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Statistics in practice
Book Review
Statistics in Practice D. G. Altman and S. M. Gore. London, England: British Medical Association, Tavistock Square, 1982, 100 pp., 7.00 pounds
This book presents two series of articles ("Statistics and Ethics," by Altman and "Statistics in Question," by Gore) which originally appeared in the British Medical Journal from November 1980 to October 1981 (with the exception of the last article by Gore, which was not originally published). Douglas Altman starts the first of these two series by stating that " . . . however praiseworthy a study may be from other points of view, if the statistical aspects are substandard then the research will be unethical." Having so stressed how he views the relation between statistics and ethics, Altman proceeds to cover a wide range of statistical considerations on study design, sample size, data collection and analysis, presentation and interpretation of results, and lastly on improving the quality of statistics in medical journals. The articles by Sheila Gore are presented as a series of questions and answers on statistical issues that are commonly encountered in planning and conducting clinical trials (first steps, trial size, design issues, randomization, between observer variation, double blind trials, trial discipline, protocol and monitoring, rash adventures) as well as in analyzing clinical data (statistics and graphs, transforming the data, art of significance testing, confidence intervals, recognizing linearity, initial impressions, survival, many variables, statistical distributions). Both series make very pleasant reading. All points are made clearly and are abundantly illustrated with real-life data. The book is primarily aimed at physicians, but the text contains so many relevant examples that it is well worth reading by statisticians alike (as a statistician I confess that I enjoyed it thoroughly). Probably the "question and answer" style will not be to everyone's liking as it is often difficult to answer the question without additional information (e.g., try to answer this question--"What is evidence of treatment effect or of association?", page 71), but it makes the text lively and allows one to cover an amazingly wide range of topics in a nontheoretical and even entertaining fashion. That the text is not fraught with statistical jargon or mathematical formulas does not however detract from its correctness. In adclifton, words of caution are issued whenever needed and recourse to a statistician is advised w h e n it comes to the more sophisticated notions. The Controlled Clinical Trials 5:315--316 (1984) O Elsevier Science Publishing Co., Inc. 1984 52 Vanderbilt Ave., New York, New York 10017
315 0197-24,56/84/$03.00
316
Marc Buyse authors nonetheless attempted (and in my opinion succeeded) to go into some notions that are often considered to be the private property of statisticians. For instance, the excellent discussions on power (even the statistical meaning of this word is ignored by most physicians) in both Altman's and Gore's series. Numerous instances of common mistakes and "things not to do" are illustrated. I am not sure that the reader will always be able to infer general rules from the particular examples quoted, but this is no doubt an inescapable difficulty inherent to the style adopted by the authors. I had a hard time finding specific aspects which I did not like and can only pinpoint small details: Survival data are sometimes used to illustrate methods that ignore censoring (pp 64, 68, 74); this is not a problem i n the examples quoted, but may convey the impression that these methods are equally appropriate as the lifetable methods, thus prompting incorrect analyses of heavily censored data sets. Confidence intervals could have been introduced in a more straightforward manner than by looking at the distribution of all likely outcomes in a trial comparing two treatments (page 73). It would have been useful to give the formula for the standard error (and confidence interval) of an estimated proportion, a simple calculation which all physicians could easily perform on their data. The issue of one-sided versus two-sided tests is one that puzzles many people. Perhaps a longer explanation would have been warranted (page 70). Again these are really minor points of detail. In summary, this is a remarkable collection of papers for all physicians who have an interest in statistics. It is likewise a "must" for the editors of medical publications. Marc Buyse EORTC Data Center 1, rue H~ger-Bordet, B---1000 Brussels, Belgium
Statistics in Practice D. G. Altman and S. M. Gore. London, England: British Medical Association, Tavistock Square, 1982, 100 pp., 7.00 pounds
This book presents two series of articles ("Statistics and Ethics," by Altman and "Statistics in Question," by Gore) which originally appeared in the British Medical Journal from November 1980 to October 1981 (with the exception of the last article by Gore, which was not originally published). Douglas Altman starts the first of these two series by stating that " . . . however praiseworthy a study may be from other points of view, if the statistical aspects are substandard then the research will be unethical." Having so stressed how he views the relation between statistics and ethics, Altman proceeds to cover a wide range of statistical considerations on study design, sample size, data collection and analysis, presentation and interpretation of results, and lastly on improving the quality of statistics in medical journals. The articles by Sheila Gore are presented as a series of questions and answers on statistical issues that are commonly encountered in planning and conducting clinical trials (first steps, trial size, design issues, randomization, between observer variation, double blind trials, trial discipline, protocol and monitoring, rash adventures) as well as in analyzing clinical data (statistics and graphs, transforming the data, art of significance testing, confidence intervals, recognizing linearity, initial impressions, survival, many variables, statistical distributions). Both series make very pleasant reading. All points are made clearly and are abundantly illustrated with real-life data. The book is primarily aimed at physicians, but the text contains so many relevant examples that it is well worth reading by statisticians alike (as a statistician I confess that I enjoyed it thoroughly). Probably the "question and answer" style will not be to everyone's liking as it is often difficult to answer the question without additional information (e.g., try to answer this question--"What is evidence of treatment effect or of association?", page 71), but it makes the text lively and allows one to cover an amazingly wide range of topics in a nontheoretical and even entertaining fashion. That the text is not fraught with statistical jargon or mathematical formulas does not however detract from its correctness. In adclifton, words of caution are issued whenever needed and recourse to a statistician is advised w h e n it comes to the more sophisticated notions. The Controlled Clinical Trials 5:315--316 (1984) O Elsevier Science Publishing Co., Inc. 1984 52 Vanderbilt Ave., New York, New York 10017
315 0197-24,56/84/$03.00
316
Marc Buyse authors nonetheless attempted (and in my opinion succeeded) to go into some notions that are often considered to be the private property of statisticians. For instance, the excellent discussions on power (even the statistical meaning of this word is ignored by most physicians) in both Altman's and Gore's series. Numerous instances of common mistakes and "things not to do" are illustrated. I am not sure that the reader will always be able to infer general rules from the particular examples quoted, but this is no doubt an inescapable difficulty inherent to the style adopted by the authors. I had a hard time finding specific aspects which I did not like and can only pinpoint small details: Survival data are sometimes used to illustrate methods that ignore censoring (pp 64, 68, 74); this is not a problem i n the examples quoted, but may convey the impression that these methods are equally appropriate as the lifetable methods, thus prompting incorrect analyses of heavily censored data sets. Confidence intervals could have been introduced in a more straightforward manner than by looking at the distribution of all likely outcomes in a trial comparing two treatments (page 73). It would have been useful to give the formula for the standard error (and confidence interval) of an estimated proportion, a simple calculation which all physicians could easily perform on their data. The issue of one-sided versus two-sided tests is one that puzzles many people. Perhaps a longer explanation would have been warranted (page 70). Again these are really minor points of detail. In summary, this is a remarkable collection of papers for all physicians who have an interest in statistics. It is likewise a "must" for the editors of medical publications. Marc Buyse EORTC Data Center 1, rue H~ger-Bordet, B---1000 Brussels, Belgium