# Corrections to "An Introduction to Medical Statistics, Third Edition" by Martin Bland

These are errors so far found in the third edition of my text book An Introduction to Medical Statistics. Some of them have already been corrected in later printings.

## Typographical errors

P 57. line 21: "42nd and 43rd" should read "43rd and 44th".
P 57. line 23: "into 100" should read "at 99".
P 61. line 23 formula: The second square should come after the bracket, not before.
P 92. last formula: "VAR(X) = E(X2 - E(X)2)" should read "VAR(X) = E(X - E(X))2 = E(X2) - (E(X))2".
P 99. line 13. In this equation VAR((Sum xi)2) + (E((Sum xi)2))2 should read VAR(Sum xi) + (E(Sum xi))2. There were two extra squares, sorry.
P 107. last line. "500" should read "5000".
P 111. line 16-17. "In fact if we add mu to a standard normal variable and multiply by sigma" should read "In fact if we multiply a standard normal variable by sigma and add mu".
P 125. line 4 "0.007880" should read "√0.007880".
P 160. Table 10.2 the standard errors 0.38 and 0.32 should read 1.67 and 1.52.
P 171. line 1 "if we antilog this we get 0.38 to 0.99" should read "if we antilog this we get 0.66 to 0.99".
P 171. line 2 "between 0.38 and 0.99" should read "between 0.66 and 0.99".
P 173. line 19 "The variance of the four group means is 5.475" should read "The variance of the four group means is 4.562".
P 173. line 23 "For the example, this is 5.475x5=27.375" should read "For the example, this is 4.562x6=27.375".
P 173. 5th line from bottom: "n-1" should read "n-m".
P 244. line 17: the second "sum of xi" should read "sum of xi2".
P 251. 9th line from bottom: "3620 ways" should read "3920 ways".
P 278 paragraph 1 line 3-4: "With 1-specificity less than 0.1, i.e. sensitivity greater than 0.9" should read "With 1-specificity less than 0.1, i.e. specificity greater than 0.9".
P 278 paragraph 3 lines 13-14: "the probability of being both test negative and disease positive" should read "the probability of being both test positive and disease negative".
P 290. line 19 "730.93 - 0.73 = 0.20" should read "73% in the control group. The difference in proportions surviving was thus 0.93 - 0.73 = 0.20."
P 295. line 10 "and in 1981 it was 15.6 per 1000 per year." should read "and in 1981 it was 14.8 per 1000 per year."
P 295. line 5 from bottom "there were as many deaths as in 1901" should read "there were almost as many deaths as in 1901".
P 324. line 27 “Table 15.7 shows the time to recurrence of gallstones”, should read "Table 15.9 shows the time to recurrence of gallstones”.
P 376 Solution to Exercise 16E, part 2 line 3: "48" should read "51".
P 376 Solution to Exercise 16E, part 2 line 4: "48" should read "51", "1.77" should be "1.88", "177" should be "188".
P 377 Solution to Exercise 16E, part 3, first three sentences should read: "We find the standard error of the SMR by root O/E = root 51/27.19 = 0.2626. The 95% confidence interval is then 1.88 - 1.96 times 0.2626 to 1.88 + 1.96 times 0.2626, or 1.37 to 2.39. Multiplying by 100 as usual, we get 137 to 239."

Many thanks to error spotters, including Christopher Andrews, Mark Atkinson, Hossein Badiei, Diego Calavia, Troels Græsholt-Knudsen, Pamela Hall, Martijn Heymans, David Jim, Jozef Kaluzay, Mona Kanaan, Edward McNeil, Hans-Rudolf Roth, and SJ Wang.

All contributions are gratefully received. I aim for perfection.