CRITERIA FOR AUTHORSHIP FOR STATISTICIANS IN MEDICAL PAPERS 2293

Table I. Summary of illustrative examples

Phase Activity Points Example
1 2° 3% 4 5*6*%' 7 Be 9°

Study design Thinking through a study 4 x x
Writing grant material 2 x
Reviewing grant application 1 xx xX

Implementation Involved in all aspects 4 xxx
Managing data management 2 x x
Answers only specific questions when asked 1 x xX

Analysis and Plans overall analysis 4 XXX xX XxX

Presentation Interprets results 2 XXX

Performs analysis 1 xX xX xX x
Total points 129835 5 6 7
Authorship Y Y YNN N N?N7Y

* Sample case. Other similar patterns (in terms of major/mid-level/minor activities) would also be possible
* For Example 6, we believe that these combinations would not occur in Practice

4.1.3. Example 3

A Statistician is involved only in two of the three highest level activities but nothing else.
This happens, for example, when a statistician is heavily involved in the implementation and
analysis of a study, but the design is developed by others, often years before the arrival of the
Statistician. This gives a total of eight points. These two major contributions are adequate for
authorship.

4.2, Examples in which being an author is not appropriate
4.2.1. Example 4

A statistician is involved in all the low-level activities, that is, overall review of the Protocol,
Tesponse to specific issues when requested by the investigator, and doing the analysis (planned
primarily by other statisticians, or at the direction of the investigator). This gives a total of three
points. Although these activities may be extremely time consuming, and meticulously done,
authorship is not appropriate for a study that produces a single publication. We consider this
example further in Section 5.3.

4.2.2, Example 5

In addition to the low-level activities in Example 4, the statistician is also involved in one
mid-level contribution for a total of five points. This situation occurs, for example, if the
statistician has done all the lower level activities, and: (a) prepared data management plans for the
grant application; or (b) has supervised data management; or (c) has summarized the results of
the analysis for the other investigators. Authorship is not appropriate for this level of involvement
for an individual publication.

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eal

2298 R. PARKER AND N. BERMAN

APPENDIX: (Continued)

Activity Points Involved

Analysis

Planning and directing the analyses; this is usually based on the analysis plan 4 Yes No
described in the grant but now includes exact model specification, resolution at

decision points, etc.

Preparing written material summarizing the results of the analyses for the other 2 Yes No
investigators and/or preparing formal reports

Doing the analyses 1 Yes No
Total points

Do special circumstances apply? Yes No

Authorship criterion (without special circumstances)
8 or more points: Yes

6-7 points: Possibly

5 or fewer points: No

ACKNOWLEDGEMENTS

This research was supported in part by grant RR 01032 to the Beth Israel Deaconess Medical
Center General Clinical Research Center (Dr. Parker) and grant RR 00425 to the General
Clinical Research Center at Harbor-University of California at Los Angeles Medical Center
(Dr. Berman) from the National Institutes of Health.

REFERENCES

1. Batshaw, M. L., Plotnick, L. P., Petty, B. G., Woolf, P. K. and Mellits, E. D. ‘Academic promotion at
a medical school: experience at Johns Hopkins University school of medicine’, New England Journal of
Medicine, 318, 741-747 (1988).

2. Moore, M. N. ‘Tenure and the university reward structure’, Nursing Research, 38, 111-116 (1989).

3. Ellwein, L. B., Khachab, M. and Waldman, R. H. ‘Assessing research productivity: evaluating journal
publication across academic departments’, Academic Medicine, 64, 319-325 (1989).

4. International Committee of Medical Journal Editors. ‘Uniform requirements for manuscripts submitted
to biomedical journals’, New England Journal of Medicine, 336, 309-315 (1997).

5. Bhopal, R. S, Rankin, J. M., McColl, E, Stacy, R., Pearson, P. H., Kaner, E. F.S. et al. ‘Team approach
to assigning authorship order is recommended’, British Medical Journal, 314, 1046-1047 (1997).

6. Digiusto, E. ‘Equity in authorship: a strategy for assigning credit when publishing’, Social Science and
Medicine, 38, 55-58 (1994).

7. Ahmed, S. M., Maurana, C. A, Engle, J. A., Uddin, D. E. and Glaus, K. D. ‘A method for assigning
authorship in multiauthored publications’, Family Medicine, 29, 42-44 (1997).

8. Goodman, N. W. ‘Survey of fulfilment of criteria for authorship in published medical research’, British
Medical Journal, 309, 1482 (1994).

9. Journal of the American Medical Association. ‘JAMA instructions for authors’, Journal of the American
Medical Association, 227, 74-79 (1997).

10. New England Journal of Medicine. ‘Information for authors’, New England Journal of Medicine, 336, 316
(1997).

11. Kassirer, J. P. ‘Authorship criteria’, Science, 268, 785-786 (1995).

12. Anesthesiology. “Guide for authors’, Anesthesiology, 86, 37A-39A (1997).

13. Journal of Clinical Endocrinology and Metabolism. ‘Instructions to authors’, Journal of Clinical
Endocrinology and Metabolism, 82, 37A—42A (1997).

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CRITERIA FOR AUTHORSHIP FOR STATISTICIANS IN MEDICAL PAPERS 2295

5.2. Rescuing a study

Another special case of Examples 8 and 9 is when the statistician is brought into a study after the
study is completed because of major problems in the design or implementation of the study. In
such circumstances, one often finds it necessary to redefine the goals of the study or to become
heavily involved in data management to resolve data problems. Although these issues should
have been resolved earlier, this would still be design and implementation activity no matter when
done. As such, a statistician involved in rescuing a study often contributes substantially to all
three areas of the study, even though becoming involved only after the study is completed, and the
point score should reflect all areas of involvement.

5.3. Staff contributions to multiple publications

A statistician may be one of a group in a large scale, long-term collaborative study that produces
many papers. Many statisticians in the group may be involved only in one or two mid-level or
lower level activities, usually data management and data analyses under the direction of a more
senior person, as described in Example 4. Such work would be done over a long period and would
contribute to many publications. We believe that co-authorship on some papers is appropriate
for the statistician, particularly those in which the statistician has had the most involvement, to
recognize the overall contribution, although the statistician does not reach the formal point
criterion. This recommendation reflects that such studies often have relatively long lists of
authors, so that the rigorous application of our 6-8 point criterion for authorship may adversely
harm statisticians involved in the study. We recommend that such groups develop a formal policy
specifying when authorship is appropriate.*-'* Appearance on a list of the study team is not
authorship.

A similar problem might arise in a consulting service, in which staff work on multiple unrelated
publications. One would hope, over time, that staff would develop their skills so that they could
be able to provide the substantive intellectual contribution necessary to justify authorship. Again,
we recommend that such groups develop a formal policy specifying when authorship would be
appropriate.

5.4. Long-term involvement with a research group

On occasion, a statistician may work with a research group over a long period, making major
contributions to the first in a series of similar projects. For example, a statistician might provide
advice on the design and analysis of a single class of study, that is then Tepeated many times with
minor modifications, for example, testing new antibiotics in a specific assay. In such a situation,
collaborators may feel that the statistician deserves authorship on all publications that arise from
the experimental programme. Although the statistician’s contribution to a specific experiment
might be relatively small, the long-term involvement with the group, and the statistician’s initial
involvement in both planning the design and the analysis of the basic experiment, would be
marginally adequate for authorship.

5.5. Authorship in response to referees

On occasion, we have been offered authorship to rebut a referee's criticism of a manuscript with
which we had no previous involvement. By being an author, we show that a ‘real statistician’
approves of the methods in the manuscript, and that the referee’s comments are incorrect.

© 1998 John Wiley & Sons, Lid ‘Statist. Med. 17, 2289-2299 (1998)



2294 R. PARKER AND N. BERMAN

4.2.3. Example 6

A statistician could conceivably earn five points by participating in a major activity and a minor
activity or participating in two mid-level activities and one minor activity. We have difficulty in
imagining a statistician actually fulfilling either role, however. For example, it seems unlikely that
a statistician could have a major impact on the study design and review the protocol! without also
writing text for it. Similarly, it seems unlikely that a statistician would have a major impact on the
study design and analyse the data, but is not heavily involved in planning the analyses. We have
similar difficulty with the plausibility of other such combinations that lead to five points.

43. Examples in which it is not clear whether authorship is appropriate
4.3.1, Example 7

A statistician makes mid-level contributions in all three areas of the study, for a total of six points.
The statistician has prepared part of the grant, has implemented data management, and helps
interpret results for the other investigators, although the analysis is primarily planned and
implemented by others. We feel that this is not quite enough to merit authorship.

4.3.2. Example 8

The statistician does the two more important activities in a single phase of the study, for example,
plans and interprets the analysis. Although the intellectual contribution may be relatively small in
the activity not included, doing only two activities in one area, without involvement in either of
the other areas, is not quite adequate for authorship.

4.3.3. Example 9

A statistician is involved in all three activities involving either the study design or the data
analysis, but has no involvement in either of the other functions of a statistician. This provides
a total of seven points. For example, a statistician may join a study as data collection nears
completion. The statistician has clearly made a major contribution in one area of the study, which
is adequate for authorship.

5. SPECIAL CONSIDERATIONS
In this section we consider several factors that may modify the decision about authorship.

5.1. Statistician involved only in the initial phases of the study

As a special case of Examples 8 and 9, a statistician may be heavily involved in the early phases of
a study, but not involved in its completion either because of changing positions, retirement, or
death. This frequently occurs in large, long-term collaborative studies. When a statistician has
strongly influenced the planning and start of a study, even if no longer participating in the project,
we feel that authorship is appropriate for the major publication(s) arising from the study. Thus,
two or more statisticians may be authors, one with primary involvement in planning and the
other with primary involvement in analysis.

When a statistician has died before the completion of the study, posthumous authorship, with
a note indicating such, is appropriate.

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CRITERIA FOR AUTHORSHIP FOR STATISTICIANS IN MEDICAL PAPERS 2297

customarily given for authorship ‘substantial contribution to conception and design, or analysis
and interpretation of data’.* We defined our guidelines operationally. It is important to note that
our guidelines are not rules. As indicated in Section 5, there are many additional factors which
affect the decision whether a statistician merits authorship.

We have assumed throughout that the statistician will participate in the writing of the
manuscript, will review the final version, and will accept responsibility for the work. Thus, we
have not focused on what makes a substantial contribution to ‘drafting the article or revising it
critically for important intellectual content’.*

To some extent, authorship relates to whether one is (and is viewed as) a ‘collaborator’ or
a ‘consultant’. We recognize that a rigorous distinction between ‘collaboration’ and ‘consultation’
is virtually impossible. This is reflected in the Encyclopedia of Statistical Sciences, where statistical
consulting includes both ‘a statistician who worked for years with a chemical engineer’ and ‘the
response of a statistician to a telephone query on how to compute a standard deviation’.!® None
the less, we believe that the two differ, even though we recognize that an absolute distinction is
probably impossible. Despite the fuzziness of these terms, there are clear implications involved in
these names, since a collaborator is usually considered a ‘scientific partner’ in the study, while
a consultant is often viewed as a ‘technical advisor’. Although the name given the relationship
should not determine the appropriateness of authorship, we have tried to separate statistical
activities into higher level activities, usually associated with collaboration, and lower level
activities associated more with consulting. Our idea is that a collaborator generally merits
authorship while a consultant generally does not. This distinction is particularly apparent in
implementation activities, with the high-level activity (‘involved in all aspects’) likely to suggest
a collaborator and the low-level activity (‘answers only specific questions when asked’) more
typical of a consultant.

In summary, we believe that authorship issues require resolution soon after one becomes
involved in a study. Although there often may be some ambiguity in determining whether the
statistician merits authorship, we hope other statisticians find our guidelines useful.

APPENDIX: CHECKLIST OF STATISTICAL CONTRIBUTIONS TO STUDY

Activity Points Involved
Study design
Substantive input into the overall design of the study and protocol development 4 Yes No
(‘thinking through a study’)
Writing one or more sections of the grant application (data analysis, data 2 Yes No
management)
Overall review of grant application prior to submission 1 Yes No
Implementation
Regular (ongoing) participation in study meetings with the other investigators 4 Yes No
Implementation of data collection and data management activities, including 2 Yes No
monitonng and supervision of data collection staff
Advising only on specific issues when requested by the principal investigator 1 Yes No
(‘answers only specific questions’)
© 1998 John Wiley & Sons, Lid Statist, Med. 17, 2289-2299 (1998)



STATISTICS IN MEDICINE
Statist. Med. 17, 2289-2299 (1998)

CRITERIA FOR AUTHORSHIP FOR STATISTICIANS
IN MEDICAL PAPERS

ROBERT A. PARKER'* AND NANCY G. BERMAN?
‘Biometrics Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston,

MA, U.S.A.
? Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, U.S.A.

SUMMARY

We organize a statistician’s potential scientific and intellectual contributions to a medical study into three
types of activities relating to design, implementation and analysis. For each type, we describe high-level,
mid-level and low-level contributions. Using this framework, we develop a point system to assess whether
authorship is justified. Although we recommend discussion and resolution of authorship issues early in the
course of any project, our system is especially useful when this has not been done. © 1998 John Wiley
& Sons, Ltd.

The making of many books is without limit
And much study is a wearying of the flesh
ECCLESIASTES: 12:12

1. INTRODUCTION

Publications are not solely a source of personal satisfaction. In academia, they are the currency of
success. Much as we deplore the phenomenon of ‘publication counting’, career decisions are often
based, at least in part, on the number of publications listed in the curriculum vitae. For example,
faculty members promoted at Johns Hopkins University School of Medicine had approximately
twice as many publications as those faculty members not promoted.’ Similarly a survey of 366
academicians found that the number of publications and the quality of the journals were the most
important considerations in tenure decisions.” Publications also are used to evaluate departments
within a university.>

The International Committee of Medical Journal Editors has specified criteria for authorship
in medical publications. Their criteria are ‘substantial contributions to (a) conception and design,

* Correspondence to: Robert A. Parker, Biometrics Center/GZ-814, Beth Israel Deaconess Medical Center, 330
Brookline Avenue, Boston, MA 02215, U.S.A. E-mail: robert. parker@bidmc harvard.edu

Contract/grant sponsor: National Institutes of Health
Contract/grant number: RRO1032, RROO425

CCC 0277-6715/98/202289-11$17.50 Received August 1997
© 1998 John Wiley & Sons, Ltd. Accepted December 1997

alt


14.

15.

16.

17.

19.

CRITERIA FOR AUTHORSHIP FOR STATISTICIANS IN MEDICAL PAPERS 2299

Barker, A. and Powell, R. A. ‘Guidelines exist on ownership of data and authorship in mulucentre
collaborations’, British Medical Journal, 314, 1046 (1997).

Bhopal, R., Rankin, J. McColl, E, Thomas, L, Kaner, E., Stacy, R. et al. ‘The vexed question of
authorship: views of researchers in a British medical faculty’, British Medical Journal, 314, 1009-1012
(1997).

Smith, R. ‘Authorship: time for a paradigm shift”, British Medical Journal, 314, 995 (1997).

Rennie, D. and Flanagin, A. ‘Authorship! Authorship! Guests, ghosts, grafters and the two-sided coin’,
Journal of the American Medical Association, 271, 469-471 (1994).

. Shapiro, D. W., Wenger, N. S. and Shapiro, M. F. ‘The contributions of authors to multiauthored

biomedical research papers’, Journal of the American Medical Association, 271, 438-442 (1994).
Joiner, B. L. ‘Consulting, statistical’, in Kotz, S. and Johnson, N. L. (eds), Encyclopedia of Statistical
Sciences, volume 2, 1982, pp. 147-155.

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2296 R. PARKER AND N. BERMAN

Although we are happy to help our colleagues with a written rebuttal to the journal editor when
appropriate, becoming an author in such a circumstance is inappropriate.

A separate case is when the referee is correct and a statistician is brought into a project for
additional analyses and revision of a manuscript. Such circumstances need to be judged in terms
of the intellectual content provided by the statistician to the revised analysis and manuscript.

5.6. Institutional pressure to be an author

Independent of intellectual contribution, ‘institutional considerations’ (politics) might be cited for
listing a statistician as an author on a manuscript on which the statistician would not normally
consider it appropriate to be an author. In such circumstances one might be prepared to accept
authorship even though one’s contribution does not warrant it. None the less, authorship implies
general responsibility for the paper as a whole. Thus, one should never agree to authorship on
a paper unless one is prepared to accept public responsibility for the conclusions in it. If the paper
does meet such a standard, however, it is not clear to us why such ‘institutional considerations’
would need to be placed on the statistician. Fortunately, we have never faced such a dilemma
ourselves.

5.7. Relationship of authorship and financial compensation

Financial support and authorship are independent for everyone involved in a study, including
both the principal investigator and the statistician. Financial compensation is intended to recover
expenses (including salary support) associated with providing service, and is necessary for the
long-term viability of both the statistician and of the investigator. As such, it is based on the time
and effort spent on a project. In contrast, authorship is related to the scientific contribution to
a study, independent of the time involved on a project. Thus, we view financial support and
scientific collaboration as independent features of our interaction with an investigator. One
cannot substitute one type of support for the other. Similarly, one type of support does not
require, or preclude the other. The basis of financial support should be the time/effort spent on
a project and the basis for authorship should be whether the statistician has made a scientific
contribution to the project.

6. DISCUSSION

We believe that issues of authorship need resolution early in every project to avoid unpleasant
surprises during manuscript preparation. Note that these unpleasant surprises are not solely on
the statistician’s side; when the statistician indicates surprise at not being offered authorship, the
investigator might also be surprised that the statistician anticipates authorship. This problem is
Not unique to statisticians; 48 per cent of respondents in a survey of a university medical faculty
had not been included as authors when they felt their authorship was deserved.’* The same article
reported that most respondents (70 per cent) felt that the criteria of the International Committee
of Medical Journal Editors were too restrictive and more than half of the respondents felt that the
criteria were not usually met. This feeling was also noted in an accompanying editorial’ and by
other authors.-17-18

In this paper, we have presented guidelines for statisticians on what constitutes a ‘substantial
contribution to a study’. This is an attempt to define standards for the first of the criteria

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?
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2292 R. PARKER AND N. BERMAN

third activity listed, responding to specific issues when raised by the investigator, is likely to
Provide the least opportunity for substantive intellectual input, since the investigator will
predefine and limit the questions and issues.

Finally, planning the appropriate analysis and directing its execution is the major contribution,
while doing the analysis under someone else's direction, although the most time consuming, is the
least intellectually challenging task. Although we have sympathy with the view that interpreting
results to investigators sometimes is more challenging than planning an analysis, determining the
right analytic approach to use is technically more demanding and is the greatest intellectual input
into this phase of the study. This is particularly true when the project requires innovative analytic
methodology.

3. PROPOSED SCORING SYSTEM FOR AUTHORSHIP

We believe that a simple scoring system, with four points for the highest level ‘1’ activities, two
points for the mid-level ‘2’ activities, and one point for the low-level ‘3’ activities adequately reflects
the relative importance of the categories. A statistician involved in every possible activity would
have a maximum of 20 points, since one cannot be both ‘involved in all aspects’ and ‘answer only
specific questions’ during study implementation. Clearly, such a statistician should be an author on
any paper involving data collected from the study. In the more general case, we believe that 6-8
points on our scale represents an adequate level of involvement to warrant authorship. One could
achieve this score with a high level of participation in at least one phase of the study, and equal lower
levels in the order phases. Although one could also attain it by several low-level activities, usually we
would expect that the statistician would participate at the highest level in at least one phase. We note
that not all combinations are likely. The Appendix contains a form that summarizes the scoring
system for use with collaborators when discussing authorship issues. We strongly recommend
discussion of these issues at the initiation of a project so that misunderstandings do not arise later.

4. EXAMPLES

The examples, summarized in Table I, are illustrative and are not an exhaustive listing of all
possibilities. All the examples below assume a project leading to a single paper. We discuss
additional considerations affecting the appropriateness of authorship in Section 5. Within each
group, we place the clearest case first.

4.1. Examples in which the statistician should be an author

4.1.1, Example 1

A statistician is involved in overall development of the protocol, is regularly involved with
investigators during the study, and plans the analysis. Others, however, do all the detailed work.
This yields a total of 12 points on our scale. This statistician has clearly made a substantive
intellectual contribution to the study and authorship is appropriate.

4.1.2. Example 2

A statistician is involved in two of the three highest level activities and does one (or more) other
activities involved in the implementation or analysis. Thus, the statistician has a total of nine or
more points on our scale and authorship is appropriate.

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CRITERIA FOR AUTHORSHIP FOR STATISTICIANS IN MEDICAL PAPERS 2291

Phase I: Design
1. Substantive input into the overall design of the study and protocol development, which
may be thought of as ‘thinking through a study’.
2. Writing one or more sections of the research Protocol or grant application (for example,
data analysis and/or data management).
3. Overall critical review to sharpen a grant application before submission, without major
substantive changes.
Phase II: Implementation
1. Regular (ongoing) participation in study meetings with the other investigators.
2. Implementation of data collection and data Management activities.
3. Advising only on specific issues when requested by the principal investigator.
Phase III: Analysis
1. Planning and directing the analyses. This is usually based on the analysis plan described
in the grant but now includes exact model specification, resolution at decision points, etc.
2. Preparing written material summarizing the results of the analyses for the other investiga-
tors and/or preparing formal reports.
3. Doing the analyses.

Each of these specific items covers a Tange of contributions. For example, the intellectual
contribution involved in ‘writing one or more sections for a grant’ differs between a single
Paragraph justifying a sample size for a two-group comparison and an analysis plan for extensive
modelling of the data. Despite this variability, the organization above Provides a useful frame-
work for determining the appropriateness of authorship, based on intellectual contribution and
work during the study.

2.1. Rationale for order given

In phase I, the most important contribution is extensive input into the overall design of the study
(‘thinking through a study’). This implies at least substantial refinement and usually substantial
modification of the original study design or aims, and modification of the Protocol so that these
aims can be achieved. In contrast, helping a colleague sharpen a grant application, without
substantial revision, is unlikely to influence substantially the study design or the chance of
funding. As such, this activity, although beneficial, is more a service than a major intellectual
contribution to a study. Thus, we view Preparing actual material for the grant application as more
important than a general review of the whole grant application. When major changes are made to
the grant based on the overall review, however, we consider this extensive input into the overall
design of the study, the highest level activity.

During the implementation phase, regular participation in study meetings with other investiga-
tors reflects the greatest involvement. The term ‘participation’ implies an active role in these
meetings, since mere attendance does not constitute involvement. Even without assigned respon-
sibilities, because of the number and extent of the meetings, the statistician is likely to provide
multiple small contributions to the study, often to ensure that the study continues to follow the
onginal design criteria. Over time, these contributions will constitute substantial intellectual
input. Implementation of data collection and data management activities, including supervision
of data management personnel, is another single large activity. Although the contribution made
by providing this service is important, it is limited to a single aspect of study implementation. The

© 1998 John Wiley & Sons, Lid. ‘Statist. Med. 17, 2289-2299 (1998)

dl |.

oon

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2290 R. PARKER AND N. BERMAN,

or analysis and interpretation of data; and to (b) drafting the article or revising it critically for
important intellectual content; and on (c) final approval of the version to be published. Condi-
tions (a), (b), and (c) must all be met.“* Criterion (c) implies that each author accepts responsibilit y
for the article. Having sufficient expertise to judge the adequacy of contributions made by others
in most multi-disciplinary papers is virtually impossible for any single author. Thus, we interpret
criterion (c) to mean that the statistician is willing to take responsibility for the study design and
data analysis in the paper, and believes that the co-authors are equally responsible and competent
in their individual specialities.

Several papers have been published presenting guidelines for assigning authorship.*~* These
are usually based on the International Committee of Medical Journal Editors’ criteria, often with
modifications to make them less stringent. Some journals ask all authors to certify that these
criteria are met as part of the submission process (for example, Journal of the American Medical
Association).? Other journals specify these requirements in their ‘Information for Authors’ (for
example, New England Journal of Medicine).° If there are many authors on a paper, the New
England Journal of Medicine requires that each author certify that the criteria are met.!! Many
other journals have similar requirements.!2-13

In this paper we focus on authorship questions as they relate to statisticians and statisticians’
activities in a study. We assume throughout this paper that the statistician would meet the
common responsibilities of all authors: the critical review of the manuscript and accepting
responsibility for the manuscript. We limit our discussion to studies and publications of substan-
tive medical issues, not statistical techniques. Although issues of authorship arise in papers about
Statistical research and methodology, we do not address those problems here. We first outline the
‘primary activities’ for a statistician involved in a study and rank them by importance of
intellectual content (Section 2). In Section 3, we provide a simple formula to estimate the overall
importance of the statistician’s intellectual contributions to a specific study. In Section 4 we
provide several examples and make a recommendation about authorship in each case. Although
others might disagree with our decisions, we offer specific advice anticipating that such an
approach will provoke discussion of the issues raised. We discuss some additional conditions that
may modify our recommendations on authorship in Section 5, and end with a general discussion
of other issues involved in authorship in Section 6.

2. DESCRIPTION OF PRIMARY ACTIVITIES

Ideally, a scientific collaborator should be actively involved in all phases of a study, including the
design, implementation, analysis of the specific results, assisting in interpreting these results in the
context of the general scientific area, and in the Preparation of the manuscript. As mentioned
above, we do not discuss ‘drafting the article or revising it critically for important intellectual
contentTM as a specific activity in this Paper, since we assume that every author routinely does
this on every paper. We have attempted to divide the remaining items into three discrete
Primary activities specifically for a statistician: design, implementation, and analysis of the
specific study. .

Within each phase, the activities are listed with the most intellectual involvement first and with
the least involvement third. Note that the time spent on an activity is not considered in our
ordering. For example, doing an analysis will usually take far longer than developing the analysis
plan, but the amount of intellectual investment in the study is far greater when designing the
analysis plan. We discuss our rationale for this ordering after presenting the activities.

© 1998 John Wiley & Sons, Lid Statist. Med. 17, 2289-2299 (1998)