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Errata for Understanding the Fundamentals of Epidemiology: an Evolving Text ERRORS NOTED IN THE 2000 EDITION (and now corrected in the posted chapter): CHAPTER ON MEASURING DISEASE AND EXPOSURES: The sample calculation of ID on page 102 should have noted that this is an approximate value because population time needs to be reduced to reflect the fact that the cases stopped contributing population time when they developed disease X (unless they became susceptible again). [posted 10/15/2000] The formula showing the mathematical relationship between CI and ID on page 108 lost a minus sign in the last term, which should be: CI = 1 - exp(-ID delta t). [posted 10/2/2000] CHAPTER ON STANDARDIZATION:The footnote for in 1,000's should be referenced for both the population and number of deaths columns for the total U.S. [posted 3/6/2004] CHAPTER ON RELATING RISK FACTORS TO HEALTH OUTCOMES:The sentence about the derivation of the prevalence ratio from the prevalence OR should have said "unexposed" instead of "exposed". The corrected sentence is: "A prevalence odds ratio can be converted into a prevalence ratio using the same formula and substituting the prevalence in the unexposed in place of CI0." [posted 3/6/2004] The table titled "5-year incidence" on page 176 should have 540 as the number of unexposed noncases and 600 total unexposed. The flow chart and text are correct. [posted 10/2/2000] A number of corrections and revisions were made to the sections on the odds ratio and on a "Unified approach to attributable risk and preventive fraction" [6/27/2003] CHAPTER ON SOURCES OF ERROR:The values of the 95% confidence limits for the stratum-specific tables of the Southern Endometrial Cancer and Estrogen Study example (page 303) are incorrect. The correct values are (2.55, 9.30) for the fee-for-service table and (2.33, 10.71) for the managed care table. [posted 5/21/2001] In the table showing the “Hypothetical scenario showing effect of misclassification bias on measures of association”, the number of unexposed noncases in the “True” table was mistyped as of 10/21/2005. The correct value should be 970, so that the total for the column is 1,000. [corrected 10/21/2005] The "overbars" in the formulas in Appendix 2 (e.g., D-"bar") had shifted out of position. The formulas have been corrected. [posted 3/20/2004]
CHAPTER ON CONFOUNDING: The parenthetical expression immediately before the subhead "Matched Studies" should read "assuming that the rates in the study population differ from those in the standard population due only to the standardizing factor and the exposure)." (i.e., the second "study" should be "standard") [posted 11/22/2003] Several corrections and clarifications were made in the Appendix on Comparability and Collapsibility, including a correction to the denominator in an algebraic demonstration: b n0 should be b / n0. [posted 3/21/2004] ERRORS NOTED IN THE 1999 EDITION: CHAPTER ON MEASURING DISEASE AND EXPOSURES: In the appendix on weighted averages, one of the formulas has an incorrect denominator in the first "equivalent formula". At present the denominator and numerator are identical in the incorrect formula. The corrected denominator has only w's, no a's (see the 2000 version now on the web site). (posted 9/6/2000) In the assignment solutions, the answer to 5d is 1.7%, not 10.7%. (posted 9/18/2000) CHAPTER ON STANDARDIZATION: The top of page 143 shows the computation of indirectly standardized rates for Miami and Alaska. Both should begin "Indirectly standardized rate and should have "x 8.13" at the right instead of "= 8.13". A corrected copy can be downloaded as a PDF file from Standardization.pdf. In the table for the solution to question 4b in the Assignment, the column labeled "Expected/Observed" should be "Observed/Expected". The interpretation of the results for that question should say "higher rates in nonwhites compared to the U.S. overall" and should note that the distribution in Wilson County is not similar to those for Johnston and Orange counties (see StandardizationSolns.pdf). (posted 12/22/1999) CHAPTER ON CONFOUNDING: In the assignment solutions, the table in #5b should have 146 + 145 = 291 as the number of cases with 3+ UTI. The computation of the OR changes accordingly. That makes the answer in #5c: "Yes, there is some confounding, since 1.7 is below both 2.0 and 2.1." A corrected copy can be downloaded as a PDF file from ConfoundingSolns.pdf (posted 11/1/1999)
ERRORS NOTED IN THE 1998 EDITION: CHAPTER ON STANDARDIZATION: On page 6, section entitled "Some points to consider", second paragraph, fourth and fifth lines. Change Alaska to Miami: "(To put the foregoing in terms of the above data for Alaska, Miami, and the U.S. population, the crude death rate for MIAMI (8.92/1,000) can be expressed as a weighted average of the age-specific death rates (1.19, 0.71, etc. per 1,000) for MIAMI, where the weights are the population proportion in each age stratum (114,350/562,887, 80,259/562,887, etc.)." (posted here 9/9/1998) On pages 17 and 18, the formula for the SMR equation should read Observed deaths in study population SMR = --------------------------------------------- EXPECTED deaths in study populationAlso on page 18, in point d), the number of expected deaths for the period 1970-79 in the 30-39 years group is 4 instead of 5 (posted here 9/13/1998)
CHAPTER ON RELATING RISK FACTORS TO HEALTH: Near the bottom of page 17, the last sentence of the "Note on terminology" should read: The cell at the upper left is conventionally referred to as cell "a" and represents "exposed cases"; the cell diagonally opposite is called "d" and represents people who are "unexposed noncases". Cell "b" is generally in the upper right, with "c" diagonally opposite; these cells represent "exposed noncases" and "unexposed cases", but there is no standard convention about which cell represents which group. (posted here 10/1/1998) ERRORS NOTED IN THE 1997 EDITION:
Chapter Volume
& page page
_____ ____ _____
II 15 29 The hypothetical case study of a follow-up
lifetable analysis of a residental drug
treatment facility needs some more work, and
some of the computations may also be incorrect.
(posted here 12/9/97)
VII 29 198 Formula for ARP at mid-page should be (OR-1)/OR
(posted here 12/9/97)
P in formula for PARP should be P
e|d E|D
for consistency with notation elsewhere that
uppercase means "present" and lower case means
"absent" (posted here 12/9/97)
X 8 301 At mid-page, RR for "Observed cohort" should be
1.82 (posted here 12/9/97)
X Assignment Solution to problem 4 was omitted. Insert
pages 335.1 and 335.2 can be viewed by clicking
here. (posted here 12/9/97)
XI 1 336 Strike "than" in next to last line of 3rd
paragraph, and change "is concern" to "is not a
concern" in 4th line from bottom. (posted
here 12/9/97)
XII 13 390 The definitions for RR11, RR10, RR01 should
refer to the risk or rate RATIO. (posted
here 12/9/97)
XIII 23 432 Under the subhead "1) Unequal sample sizes",
the formula for Unequal sample sizes should begin:
"B ="
instead of
"D ="
(posted here 12/9/97)
Previous editions are no longer "supported".
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Victor J. Schoenbach (vjs@unc.edu), errata.htm, last updated 3/6/2004, 3/20-21/2004, 7/8/2004, 10/21/2005 |