | r=9 | r=10 | r=11 |
0.03 | 76 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A |
---|
0.04 | 57 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A |
---|
0.05 | 45 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A |
---|
0.06 | 38 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A |
---|
0.07 | 32 | R | R | A | A | A | A | R | 10(3) | 21(4) | 30(5) | A | A | A | A | A | A | A |
---|
0.08 | 28 | R | R | A | A | A | A | 6(3) | 19(4) | 30(5) | 40(6) | 48(7) | 55(7) | 61(8) | A | A | A | A |
---|
0.09 | 25 | R | R | A | A | A | A | 13(4) | 27(5) | 38(6) | 48(7) | 57(8) | 63(8) | 68(9) | 72(9) | A | A | A |
---|
0.10 | 22 | R | R | A | A | A | A | 20(5) | 35(6) | 47(7) | 57(8) | 65(9) | 71(10) | 75(10) | 78(10) | 78(10) | A | A |
---|
0.11 | 20 | R | R | A | A | A | A | 25(5) | 41(7) | 54(9) | 64(10) | 71(11) | 76(11) | 80(11) | 80(11) | 80(11) | 77(11) | A |
---|
0.12 | 19 | R | R | A | A | A | A | 28(6) | 45(8) | 57(10) | 67(11) | 74(12) | 79(12) | 81(12) | 81(12) | 79(12) | 75(12) | A |
---|
0.13 | 17 | R | 1(3) | A | A | A | A | 35(7) | 52(9) | 65(11) | 74(12) | 80(13) | 83(13) | 83(13) | 81(13) | 76(13) | 69(12) | A |
---|
0.14 | 16 | R | 2(3) | A | A | A | A | 38(8) | 55(10) | 68(12) | 77(14) | 82(14) | 84(14) | 83(14) | 79(14) | 73(13) | 64(12) | A |
---|
0.15 | 15 | R | 4(3) | 7(4) | A | A | A | 42(9) | 59(12) | 72(14) | 80(15) | 85(15) | 85(15) | 83(15) | 77(14) | 68(13) | 56(11) | A |
---|
0.16 | 14 | R | 6(4) | 9(4) | A | A | A | 46(10) | 64(13) | 76(15) | 83(16) | 86(16) | 85(16) | 81(16) | 72(14) | 61(12) | A | A |
---|
0.17 | 13 | 3(3) | 8(4) | 11(5) | 12(5) | A | A | 50(11) | 68(14) | 80(16) | 86(17) | 87(17) | 84(17) | 77(16) | 66(14) | 51(11) | A | A |
---|
0.18 | 12 | 5(4) | 10(4) | 12(5) | 13(5) | A | A | 55(13) | 73(16) | 84(18) | 88(19) | 87(18) | 81(17) | 71(15) | 56(13) | 38(10) | A | A |
---|
0.19 | 11 | 7(4) | 11(5) | 14(5) | 14(5) | A | A | 60(14) | 77(17) | 87(19) | 89(20) | 86(19) | 76(17) | 62(14) | 43(11) | A | A | A |
---|
0.20 | 11 | 7(4) | 11(5) | 14(5) | 14(5) | A | A | 60(15) | 77(18) | 87(20) | 89(20) | 86(20) | 76(18) | 62(15) | 43(11) | A | A | A |
---|
0.22 | 10 | 9(5) | 13(6) | 15(6) | 15(6) | 13(6) | A | 65(17) | 82(21) | 90(22) | 89(22) | 82(21) | 68(18) | 48(13) | A | A | A | |
---|
0.24 | 9 | 11(5) | 15(6) | 16(6) | 15(6) | 12(6) | A | 71(20) | 87(24) | 91(24) | 87(24) | 74(20) | 54(16) | 30(10) | A | A | | |
---|
0.26 | 8 | 14(6) | 17(7) | 17(7) | 15(6) | A | A | 77(23) | 91(26) | 91(26) | 81(24) | 61(18) | 35(12) | A | A | | | |
---|
0.28 | 8 | 14(7) | 17(8) | 17(8) | 15(7) | 10(6) | A | 77(24) | 91(28) | 91(28) | 81(25) | 61(20) | 35(13) | A | A | | | |
---|
0.30 | 7 | 16(7) | 18(8) | 17(8) | 12(6) | A | A | 83(27) | 93(30) | 88(29) | 69(23) | 41(15) | A | A | | | | |
---|
0.35 | 6 | 18(9) | 19(9) | 15(8) | 8(5) | A | A | 90(34) | 93(35) | 78(30) | 49(20) | 12(7) | A | | | | | |
---|
0.40 | 5 | 20(10) | 19(10) | 11(7) | A | A | | 95(40) | 88(38) | 58(26) | 17(9) | A | | | | | | |
---|
0.45 | 4 | 21(12) | 15(9) | 3(4) | A | | | 96(45) | 70(34) | 22(12) | A | | | | | | | |
---|
0.50 | 4 | 21(13) | 15(10) | 3(4) | A | | | 96(50) | 70(37) | 22(13) | A | | | | | | | |
---|
0.50 | 4 | 21(13) | 15(10) | 3(4) | A | | | 96(50) | 70(37) | 22(13) | A | | | | | | | |
---|
0.60 | 3 | 19(14) | 6(6) | A | | | | 85(53) | 31(21) | A | | | | | | | | |
---|
0.70 | 2 | 10(9) | A | | | | | 45(33) | A | | | | | | | | | |
---|
0.80 | 2 | 10(10) | A | | | | | 45(38) | A | | | | | | | | | |
---|
0.90 | 2 | 10(11) | A | | | | | 45(43) | A | | | | | | | | | |
---|
Power=0.95, π=proportion of success required, ε=Error of accepting treatment Stage 1 : s1=sample size for stage 1 r=numbers success in stage 1 Stagte 2 [cells] : sample size for stage 2 + (total number of successes required to accept treatment, inclusive of stage 1 and 2) R = Reject and A = Accept treatment for further studies at the end of stage 1
| | Error (ε) = 0.1 | Error (ε) = 0.05 |
π | s1 | r=1 | r=2 | r=3 | r=4 | r=5 | r=6 | r=1 | r=2 | r=3 | r=4 | r=5 | r=6 | r=7 | r=8 | r=9 | r=10 | r=11 | r=12 | r=13 |
0.03 | 99 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A | A | A |
---|
0.04 | 74 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A | A | A |
---|
0.05 | 59 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A | A | A |
---|
0.06 | 49 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A | A | A |
---|
0.07 | 42 | R | R | A | A | A | A | R | R | A | A | A | A | A | A | A | A | A | A | A |
---|
0.08 | 36 | R | R | A | A | A | A | R | 2(4) | 12(4) | 21(5) | 28(6) | A | A | A | A | A | A | A | A |
---|
0.09 | 32 | R | R | A | A | A | A | R | 10(4) | 21(5) | 30(6) | 38(7) | 45(7) | 51(8) | A | A | A | A | A | A |
---|
0.10 | 29 | R | R | A | A | A | A | 4(4) | 17(5) | 28(6) | 37(7) | 46(8) | 52(9) | 58(9) | 63(10) | 67(10) | A | A | A | A |
---|
0.11 | 26 | R | R | A | A | A | A | 11(5) | 24(6) | 36(7) | 46(8) | 54(9) | 60(10) | 66(11) | 70(11) | 73(11) | 74(11) | A | A | A |
---|
0.12 | 24 | R | R | A | A | A | A | 15(5) | 29(7) | 41(8) | 51(9) | 59(10) | 66(11) | 71(12) | 74(12) | 76(12) | 76(12) | 76(12) | A | A |
---|
0.13 | 22 | R | R | A | A | A | A | 20(6) | 35(8) | 47(9) | 57(11) | 65(12) | 71(13) | 75(13) | 78(13) | 78(13) | 78(13) | 75(13) | 71(13) | A |
---|
0.14 | 20 | R | R | A | A | A | A | 25(7) | 41(9) | 54(11) | 64(12) | 71(13) | 76(14) | 80(14) | 80(14) | 80(14) | 77(14) | 72(13) | 66(13) | A |
---|
0.15 | 19 | R | R | A | A | A | A | 28(8) | 45(10) | 57(12) | 67(13) | 74(14) | 79(15) | 81(15) | 81(15) | 79(15) | 75(15) | 69(14) | A | A |
---|
0.16 | 18 | R | R | 2(4) | A | A | A | 31(8) | 48(11) | 61(13) | 70(15) | 77(16) | 81(16) | 82(16) | 81(16) | 78(16) | 73(15) | 65(14) | A | A |
---|
0.17 | 17 | R | R | 4(4) | A | A | A | 35(9) | 52(12) | 65(14) | 74(16) | 80(17) | 83(17) | 83(17) | 81(17) | 76(16) | 69(15) | 59(13) | A | A |
---|
0.18 | 16 | R | 2(4) | 5(4) | 8(5) | A | A | 38(10) | 55(13) | 68(16) | 77(17) | 82(18) | 84(19) | 83(18) | 79(18) | 73(17) | 64(15) | 52(13) | A | A |
---|
0.19 | 15 | R | 4(4) | 7(5) | 9(5) | A | A | 42(11) | 59(15) | 72(17) | 80(19) | 85(20) | 85(20) | 83(19) | 77(18) | 68(16) | 56(14) | A | A | A |
---|
0.20 | 14 | R | 6(4) | 9(5) | 11(5) | A | A | 46(12) | 64(16) | 76(18) | 83(20) | 86(20) | 85(20) | 81(19) | 72(18) | 61(15) | 47(13) | A | A | A |
---|
0.22 | 13 | 3(4) | 8(5) | 11(6) | 12(6) | 12(6) | A | 50(14) | 68(18) | 80(21) | 86(22) | 87(22) | 84(22) | 77(20) | 66(18) | 51(15) | 34(11) | A | A | A |
---|
0.24 | 11 | 7(5) | 11(6) | 14(6) | 14(6) | 14(6) | A | 60(18) | 77(22) | 87(24) | 89(24) | 86(24) | 76(21) | 62(18) | 43(13) | A | A | A | | |
---|
0.26 | 10 | 9(5) | 13(6) | 15(7) | 15(7) | 13(6) | A | 65(20) | 82(24) | 90(26) | 89(26) | 82(24) | 68(21) | 48(16) | 25(10) | A | A | | | |
---|
0.28 | 10 | 9(6) | 13(7) | 15(8) | 15(8) | 13(7) | A | 65(22) | 82(26) | 90(29) | 89(28) | 82(26) | 68(22) | 48(17) | 25(10) | A | A | | | |
---|
0.30 | 9 | 11(6) | 15(8) | 16(8) | 15(8) | 12(7) | A | 71(24) | 87(29) | 91(30) | 87(29) | 74(25) | 54(19) | 30(12) | A | A | | | | |
---|
0.35 | 7 | 16(9) | 18(9) | 17(9) | 12(7) | A | A | 83(32) | 93(35) | 88(34) | 69(27) | 41(17) | A | A | | | | | | |
---|
0.40 | 6 | 18(10) | 19(10) | 15(9) | 8(6) | A | A | 90(39) | 93(40) | 78(34) | 49(22) | 12(8) | A | | | | | | | |
---|
0.45 | 6 | 18(11) | 19(12) | 15(10) | 8(7) | A | A | 90(44) | 93(45) | 78(38) | 49(25) | 12(9) | A | | | | | | | |
---|
0.50 | 5 | 20(13) | 19(12) | 11(8) | A | A | | 95(50) | 88(47) | 58(32) | 17(11) | A | | | | | | | | |
---|
0.50 | 5 | 20(13) | 19(12) | 11(8) | A | A | | 95(50) | 88(47) | 58(32) | 17(11) | A | | | | | | | | |
---|
0.60 | 4 | 21(15) | 15(12) | 3(5) | A | | | 96(60) | 70(45) | 22(16) | A | | | | | | | | | |
---|
0.70 | 3 | 19(16) | 6(7) | A | | | | 85(62) | 31(24) | A | | | | | | | | | | |
---|
0.80 | 2 | 10(10) | A | | | | | 45(38) | A | | | | | | | | | | | |
---|
0.90 | 2 | 10(11) | A | | | | | 45(43) | A | | | | | | | | | | | |
---|
The following is the code for Gehan's two stage procedure for Phase II studies. I have adapted the formulae as described in the text book by Machin et. el.. Those interested can copy, use, and modify these codes
" Phase II Gehan
Gehan E A (1961) The determination of the number of patients required in a preliminary and
a follow-up trial of a new chemotherapeutic agent Journal of Chronic Diseases. 13:4, Pages 346-353
Machin D, Campbell M, Fayers, P, Pinol A (1997) Sample Size Tables for Clinical Studies. Second Ed.
Blackwell Science IBSN 0-86542-870-0 p. 255-256
"
# Data
errorI = 0.05 # alpha Type I Error
power = 0.8 # power 1-beta
pa = 0.4 # success rate above which treatment is accepted
# Sample Size for Stage 1
s1 = ceiling(log(1 - power) / log( 1 - pa))
# Functions for Stage 2
FindGX <- function(n, r, m)
{
x = 0
for(s in 0 : r)
{
f = choose(n, s)
p = n - s
x = x + f * m^s * (1 - m)^p
}
x
}
FindGMu <- function(n, r) #iterations to find the correct mu
{
mL = 0.0001;
mR = 0.9999;
m = 0.5;
xL = FindGX(n, r, mL) - 0.25
x = FindGX(n, r, m) - 0.25
xR = FindGX(n, r, mR) - 0.25;
if((xL * x)>0 & (xR * x)<0)
{
mL = m
}
else
{
if((xL * x)<0 & (xR * x)>0)
{
mR = m;
}
else
{
return(0)
}
}
while(abs(x)>0.0001)
{
m = (mL + mR) / 2
xL = FindGX(n, r, mL) - 0.25
x = FindGX(n, r, m) - 0.25
if((xL * x)>0)
{
mL = m
}
else
{
mR = m
}
}
m
}
# Main Program for Stage 2
# Create vectors to contain results
r1 <- 0 : ssiz1 # number of successes in stage 1
ssiz2 <- 0 : ssiz1 # maximum samples size for stage 2
minSuc <- 0 : ssiz1 # minimum number of successes for tmt to be accepted
ssiz2[1] = "Reject" # r1=0 treatment rejected no stage 2
minSuc[1] = "Reject"
ssiz2[ssiz1 + 1] = "Accept" # r1=all treatment accepted no stage 2
minSuc[ssiz1 + 1] = "Accept"
for(i in 2 : ssiz1-1)
{
mu = FindGMu(s1, i)
s2 = ceiling(mu * (1 - mu) / errorI^2 - s1)
tot = s1 + s2
ns = ceiling(pa * tot)
ssiz2[i+1] = s2
minSuc[i+1] = ns
}
# Result display
# Sample Size Sate 1
s1
# Stage 2 : r1=number of successes in stage 1
# ssiz2 = sample size in stage 2
# minSuc = minimum number of successes required in stage 2 for tmt to be accepted
outDF <- data.frame(r1,ssiz2,minSuc)
outDF
|