6rournal of Epidemiology and Community Health 1997;51:612-622

Review article

Which book? A comparative review of25 introductory epidemiology textbooks

Raj Bhopal

We are witnessing an epidemic of epidemiol-ogy. One outcome is a greater demand forbooks to meet the needs of an increasinglydiverse student body. A widening range of pro-fessionals and researchers are discovering thepower and fascination of the subject, and theirheterogeneity of specialist knowledge andinterest poses special challenge. Revisions ofclassics and many new texts mean difficultchoices for teachers and students. The rise ofepidemiology will spur new writings so we cananticipate even more.This review is primarily to help students and

teachers to find the first textbook for the keenpostgraduate or undergraduate. Practitionersmay welcome this as a way of tracking down thebook which covers epidemiology in the stylethey prefer. Aspiring text book writers mightsee gaps for future work.

I have concentrated on books publishedsince 1980 and in choosing which books toreview I was guided by these questions: Mightstudents chose this book as their first textbook?Might teachers recommend this book for gen-eral, introductory reading? Is the book attrac-tive to students and teachers on the basis ofreputation? Is it already in use as a general text?If yes, my tendency was to review it. Specialist,advanced, and reference works were excluded,especially if the author(s) did not consider thebook as introductory. Some books consisting ofexercises and meant for self study have beenincluded if they tried to cover the theory andprinciples too. I hope to have included the maincontenders for the first textbook role inEnglish-based courses in epidemiology in theUSA and Europe. (Inevitably, some will havebeen omitted intentionally or unintentionally.)

Department ofEpidemiology andPublic Health, MedicalSchool, University ofNewcastle Upon Tyne,Newcastle NE24HHR Bhopal

Correspondence to:Professor R Bhopal.R.S.Bhopal(q,ancl.ac.uk

Accepted for publicationJuly 1997

ApproachThe books were scanned to assess theirpurposes, audience, and approach, and thenlooked at more closely (sometimes selectively,sometimes in full) in relation to seven funda-mental issues which I wanted to read about andwhich I consider to be so important to modernepidemiology that no modern text should omitthem:0 The epidemiological way of thinking about:1. Population, and especially how this differs

from demographic and statistical ideas, and

the distinction between individual andpopulation causes of disease

2. Causality, and3. The natural history of disease* The idea behind and methods of:4. Standardisation of rates and5. The case-control study* The application of epidemiology to:6. Screening and7. Health care.The first three choices are self contained

topics and so fundamental that the reason forchoosing them is self evident. Standardisationwas picked as an example of the basictechniques for controlling for confounding,and because of the challenge to writers ofexplaining the similarities and differencesbetween the direct and indirect method. Thecase-control study was a benchmark of howwell methods were explained, with the issue ofthe odds ratio as an estimate of the relative riskproviding fertile material to assess the explana-tion of an important theme in analysis andinterpretation. Increasingly, epidemiology isbeing applied to health care and several booksare on this alone. I chose screening as a longestablished theme in introductory epidemio-logical books, and health care as a relativelyneglected but emergent theme. As with anyother sample, bias can lead to an erroneousconclusion. This sampling, however, permitscomparison between books and a reviewsuitable as a journal article rather than a bookin itselflOn average about three hours were spent per

book. The material was found using thecontents page, index, and by quickly scanningthe pages. I have veered to description ratherthan critique, though I have given someopinion. The books are placed in someapproximate order of complexity and are alsosummarised in table 1. Cost is not given, for inmy view this is trivial in relation to the true cost(and value) of an epidemiological education.(Where books are similar, the cost mayoccasionally be influential.)This is, of course, a personal and subjective

review. Nonetheless, I hope there is enoughfactual material to help steer students andteachers, even when they do not agree with myopinions.

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Table 1 Summary of the 25 reviewed books

Year, ed, & pages of Focus on theory &main text (size of method, or Exercises andlor

Authors & ref no pp if small or large) Scope & setting(s) application, or both? study questions? Audience?

Ahlbom A, Norell S4 1s' 1984 76 (small) Epidemiology Theory Yes U/gradBarker DJP, Rose G' 4th 1990 152 Epidemiology, public health, clinical Application, theory No U/grad

(small)Beaglehole R, Bonita R, 1' 1993 153 Epidemiology, public health Theory, application Yes U/grad

Kjellstrom T'Coggon D, Rose G, Barker DJP' 3rd 1993 63 Epidemiology Theory No U/grad

(small)Farmer R, Miller D, Lawrenson R"' 4t' 1996 274 Epidemiology, public health Theory, application No U/grad (parts, p/grad)Fletcher RH, Fletcher SW, 3rd 1996 270 Epidemiology, clinical Theory, application No P/grad, practitioner,Wagner EH5" u/grad

Friedman GD"4 4"h 1994 328 Epidemiology, clinical, public health Theory Yes P/grad, u/grad(small)

Friis RH, Sellers TA8 15 1996 403 Epidemiology, occupational, social Theory, application Yes U/grad, p/grad,science practitioner

Gordis L" 15 1996 263 Epidemiology, public health, clinical Theory, application Yes P/grad, practitioner,U/grad

Greenberg RS, Daniels SR, 2nd 1996 178 Epidemiology, clinical Theory, application Yes U/grad, p/gradFlanders WD, Eley JW,Boring JR"

Harkness GA'2 ls 1995 262 Epidemiology, public health, nursing Theory, application Yes P/grad, practitioner,u/grad

Hennekens CH, Buring JE5 1s' 1987 344 Epidemiology Theory, application Yes P/grad, researcherJekel JF, Elmore JG, Katz DL7 1' 1996 272 Epidemiology, statistics, clinical, Theory, application No U/grad, p/grad

public healthLilienfeld D, Stolley PD"6 3rd 1994 285 Epidemiology Theory, application Yes P/grad, u/gradMausner J, Kramer S15 2nd 1985 353 Epidemiology, occupational Theory, application No P/grad, u/grad,

researcherMcMahon B, Trichopoulos D" 2nd 1996 302 Epidemiology Theory No P/grad, researcher,

practitionerMorton RF, Hebel JR, 4"h 1996 198 Epidemiology Theory, application Yes U/grad, p/gradMcCarter RJ2"

Norell SE2' 1' 1995 190 Epidemiology Theory Yes P/gradPage RM, Cole GE, 1"s 1995 392 Epidemiology, statistics Theory, application Yes U/grad, p/grad,Timmreck TCs (large) practitioner

Rothman KJ" 1st 1986 349 Epidemiology Theory No P/grad, researcherSackett DL, Haynes RB, 2nd 1991 421 Epidemiology, clinical Application, theory No Practitioner,p/grad,

Guyatt GH, Tugwell p25 u/gradSchuman SH23 1" 1986 217 Epidemiology, clinical Application, theory No PractitionerSilman AJ22 1't 1995 166 Epidemiology Application No Practitioner, p/gradTimmreck TC" P 1994 415 Epidemiology Theory, application Yes UnsureUnwin N, Carr S, Leeson J' 1st 1997 145 Epidemiology, public health Theory, application Yes U/grad

U/grad, undergraduate; p/grad, postgraduate.

ReviewSummary descriptive data are given in table 1.

BASIC BOOKS, PROBABLY SUITABLE FOR

UNDERGRADUATES AND PROFESSIONALS WITH

LI1TLE PREVIOUS EXPOSURE TO EPIDEMIOLOGY

Epidemiology for the uninitiated (Coggon D, Rose,G, and Barker D P)

Epidemiology for the uninitiated' is said to be forthe novice. It is described as short (true) andauthoritative. The opening places epidemiol-ogy in its population context and introducescomparison between groups as its key strategy.

Chapters on disease measurement are suffi-cient, but the chapters on study design are

skimpy. There are no references, a short bibli-ography is a mix of books for the novice andadvanced texts; there are no exercises, no sum-

maries (though each chapter is one). Informa-tion on concepts is minimal. This text could beread in two hours, and absorbed in a day.* Population: three pages emphasise the con-

cept.* Causality: necessary, but insufficient!* Natural history of disease: not covered, not

indexed, but referred to in screening.* Standardisation of rates: you can find out

how to do it in three pages, but not why,which method to choose, or what the limita-tions are.

* Case-control study: the idea is introducedbut nothing on analysis and interpretation.

* Screening: the background needed to under-stand why screening programme evaluationmay be difficult is covered, but knowledge ofsensitivity and specificity is assumed (notindexed).

* Health care epidemiology: not covered.Overall verdict: a quickie for undergraduates,but too limited.

Epidemiology in Medical Practice (Barker D J P]Rose G)Epidemiology in Medical Practice2 is said to be forclinicians and medical undergraduates. Theapproach is squarely public health, not clinicalepidemiology. There are three sections: de-scription of disease in the community, preven-tion of disease, and epidemiology and patientcare. There is some repetition and fragmenta-tion of material on study methods. There areno references, no exercises, no synthesis, andno history of the subject, but there is breadthand deep insight here.* Population: brief differentiation of the epide-

miological and demographic concepts.* Causality: covers the basics and introduces

the nuance of causes in populations versusthe individual.

* Natural history: not defined or indexed, butis the dominant theme of a chapter onoutcome and prognosis.

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* Standardisation of rates: a good workedexample, but no explanation of why, whichmethod to choose or the limitations.

* Case-control study: the material is inte-grated effectively with that on cohort studies,bias and causation and is very clear. Analysisand interpretation are not covered.

* Screening: the clinical and public healthbackground and the assessment of screeningtests are covered, but the difficulties ofevaluation are not.

* Health care epidemiology: effective chapterfocusing on need, demand, and evaluation,not planning or policy.

Overall verdict: much to commend it to medicalundergraduates.

An Introductory Study Guide to Public Healthand Epidemiology (Unwin N, Carr S, Leeson 7)An Introductory Study Guide to Public Healthand Epidemiology3 hopes to introduce nursingstudents and practitioners to the "public healthperspective". It engages the student in criticalthinking with each chapter starting withquestions and study outcomes, and integratingnumerous exercises in the text giving them highpriority (the student is encouraged to do thembefore reading on). There is a "summary"which is a set of questions with space so it canbe written by the student; a novel idea! A policyof avoiding calculations, deliberate or other-wise, seems to be in effect; sometimes to thedetriment of the book.* Population: the population idea, and the

prevention paradox, is introduced giving aflavour of the epidemiological concept ofpopulation.

* Causality: there is a clear-cut framework anda broad consideration of the concept in epi-demiology, but the discussion of judging thelikelihood of causality is bare.

* Natural history: not found.* Standardisation of rates: exemplary text,

examples, and interpretation which wouldhave been strengthened by asking studentsto do the calculations.

* Case-control study: the essence of the designis captured in three easy pages and adiagram.

* Screening: a detailed exposition of screen-ing, but not strong on evaluation or explain-ing difficult ideas like lead time bias. It avoidscalculation of the measures of the quality ofa test, but can students understand the con-cepts of sensitivity and specificity without anexample or calculation?

* Health care epidemiology: there is heavyemphasis on applications with four chapters(health promotion, health needs assessment,and two on effectiveness of health care), butonly occasionally do they draw upon or inte-grate with the epidemiology.

Overall verdict: this book fills a niche. Itintegrates passive and active learning, and isconsistently introductory. I doubt if nurseswould recognise that this book was written forthem. It is an option for anyone starting out inepidemiology and will appeal to those who likeideas and are wary of numbers.

Introduction to Modern Epidemiology (AhlbomA, Norell S)Introduction to Modern Epidemiology4 is inspiredby the approach taken by the Harvardapproach captured by Rothman's Modern Epi-demiology (see below) and uses the same defini-tion, the science of the occurrence of disease inhuman populations. This book echoes manyideas in Rothman's text. Its characteristics arebrevity and exercises. The exercises andanswers occupy about 35 of the 97 pages. Theexercises clearly convey the message that thisvision of epidemiology is about quantifyingdisease and designing studies. The difficulty ofmany of the exercises contrasts with the brevityof the explanatory text.* Population: is not specifically discussed.* Causality: the definition used is simple:

reducing the causal factor reduces thedisease, with no discussion of the immensedifficulties in practice, and the discussion isfocused on one model (necessary andsufficient).

* Natural history of disease: not covered.* Standardisation of rates: in two pages you

can learn about the conceptual basis of bothdirect and indirect standardisation, but notwhich method to choose or the limitations.The associated exercises are testing.

* Case-control study: the short discussion isunbalanced. For example, the reasons fordoing case-control studies are handled in asentence or two, but the mode of analysis togenerate a "relative risk" and the advantagesover cohort studies occupy more than twopages.

* Screening: the idea of screening and screen-ing programme evaluation are not covered,but the chapter on sensitivity and specificityis very clear. Unusually, the effect ofsensitivity and specificity on errors in meas-uring prevalence is emphasised.

* Health care epidemiology: not covered.Overall verdict: The preface says that newerconcepts have been woven into the existingdogma. As with Modern Epidemiology, one aimseems to be to contest if not elbow out the"established dogma". Books which offer a dif-ferent view are of especial value for postgradu-ates and this may be good preparation for tack-ling the tougher Modern Epidemiology.

Basic Epidemiological Methods and Biostatistics(Page R M, Cole G E, Timmreck T C)Basic Epidemiological Methods and Biostatistics5is designed for diverse courses. It emphasiseslearning concepts and principles throughapplication. Chapters include objectives, sum-maries, key terms, tough exercises (answersgiven) and references. Review questions anddetailed examples of studies sprinkle the book.The first chapter, introducing the principlesand history of epidemiology, is followed byeight on methods. There is emphasis on infec-tious disease epidemiology. The book closeswith questions for self-evaluation. A glossaryand an excellent book list are included.* Population: no solid discussion.* Causality: clear foundation material.

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* Natural history: short, but rounded explana-tion.

* Standardisation of rates: exceptional claritywith involvement of the reader in performingthe calculations.

* Case-control study: a straightforward expla-nation except for confusing text on the basisof the odds ratio as an estimate of the relativerisk. The case-control study is also detailedin a chapter on thinking through doing a

study to solve a problem.* Screening: not discussed, but sensitivity and

specificity considered in relation to validity.* Health care epidemiology: not considered.Overall verdict: Good for methods and some

concepts and of especial value for readers wholike self-study. Despite its size this book isabout right for the undergraduate.

Basic Epidemiology (Beaglehole R, Bonita R,Kjellstrom T)Basic Epidemiology,6 a succinct WHO product,is said to be for an international audience ofundergraduate medical and public healthstudents and for health professionals. There isa separate teacher's guide. In 167 illustratedpages it covers epidemiology and its applica-tions, and throws in chapters on statistics andcontinuing epidemiological education. Theopening emphasises the uses of epidemiologyand its achievements. The remainder gives theideas behind, limitations of, and interpretationof epidemiological studies. For example, thecase-control study is described in two pages

while causation in epidemiology has 11. Com-municable disease epidemiology, clinical epide-miology, environmental and occupational epi-demiology and health service and policy allreceive a chapter. A comprehensive referencelist and a set of study questions and answers

round off this remarkable book.* Population: concise paragraph.* Causality: first rate discussion of the key

ideas, in 11 pages.* Natural history: very short coverage.* Standardisation of rates: the idea is ex-

plained, but not how to do it or the pros andcons of different methods.

* Case-control study: clear exposition of theidea with examples all in about three pages.

* Screening: everything the undergraduateneeds to know in about four pages.

* Health care epidemiology: comprehensive,compact discussion of epidemiology in bothplanning and policy.

Overall verdict: this book presents a broad anddeep vision of the role of epidemiology and isadmirably suited to undergraduates, but wouldrepay study by everyone.

Epidemiology, Biostatistics and PreventiveMedicine (Jekel JfE Elmore 7 G, Katz DL)Epidemiology, Biostatistics and PreventiveMedicine7 justifies its ambitious goal of provid-ing comprehensive and integrated content as

logical because epidemiology is the science ofpreventive medicine and public health andbiostatistics is the quantitative foundation ofepidemiology. It accomplishes this goal! The

target audience is medical students and profes-sionals. The text is in two tones, clearly laidout, and referenced. There are no exercises orstudy questions.* Population: mentioned in passing.* Causality: fully and mostly logically dis-

cussed with good examples, but uses inad-equately defined concepts and terms.

* Natural history: patchy discussions at oddswith my understanding.

* Standardisation of rates: crystal clear in lessthan three pages, but stops short of discuss-ing pros and cons of each method.

* Case-control study: the two to three pagediscussion is adequate, but the material isfragmented.

* Screening: postgraduates should read therich discussion of screening tests andprogrammes, which covers all the usualmaterial and Bayes' theorem.

* Health care epidemiology: health care andpublic health are amply discussed, but not inthe context of epidemiology.

Overall verdict: impressive package, though thevariable depth of coverage is confusing: someparts are elementary, some complex.

Epidemiology for Public Health Practice (Friis RH, Sellers TA)Epidemiology for Public Health Practice8 isintended for a broad audience, but socialscience students specifically. An emphasis onpractical public health problems is its basis,and the book opens with "A nightmare inNigeria" a potentially serious environmentalthreat that caused consternation for residentsand the New York state Health Department.Chapters are organised around learning objec-tives, outlines, case studies, study questionsand exercises, and plentiful references. Infec-tion, occupational health and, uniquely, psy-chology, behaviour, and social factors arepicked out for specific chapters.* Population: not explained.* Causality: interesting, up-to-date, histori-

cally based account.* Natural history: a discussion was not found,

but the term is used.* Standardisation of rates: brief material

which requires careful reading.* Case-control study: a highly readable and

clear 12 page account. The odds ratio is par-ticularly well explained.

* Screening: the material is admirably chosenand comprehensive excepting evaluation ofscreening programmes which is too brief.

* Health care epidemiology: in about fourpages the scope of epidemiology in healthcare is introduced.

Overall verdict: There is much of value here.The scenarios are lively. The depth is variable.

Medical Epidemiology (Greenberg R S, Daniels SR, Flanders WD, EleyJ WBoringJ_ R)Medical Epidemiology9 is written for medicalstudents. The authors hope that it will suitothers, but it demands a medical vocabulary(the glossary covers only epidemiology). Inaddition to the basics, there are chapters on

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epidemiology in genetics, clinical decisionmaking, and interpreting the epidemiologicalliterature. Each chapter starts with a patientprofile, and has chapter summaries, rich andinteresting illustrations, study questions usingthe MCQ format, and ample further readingand references.* Population: there is some discussion of the

population concept, but the message is con-fused by the unrelenting emphas on indi-viduals, eg epidemiologists are said to exam-ine disease in groups to learn why certainindividuals (my emphasis) develop the dis-ease and others do not. But, epidemiologyinforms us why certain groups of individualsget disease.

* Causality: a realistic scenario of breastcancer risk in a woman whose mother died ofthe disease leads into a clear discussionwhich stresses the difficulties in reaching adecision.

* Natural history: the weakness of the index isshown by the lack of an entry for a subjectwhich is given attention, but with emphasison the course of disease around and afterdiagnosis.

* Standardisation of rates: not indexed, butthere is a good example of direct standardi-sation and clear text.

* Case-control study: the discussion is deepand detailed, particularly on the benefits anddisadvantages of matching. Some weak-nesses in the book are apparent here. First,the case material on eosinophilia myalgiasyndrome gets in the way of the exposition.Second, there are errors eg misspelling, anduse of Reye's syndrome in fig 9.2 instead ofeosinophilia myalgia syndrome, as stated inthe text and legend.

* Screening: detailed discussion of screeningtests and programme evaluation in thecontext of breast cancer.

* Health care epidemiology: not covered.Overall verdict: a challenge for undergraduatemedical students for whom it is customdesigned. It may well capture their attention,but will it orientate them to the populationbased, public health responsibilities of themedical profession or will they see epidemiol-ogy as a tool for individually orientated clinicalpractice?

Lecture notes on Epidemiology and Public HealthMedicine (Farmer R, Miller D, Lawrenson R)Lecture notes on Epidemiology and Public HealthMedicine'" is aimed at medical students anddoctors, and argues that medicine and epide-miology are intertwined. The material isorganised into three sections: epidemiology(45% of the book), prevention and control ofdiseases (30%), and health services (15%).Cause and risk provide the lead into the epide-miological methods. The role of epidemiologyis clear in relation to prevention, but there is nointegration of health care and epidemiology.The use of a chapter index, ample headings,and brief examples of published studiesensures clarity of organisation. Green tones to

highlight headings, boxes, tables, and figures

gives unusual freshness. There are no exercisesor text references (though further readings arerelevant).* Population: insubstantial regarding epidemi-

ology, but ample on demography.* Causality: covers the basics, but defines

causes and determinants as different whichis curious.

* Natural history: passing statements, but noproper discussion.

* Standardisation of rates: skeletal text withworked examples.

* Case-control study: complex language is abarrier, but the text is clear and logical, andfour brief and important examples illustratethe power and limitations of the method.

* Screening: 12 exquisitely clear pages covereverything but the difficulties of evaluation.

* Health care epidemiology: the material onhealth care does not get to grips with howepidemiology fits in.

Overall verdict: suitable for the medical under-graduate, and a gentle introduction to thosetraining in public health medicine. The pub-lisher's claims that it sets epidemiology into aglobal and clinical context and helps doctors tomake clinical decisions are exaggerations.

An Introduction to Epidemiology (Timreck T C)An Introduction to Epidemiology" claims to be abasic text for a range of health degreeprogrammes at undergraduate and postgradu-ate levels and a handbook for field epidemiolo-gists. Each chapter has explicit objectives,much detail, coverage of practice and princi-ples and stretching study questions to whichanswers are in a separate instructors' manual.The history of epidemiology is detailed, whilethe material on statistics is limited to descrip-tion of disease patterns. The appendix containsfive major case studies.* Population: not specifically discussed.* Causality: a repetitive, long, infection-

dominated, and awkward discussion whichmakes a difficult topic.. difficult.

* Natural history of disease: not found and notindexed.

* Standardisation of rates: inadequate yetrepetitive explanation of the underlying con-cept and no instruction or examples of howto do it.

* Case-control study: confusing terminologycharacterises an idiosyncratic account.

* Screening: the lengthy text does not coverscreening programme evaluation.

* Health care epidemiology: not covered.Overall verdict: an idiosyncratic amalgam ofmaterial, with a heavy infection focus. Not clearenough for undergraduates and insufficientdepth for postgraduates.

MORE ADVANCED BOOKS, PROBABLY FOR

POSTGRADUATES AND PROFESSIONALS WITH SOME

PREVIOUS BACKGROUND IN EPIDEMIOLOGY

Epidemiology in Nursing Practice (Harkness G A)Epidemiology in Nursing Practice'2 examines theprinciples from a nursing perspective, showsthe uses of epidemiological knowledge andmethods in both practice and the evaluation of

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practice. The book has two major sections:concepts and applications. The latter is writtenby authors in practice, the former mainly byHarkness. Part 1 is opened by a diagram juxta-posing Florence Nightingale's lamp and theBroad Street Pump. The book has an appendixon presenting data and a glossary. Each chapterhas objectives, key words, a summary, criticalthinking questions, references, and is richly andimaginatively illustrated. The book borrowsexamples freely from other texts. I was struckby the huge, but largely ignored, contributionof Florence Nightingale (and other nurses) toepidemiology and public health. Nightingale'sbold, imaginative and effective polar area

diagrams (p 10) should be seen by all epidemi-ologists.* Population: the idea suffuses the text, but is

not specifically discussed.* Causality: in three pages the complexity of

the subject is captured together with thebasics of the epidemiological approach.

* Natural history: set and discussed in thecontext of prevention but not as a keyconcept in its own right.

* Standardisation of rates: the direct method isexplained adequately, but the indirectmethod is covered poorly and the example isnot illuminating.

* Case-control study: extremely helpful expo-sition with a first class example.

* Screening: a solid introduction to thepractice of screening precedes the epidemio-logical principles, which are effectivelystated.

* Health care epidemiology: several chaptersdiscuss and demonstrate how epidemiologyis put to use in policy and practice.

Overall verdict: A comprehensive introductionto the science and craft of epidemiology whichmore than achieves its objectives. Potentially ofgreat interest to health professionals, nurses

and non-nurses alike.

Epidemiology (Gordis L)Epidemiology'3 has the goal of demonstratingthat epidemiology is essential to clinicalpractice and health care and not just publichealth and health policy. A mixture of theory,application, inspiring examples, a rich selectionof illustrations and, uniquely, humorous car-

toons, is effectively integrated. The structure islogical and coherent. Basic concepts are brieflyand clearly reviewed. Sources of data andmeasurement of disease are presented within a

critical framework. The terminology and con-

tent is modern but many examples (often bor-rowed from other textbooks) are historical.Summaries and multiple choice review ques-

tions end each chapter. The book is modern-for example, genetic markers are given promi-

nence in the discussion of environment/geneticinteractions. The practical applications ofepidemiology are made explicit in four chap-ters. The book's hallmark is integration, a diffi-cult task eased by single authorship.* Population: no specific discussion.

* Causality: a dominating theme stronglyillustrated in the context of modern dayproblems.

* Natural history of disease: thorough, andfocused on clinical prognosis and screening.

* Standardisation of rates: short text with veryeffective examples.

* Case-control study: 15 pages of clear expla-nation with a first class exposition on theodds ratio.

* Screening: full coverage, albeit in separatesections, of the evaluation of both screeningtests and of programmes.

* Health care epidemiology: evaluation is cov-ered and to a limited extent development ofhealth policy. Health needs assessment andpriority setting are not.

Overall verdict: Great merit as an introductionfor postgraduates, and excellent potential foruse selectively with undergraduates.

Primer ofEpidemiology (Friedman GD)Primer of Epidemiology'4 is aimed at physicians,medical students, and other health care profes-sionals. The clinical emphasis is strong with achapter on epidemiology in clinical practice.The writing is clear and brief yet the explana-tions avoid oversimplification. Multivariateanalysis is introduced clearly. Chapters containopen and closed questions with detailedanswers. The last chapter summarises eachchapter! There is emphasis on doing epidemi-ology, with detailed discussion throughout ofpublished studies and a chapter on how to do astudy. Weight is given to the cross-sectionalstudy. This text is a general book whichembraces clinical epidemiology.* Population: no specific discussion.* Causality: a straightforward account, weak-

ened by absence of solid examples.* Natural history of disease: insufficient even

for the undergraduate.* Standardisation of rates: short and inad-

equate on the indirect method.* Case-control study: the 25 page chapter is

clear but sits uneasily between the needs ofpostgraduates and undergraduates. Threesummaries of actual studies are interesting,informative and well chosen, adding greatvalue to the theoretical material.

* Screening: succinct, and interesting.* Health care epidemiology: minimal cover-

age.Overall verdict: Good for examples, exercises,and selected readings.

Epidemiology-an Introductory Text (Mausner_7S, Kramer S)Epidemiology-an Introductory Text'5 is for abroad range of students for the authorscontend that all health professionals should befamiliar with epidemiology. In addition to theusual principles and methods, this book haschapters on population and health and occupa-tional epidemiology. The first two chaptersemphasise that epidemiology underpins popu-lation medicine, and particularly prevention.Measurement is given prominence. A conciseilluminative discussion of time, place, and

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person is developed as descriptive epidemiol-ogy, while all formal studies are under theumbrella term "analytic" and subdivided intoobservational and experimental. Observationalstudies are again divided into retrospective andprospective, the terms case-control and cohortbeing subservient. The cross-sectional design isdismissed in a paragraph while the trial gets afull chapter. Causality is only discussed in thecontext of analytic studies. The rationale for achapter on demography is unclear, as is thereasoning for two specific aspects of epidemiol-ogy, infection and occupation. Both chaptersintroduce new concepts.* Population: emphasis on population as

related to epidemiology and demography.* Causality: a rounded discussion with good

examples.* Natural history of disease: a clear account

sufficient for undergraduates (not indexed).* Standardisation of rates: a clear exposition

with good examples but dispersed acrosschapters.

* Case-control study: unfortunately these arecalled retrospectives studies in chapter 7 andcase-control in chapter 12 (and the indexrefers only to the latter). In about 15 pagesthe student is given a foundation foradvanced study.

* Screening: a 24 page chapter covers the sub-ject comprehensively and clearly.

* Health care epidemiology: not covered.Overall verdict: The book has breadth, crystalclear explanations of concepts, and pertinentexamples. It was published in 1985, and usesnomenclature and classification which havenow been superseded. I have used this book for10 years to great advantage and hope a muchneeded revision is forthcoming.

Foundations ofEpidemiology (Lilienfeld D E,Stolley P D)Foundations of Epidemiology'" hopes to integratethe concepts and applications of epidemiologyfor both students and practitioners. Theemphasis is on aetiology. Notable strengths areboth American and European perspectives,chapter summaries, exercises and answers, anappendix of statistical methods, a concisehistory of epidemiology, and both author andgeneral index. Discussion of time, place, andperson is fragmented across chapters. Someterms are confusing. For example the conceptof "demographic" studies in epidemiology(studies of mortality and morbidity statistics) isunfortunate, particularly as these are said to bestudies of populations, as distinct from epide-miological studies which are said to be of indi-viduals. The terms concurrent and non-concurrent are used as qualifiers for cohortstudies. The idiosyncrasies also apply toconcepts as in the definition of ecologicalfallacy, which is defined as a confounding varn-able, and the natural history of disease and thespectrum of human response are conflated. Achapter on epidemiology in clinical practiceconsists of leftovers.* Population: no distinct discussion, but the

concept infuses the text.

* Causality: a historically based 13 page clearaccount.

* Natural history of disease: discussed brieflyas the spectrum of disease.

* Standardisation of rates: four pages of crystalclear text with an effective example.

* Case-control study: 22 pages of clear expla-nation with excellent examples and extrastatistical material in appendices ensuressuitability for the postgraduate.

* Screening: skeletal coverage in the context ofa chapter on morbidity statistics.

* Health care epidemiology: not covered.Overall verdict: A postgraduate text which hasmany strengths (which have gained it a bigreputation), but is not comprehensive and hasidiosyncrasies in the terminology (it needsrevision, and opportunities to do this in recenteditions have not been taken).

Epidemiology in Medicine (Hennekens C H,Buring

_E)

Epidemiology in Medicine'7 aims to be a bridge toadvanced work. The emphasis, however, is onmethods, including statistics, and despite thetitle it is not focused on clinical epidemiology.Chapters are fully referenced and end in studyquestions. Screening is the sole topic of thesection on disease control. This is a methodsbook which skips many of the concepts key tothe practice of epidemiology, whether in publichealth or medicine.* Population: alluded to in the opening pages.* Causality: cause and effect is thoroughly dis-

cussed in the context of interpretation ofassociations with a detailed example ofsmoking.

* Natural history: not indexed and covered inpassing under screening.

* Standardisation of rates: both the direct andindirect methods are clearly explained butthe two are not contrasted.

* Case-control study: the material is detailedand clear but fragmented across chapters.

* Screening: a full and straight account.* Health care epidemiology: not covered.Overall verdict: this book glosses over some fun-damentals concepts but is a readable advancedbook for the postgraduate already equippedwith some of the concepts. (The book is greatlyappreciated by students.)

Epidemiology: Principles and Methods(McMahon B, Trichopoulos D)Epidemiology: Principles and Methods'" is said tobe for the novice and a bridge to moreadvanced material. Its systematic examinationof variation in disease as the underlyingstrategy of epidemiology and the chapters oncause, and time, place, and person are thebackbone of the book. The list of 613references is a huge resource. There is anemphasis on causal epidemiology, with nearlyhalf of the book devoted to cohort andcase-control studies, and virtually nothing oncross sectional and trial designs. Some con-cepts are well discussed but others (icebergof disease and epidemiological triangle) areomitted.

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* Population: no substantial discussion.* Causality: a critical, original and full discus-

sion.* Natural history of disease: brief and insuffi-

cient for undergraduates.* Standardisation of rates: an exposition made

difficult without examples or illustrativedata.

* Case-control study: 73 pages of advancedmaterial for researchers planning such astudy.

* Epidemiology of screening: not covered* Health care epidemiology: not covered.Overall verdict: a resource for selective reading,not an introductory textbook.

Modern Epidemiology (Rothman KJ)Modern Epidemiology'9 has two ambitious goals,to integrate the ideas of epidemiology as a sci-ence and to present the material simply so it isuseful to novice and advanced student alike.The passionate argument that epidemiology isa coherent and distinct science (albeit "anembryo") with its own theory is introducedearly, particularly by placing it in the context ofthe history of science and of causal thinking.Measurement and analysis of the occurrence ofdisease is the focus of the book, whichintroduces types of epidemiological study in 26pages compared to about 160 for analysis. Thetext is passionately written, with the overt wishto overturn traditional tenets. The chaptersend with a summary and references but thereare no self-tests of understanding.* Population: not explained.* Causality: complex discussion of a generalmodel of causation is followed by a nihilistictreatment of the epidemiological criteria forcausality, as proposed by Hill and many oth-ers.

* Natural history: not covered.* Standardisation of rates: in 9 pages, with a

striking example, the underlying unity ofconception of the direct and indirect meth-ods, and the theoretical fault in comparingtwo SMR's with each other, is demonstrated.

* Case-control study: advanced and criticalevaluation of the study in the context of theparadigms of science.

* Screening: not covered.* Health care epidemiology: not covered.Overall verdict: a thought provoking book tochallenge the advanced postgraduate, and theresearcher, who wants to rethink epidemiology.Modern epidemiology, however, is broadeningits theory and applications while this bookwould have us think ofthe science as somewhatnarrow, and focused on measurement.

BOOKS WHICH EMPHASISE SELF LEARNING,EXERCISES AND THE PRACTICAL APPLICATION OFEPIDEMIOLOGY

A study guide to epidemiology and biostatistics(Morton R E, Hebel Jf R, McCarter R Jt)A study guide to epidemiology and biostatistics 20 isdesigned for a wide range of health science stu-dents and for either self instruction or as a com-panion to a didactic course. It comprises notes

on the principles, a large set of exercises (whichare the crux of the book), and multiple choicequestions. Two overall goals-to use epidemio-logical methods to evaluate evidence for medicaldecision making and assess data using epidemio-logical and statistical principles-and 45 objec-tives are given together with expected perform-ance on the MCQ. The objectives are as specificas "define incidence and prevalence", and asgeneral as undertake "critical examination of apublished scientific article". Each chapter hasobjectives, explanatory text, exercises, answers,and guided reading. The book ends with 13blank pages, so there is no excuse for evading theexercises!* Population: emphasised in the definition, but

not indexed.* Causality: the discussion focuses on inter-

pretation of associations, in the light ofcausal criteria. The associated questions areelementary in the extreme and do not testwhether the ambitious objectives have beenachieved.

* Natural history of disease: not indexed ordiscussed but knowledge is assumed indiscussing screening.

* Standardisation of rates: not indexed, butdirect standardisation is covered excellently.The questions reach but do not advance thereader's knowledge beyond the explanatorytext.

* Case-control study: a thoughtful, readable,well illustrated exposition. The associatedexercises are searching.

* Screening: the ideas behind screening arecovered but programme evaluation is not.The material on sensitivity and specificity isvery clear and the exercises develop under-standing.

* Health care epidemiology: not covered.Overall verdict: All students and teachers shouldbe aware of this book which would be ideal forstudents who learn by doing. The coverage ofprinciples may just suffice for undergraduates,but postgraduates will need much more.

Workbook ofEpidemiology (Norrell S E)Workbook of Epidemiology2' proposes to fill thegap between the principles and applications ofepidemiology. It does this by the use ofhundreds of exercises and questions, supportedby sparse text. Altogether 1 6 pages of answersare added to the 190 on general text.* Population: not covered.* Natural history: not done.* Causality: some notes but not systematic.* Standardisation of rates: not covered.* Case-control study: a few notes.* Screening: only sensitivity and specificity are

covered.* Health care epidemiology: not covered.Overall verdict: a specialist book for thoseequipped with the basics, or willing to workwith a general textbook, and wish to learn thetechniques of a few study designs through selftest and examples.

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Epidemiological Studies:A Practical Guide(Silman A)Epidemiological Studies: A Practical Guide22 hasthe tough but limited roles of filling the gapsbetween the theoretical texts and texts ondisease epidemiology and training readers toundertake simple epidemiological studiesthemselves. It does so in a systematic and clearmanner (a cookbook style). There are no exer-cises for the reader to test out their understand-ing and no references. There are ample unref-erenced, and presumably fictional, examples.* Population: no discussion of concept but

patient populations are seen as distinct fromwell ones.

* Causality: Touched on but the reader wouldneed to go elsewhere for understanding.

* Natural history: no discussion.* Standardisation of rates: the reader is

unlikely to understand or be able to applythe technique after reading the 3/4 page text.

* Case-control study: the tools to do and ana-lyse this type of study are provided, albeitacross several chapters.

* Screening: the relationship between sensitiv-ity and specificity is covered in the context ofvalidity, not screening.

* Health care epidemiology: not covered.Overall verdict: less than the title implies, buteminently suitable for those primed withtheory and ready to do cross sectional,case-control, and cohort surveys.

BOOKS INTRODUCING EPIDEMIOLOGY IN CLINICAL

PRACTICE

Practice-based Epidemiology: An Introduction(Schuman S H)Practice-based Epidemiology: An Introduction 3 isfor clinicians but it is not clinical epidemiologybut epidemiology to inspire them. Vivid casestudies, a strong emphasis on clinical medicineand worked examples to show how straightfor-ward the approaches can be, characterise thebook. Each chapter has highlights, not summa-ries! There are no exercises, but amplereferences and examples.* Population: not considered specifically.* Causality: not specifically covered.* Natural history: used not explained.* Standardisation of rates: the idea is intro-

duced but not the vital concepts of directand indirect adjustment.

* Case-control study: not covered, except todefine it.

* Screening: set in the context of clinical deci-sion making, but principles are there.

* Health care epidemiology: not covered.Overall verdict: Not for the student, but couldserve to entice clinicians to the cause of epide-miology!

Clinical Epidemiology. The Essentials (Fletcher RH, Fletcher S W, Wagner E H)Clinical Epidemiology. The Essentials24 is forclinicians (and medical students). Epidemio-logical and public health ideas and theory areinterwoven into the clinical paradigm whichthe book follows. There are no exercises or

detailed examples, but ample references andfurther reading.* Population: a succinct discussion of the con-

cept of population, the difference betweenthe population at large and the population ofpatients, and the implications of studying thelatter.

* Causality: a masterly account, meeting theneeds of the senior student. ( A minor gripeis that I found fig 1 1.10 an unconvincing andunhelpful simplification).

S

0Natural history: extremely brieflStandardisation of rates: cursory.

* Case-control study: a thorough and criticaloverview, set in the context of case studiesand compared with the cohort study.

* Screening: a great strength of this detailedmaterial is the rich clinical content.

* Health care epidemiology: not specificallycovered.

Overall verdict: This book is fine epidemiologyin any setting and has strengths for allpostgraduates, not just those in medicine(indeed the examples may be particularlyimportant to non-medical epidemiologists)and the keen undergraduate. But it is not com-prehensive.

Clinical Epidemiology. A Basic Science forClinical Medicine (Sackett D L, Haynes R B,Guyatt G H, Tugwell P)Oddly, the authors don't state the intendedreadership. Clinical Epidemiology25 is, however,for the user and not the doer of research. Asmedical and epidemiology students tend to"discover" this book it is wise for epidemiologyteachers to know about it. It is more than clini-cal epidemiology, it is a primer on criticalthinking and continuing education, and one ofthe three sections is on keeping up to date, theothers being diagnosis and management. Thechapters actively engage the reader by askingquestions and by use of humour and anecdote.The authors don't disguise their personalities.Exercises are integrated into the text. There areample references.* Population: not covered.* Causality: a discussion of the issues is set in

the context of ascertaining whether a treat-ment causes a benefit or a side-effect andguidance on how to assess papers purportingto demonstrate cause and effect.

* Natural history: brief but highly relevanttext.

* Standardisation of rates: not covered.* Case-control study: the material is enough towarn the reader to interpret this researchwith care.

* Screening: the coverage is detailed andinteresting, and set in the context ofdiagnostic tests and of early diagnosis.

* Health care epidemiology: not covered.Overall verdict: Truly, the application of epide-miology to clinical medicine. An inspiration tothe rigorous medical student and clinician anda huge resource to the general epidemiologist,wanting to see the science and craft from a newperspective.

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621Review of introductory textbooks

Conclusions and recommendationsThere is remarkable diversity of approach,subject matter, content, and interpretation ofbasic facts and concepts. This is both encour-aging and worrisome. The science and craft ofepidemiology is diverse and textbooks shouldacknowledge this. Variety also helps to meet theneeds of individuals. For example, somestudents benefit from objectives and summa-ries, others find them irksome. Some will doexercises and learn from them, others are look-ing for theoretical understanding. Nonetheless,there is a worrying diversity ofterminology andinterpretation of basic ideas such as whetherthe case-control study is a valuable or weakform of investigation. After this review, I amconfused!The conclusion is that both students and

teachers need to be wary that the chosenbook(s) are providing messages which, at least,are not at conflict with their own teachings and,at worst, are not simply misleading. The termi-nology is likely to be different in every book.This review has shown me just how importantthe Dictionary of Epidemiology by Last is.26 Allstudents and courses will be reliant on that totranslate across texts and courses. (In passing,epidemiology is no different to other disci-plines; even mathematics, the paragon of preci-sion, has numerous words for simple conceptssuch as multiplication eg product!)

Strikingly, some basic texts make little roomfor concepts. I was stunned by how the epide-miological idea of population health was sorarely discussed beyond the definition. Theattention given to exercises and learning bydoing (an important part of this group of text-books) is welcome. Educationally beneficialexercises are, however, easier to create forcalculations, but less easy for ideas such ascausality, a problem which needs a solution ifepidemiology is not to degenerate into medicalarithmetic.Most texts are north American but an

increasing number are European (Beaglehole isan international collaboration). A distinctioncan be seen. European texts almost invariablyembed their material in a public health or, lesscommonly, a clinical framework and emphasisepractical applications. They are strong in mak-ing explicit the public health importance ofepidemiology. North American texts are lesstied to public health, more inclined to clinicalexamples, and are more technical with strongemphasis on methods and analysis.

Since the practical applications are depend-ent on the context, the value of texts whichemphasise the applications are more limitedinternationally. For example, American textsput relatively little emphasis on gaining com-munity based controls, and when they do, theyemphasise random digit dialling to gaintelephone controls-British ones emphasisethe use of community registers. Nevertheless,there is much to be learned from transatlanticexchange of epidemiological ideas.

I was struck by how much there is for thegeneralist to learn from the specialist perspec-tives; for example the clinical epidemiology

books teach a great deal of general epidemiol-ogy. The overall messages seem to me to be:* Students are spoilt for choice and should

exercise this privilege by examining optionscarefully for texts which suit their ownlearning style.

* Teachers should ensure their own emphases,terminology, and conceptual understandingis compatible with the text.

* There is a need for a more coherent vocabu-lary in epidemiology. Rothman explainedthis variability as a feature of an embryonicscience, but growing up places responsibilityon us all to define the language, to agreesynonyms, and to vary only when the ration-ale is explicit and strong.

* To maximise the rewards of reading, stu-dents and teachers should use different textsfor different topics, even though they maybenefit from using one textbook for generalreference.

Each epidemiologist will have their ownfavourites. I have always found Mausner andKramer's explanations of concepts exemplaryand brief; try it if you have a conceptual block(but sadly the book is outdated now). Rothmanprovides a serious challenge in methods andanalysis. Sackett is simply something different,exciting, and important, at least in clinical careand its interface with public health. Jekel packsin a great deal for the beginner. Barkercombines breadth and depth with surprisingbrevity. Morton is an attractive self reader andself test. The book by Gordis has become myoverall favourite as a first serious textbook inepidemiology; it is ideal for the master's levelentrant and has a great deal of material suitablefor the undergraduate. It is modern in the sensethat it encapsulates what epidemiology is tryingto do in the 1990s and is up to date in terms ofinformation.

I am grateful for the choice. I look forward tomore.

Potential conflict of interest: Dr Nigel Unwin, first author ofAnIntroductory Study Guide to Public Health and Epidemiology, hasan appointment of Senior Lecturer in the Department ofEpidemiology and Public Health, in which the author alsoworks.

I thank: Professor Johann Mackenbach for suggesting thisreview; the editor and the editorial board of the Journal of Epi-demiology and Community Health for inviting me to do it;Lorna Tittle of the JECH for helping acquire some of the books;all the colleagues and students who commented on earlier draftsbut especially Denise Howel, Carl Shy, Richard Thomson,Richard Edwards, David Chappel, and Halina Greiser. I alsothank the University of Newcastle upon Tyne, and mycolleagues in the Department of Epidemiology and PublicHealth, for supporting my sabbatical leave, which made thereview possible. Finally, I thank the Department of Epidemiol-ogy at the School of Public Health, University ofNorth Carolinaat Chapel Hill for administrative (in particular by BetsySeagroves) and academic support. The review was preparedwhile I held the post of Visiting Professor there.

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4 Ahlbom A, Norell S. Introduction to modern epidemiology.Chestnut Hill: Epidemiology Resources Inc, 1984.

5 Page RM, Cole, GE, Timmreck TC. Basic epidemiologicalmethods and biostatistics. Boston: Jones and BartlettPublishers, 1995.

6 Beaglehole R, Bonita R, Kjellstrom T Basic epidemiology.Geneva: World Health Organisation, 1994.

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